This document summarizes research conducted on adding waste wood chippings and silica fume to concrete to improve its flexural strength capacity. Three groups of concrete beams were produced: a control group with plain concrete, a second group with wood chippings added, and a third group with both wood chippings and silica fume added. Flexural tests were performed and results showed that additions of wood and silica fume reduced flexural strength but increased maximum deflection before failure. The results were encouraging for developing more sustainable concrete technologies.
This document describes the design and analysis of a leaf spring made of sisal fiber reinforced glass epoxy composite. It begins with an abstract that outlines the goal of replacing steel leaf springs with composites to reduce weight and increase fuel economy. It then reviews relevant literature on composite leaf springs. The objectives and methodology are described, including fabrication of composite specimens using hand layup. Tests are performed to determine material properties and compare different fiber volume fractions. A steel leaf spring is modeled and analyzed in ANSYS to determine stresses and deflection. A composite leaf spring is also modeled and tested experimentally to verify analytical and FEA results. The composite leaf spring shows stresses within acceptable limits for the material.
Experimental investigation on ternary blended cement mortarsAbdulRazakBH
ABSTRACT – Usage of Ground granulated blast furnace slag(GGBS) and silica fume(SF) in the blended concrete alongside ordinary portland cement(OPC) has been in practice owing to low cost of production, denser microstructure leading to enhanced durability with satisfactory strength properties of concrete. The present study focusses on usage of GGBS and Silica Fume in ternary blended mortars. 1:4 and 1:6 mortars are studied for compressive strength at 3,7, and 28 days of age. Results indicated that compressive strength of mortar cubes was at par with that of control mix upto mixes with 30% GGBS and 10% Silica Fume. Cost analysis indicated a decrease in cost of binder from the mixes with 30% GGBS and 10% Silica Fume in comparison with control mix.
Keywords- GGBS, M-Sand, Silica Fume, Blended Mortar, Compressive strength
The document summarizes an experimental study on the mechanical behavior of high strength fibre reinforced concrete (HSFRC). Concrete mixes were produced by adding two types of hooked end steel fibres at volume fractions ranging from 0.5% to 4% to a base high strength concrete of grade M80. A total of 147 specimens of cubes, cylinders and prisms were tested to determine the compressive strength, split tensile strength, and flexural strength of the HSFRC mixes. The results indicated that the addition of steel fibres led to significant improvements in the mechanical properties of the high strength concrete. The compressive strength, split tensile strength and flexural strength all increased with the addition of fibres up to an optimal volume
Performance evaluation of hybrid fibre reinforced concrete subjected to freez...eSAT Journals
Abstract Durability is the ability to last a long time without significant deterioration. Hybrid fiber reinforced concrete (HFRC) proves to be durable material, which is effective in resisting the damage caused due to freezing and thawing due to synergistic performance of hybrid fibers. The objectives of the work described in this paper were aimed at comparing the relative strength of Hybrid fiber reinforced concrete (HFRC) with that of mono fiber reinforced concrete (FRC) and plain concrete without fibers (ref. mix) subjected to freezing and thawing. The combination of fibers used in the experimentation are (Steel + Polypropylene),(Steel +Galvanized Iron),(Steel + High density polyethylene).Strength parameters considered are compressive strength, split tensile strength, flexural strength and impact strength and tested as per relevant IS specifications. It has been concluded that the performance of hybrid fibers in concrete is better than that of mono fiber concrete for improved durability in resisting the destructive effect of freezing and thawing and also for strength enhancement. Keywords: Fiber reinforced concrete, hybrid fiber reinforced concrete, freezing and thawing, frost action, synergic effect.
This study investigated the effects of fly ash and glass fiber additions on the properties of concrete. Fly ash was used to replace cement at levels of 30%, 35%, and 40% by volume. Standard M30 concrete without fly ash served as the control. The concrete mixtures also included glass fibers added at levels of 0.5%, 1%, and 2%. Testing found that concrete with 35% fly ash replacement and 1% glass fibers exhibited the highest compressive strength at 36.4% above the control and highest splitting tensile strength at 19.7% above the control after 28 days of curing. The study aimed to determine the optimum levels of fly ash and glass fibers for improving concrete properties.
IRJET- Experimental Investigation on Glass Fibre Reinforced ConcreteIRJET Journal
This document summarizes an experimental investigation on the properties of glass fibre reinforced concrete (GFRC). Testing was conducted on conventional concrete (Mix 1) and GFRC (Mix 2) to determine workability, compressive strength, split tensile strength, and flexural strength at 7 and 28 days. The results showed that GFRC had higher strengths in all areas compared to conventional concrete, with compressive strength approximately 20-25% greater. Specifically, at 28 days Mix 2 achieved 41.1 MPa for compressive strength, 3.97 MPa for split tensile strength, and 4.92 MPa for flexural strength compared to Mix 1's results of 33.22 MPa, 3.17 MPa,
Experimental Study on Strength of Concrete with Addition of Chopped Glass FiberIRJET Journal
This study experimentally investigated the effect of adding chopped glass fibers on the strength properties of concrete. Glass fibers were added at 0.3%, 0.5%, and 0.7% of the total binder content. The compressive strength, split tensile strength, and flexural strength of concrete specimens containing different amounts of glass fibers were tested at 7 and 28 days. The results showed that the strengths increased with higher glass fiber content, with the 0.7% fiber mix achieving the highest strengths. Non-destructive rebound hammer and ultrasonic pulse velocity tests also indicated that concretes with glass fibers had better strength and quality than plain concrete without fibers.
6.a review on wear behaviour of clutch plate made of peek composite materialEditorJST
The conventional clutch plate made of carbon fiber and ceramic mixture of copper, iron, tin bronze,
silicon dioxide, and/or graphite, typical alloy is a lamellar pearlitic gray iron like G11H20b of which, it can be
replaced by developing of new materials for reducing the wear rate of the clutch plate the materials chosen is
Poly Ether Ether Ketone (PEEK) based composites mixed with silicon carbide powder shows better results in
which it can be manufactured by the injection moulding process and it is tested in Friction and wear experiment
wear run under constant temperature in a pin-on-disc arrangement, PEEK and its composites used in this
investigated the friction coefficient decreases with the increasing load on PEEK. The composite showed a very
low friction coefficient and wear rate increase in the normal applied load sliding distance decreases wear rate.
Further the wear and friction behaviour decreases with increases the gradually by addition of fillers.
This document describes the design and analysis of a leaf spring made of sisal fiber reinforced glass epoxy composite. It begins with an abstract that outlines the goal of replacing steel leaf springs with composites to reduce weight and increase fuel economy. It then reviews relevant literature on composite leaf springs. The objectives and methodology are described, including fabrication of composite specimens using hand layup. Tests are performed to determine material properties and compare different fiber volume fractions. A steel leaf spring is modeled and analyzed in ANSYS to determine stresses and deflection. A composite leaf spring is also modeled and tested experimentally to verify analytical and FEA results. The composite leaf spring shows stresses within acceptable limits for the material.
Experimental investigation on ternary blended cement mortarsAbdulRazakBH
ABSTRACT – Usage of Ground granulated blast furnace slag(GGBS) and silica fume(SF) in the blended concrete alongside ordinary portland cement(OPC) has been in practice owing to low cost of production, denser microstructure leading to enhanced durability with satisfactory strength properties of concrete. The present study focusses on usage of GGBS and Silica Fume in ternary blended mortars. 1:4 and 1:6 mortars are studied for compressive strength at 3,7, and 28 days of age. Results indicated that compressive strength of mortar cubes was at par with that of control mix upto mixes with 30% GGBS and 10% Silica Fume. Cost analysis indicated a decrease in cost of binder from the mixes with 30% GGBS and 10% Silica Fume in comparison with control mix.
Keywords- GGBS, M-Sand, Silica Fume, Blended Mortar, Compressive strength
The document summarizes an experimental study on the mechanical behavior of high strength fibre reinforced concrete (HSFRC). Concrete mixes were produced by adding two types of hooked end steel fibres at volume fractions ranging from 0.5% to 4% to a base high strength concrete of grade M80. A total of 147 specimens of cubes, cylinders and prisms were tested to determine the compressive strength, split tensile strength, and flexural strength of the HSFRC mixes. The results indicated that the addition of steel fibres led to significant improvements in the mechanical properties of the high strength concrete. The compressive strength, split tensile strength and flexural strength all increased with the addition of fibres up to an optimal volume
Performance evaluation of hybrid fibre reinforced concrete subjected to freez...eSAT Journals
Abstract Durability is the ability to last a long time without significant deterioration. Hybrid fiber reinforced concrete (HFRC) proves to be durable material, which is effective in resisting the damage caused due to freezing and thawing due to synergistic performance of hybrid fibers. The objectives of the work described in this paper were aimed at comparing the relative strength of Hybrid fiber reinforced concrete (HFRC) with that of mono fiber reinforced concrete (FRC) and plain concrete without fibers (ref. mix) subjected to freezing and thawing. The combination of fibers used in the experimentation are (Steel + Polypropylene),(Steel +Galvanized Iron),(Steel + High density polyethylene).Strength parameters considered are compressive strength, split tensile strength, flexural strength and impact strength and tested as per relevant IS specifications. It has been concluded that the performance of hybrid fibers in concrete is better than that of mono fiber concrete for improved durability in resisting the destructive effect of freezing and thawing and also for strength enhancement. Keywords: Fiber reinforced concrete, hybrid fiber reinforced concrete, freezing and thawing, frost action, synergic effect.
This study investigated the effects of fly ash and glass fiber additions on the properties of concrete. Fly ash was used to replace cement at levels of 30%, 35%, and 40% by volume. Standard M30 concrete without fly ash served as the control. The concrete mixtures also included glass fibers added at levels of 0.5%, 1%, and 2%. Testing found that concrete with 35% fly ash replacement and 1% glass fibers exhibited the highest compressive strength at 36.4% above the control and highest splitting tensile strength at 19.7% above the control after 28 days of curing. The study aimed to determine the optimum levels of fly ash and glass fibers for improving concrete properties.
IRJET- Experimental Investigation on Glass Fibre Reinforced ConcreteIRJET Journal
This document summarizes an experimental investigation on the properties of glass fibre reinforced concrete (GFRC). Testing was conducted on conventional concrete (Mix 1) and GFRC (Mix 2) to determine workability, compressive strength, split tensile strength, and flexural strength at 7 and 28 days. The results showed that GFRC had higher strengths in all areas compared to conventional concrete, with compressive strength approximately 20-25% greater. Specifically, at 28 days Mix 2 achieved 41.1 MPa for compressive strength, 3.97 MPa for split tensile strength, and 4.92 MPa for flexural strength compared to Mix 1's results of 33.22 MPa, 3.17 MPa,
Experimental Study on Strength of Concrete with Addition of Chopped Glass FiberIRJET Journal
This study experimentally investigated the effect of adding chopped glass fibers on the strength properties of concrete. Glass fibers were added at 0.3%, 0.5%, and 0.7% of the total binder content. The compressive strength, split tensile strength, and flexural strength of concrete specimens containing different amounts of glass fibers were tested at 7 and 28 days. The results showed that the strengths increased with higher glass fiber content, with the 0.7% fiber mix achieving the highest strengths. Non-destructive rebound hammer and ultrasonic pulse velocity tests also indicated that concretes with glass fibers had better strength and quality than plain concrete without fibers.
