This paper investigates the workability and mechanical properties of concrete containing alkali-activated slag as the binder. Two types of activators were used: sodium hydroxide with sodium carbonate, and sodium silicate with hydrated lime. The fresh and hardened concrete properties of these alkali-activated slag concretes were compared to ordinary portland cement concrete. The results showed that concrete activated with powdered sodium silicate and lime had minimal slump loss over 2 hours and achieved similar 1-day compressive strengths as portland cement concrete when cured at normal temperatures. However, it exhibited higher drying shrinkage. Overall, alkali-activated slag concrete shows potential as a viable alternative to portland cement concrete.
This paper presents the findings of an investigation on the compressive strength of concrete containing
Groundnut Husk Ash (GHA) blended with Rice Husk Ash (RHA) and its resistance to acid aggression, as well
as regression models of the concrete resistance in acidic environment. The GHA and RHA used were obtained
by controlled burning of groundnut husk and rice husk, respectively in a kiln to a temperature of 600 oC, and
after allowing cooling, sieved through sieve 75 µm and characterized. The compressive strength of GHA-RHAConcrete
was investigated at replacement levels of 0, 10, 20, 30 and 40 %, respectively by weight of cement. A
total of seventy five 150 mm cubes of GHA-RHA-Concrete grade 20 were tested for compressive strength at 3,
7, 28, 60 and 90 days of curing. Also, thirty 100 mm cubes were exposed to attack from 10 % concentration of
diluted solution of sulphuric acid (H2SO4) and nitric acid (HNO3), respectively and the concrete resistance was
also modeled using Minitab statistical software to establish regression models. The result of the investigations
showed that the compressive strength of the concrete decreased with increase in GHA-RHA content. However
15 % replacement with GHA-RHA was considered as optimum for structural concrete. The use of GHA
admixed with 10 % RHA in concrete improved its resistance against sulphuric and nitric acids aggression. The
average weight loss of GHA-RHA- concrete after 28 days of exposure in sulphuric acid and nitric acid were
11.6 % and 11.7 %, respectively as opposed to 22.4 % and 15.1 %, respectively for plain Portland cement
concrete. The regression models of GHA-RHA-Concrete for resistance against sulphuric and nitric acids were
developed with R2
values of 0.668 and 0.655, respectively and were