6.a review on wear behaviour of clutch plate made of peek composite materialEditorJST
The conventional clutch plate made of carbon fiber and ceramic mixture of copper, iron, tin bronze,
silicon dioxide, and/or graphite, typical alloy is a lamellar pearlitic gray iron like G11H20b of which, it can be
replaced by developing of new materials for reducing the wear rate of the clutch plate the materials chosen is
Poly Ether Ether Ketone (PEEK) based composites mixed with silicon carbide powder shows better results in
which it can be manufactured by the injection moulding process and it is tested in Friction and wear experiment
wear run under constant temperature in a pin-on-disc arrangement, PEEK and its composites used in this
investigated the friction coefficient decreases with the increasing load on PEEK. The composite showed a very
low friction coefficient and wear rate increase in the normal applied load sliding distance decreases wear rate.
Further the wear and friction behaviour decreases with increases the gradually by addition of fillers.
This document summarizes a study on the use of glass fibers in reinforced concrete. Glass fiber reinforced concrete was produced using CEM-FILL glass fibers added at 0.33-1% by weight of concrete. Beams, cubes, and cylinders were cast and tested to determine the compressive strength, flexural strength, and modulus of elasticity of the fiber reinforced concrete. The results showed that at 28 days the compressive strength increased by 37% and flexural strength increased by 5.19% compared to normal concrete without fibers. The addition of glass fibers was found to improve the toughness, flexural strength, ductility, and compressive strength of the concrete.
Iaetsd experimental study on properties of ternary blended fibreIaetsd Iaetsd
This document summarizes an experimental study on the properties of self-compacting concrete (SCC) blended with ternary fibers including fly ash, rice husk ash, and steel fibers. The study found that replacing some of the cement content in SCC with these mineral admixtures and fibers can improve the strength and durability of SCC while making it more cost effective. Specifically, the study observed overall improvements in the compressive strength, split tensile strength, and flexural strength of SCC mixtures with varying blends of fly ash, rice husk ash, and steel fibers.
A Study on Properties of Foamed Concrete with Natural and Synthetic Foaming A...IRJET Journal
This study investigated the properties of foamed concrete made with natural and synthetic foaming agents. Foamed concrete is a lightweight material made of cement, water, fine aggregate, and air voids. Two foaming agents were used: soap nut (natural) and a synthetic agent. Silica fume was also added as a partial replacement for cement to increase strength. Results showed that concrete with the natural foaming agent had higher density and lower strength and elastic modulus than with the synthetic agent. However, natural agents are less expensive. In general, compressive strength was highest with silica fume addition. The study concluded that both natural and synthetic foaming agents can produce foamed concrete, but the natural material produces lower strength concrete
The document summarizes an experiment that tested 24 bamboo reinforced concrete beam specimens to investigate the effect of adding bamboo pegs along the bamboo reinforcements. The beams varied in concrete strength (23 MPa and 31 MPa), peg spacing (6 cm and 12 cm), and reinforcement ratio (0.8% and 1.6%). Beams with pegs showed higher strength capacity than control beams without pegs. While there were small differences between 6 cm and 12 cm peg spacing, all specimens with pegs performed better than those without, demonstrating that adding pegs increased the bonding strength between the bamboo reinforcement and concrete.
This document summarizes an experimental investigation on the effect of industrial byproducts on the strength properties of high performance concrete. Specifically, it examines partially replacing cement, fine aggregate, and coarse aggregate with silica fume, bottom ash, and steel slag aggregate. There were a total of 15 mixes created with different material contents, including one conventional concrete mix. Testing found that replacing cement with 5% silica fume and replacing fine and coarse aggregate with 10% bottom ash and steel slag achieved higher strengths compared to other mixes. The mixes were classified as binary combinations of two materials or ternary combinations of all three materials.
Experimental Study on Composite Concrete RC Frame Structure using Sisal Fibreijtsrd
This project aims to compare the mechanical properties of Sisal fiber in the improvement of load carrying capacity of concrete structure in different layers. Beams and columns may be strengthened in flexure through the use of sisal fiber bonded to their tension zone using epoxy as a common adhesive. Due to several advantages of sisal fibre wrapping over conventional techniques used for structural repair and strengthening. In our project is study about load carrying capacity of an RCC frame wrapped with sisal fiber. An experimental study is to predict the maximum load carrying capacity, deflection of the composite RCC structure. Finally the results are compared with conventional framed structure, which is suitable for strength and rehabilitate the concrete structure. P. Vanmathi | A. Dharani "Experimental Study on Composite Concrete RC Frame Structure using Sisal Fibre" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-4 , June 2020, URL: https://www.ijtsrd.com/papers/ijtsrd31115.pdf Paper Url :https://www.ijtsrd.com/engineering/structural-engineering/31115/experimental-study-on-composite-concrete-rc-frame-structure-using-sisal-fibre/p-vanmathi
IRJET- Experimental Study on Recron Fiber Reinforced Concrete Blended with Fl...IRJET Journal
This document provides a review of experimental studies on fiber reinforced concrete blended with fly ash and metakaolin. It discusses three main points:
1) Previous studies have found that adding recron fibers to concrete increases its compressive, tensile, and flexural strengths. It reduces cracking and permeability.
2) The addition of fly ash and metakaolin as cement replacements is also found to improve concrete properties like strength and durability. Metakaolin increases strength while fly ash reduces costs.
3) Engineered cementitious concrete (ECC) is a ductile fiber reinforced concrete without coarse aggregates. Studies show ECC can withstand higher tensile strains than normal concrete due to its fiber reinforcement and crack-cont
The document discusses testing the flexural strength of concrete. It provides details on the test setup and procedures. The flexural strength test is used to determine a material's ability to resist bending or deformation under a load. The test involves placing a concrete specimen on supporting rollers spaced at specific distances and applying a load through top rollers at the midpoint. The maximum load applied before failure is used to calculate the flexural strength based on the specimen's dimensions and load. Test equipment requirements and specifications are also outlined.
An Experimental Investigation on Steel Fiber Reinforced Concrete with Partial...IRJET Journal
This document summarizes an experimental investigation on steel fiber reinforced concrete with partial replacement of natural sand by manufactured sand. Cubes, cylinders, prisms, and L-shaped specimens of M30 grade concrete with 50% replacement of natural sand by manufactured sand and 1% steel fibers were cast and tested at 7, 14, and 28 days to evaluate mechanical properties. The tests included compressive strength, split tensile strength, flexural strength, shear strength, and the effect of high temperatures. The study aims to compare the mechanical performance of steel fiber reinforced concrete with manufactured sand to normal concrete.
Some Studies on Strength Properties of Tetra Blended Concrete with Partial Re...IRJET Journal
This document presents the results of a study on the strength properties of concrete with partial cement replacement using various pozzolanic materials and micro Al2O3 powder. Cement in the concrete mixes was replaced with slag, silica fume, pulverized quartz powder, and micro Al2O3 powder individually and in combinations. The compressive strength, split tensile strength, and flexural strength of the concrete mixes were tested at 7 and 28 days. It was found that the tetra blended concrete mix with 16% replacement of cement with pozzolanic materials (slag, silica fume, pulverized quartz powder) and 1% micro Al2O3 powder yielded the highest compressive strength
Properties of Glass Fibre Reinforced Geopolymer ConcreteIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
UTILIZATION OF BAMBOO FIBER IN IMPROVING THE PROPERTIES OF STONE MATRIX ASPHA...rajatpalya
Utilization of bamboo fiber in improving the properties of stone matrix asphalt mixes. Stone matrix asphalt provides long-term deformation resistance and durability. Bamboo fiber was used as a stabilizer due to its low cost and natural availability. Stone matrix asphalt samples were prepared with and without bamboo fiber at varying bitumen contents. The optimum bitumen content was found to be 5% for mixes using stone aggregate and bamboo fiber, which showed better stability compared to mixes without fiber. The use of bamboo fiber as a stabilizer improved the properties of the stone matrix asphalt mixes.
This document discusses a study investigating the influence of polypropylene fiber (PPF) and silica fume (SF) on the compressive and tensile strengths of concrete. Sixteen concrete mixes were tested with varying amounts of PPF (0.25-0.75% by volume) and SF (6-18% replacing cement by mass). Test results showed that SF increased compressive and tensile strengths up to 45% and 24.5% respectively, while PPF generally decreased strengths, with higher PPF contents causing greater decreases in strength. When both materials were used, strengths were highest with SF only and lowest with higher amounts of both PPF and SF. The study concluded that SF improves concrete strengths
ENHANCEMENT OF SEISMIC PERFORMANCE OF STRUCTURES USING HyFRCIEI GSC
Presentation on ENHANCEMENT OF SEISMIC PERFORMANCE OF STRUCTURES USING HyFRC by Needhi Kotoky Under the supervision of Dr. Anjan Dutta and Dr. Sajal K. Deb Department of Civil EngineeringIndian Institute of Technology Guwahati
IRJET- Experimental Study on Geopolymer Concrete by using Glass FibresIRJET Journal
The document presents the results of an experimental study on geopolymer concrete reinforced with glass fibers. Geopolymer concrete is an environmentally friendly alternative to traditional Portland cement concrete that uses industrial byproducts like fly ash instead of cement. The study aimed to determine the effects of adding 1-4% glass fibers by volume on the mechanical properties of geopolymer concrete. Specimens containing various amounts of glass fibers were tested to evaluate properties like compressive strength, flexural strength, and workability. The results showed that workability decreased slightly with higher fiber content, while compressive and flexural strengths generally increased up to 3% fiber content compared to plain geopolymer concrete without fibers.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
Information Engineering and Technology,
Mechanical, Industrial and Manufacturing Engineering,
Automation and Mechatronics Engineering,
Material and Chemical Engineering,
Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
Environmental Engineering,
Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Experimental study on behaviour of concrete using steel fiber as a tensile ma...KavinKumarR3
Concrete is widely used in all over the world. It gives a compression strength and when it is collaborate with the steel the tension strength is increased. Traditional reinforcement will takes time. So by using the steel fibers in the concrete it will gives the high strength and durability. The fiber will leads to compensate the weakness in the concrete. Steel fiber reinforced concrete (SFRC) is successfully used in the slabs, flooring, and even in beams. The formation has proved the high tensile strength when it added in the concrete.
Experimental Evaluation of effect of filler on tensile behaviour of E-glass/e...IJRES Journal
The present work describes the processing and tensile characterization of polymer matrix composites (PMC). Two types of E-glass laminates namely woven and chopped are used as a reinforcing materials and epoxy resin constitutes matrix system. Several works has been carried out to prove that strength of glass fibre composites progressively increased with adding fillers. Keeping this in mind the present work successeded in using wollastonite as a filler material, tensile test samples from both woven and chopped type were prepared and tests are conducted as per ASTM standards and corresponding results are tabulated and discussed. The present work also highlights the tensile strength for both woven and chopped laminates were compared. It is observed that use of wollastonite filler influences greatly on tensile properties of polymer matrix composites. And it is also cleared that woven laminates shows higher resistance to tensile loading as compared to chopped laminates.
The document provides information on investment opportunities in the Atyrau region of Kazakhstan. Some key points:
- Atyrau region accounts for 25% of Kazakhstan's industrial production and over 35% of its oil and gas extraction. It has large reserves of oil and gas.
- Priority sectors for investment and development include petrochemicals, machine building, gas/oil production, agriculture, and alternative energy. 44 investment projects worth $8 billion are proposed.
- The region cooperates with over 50 countries and hosts 900 foreign companies. A special economic zone offers tax benefits to registered companies to encourage investment.
- Several specific investment project proposals are described, ranging from $2-400 million
Kostanay province is located in northern Kazakhstan and borders several other Kazakh and Russian provinces. It has an area of 196,000 square km and a population of 880,900 people. The province has rich mineral resources such as iron ore, bauxite, coal, and other deposits. Its economy relies heavily on mining and manufacturing industries. Several investment opportunities are described, including constructing a wind farm, waste processing plant, and logistics center, as well as developing a kaolin-quartz-feldspar deposit.
This document summarizes a study on the use of glass fibers in reinforced concrete. Glass fiber reinforced concrete was produced using CEM-FILL glass fibers added at 0.33-1% by weight of concrete. Beams, cubes, and cylinders were cast and tested to determine the compressive strength, flexural strength, and modulus of elasticity of the fiber reinforced concrete. The results showed that at 28 days the compressive strength increased by 37% and flexural strength increased by 5.19% compared to normal concrete without fibers. The addition of glass fibers was found to improve the toughness, flexural strength, ductility, and compressive strength of the concrete.
Iaetsd experimental study on properties of ternary blended fibreIaetsd Iaetsd
This document summarizes an experimental study on the properties of self-compacting concrete (SCC) blended with ternary fibers including fly ash, rice husk ash, and steel fibers. The study found that replacing some of the cement content in SCC with these mineral admixtures and fibers can improve the strength and durability of SCC while making it more cost effective. Specifically, the study observed overall improvements in the compressive strength, split tensile strength, and flexural strength of SCC mixtures with varying blends of fly ash, rice husk ash, and steel fibers.
A Study on Properties of Foamed Concrete with Natural and Synthetic Foaming A...IRJET Journal
This study investigated the properties of foamed concrete made with natural and synthetic foaming agents. Foamed concrete is a lightweight material made of cement, water, fine aggregate, and air voids. Two foaming agents were used: soap nut (natural) and a synthetic agent. Silica fume was also added as a partial replacement for cement to increase strength. Results showed that concrete with the natural foaming agent had higher density and lower strength and elastic modulus than with the synthetic agent. However, natural agents are less expensive. In general, compressive strength was highest with silica fume addition. The study concluded that both natural and synthetic foaming agents can produce foamed concrete, but the natural material produces lower strength concrete
The document summarizes an experiment that tested 24 bamboo reinforced concrete beam specimens to investigate the effect of adding bamboo pegs along the bamboo reinforcements. The beams varied in concrete strength (23 MPa and 31 MPa), peg spacing (6 cm and 12 cm), and reinforcement ratio (0.8% and 1.6%). Beams with pegs showed higher strength capacity than control beams without pegs. While there were small differences between 6 cm and 12 cm peg spacing, all specimens with pegs performed better than those without, demonstrating that adding pegs increased the bonding strength between the bamboo reinforcement and concrete.
This document summarizes an experimental investigation on the effect of industrial byproducts on the strength properties of high performance concrete. Specifically, it examines partially replacing cement, fine aggregate, and coarse aggregate with silica fume, bottom ash, and steel slag aggregate. There were a total of 15 mixes created with different material contents, including one conventional concrete mix. Testing found that replacing cement with 5% silica fume and replacing fine and coarse aggregate with 10% bottom ash and steel slag achieved higher strengths compared to other mixes. The mixes were classified as binary combinations of two materials or ternary combinations of all three materials.
Experimental Study on Composite Concrete RC Frame Structure using Sisal Fibreijtsrd
This project aims to compare the mechanical properties of Sisal fiber in the improvement of load carrying capacity of concrete structure in different layers. Beams and columns may be strengthened in flexure through the use of sisal fiber bonded to their tension zone using epoxy as a common adhesive. Due to several advantages of sisal fibre wrapping over conventional techniques used for structural repair and strengthening. In our project is study about load carrying capacity of an RCC frame wrapped with sisal fiber. An experimental study is to predict the maximum load carrying capacity, deflection of the composite RCC structure. Finally the results are compared with conventional framed structure, which is suitable for strength and rehabilitate the concrete structure. P. Vanmathi | A. Dharani "Experimental Study on Composite Concrete RC Frame Structure using Sisal Fibre" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-4 , June 2020, URL: https://www.ijtsrd.com/papers/ijtsrd31115.pdf Paper Url :https://www.ijtsrd.com/engineering/structural-engineering/31115/experimental-study-on-composite-concrete-rc-frame-structure-using-sisal-fibre/p-vanmathi
IRJET- Experimental Study on Recron Fiber Reinforced Concrete Blended with Fl...IRJET Journal
This document provides a review of experimental studies on fiber reinforced concrete blended with fly ash and metakaolin. It discusses three main points:
1) Previous studies have found that adding recron fibers to concrete increases its compressive, tensile, and flexural strengths. It reduces cracking and permeability.
2) The addition of fly ash and metakaolin as cement replacements is also found to improve concrete properties like strength and durability. Metakaolin increases strength while fly ash reduces costs.
3) Engineered cementitious concrete (ECC) is a ductile fiber reinforced concrete without coarse aggregates. Studies show ECC can withstand higher tensile strains than normal concrete due to its fiber reinforcement and crack-cont
The document discusses testing the flexural strength of concrete. It provides details on the test setup and procedures. The flexural strength test is used to determine a material's ability to resist bending or deformation under a load. The test involves placing a concrete specimen on supporting rollers spaced at specific distances and applying a load through top rollers at the midpoint. The maximum load applied before failure is used to calculate the flexural strength based on the specimen's dimensions and load. Test equipment requirements and specifications are also outlined.
An Experimental Investigation on Steel Fiber Reinforced Concrete with Partial...IRJET Journal
This document summarizes an experimental investigation on steel fiber reinforced concrete with partial replacement of natural sand by manufactured sand. Cubes, cylinders, prisms, and L-shaped specimens of M30 grade concrete with 50% replacement of natural sand by manufactured sand and 1% steel fibers were cast and tested at 7, 14, and 28 days to evaluate mechanical properties. The tests included compressive strength, split tensile strength, flexural strength, shear strength, and the effect of high temperatures. The study aims to compare the mechanical performance of steel fiber reinforced concrete with manufactured sand to normal concrete.
Some Studies on Strength Properties of Tetra Blended Concrete with Partial Re...IRJET Journal
This document presents the results of a study on the strength properties of concrete with partial cement replacement using various pozzolanic materials and micro Al2O3 powder. Cement in the concrete mixes was replaced with slag, silica fume, pulverized quartz powder, and micro Al2O3 powder individually and in combinations. The compressive strength, split tensile strength, and flexural strength of the concrete mixes were tested at 7 and 28 days. It was found that the tetra blended concrete mix with 16% replacement of cement with pozzolanic materials (slag, silica fume, pulverized quartz powder) and 1% micro Al2O3 powder yielded the highest compressive strength
Properties of Glass Fibre Reinforced Geopolymer ConcreteIJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
International Journal of Modern Engineering Research (IJMER) covers all the fields of engineering and science: Electrical Engineering, Mechanical Engineering, Civil Engineering, Chemical Engineering, Computer Engineering, Agricultural Engineering, Aerospace Engineering, Thermodynamics, Structural Engineering, Control Engineering, Robotics, Mechatronics, Fluid Mechanics, Nanotechnology, Simulators, Web-based Learning, Remote Laboratories, Engineering Design Methods, Education Research, Students' Satisfaction and Motivation, Global Projects, and Assessment…. And many more.
UTILIZATION OF BAMBOO FIBER IN IMPROVING THE PROPERTIES OF STONE MATRIX ASPHA...rajatpalya
Utilization of bamboo fiber in improving the properties of stone matrix asphalt mixes. Stone matrix asphalt provides long-term deformation resistance and durability. Bamboo fiber was used as a stabilizer due to its low cost and natural availability. Stone matrix asphalt samples were prepared with and without bamboo fiber at varying bitumen contents. The optimum bitumen content was found to be 5% for mixes using stone aggregate and bamboo fiber, which showed better stability compared to mixes without fiber. The use of bamboo fiber as a stabilizer improved the properties of the stone matrix asphalt mixes.
This document discusses a study investigating the influence of polypropylene fiber (PPF) and silica fume (SF) on the compressive and tensile strengths of concrete. Sixteen concrete mixes were tested with varying amounts of PPF (0.25-0.75% by volume) and SF (6-18% replacing cement by mass). Test results showed that SF increased compressive and tensile strengths up to 45% and 24.5% respectively, while PPF generally decreased strengths, with higher PPF contents causing greater decreases in strength. When both materials were used, strengths were highest with SF only and lowest with higher amounts of both PPF and SF. The study concluded that SF improves concrete strengths
ENHANCEMENT OF SEISMIC PERFORMANCE OF STRUCTURES USING HyFRCIEI GSC
Presentation on ENHANCEMENT OF SEISMIC PERFORMANCE OF STRUCTURES USING HyFRC by Needhi Kotoky Under the supervision of Dr. Anjan Dutta and Dr. Sajal K. Deb Department of Civil EngineeringIndian Institute of Technology Guwahati
IRJET- Experimental Study on Geopolymer Concrete by using Glass FibresIRJET Journal
The document presents the results of an experimental study on geopolymer concrete reinforced with glass fibers. Geopolymer concrete is an environmentally friendly alternative to traditional Portland cement concrete that uses industrial byproducts like fly ash instead of cement. The study aimed to determine the effects of adding 1-4% glass fibers by volume on the mechanical properties of geopolymer concrete. Specimens containing various amounts of glass fibers were tested to evaluate properties like compressive strength, flexural strength, and workability. The results showed that workability decreased slightly with higher fiber content, while compressive and flexural strengths generally increased up to 3% fiber content compared to plain geopolymer concrete without fibers.
International Journal of Engineering Research and DevelopmentIJERD Editor
Electrical, Electronics and Computer Engineering,
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Automation and Mechatronics Engineering,
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Civil and Architecture Engineering,
Biotechnology and Bio Engineering,
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Petroleum and Mining Engineering,
Marine and Agriculture engineering,
Aerospace Engineering.
Experimental study on behaviour of concrete using steel fiber as a tensile ma...KavinKumarR3
Concrete is widely used in all over the world. It gives a compression strength and when it is collaborate with the steel the tension strength is increased. Traditional reinforcement will takes time. So by using the steel fibers in the concrete it will gives the high strength and durability. The fiber will leads to compensate the weakness in the concrete. Steel fiber reinforced concrete (SFRC) is successfully used in the slabs, flooring, and even in beams. The formation has proved the high tensile strength when it added in the concrete.
Experimental Evaluation of effect of filler on tensile behaviour of E-glass/e...IJRES Journal
The present work describes the processing and tensile characterization of polymer matrix composites (PMC). Two types of E-glass laminates namely woven and chopped are used as a reinforcing materials and epoxy resin constitutes matrix system. Several works has been carried out to prove that strength of glass fibre composites progressively increased with adding fillers. Keeping this in mind the present work successeded in using wollastonite as a filler material, tensile test samples from both woven and chopped type were prepared and tests are conducted as per ASTM standards and corresponding results are tabulated and discussed. The present work also highlights the tensile strength for both woven and chopped laminates were compared. It is observed that use of wollastonite filler influences greatly on tensile properties of polymer matrix composites. And it is also cleared that woven laminates shows higher resistance to tensile loading as compared to chopped laminates.
The document provides information on investment opportunities in the Atyrau region of Kazakhstan. Some key points:
- Atyrau region accounts for 25% of Kazakhstan's industrial production and over 35% of its oil and gas extraction. It has large reserves of oil and gas.
- Priority sectors for investment and development include petrochemicals, machine building, gas/oil production, agriculture, and alternative energy. 44 investment projects worth $8 billion are proposed.
- The region cooperates with over 50 countries and hosts 900 foreign companies. A special economic zone offers tax benefits to registered companies to encourage investment.
- Several specific investment project proposals are described, ranging from $2-400 million
Kostanay province is located in northern Kazakhstan and borders several other Kazakh and Russian provinces. It has an area of 196,000 square km and a population of 880,900 people. The province has rich mineral resources such as iron ore, bauxite, coal, and other deposits. Its economy relies heavily on mining and manufacturing industries. Several investment opportunities are described, including constructing a wind farm, waste processing plant, and logistics center, as well as developing a kaolin-quartz-feldspar deposit.
The document summarizes information about West Kazakhstan Region. It describes the region's economy, which focuses on oil and gas, machine building, construction materials, and agriculture. It provides statistics on the region's GDP, population, education system, agriculture output, and industrial sectors. It also outlines promising investment projects in machine building, agriculture, construction materials, transport/logistics, tourism, and contributions to Expo 2017.
The report provides an overview of investment opportunities in the Pavlodar region of Kazakhstan. The Pavlodar region has a population of over 750,000 people and borders Russia and other regions of Kazakhstan. It has significant natural resources such as coal, nickel, gold, copper, and molybdenum. There are over 800 industrial enterprises in the region producing aluminum, electricity, coal, and other goods. The region also has a special economic zone called "Pavlodar" that offers tax incentives for chemical and petrochemical manufacturing projects. Total investments in the region in the first 7 months of 2014 were $1.1 billion from both domestic and foreign sources.
The document outlines various governmental measures of support for investors in Kazakhstan, including incentives for priority investment projects such as exemptions from customs duties, tax exemptions, and subsidies of up to 30% of investment costs. It also discusses the establishment of an Investment Ombudsman to assist investors and consider appeals, as well as business incubators and industrial zones in Atyrau that offer affordable rental space and infrastructure to support new businesses.
The document summarizes investment opportunities in the Atyrau region of Kazakhstan. The Atyrau region has significant oil, gas, and mineral resources, accounting for over 35% of Kazakhstan's oil and gas extraction. It aims to diversify its economy by developing petrochemicals, machine building, agriculture, renewable energy, and other industries. The region has launched an industrial development program involving 44 projects worth $8 billion USD focused on petrochemicals, modular housing, drilling equipment, and other sectors. It works to attract investment through special economic zones, tax benefits, and a "one window" approach through organizations like Atyrau Innovations and SEC "Atyrau".
STRATEGIC HUMAN RESOURCE MANAGEMENT AND SUSTAINABLE COMPETITIVE ADVANTAGE: TH...pitaloka .
This document summarizes a research paper on strategic human resource management and sustainable competitive advantage. It discusses two main approaches to SHRM - outside-in and inside-out. While both have advantages, the inside-out approach based on resource-based view has limitations in dynamic environments. The document proposes that dynamic capabilities and continuous innovation are needed to achieve sustained competitive advantage. It argues that human resource flexibility, knowledge capital, and developing innovation capabilities can help firms adapt strategically to changes in their environment over time.
The document summarizes investment opportunities in the Atyrau region of Kazakhstan. The Atyrau region has significant oil, gas, and mineral resources, accounting for over 35% of Kazakhstan's oil and gas extraction. It aims to diversify its economy by developing petrochemicals, machine building, agriculture, renewable energy, and other industries. The region has launched a Forced Industrial-Innovative Development program with 44 investment projects worth $8 billion USD focused on petrochemicals, housing construction, and heavy equipment. The region provides incentives for investors including tax breaks and assists with all stages of new projects.
Kazakhstan is an attractive location for foreign investment for several reasons:
1. It has substantial natural resources and ranks highly globally in reserves of minerals and mining.
2. The country has political stability and a good investment climate according to international rankings.
3. The government offers many support programs for investors, including tax benefits, customs privileges, and preferential treatment in special economic zones.
IDenTV Video Content Recognition OverviewAmro Shihadah
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The result of this pioneering work is the Intelligent Video Platform, a commercial-ready, breakthrough technology that enables high-speed visual content recognition and indexing, combined with real-time search and verification of massive amounts of video with extreme accuracy, efficiency, and scalability. Offering true video big data analytics. State-of-the art machine learning and artificial intelligence techniques make the IVP highly accurate and efficient.
From the DevOps Lisbon Meetup @Beta-i (May 2016)
Presenter: Filipe Bartolomeu
Title: What I've Learned About Test Automation and DevOps
Agile/DevOps methodologies amplified the deployment frequency one order of magnitude. That wouldn’t be achievable without quality assurance. That’s where Test Automation (TA) comes into place. A presentation about pitfalls, techniques and current trends of Test Automation.
STRATEGIC HUMAN RESOURCE MANAGEMENT AND SUSTAINABLE COMPETITIVE ADVANTAGE: TH...pitaloka .
Researches on strategic human resource management have given major attention to the issues related to HR management
(managing people) on corporate level as a whole and integrated, than solely focuses on individual practice of HRM which is independent from other strategies of firm. This is because in order to achieve sustainable superior performance and competitive advantage, integration and confortabillitty between selected strategy and human resource policy are required to execute the strategy itself.
Inside-out approach supported by Resource Based View theory is not completely able to displace the outside-in approach in the process of HRM strategy formulation and implementation. This is caused by the fact that each of the approaches has its own advantages and disadvantages over others. The problem is how to make the role and function of strategic HRM able to directly answer all of challenges and create real solutions and add real value on the creation (value creation) so that firm wins the competition. Therefore, the role and functions of HRM must be aimed onto how to create and manage the core competencies to keep it dynamic and flexible (dynamic capabilities) to motivate the emergence of sustainable creativity and innovation which are integrated into every activity, practice, and strategy of HRM (HR Strategy) so that firm is able to adapt, integrate, arrange, and readjust its resources with the environmental changes as necessary.
This document summarizes a study on the effects of adding admixtures and synthetic polymer fibers to concrete of different strengths. Testing of 54 concrete cylinders showed that the addition of admixtures and fibers increased compressive strength more than reference concrete, allowing a reduction in cement percentage. The highest strengths were achieved with admixture-added concrete, followed by fiber-added and normal concrete. While fibers did not significantly boost strength on their own, the combination of admixtures and fibers promises sustainable, durable concrete structures.
. effect of different types of cement on fresh and mechanical properties of c...ENGJiidhe
The document reviews several studies that investigated the effect of different cement types on the fresh and mechanical properties of concrete. The cement types investigated included ordinary Portland cement, fly ash-based cement, slag cement, and cement with supplementary materials like silica fume, metakaolin, and polyethylene therephthalate. The studies found that workability generally decreased with the addition of supplementary materials but mechanical properties like compressive strength and durability increased. The performance of concrete depended on factors like water-cement ratio, curing conditions, and the replacement levels of supplementary materials. Overall, the studies emphasized that choosing the appropriate cement type and optimizing the mix design can improve the properties of concrete for different applications.
IRJET- A Review: Effect of Carbon Fiber on Different Mixes of ConcreteIRJET Journal
The document reviews research on the effect of adding carbon fibers to concrete mixes. It summarizes several studies that tested how different percentages of carbon fiber content affected the compressive, tensile, and flexural strengths of various concrete grades. The studies found that carbon fibers increased strength properties like compressive strength by up to 2%, flexural strength by up to 45%, and tensile strength by up to 11%. Higher fiber contents of 0.75-1.0% produced the largest improvements in strength, especially at later curing periods of 14-28 days. Carbon fibers improved durability, cracking resistance, and other concrete properties.
Improving the Properties of Self-compacted Concrete with Using Combined Silic...Pouyan Fakharian
The viscosity is the main property of self- compacted concrete (SCC) and using of pozzolan material such as metakaolin (MK) and Silica fume (SF) can help to achieve that goal. The effect of simultaneous substitution of MK and SF instead of cement on the rheological and mechanical properties of self-compacted concrete was experimentally investigated in this paper. Seventeen mix designs were cast with a substitution weight percentage (5, 10, 15, 20 %) in water to adhesive material ratio equal 0.32. All mixes were examined by compressive, tensile strengths and water absorption tests with an appropriate fluidity, without having signs of segregation or instability. The test results were indicated that the SCC mixes containing MK and SF had higher compressive and tensile strengths in comparison with no-pozzolan concrete. The comparison of linear multiple regression techniques (LMRT) and nonlinear multiple regression technique outputs with experimental results showed an appropriate similarity.
IRJET- Experimental Analysis and Study the Effect of Waste Glass Wool Fib...IRJET Journal
This document discusses an experimental study on the effect of adding waste glass wool fiber to concrete properties. Glass wool fiber is a byproduct of glass manufacturing and is considered waste. The study aims to reuse this waste by adding glass wool fiber in amounts from 0.5% to 3% of cement weight to produce glass wool fiber reinforced concrete (GWFC). The concrete grade used is M25. The study assesses the compressive, tensile, and flexural strengths of the GWFC through laboratory testing and compares it to conventional concrete. Previous studies that investigated using glass wool fiber in concrete are also reviewed.
This study investigated the mechanical and durability properties of high strength concrete (HPC) using silica fume and steel fiber additions. The concrete mixtures contained 10% silica fume replacement of cement by weight, and steel fiber contents of 1%, 1.5%, and 2% by volume. Testing showed that HPC with 2% steel fiber provided the highest compressive, split tensile, and flexural strengths. Impact resistance and modulus of elasticity also increased with higher steel fiber content. Addition of silica fume and steel fiber improved the bond strength and reduced chloride permeability compared to normal concrete. This experimental investigation demonstrated that using silica fume and steel fiber can enhance the mechanical and durability characteristics of high strength
This document provides a review of research on producing floating concrete using lightweight materials like expanded polystyrene beads and pumice stone. It summarizes 10 previous studies that investigated using these materials to partially replace traditional aggregates in concrete. The studies found that this could produce concrete with compressive strengths and densities low enough to float. Replacing more traditional materials increased workability but decreased strength. Proportions and sizes of replacement materials affected properties. Overall, the studies showed it is possible to create floating concrete for applications like building barges and slabs.
dding fibers to concrete helps enhance its tensile strength and ductility. Synthetic fibres
are preferable to steel ones which suffer from corrosion that reduces their functionality with time.
More consideration is given to synthetic fibres as they can be sourced from waste plastics and their
incorporation in concrete is considered a new recycling pathway
Effect of Fibres on the Compressive Strength of Hollow Concrete Blocksijtsrd
Concrete is the most often utilised material in building. Cementitious material improvement is critical since it is the most versatile material used in building. The two key established drawbacks of ordinary concrete are destructive behaviour combining brittle failure and inadequate tensile strength. The purpose of this paper is to investigate the impact of adding various types of fibres to hollow concrete blocks. Polypropylene, steel, glass, nylon, and coconut fibres were employed in various proportions in the current work. The inquiry programs major goal is to determine the optimal fibre content as well as the impact of fibre addition on the compressive strength of hollow concrete blocks. After that, the compressive strength of the hollow concrete block samples was measured. The hollow concrete block samples were tested for compressive strength after 28 days of curing period and a notable increase in compressive strength is observed for all the percentage addition of fibres when compared with the hollow concrete block without fibres. Ms. Anshu Arya "Effect of Fibres on the Compressive Strength of Hollow Concrete Blocks" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-6 | Issue-2 , February 2022, URL: https://www.ijtsrd.com/papers/ijtsrd49243.pdf Paper URL: https://www.ijtsrd.com/engineering/civil-engineering/49243/effect-of-fibres-on-the-compressive-strength-of-hollow-concrete-blocks/ms-anshu-arya
Glass Fibre Concrete: Investigation on Strength and Fire Resistant PropertiesIOSR Journals
Abstract: Over the decades, there has been a significant increase in the use of fibres in concrete for improving
its properties such as tensile strength and ductility. The fibre concrete is also used in retrofitting existing
concrete structures. Among many different types of fibres available today, glass fibre is a recent introduction in
the field of concrete technology. Glass fibre has the advantages of having higher tensile strength and fire
resistant properties, thus reducing the loss of damage during fire accident of concrete structures. In this
investigation glass fibres of 450 mm length are added to the concrete by volume fraction of up to 1% to
determine its strength and fire resistant characteristics. Comparison of the strength and fire-resistance
performance of conventional concrete and glass fibre concrete was made. The paper presents the details of the
experimental investigations and the conclusions drawn there from
This document summarizes a study that assessed the fresh and hardened properties of self-consolidating concrete (SCC) containing steel, polypropylene, and hybrid fibers at various high temperatures. Four SCC mixtures were tested: a control without fibers, one with 1% polypropylene fibers, one with 1% steel fibers, and one with 0.5% of each steel and polypropylene fibers. All mixtures met standards for workability and passing ability. The inclusion of fibers slightly reduced workability. Mechanical properties generally increased with temperature up to 200°C then decreased at higher temperatures. Fiber-reinforced SCC exhibited improved spalling resistance compared to plain SCC.
IRJET - Experimental Investigation on Flexural Behaviour of Reinforced Concre...IRJET Journal
This document presents an experimental investigation on the flexural behavior of reinforced concrete with milled carbon fibers. Concrete specimens containing 0.5%, 1%, 1.5%, and 2% milled carbon fibers by weight of cement were tested to determine their compressive strength, split tensile strength, and flexural strength after 7, 14, and 28 days of curing. The results showed that adding milled carbon fibers increased the compressive strength by up to 32%, tensile strength by over 100%, flexural strength by 62.5%, and reduced deflection. The document concludes that adding milled carbon fibers improves the mechanical properties of concrete.
Influence of GGBS on Mechanical Properties of Low Traffic Concrete Paver BlocksAbdulRazakBH
Abstract: Supplementary cementitious materials (SCM) are the integral part of modern concrete with significant enhancement
in concrete performance. Low cost of production, low heat of hydration along with improved mechanical properties encourage
the replacement of ordinary Portland cement (OPC) with SCMs to a greater extent. The study focusses on influence of Ground
granulated blast furnace slag (GGBS) as SCM in production of concrete paver blocks. Compressive strength, split tensile
strength, and flexural strength are the properties under consideration. Improved compressive strength and flexural strength was
observed in blended concrete with 20% and 40% GGBS replacement levels.
Keywords: GGBS, M-Sand, Paver Blocks, Split tensile strength, Flexural strength
Ternary blended concrete using fly ash and silica fume. PPTMd Faiz Ali
The document discusses a study on the strength properties of ternary blended concrete using fly ash and silica fume. Fly ash and silica fume are used to partially replace cement in concrete mixes. Experimental testing was conducted on concrete mixes with various replacement levels of fly ash and silica fume. The compressive strength and split tensile strength of the mixes were tested at 7 and 28 days. The results showed that the mix with 10% fly ash and 10% silica fume replacement achieved the highest strengths, while the mix with 8% fly ash and 12% silica fume replacement achieved the lowest strengths.
Analysis of Characteristics Behaviour use of Locally Materials in Highway Sub...ijtsrd
This document summarizes a study on the use of polyethylene fiber and waste tire fibers as reinforcement in concrete for pavement applications. Tests were conducted on concrete mixes with 1.5% polyethylene and tire fibers by volume. Results showed an increase in 28-day compressive strength of up to 18% and increases in flexural strength and shear strength of up to 39% and 32% respectively. There were also reductions in deflection of up to 22% and 36% for flexural and shear tests. The study concluded that polyethylene and tire fibers can be efficiently used as reinforcement in concrete and provide gains in strength properties while enabling waste materials to be reused.
Hence, it can be concluded concrete prepared with 3% NS and 6%
SF combination can be recommended for the structural applications. The increase in the strength
properties of concrete is due to the availability of additional binder in the presence of NS and SF.
The improved durability property of concrete is due to proper packing of NS and SF particles results
in reduction in voids and leading to dense concrete.
Modelling of sample beam concrete when added fiber glass to know flexural str...AI Publications
Background: This research mainly consists of determining whether concrete with the addition of fiberglass helps in its physical and mechanical properties and properties on the compressive, bending and adsorption forces of concrete in Iraq. Aim of project: this paper aims to modelling of sample beam concrete when added fibre glass to know flexural strength. material and method: In this study, 4 samples were collected were distributed on (control sample - and 3 samples to which fibers were added in different proportions with dimension1000mmlength -150 width-150height ).The tests applied in this experiment were based on the discipline positioning test at the age of 28 days and The L.V.D.T deviation reader was relied upon until a failure occurred the sample ,The modelling of concrete beams was based on the according blender program. Results : These obtained data were analysed using Microsoft Excel and SPSS. result showed compressive strength test of concrete beams had an increase compared to the control group when added 1.5% with 9.2%. It was noted that there were statistical differences between samples to which glass concrete fibers were added with the control group at p value <0.001 .the tensile strength achieved the highest value increase when glass fibers were added with 1.5% to become 5.3 MPA, The results of the three-dimensional modelling of concrete beams using the blender program appeared Great accuracy and convergence compared to the laboratory results of the research samples Conclusion: Reinforced concrete beams reinforced with glass fibers showed greater tensile and compression resistance compared to traditional reinforced concrete beams in order to achieve them and modelling the results helped in obtaining more accurate results, although there was no significant difference in the extracted result
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
2. 2
UNIVERSITY OF NORTHUMBRIA AT NEWCASTLE
SCHOOL OF THE BUILT ENVIRONMENT
The Effects of Adding Waste Wood Chippings and Silica Fume to the Flexural Strength
Capacity of Concrete
A DISSERTATION SUBMITTED TO THE SCHOOOL OF THE BUILT
ENVIRONMENT IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR
THE DEGREE OF
BSc Architectural Technology
By 06012242
APRIL 2010
3. 3
Abstract
This piece of research investigates the effects of adding waste wood chippings form the
timber industry, and silica fume, to the flexural strength capacity of concrete. Three groups of
concrete beams were made, group 1 consisting of plain concrete, group 2 had wood chippings
added to the mix and group 3 was a hybrid of wood chippings and silica fume. After
compiling a suitable methodology and carrying out a flexural test programme, results showed
that additions of wood and silica fume reduce flexural strength, however wood and silica
additions are shown to increase maximum deflection before failure of the concrete beams.
The results were encouraging towards the research and production of more sustainable
concrete technologies.
i
4. 4
Table of Contents
Abstract i
1.0 Proposal 5
1.1 Hypothesis 5
1.2 Research Aims 5
1.3 Objectives 6
2.0 Literature Review 7
2.1 An overview of sustainable concrete 7
2.1.1 Fly Ash Concrete 7
2.1.2 Wood Chippings in Concrete 8
2.2 Flexural Testing of Fly Ash and Wood Chip Concrete 8
2.3 Mineral Based Composites 9
2.4 Optimum Ratios 9
2.5 Conclusion 9
3.0 Methodology 10
3.1 Structural Elements and the Need to Perform Flexural Testing 10
3.2 Production of Beams 10
3.2.1 Materials 10
3.2.2 Mix Design 11
3.2.3 Quantities 11
3.2.4 Slump Testing 11
3.2.5 Pouring and Compacting the Concrete 12
3.3 Curing 12
3.4 Methods of Performing Flexural Tests 12
3.4.1 Loading Rate 13
3.5 Calculating Flexural Strength 13
4.0 Results and Analysis 14
4.1 Results of Plain Concrete Beam Flexural Testing Programme 14
4.2 Results from using Wood Chippings as Addition to the Concrete Beams 15
4.3 Results from using Wood Chippings and Silica Fume as Addition
to the Concrete Beams 16
4.4 Overview of Flexural Strength Results 17
4.5 Analysis of Results 17
4.6 Determining the Density Characteristics of the Concrete Mixes 18
4.7 Drying Curve 20
5.0 Conclusions 23
5.1 Research Limitations 23
6.0 Recommendations 25
7.0 References 26
8.0 Appendices 28
5. 5
1.0 Proposal
There has been extensive research into trying to increase the sustainability of concrete whilst
retaining high levels of flexural strength.
The core of this research seems to be investigating the use of mineral based composites
(MBCs). Research conducted by Blanksvard (2009), highlights the drawbacks of using
epoxies, and concludes that in compressive strength tests that MBCs contribute to increasing
load bearing capacity for strengthened concrete considerably.
Further research into MBCs reveals that there is actually however, conflicting results to the
levels of strength improvement in concrete. One such study tested flexural strength as oppose
to compressive and concluded that the ‘stress at the cut off point is considerably smaller for
the MBC system compared to that of the epoxy based carbon fibre reinforced polymer
(CFRP) system’ (Johansson, 2005).
Increased research into mineral bonding agents (MBAs) brings to attention that the use of fly
ash in concrete is very common practice, as well as other recycled agents such as crushed
glass and silica fume. A research paper on the effects of fly ash in concrete concluded that
each tonne of cement that can be replaced by fly ash reduces CO² emissions by 1 tonne also
(Bjork, 1999). Another piece of research also uses fly ash as well as mixing in waste wood
ash, replacing 25-35% of cement used. This was found to significantly improve the
performance of concrete in both compression and flexural testing (Naik, 2002).
A research publication that tested the effects of untreated sawdust as an additive to polymer
concrete, concluded wood waste did improve flexural strength and fracture toughness when
applied as reinforcement to polymer concrete, (Reis, 2006). However, this is thought not to
be the same case for compression, as research by Becchio (2009), concluded that when wood
waste was used as an aggregate, compression strength tests indicate a reduced performance in
mechanical properties such as crushing resistance and bulk density.
Research by Coatanlem (2005), and concluded that by saturating wood chippings with
sodium silicate, improves significantly the compressive strength of concrete. However, it also
concluded that without the sodium silicate, the compressive strength was reduced. This is
thought to be as the sodium silicate improves the bond between the wood – cement interface.
This research conducted tests on compression alone, failing to expand the investigation
beyond this parameter. Therefore the behaviour of this mix design on flexural strength has to
be investigated.
As no tests have currently been done on flexural performance and with conflicting research
conclusions, a further investigation may be proposed to research into the effects of using
untreated wood chippings as reinforcement, with the additive of silica fume to improve the
bond interface, thus filling this knowledge gap.
1.1 Hypothesis
It is suggested that if waste wood chippings and silica fume is added as reinforcement to a
concrete beam, then the flexural strength of concrete beams will be improved.
1.2 Research Aims
To test to see if the use of waste wood chippings from the timber industry and the addition of
silica fume, can improve flexural performance of concrete.
6. 6
1.3 Objectives
1) To test 10 concrete beams with no reinforcement
2) To test 10 concrete beams with waste wood chipping added as reinforcement
3) To test 10 concrete beams with waste wood chipping and silica fume added as
reinforcement
4) To record results appropriately
5) To compare and analyse the 3 groups of test results
6) To evaluate the effectiveness of adding waste wood chippings and silica fume to
concrete mixes.
The following chapter will consider existing research into sustainable concrete, looking at the
additions of by-products to concrete to improve sustainability as well as maintaining adequate
levels of strength.
7. 7
2.0 Literature Review
This chapter intends to review existing pieces of research into the production of sustainable
concrete. The need for sustainable concrete and the search for suitable by-products, with
specific reference to mineral based composites, will be addressed within this chapter.
Extensive research has been carried out into trying to increase the sustainability of concrete,
Li-hua (2009), Naik (2002), Becchio (2009), Turgut (2007), whilst retaining high levels of
both compressive and flexural strength. The following section will outline research that has
been conducted into improving sustainability of concrete whilst trying to retain high
compressive strength values.
2.1 An Overview of Sustainable Concrete.
Research carried out by Canbaz et al. (2004) used waste glass, as a course aggregate within
concrete. The glass used was between 4-16mm and used in a mix proportion of up to 60%.
Testing of this determined that it actually had a slight reduction in compressive strength. A
study was conducted by Shayan (2002) looks at glass ground in to a fine powder and added to
the mix, replacing 30% of the cement used. The results from this test found that this did
provide a significant increase to the concrete’s compressive strength. In addition to this,
Soroushian et al, (2003) found that the addition of recycled plastics also has a positive effect
of concrete compressive strengths. Galetakis (2004) also conducted compression tests using
limestone dust as an addition with Portland cement mix, while the dust/cement ratio was
found to be the key factor, results showed that compressive strengths can be increased.
The studies discussed above show that many materials have been used as aggregates in
concrete. However, whilst many different pieces of research have been carried out using
different waste materials as additions to the concrete mix, the most extensive amounts with
the most positive results, come from testing carried out using ash or wood chipping additions.
Focusing on compression tests, the next section reviews studies that have used ash as an
addition to the concrete mix.
2.1.1 Fly Ash Concrete
Very early research was carried out by Miller et al. (1975) into the use of fly ash, as well as
other reclaimed materials, as alternative aggregates. The research found that fly ash offered
the most improvement to concretes compressive strength. The most recent and in depth piece
of research conducted undertaken by Naik (2002) using fly ash alone, tests were conducted
using between 25-35% of fly ash blended with the concrete mix. After a 28 day curing period
it was concluded that the compressive strength of the concrete was significantly increased.
Research previous to this was also carried out by Carette (1993) using between 55-60% fly
ash in a concrete mix, concluded that after 91 days curing that the concretes compressive
strength was up to 50 N/mm². However, another study conducted by Bjork (1999) found that
by using a water/cement ratio of 0.3, can have as much as 60% of the cement replaced with
fly ash and can produce a 55 N/mm² a compressive strength concrete after 28 days. A study
by Li-hua (2009) confirmed that the addition of fly ash content between 10-55% will improve
compressive strengths as well as improving workability and durability, however more than
55% content will reduce compressive values after 90 days, as the compressive strength of fly
itself is less that concrete.
The above research shows that the addition of fly ash to concrete can significantly improve
compressive strength; this is because fly ash is comprised of the non-combustible mineral
portion of coal consumed in a coal fuelled power plant. The particles are glassy and spherical
8. shaped that are typically finer than cement particles. The fly ash undergoes a ‘pozzolanic
reaction’ with the lime created by the hydration (chemical reaction) of cement and water, to
create the same binder (calcium silicate hydrate) as cement. The pozzolanic reaction that
takes place is the fly ash changing into a siliceous material that reacts with the lime, forming
a compound that is cementitious at normal temperatures. It is this pozzolanic reaction that
will be looked at in section 2.3, when silica is looked at as a mineral based composite.
After looking at the effects of fly ash, as previously mentioned, the addition of waste wood
also has had extensive research carried out on its effect to compressive strengths on concrete.
Section 2.1.2 will give an overview to these.
8
2.1.2 Wood Chippings in Concrete
Research by Becchio (2009) tried to increase sustainability of concrete by replacing natural
aggregates in the mix, with waste wood chippings. Different mix proportions were of
cement/admixture/water was made and cubes formed. Their compressive strength was tested
after a 28 day curing period. The testing concluded that in all cases the addition of wood
waste decreased the compressive strength of the concrete, the decrease in strength was found
to be in proportion to the drop in density as wood in less dense than aggregate. A previous
study to this was performed by Turgut (2007) who investigated the use of high levels of
waste sawdust to concrete mixes, and the results obtained were enough to satisfy international
standards. Although this test does not increase the compressive strength, it shows that equal
strengths can be achieved by using sustainable methods. A much earlier piece of research was
carried out by Al Rim et. al. (2000) also reused wood waste as an aggregate for concrete,
although the research was aimed at the thermal properties of this, it did conclude that the
addition of the wood waste reduced the compressive strength.
The studies and tests in the previous paragraph show contradicting results for the addition of
wood wastes to the concrete mixes, this could be due to a number of factors. However, all of
the previous research looked at, measured concrete under compression testing. The next
section will focus on tests that have been carried out to increase the flexural strength of
concrete, and see if the same materials have the same effects.
2.2 Flexural Testing of Fly Ash and Wood Chip Concrete
Coatanlem (2002) conducted research using waste wood chippings as fibres for concrete
reinforcement. The wood chippings were between 0.5-10.0mm and the beams were
40x40x160mm. The optimum wood/cement ratio was 3.6, and the optimum water cement
ratio was 0.75. After 28 days, the beams were tested and it was found that the flexural
strength of all the samples was less than 10MPa; this is a significant reduction to that of
normal Portland cement, recording 45MPa. Research by Reis (2006) tested plain epoxy
polymer concrete reinforced with wood waste. Mixes were made with varying proportions of
cement and waste wood. Flexural strengths were then tested and compared to that of plain
epoxy polymer concrete. The results obtained showed that flexural strength increased by
6.03%.
The comparison between the two above studies by Coatanlem (2002) and Reis (2006) show
that wood chippings alone will not increase the flexural strength of concrete, but adding
wood waste to an epoxy polymer concrete will improve the strength. However, the use of
epoxy concrete poses disadvantages such as hazardous working environments for the
workers, as well as being sensitive to moisture and thermal conditions, (Tliljsten et al. 2006).
9. 9
The next section will discuss research into Mineral based Composites; these are designed to
be a more sustainable, replacement to epoxy adhesives.
2.3 Mineral Based Composites
Blanksvard (2009) has carried out extensive research into the use of Mineral Based
Composites (MBCs) as an addition to carbon fibre reinforced concrete. The first part of his
research uses MBCs as a strengthening system to repair concrete. However flexural tests
were also conducted within this research to expand the data collection. This research
concluded that the uses of minerals, such as silica fume, improve the bond between the
cement, to the reinforcement fibres. The reaction that improves the bond is the same as
discussed in section 2.1.1, as the use of minerals like silica fume undergoes a pozzolanic
reaction. This result would explain the difference in the two previously discussed tests carried
out by Coatanlem (2002) and Reis (2006), as Reis used the wood chippings in epoxy
concrete, so the epoxy would have created a stronger bond between the cement and the wood
chippings. Blanksvard also concluded that for flexural strength to be improved, optimum
ratios of water/cement and also polymer/cement ratios need to be found. These are addressed
in the following section.
2.4 Optimum Ratios
Research conducted by Schulze (1999) show that the flexural strength of concrete can be
increased substantially by altering the water/cement ratio, within a modified mortar. This
confirmed earlier research by Beton (1990). Research into polymer/cement ratios was
conducted by Pascal et al. (2004) and Van Gemert et al. (2005) who found that increases in
flexural strength were found significant when polymer/cement ratios were between 10% and
15% weight content. Ratios higher than this are shown to result in a decrease in the strength
properties. The research by Pascal et al. (2004) and Van Gemert et al. (2005) confirmed the
earlier findings from Rao (2003) and Huang Cheng-Yi et. al. (1985), whose work addressed
the performance of silica fume within concrete. Both of these researchers tested silica fume
levels between 0% and 30% content by weight within a mix and found that optimum levels
for increasing flexural strength lie between 15% and 22% by weight.
2.5 Conclusion
From the research presented, it has been shown that the flexural strength of concrete can
actually decrease by replacing aggregates and fibres with only recycled materials such as
wood, ash and glass. It has also been shown that in many cases the addition of epoxies and
Mineral Based Composites can then go on to increase the flexural strength of concrete as the
bond between the recycled fibres and the cementitious material is strengthened. Further
research into these bonds concluded that water/cement and polymer/cement ratios are of
significance to the flexural strength. The use of Mineral Based Composites, such as silica
fume, increase sustainability of concrete as it is a by product of producing silicon metal.
Silica fume also increases workability, compared to an epoxy resin. The tests looked at above
use silica fume with polymer fibres, and no tests were found that adopted silica fume as an
additive to concrete reinforced with waste wood chippings acting as a fibre addition. The
study by Reis (2006) did use wood chippings, but with epoxy concrete.
The intention of this work is to address the knowledge gap in the research, as presented
within this chapter, by exploring the use of silica fume as an epoxy replacement to concrete
reinforced with waste wood chippings. Chapter 3.0 identifies the methodology used to
explore this work.
10. 10
3.0 Methodology
The previous chapter indentified an apparent lack of data on sustainable methods to improve
the flexural strength of concrete, with specific reference to the use of silica fume and waste
wood chippings. This chapter will justify the use of a flexural test programme and determine
the materials used in the production of the beam test programme in address.
3.1 Structural Elements and the Need to Perform Flexural Testing
From research presented in the literature review, it is shown that tests have been carried out
on improving both compressive and flexural strengths of concrete. However the research
presented does not focus on increasing the sustainability of concrete. In order to collect data
for the improvement of flexural strength of a concrete beam then a test was required. Whilst
other forms of data collection, such as comparing case studies, may have given an indication
of what is likely to happen to the flexural strength, actual first hand data could not be
obtained without testing.
There are also a number of different practical uses for flexural strength improvement,
as concrete is widely used as a material for structural elements such as beams and other
framing members. It is important that when adopted for this type of application, it can
withstand loads without failing. Beams spanning across any length within a building will be
under flexural loading, whether it be carrying dead or live loads.
With a huge pressure on the modern day construction industry to increase
sustainability and reduce carbon emissions, it is important that methods for meeting
sustainability criteria are explored without compromising strength. The implications of this
are that higher strength and sustainability within concrete will offer greater opportunities for
architects, technologists, contractors and clients to want to use concrete. As well as this, with
higher flexural strengths, larger spans can be reached allowing architects to design more
diverse buildings. The next chapter will look at the how the beams to be tested were
produced.
3.2 Production of Beams
As discussed within the literature review, beams will be tested with the addition of waste
wood chippings and silica fume. The following sections will look at beam design, including
acquiring the materials, ratios of materials used and the quantities of beams made.
3.2.1 Materials
The wood chippings that were added to the mix came from a local timber merchant, and were
ungraded, untreated and from a variety of trees. The decision to use chippings like these was
to add to the sustainability of the beams, as costs are incurred to sort and grade the wood, as
well as treat it. The idea was that the wood chippings were used as ‘raw’ waste from the
timber industry. The silica fume was obtained from an international chemical company who
specialize in making environmentally friendly metals and materials. The silica fume used was
undensified meaning that the grains are slightly larger than those of densified silica, also the
undensified silica fume is easier to work with and offers no hazardous working conditions
with regard to skin contact and inhalation. The silica fume fully conformed to the American
Society for testing Materials code C1240 for the Standard Specification for Silica Fume Used
in Cementitious Mixtures (ASTM C1240 -05). The cement used was ordinary Portland
cement which conforms to BS 12, this was the same as all of the tests presented within the
literature review and is the most readily available to use. The aggregates, sand and water
were all readily available from the universities laboratory.
11. 11
3.2.2 Mix Design
As presented in the literature review Schulze (1999) and Rao (2003) showed that optimum
ratios of water/cement and silica fume/cement can have major influences on the flexural
strength of concrete. The optimum silica fume amount was found to be between 15-22% of
the mix, however later research by Van Gemert et al. (2005) suggested 15% of a silica
addition was the maximum before a decrease in flexural strength would appear. For that
reason a 15% addition was added to the mix.
The ratio of wood chippings to the mix was chosen at cement/wood ratio of 3. This
was due to recent research by Becchio (2009) suggesting this was the optimum ratio. Earlier
research by Coatanlem (2002) as presented in the literature review suggested 3.6, however
this was also rounded down to 3 for the testing. This research also concluded that the
optimum water/cement ratio was 0.75 so in order to maintain validity the same ratio was
used.
The ratio of mix between cement/sand/gravel was 3/6/10 in accordance to BS 8500.
For all beams made, the cement sand and gravel were mixed first, and then the correct
amount of water added accordingly. Mixing was followed by the addition of the wood
chippings to the batches that included both wood and silica fume. The silica fume was added
last and mixed in full accordance with the manufacturer’s guidelines for mixing (See
Appendix 1).
3.2.3 Quantities
With the above ratios used, this section will look at exactly how much of each material was
added to the mix. 30 beams were made in total, 10 beams in a control group with plain
concrete. 10 beams with wood chipping alone and the final 10 beams were a hybrid of silica
fume and wood chipping. The decision to use 10 beams within each group was made by
looking at research in the literature review, where research carried out by Shayan (2002),
Galetakis (2004), Naik (2002) and Becchio (2009) all used between 6 and 10 specimens for
each group. By using 10, it is also easier to identify any anomalous results and calculate
levels of significant difference between groups. Table 1 below shows the quantities for all
materials used.
All amounts are based on batching 10 beams per group and include a 10% waste addition.
Cement Sand Gravel Wood Silica Fume Water
Plain group 21.56kg 38.81kg 58.00kg 0.00kg 0.00kg 16.17kg
Wood alone 21.56kg 38.81kg 58.00kg 21.56kg 0.00kg 16.17kg
Hybrid 21.56kg 38.81kg 58.00kg 21.56kg 3.25kg 16.17kg
Table 1.
3.2.4 Slump Testing
A slump test measures the workability of the concrete, showing how easy the concrete is to
place handle and compact. Slump tests must measure within a set range or tolerance from the
target slump. A slump test was not carried out within this experiment as the mix would give
different slump values due to the wood and silica additions and no target slump are values are
specified for this type of mix. As well as this, all the quantities of materials were carefully
measured and mixed in the exact same way; there were also time constraints within the
laboratories making it difficult to complete a slump test. For producing plain concrete without
limitations, a slump test must always be carried out.
12. 12
3.2.5 Pouring and Compacting the Concrete.
All beams dimensions were the same at 100mm x 100mm x 500mm; this size was chose as it
was the same dimensions as flexural testing carried out by Reis (2006). Pouring the concrete
into the moulds must be carried out in a precise method. Using a trowel, the beams moulds
were filled half way then compacted using steel hand tamp. Compaction takes place in order
to reduced air content within the concrete, improving its performance, there should be a
minimum of 100 compactions before pouring the remaining half into the mould, before a
further 100 compactions are made (www.brmca.org.uk/Placing, 2009). The beam should be
finished with a float to remove excess mix from the edges of the mould, this makes it easier
to remove the beams from the moulds after curing. This process was repeated for each beam.
3.3 Curing
The curing period for the beams was 28 days; this was the same as all of the tests presented in
the literature review. 28 days is also the advised time given by Portland cement
(http://www.concrete.net.au, 2004). During the curing period, the mass of each beam was
obtained by weighing the beams every 2 days in order to monitor their change in mass over
the 28 day period. This gave the opportunity to look at the beams’ densities and compare
differences between the groups.
3.4 Methods of Performing Flexural Tests.
The two main methods of testing flexural capacity of concrete are known as either the ‘single
point’ load test or the ‘third point’ load test. Figure 1 below shows diagrammatically the two
tests..
A B
Figure 1. Flexure testing diagrams (Taken from www.nrmca.org/aboutconcrete, 2005)
Figure 1A, shows the third point test as it applies the loads across two points at one third
proportions of the beam. Figure 1B shows the single point test where the entire load is
applied to the centre of the beam.
With a brittle material such as concrete, the single point test is more common, although this
test only provides data for flexural strength only, not stiffness
(http://www.instron.co.uk/application /flexure, 2010). Research was also carried out into the
difference between single point and third point tests, concluding that after testing 4 different
types of polymers, that between the two tests no significant difference could be found in the
results for modulus of rupture, (Chitchumnong et al. 1989). Figure 2 below shows the
difference in between the two types of flexural test, displayed using a bending moment
diagram.
13. 13
A B
Figure 2. Bending Moment Diagrams (Taken from www.nrmca.org/aboutconcrete,
2005)
The areas shaded in red are the areas of the beam to which load will be exerted. Figure 2A
shows how the stress is applied constantly over a large area. With this method the position of
the first crack is unforced and can appear anywhere within the shaded region. However this
means that the crack will follow the weakest path through the concrete beam that it can find.
Figure 2B shows that the stress is applied to a smaller area than the third point test. The
position of the first crack in the single point test is forced at a single point meaning that the
crack cannot just follow the weakest path.
With these pieces of research presented, a single point test was used, as use of the third point
loading machine was limited and also was unable to be linked to a computer programme
measuring the applied loads and deflection. All testing carried out conformed to BS EN
12390-5:2009, which specifies a method for testing the flexural strength of specimens of
hardened concrete.
3.4.1 Loading Rate
The loading rate applied was 1.1mm/minute, this is the rate proposed in research by
Coatanlem (2002). There is no set rate at which the load can be applied, however for tests
similar to this, it is recommended between 0.5 and 1.5 mm/minute
(http://www.astm.org/Standards, 2010).
3.5 Calculating Flexural Strength
Flexural strength, considered as the strength under normal stresses, was determined by
applying the following equation known from the strength of materials:
R = 3P L Where,
2bd² R = Modulus, measured in N/mm².
P = Correct load indicated, Newtons.
L = Span length between supports, mm.
b = Width of beam, mm.
d = Depth of beam, mm.
(www.astm.org, 2009)
14. First crack
0 0.15 0.30 0.45 0.60 0.75 0.90 1.05 1.20 1.35 1.50
14
4.0 Results and Analysis
In this chapter the results for the flexural tests of the three groups are presented. Each groups
individual beams maximum load, deflection and flexural strength have been placed in a table
of results along with a graph representing the relationship between load and deflection. The
results for the plain concrete beams are shown in Section 4.1.
4.1 Results of Plain Concrete Beam Flexural Testing Programme.
After completing the flexural test programme for the plain concrete beams, the results were
recorded and are displayed below in Table 2.
Max. Load (N) Max. Deflection (mm) Flexural Strength (N/mm²)
Plain 1 10792.82 2.60 4.86
Plain 2 11400.82 1.87 5.13
Plain 3 13835.71 1.77 6.22
Plain 4 11370.79 2.28 5.11
Plain 5 13106.59 0.98 5.89
Plain 6 11398.64 0.55 5.12
Plain 7 10749.95 1.60 4.83
Mean Value 11807.90 1.66 5.31
Table 2. The table shows the maximum load, deflection and flexural strength for plain
concrete beams.
The maximum loads for the 7 plain beams were averaged and plotted against the average
maximum deflection in the graph shown in Figure 3 below.
14000
12000
10000
8000
6000
4000
2000
0
Load applied (N)
Deflection mm
Deflection (mm)
Figure 3. Graph showing the relationship between load and deflection for plain concrete
beams.
15. First crack
0 1.50 3.00 4.50 6.00 Axi7s. 5T0it le 9.00 10.50 12.00 13.50 15.00
15
4.2 Results from using Wood Chippings as Addition to the Concrete Beams.
The results for wood chippings alone are presented within Table 3 below.
Max. Load (N) Max. Deflection (mm) Flexural Strength (N/mm²)
Wood 1 6057.04 22.00 2.73
Wood 2 8660.77 12.15 3.89
Wood 3 10137.44 10.73 4.56
Wood 4 5758.72 20.19 2.59
Wood 5 6883.53 15.14 3.09
Wood 6 7428.96 12.47 3.45
Wood 7 6575.69 9.81 2.96
Wood 8 8187.26 14.69 3.68
Mean Value 7461.18 14.65 3.36
Table 3. Results from the flexural testing programme for using wood chippings alone as an
additive to concrete beams.
As was done for the plain concrete group beams, the maximum loads for the 8 beams were
averaged and plotted against the average maximum deflection in the graph shown in Figure 4
below.
8000
7000
6000
5000
4000
3000
2000
1000
0
Load applied (N)
Deflection (mm)
Figure 4. Graph showing the relationship between load and deflection for concrete beams
with wood chipping added
16. 4.3 Results from using Wood Chippings and Silica Fume as Addition to the Concrete Beams.
First crack
0 1.50 3.00 4.50 6.00 7.50 9.A00x i s T 1it0le.50 12.00 13.50 15.00 16.5 18.00
16
The results recorded from the flexural testing of wood chippings and silica fume within
concrete beams are presented within Table 4 below.
Max. Load (N) Max. Deflection (mm) Flexural Strength (N/mm²)
Hybrid 1 4115.64 22.36 1.85
Hybrid 2 4454.58 23.44 2.01
Hybrid 3 3665.14 19.99 1.65
Hybrid 4 5561.08 17.44 2.50
Hybrid 5 4217.87 19.35 1.89
Hybrid 6 6531.98 12.41 2.93
Hybrid 7 5463.34 14.89 2.74
Hybrid 8 6100.41 19.52 2.89
Hybrid 9 7310.51 19.36 3.29
Mean Value 5268.95 18.75 2.41
Table 4. Results from the flexural testing programme for using wood chippings and silica
fume as an additive to concrete beams.
The maximum loads for the 9 hybrid beams were averaged and plotted against the average
maximum deflection in the graph shown in Figure 5 below.
6000
5000
4000
3000
2000
1000
0
Load applied (N)
Deflection (mm)
Figure 5. Graph showing the relationship between load and deflection for concrete beams
with both silica fume and wood chippings added
17. 17
4.4 Overview of Flexural Strength Results.
The table below gives an overview comparison between the 3 groups, comparing average
maximum loads, maximum deflection and flexural strength.
Group Average Max load
(N)
Average Max
Deflection (mm)
Average Flexural
strength (N/mm²)
Plain 11807.90 1.66 5.31
Wood alone 7461.18 14.65 3.36
Hybrid 5268.95 18.75 2.41
Table 5. Showing the average results for the 3 groups maximum load, maximum deflection
and flexural strength.
When comparing the wood alone to plain concrete, the maximum load achieved is decreased
by 36.8%, however the average maximum deflection reached before complete shear is
increased by 782.5%. When comparing the hybrid concrete group average maximum load to
the average for plain concrete maximum load, the maximum load before first crack is 56.5%
lower. The position of first crack is shown in Figures 3, 4 and 5. However, the maximum
deflection recorded for the hybrid concrete beams is 1029.5% greater than that of the plain
concrete beams. The flexural strength of the hybrid beams decreased by 55.6% when
compared to the plain beams. The flexural strength of the beams with wood chippings alone
decreased by 37.7% when compared to the plain group.
4.5 Analysis of Results.
In order to explain these results, a more detailed look at what is happening to the beams must
be taken. As presented within the literature review, Section 2.3, silica fume undergoes a
pozzolanic reaction, improving the bonds between the cementitious materials to the wood
reinforcement. The improvement of the bonds between the wood and the concrete suggests
this is why maximum deflection values are increased even between the wood chipping
beams, and the hybrid beams, as the bonds are stronger and pull out is resisted further. The
term ‘pull out’ refers to the wood reinforcement being de-bonded from the concrete due to
the load applied, and removed without the wood breaking. Plate 1 below shows a photograph
of a beam that exhibits pull out after it had failed and had been removed from the flexural
testing machine.
Plate 1. Photograph of a failed beam showing pull
out of the wood reinforcement
Large areas are left where the wood
chipping reinforcement has been de-bonded
and pulled out from the
concrete beam.
18. Here, a length of wood chipping is shown
to have been pulled out from the concrete
beam
It can be seen here that wood chippings
within the beam are spanning the crack and
acting as reinforcement to the beam.
18
Plate 2, shows a concrete beam where it possible to see the wood chippings within acting a
reinforcement to the beam.
Plate 2. Shows the wood waste within the
beam acting as reinforcement.
Whilst the addition of silica fume increased the maximum deflection, it also reduced the
maximum load the beams can withstand as well as reducing the flexural strength. The basic
theory of concrete flexural strength is that flexural strength of concrete decreases as density
decreases, (Rossignolo, 2002. Park, 1975). This may potentially explain the reason the plain
concrete groups flexural strength is higher, as the density of the wood chippings present in
the other two concrete group beams being a lot less than that of concrete, therefore reducing
the density of the beam. The next section will consider the density of the beams as a reason
for reduced flexural strength.
4.6 Determining the Density Characteristics of the Concrete Mixes.
After the beams were taken out of the moulds for testing they were weighed, and from this
the density could be calculated. Figure 6 below shows the densities of the 3 groups.
2500
2400
2300
2200
2100
2000
1900
1800
Plain Wood alone Wood & Silica fume
Density (kg/m³)
Density kg/m³
Figure 6. Bar chart showing the density of the 3 concrete groups after 28 days.
19. Comparing the plain beam densities, to that of the wood chipping group it can be shown that
a 9.30% reduction in density is achieved. The hybrid beams have a 6.60% reduction in
density compared to the wood alone, and a 15.30% reduction compared to the plain group.
Table 6 below shows averages across the 3 groups for maximum load, maximum deflection,
flexural strength and also density.
19
Group Average Max
load, (N)
Average Max
Deflection,(mm)
Average Flexural
strength (N/mm²)
Density (kg/m³)
Plain 11807.90 1.66 5.31 2380
Wood 7461.18 14.65 3.36 2160
Hybrid 5268.95 18.75 2.41 2040
Table 6. Shows averages for maximum loads, deflections, flexural strength and density.
By presenting data from Table 6 in graphical form, such as Figures 7 and 8. It is possible to
see that density and load are proportional, as well as density and flexural strength, as the lines
on both graphs are straight.
2500
2400
2300
2200
2100
2000
1900
1800
Wood
Hybrid
2 3 4 5
Density (kg/m³)
Flexural strength (N/mm²)
Plain
Figure 7. Graph showing the relationship between density and flexural strength for the three
groups tested.
20. 20
2500
2400
2300
2200
2100
2000
1900
1800
Hybrid
Wood
Plain
5115
5480
5845
6211
6576
6941
7306
7672
8037
8402
8767
9133
9498
9863
10228
10594
10959
11324
11689
Density (kg/m³)
Maximum load, (N)
Figure 8. Graph showing the relationship between density and maximum load for the three
groups tested.
This means that by adding wood chippings to the mix, the density is reduced and this in turn
reduces the flexural strength of the concrete. However by adding silica fume, the bonds at the
interface between the concrete and the wood are improved, thus further deflection is
measured before failure.
Whilst the data above gives reason to why the flexural strength is the reduced with the
addition of wood chippings, the hybrid group’s average maximum load and flexural strength
decreases further than that of the wood chippings alone, this is an unexpected result as the
same weight of wood chippings was use for both of the groups. One reason for this could be
that although the same weight of wood chipping was used, the volume of the wood chippings
may have increased; this would explain the drop in density therefore the decrease in flexural
strength. However, other reasons may be established by looking at the rate of drying for all
beams. The next section will consider the drying curves for the beams.
4.7 Drying Curves.
This section will look at the drying rates for the 3 groups and analyse factors that influence
the final density of the beams. Figure 8 below shows the rate at which each group of beams
dried out over 28 days.
21. 21
3000
2500
2000
1500
1000
500
0
Density kg/m³
Days
Plain
Series1
Wood
Series2
Series3
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28
Days
Hybrid
Figure 8. Graph showing the drying curves for the 3 groups over a 28 day drying period
From the graph it is possible to see that the hybrid beams dry out and lose density the more
rapidly over the 28 day drying process. Research by Kadri (2009) suggests that the presence
of the silica fume in concrete will accelerate exothermic reactions during the hydration
process. Exothermic reactions begin to occur when the cement first comes into contact with
water in the mix and heat is produced. The main reaction that occurs is between the aluminate
within the Portland cement, and water. This reaction forms an aluminate-rich gel; the gel will
then react with sulphates within the solution to form what is known as ettringite
(http://www.understanding-cement.com/hydration.html, 2010). Ettringite is a crystal like
structure and forms in microscopic needles such as shown in Plate 3.
In the photograph microscopic needles
of white ettringite can be seen forming
in tiny air voids within concrete.
Plate 3. Photograph showing the microscopic needles
of ettringite. (Taken from http://www.cement.org/tech,
2010)
22. The silica fume within the concrete was added to improve the bond between the concrete by
drawing in the ettringite needles to the woods surface in accordance to the findings of section
2.1.1 of the literature review. However, this has meant that the spaces within the concrete
where the ettringite crystals were before being drawn to the wood chippings are now tiny air
voids (http://www.cement.org/tech, 2010). With these air voids present in the concrete, it is
suggested that the concrete beams are able to dry out faster, become less dense and will have
less flexural strength due to this. The hybrid beams have exhibited all of these properties,
being less dense than both the other groups, and having a smaller flexural strength value than
the plain concrete and the concrete with only wood chipping added.
From this chapter it is possible to see clear differences between the plain, wood chipping
alone and hybrid mixes. The results have been analysed and contextualised against our
current knowledge of concrete materials behaviour and structure. From doing this it can be
suggested that the introduction of silica fume to a mix can improve the deflection reached
before complete failure occurs. It can also be suggested that silica fume and wood chippings
decrease the flexural performance of concrete beams due to the decrease in density.
22
Chapter 5 will conclude the research and reflect upon the hypothesis, research aims and
objectives of the flexural testing programme.
23. 23
5.0 Conclusions
In this study the effects of adding waste wood chippings and silica fume to concrete were
investigated and analyzed. The aims of the study were see if the use of waste wood chippings
from the timber industry and the addition of silica fume, would improve flexural performance
of concrete, or not. The main objectives of the study were (1) to test 10 concrete beams with
no reinforcement, (2) test 10 concrete beams with waste wood chipping added as
reinforcement (3) test 10 concrete beams with waste wood chipping and silica fume added as
reinforcement, (4) to record the results appropriately, (5) to compare and analyse the 3 groups
of test results and (6) to evaluate the effectiveness of adding waste wood chippings and silica
fume to concrete mixes. By conducting testing in accordance with the method presented in
Chapter 3, results of the flexural testing programme were obtained and analysed in Chapter 4.
From analysing the results of the flexural testing programme carried out, the following
conclusions were derived.
1 The results of the flexural testing programme indicate that the addition of wood
chippings and silica fume does not improve the flexural strength of concrete, the
values for both wood chipping and silica fume groups were lower than that of
plain concrete.
2 The addition of wood chipping alone improves maximum deflection, compared to
plain concrete.
3 The addition of wood chippings and silica fume improves maximum deflection by
the greatest value.
4 Due to the addition of silica fume, ettringite crystals are drawn towards the wood,
leaving air holes, reducing density and strength even further than wood chippings
alone.
The hypothesis in Section 1.1, suggested that if waste wood chippings and silica fume is
added as reinforcement to a concrete beam, then the flexural strength of concrete beams will
be improved. From the conclusions drawn, this can be rejected. The aims of the investigation
stated in section 1.2 have been met, and the objectives stated in Section 1.3 have also been
achieved.
Although the hypothesis for this investigation was rejected, this study shows feasibility for
producing a more sustainable concrete. There are many different reasons for the results
obtained from this investigation; there are also many opportunities for further research and
testing to be carried out within this area. Section 6.0 will suggest recommendations for
further studies.
5.1 Research Limitations
The data gather from the flexural testing programme made for interesting analysis. By
collecting data from previous similar studies in the literature review and compiling the
methodology, it is apparent that many variations could be made within this research, with
reference to mix design and testing methodology.
It was extremely difficult to acquire the silica fume, as it was necessary for it to be shipped
from Holland, in only very small amounts. With more accessibility to silica fume, further
testing could have been conducted using different amounts of silica fume.
Another major limitation was the time available to test concrete within the laboratories, as
compression testing on concrete cubes would have provided a further insight into the effects
24. of adding waste wood and silica fume to concrete. If more time was available, a further 10
beams would have been tested using silica fume as the only addition to the concrete mix, to
allow for comparisons to the concrete beams with wood chipping alone and the hybrid
concrete beams. It would also be useful to measure the flexural strengths of the 3 groups of
concrete after a 60 day curing period, as this is suggested to increase flexural strengths further
(Naik, 2002).
Whilst this chapter has concluded the findings from this research and assessed the limitations.
The next chapter will consider recommendations for future research.
24
25. 25
6.0 Recommendations for Future Research
The replacement of cement by materials that induce a pozzolanic reaction, such as fly ash
Naik (2002), or silica fume, can have advantages for both sustainability and to the strength of
concrete. Although this investigation rejected the hypothesis that suggested that if waste
wood chippings and silica fume is added as reinforcement to a concrete beam, then the
flexural strength of concrete beams will be improved, it is still important to drive forward
sustainability issues by means of reducing carbon emissions, reducing materials used and
costs of production. There are many different variations to the methodology of the flexural
testing programme undertaken within this study, with reference to the mix design. This
chapter will address these variations in order to recommend and benefit future studies within
this area.
By varying the content ratios between the water, silica fume and waste wood chippings is
suggested to give different results for both flexural strength tests and compressive strength
tests. (Schulze, 1999, Beton, 1990., Pascal et al., 2004. and Van Gemert et al. 2005)
With reference to the mixing method of the batches, it is suggested that pre soaking the wood
chippings to draw cementitious particles into the wood will improve the bond between the
wood and the concrete further than if no pre soaking takes place, (Reis, 2006). As well as
varying the method of adding the wood, the method of which the silica fume was batched
could also be altered, for this research the silica was batched in accordance to the
manufacturer and supplier, however there are different suggestions to mixing which
potentially increase the strength of concrete, (Blanksvard, 2009).
The above recommendations provide platforms for future research to improve upon current
knowledge of concrete behaviour, and can potentially lead to more sustainable methods of
making concrete. The recommendations made, are based upon researchers conducting tests
without the limitations this paper has identified in Section 5.1.
26. 26
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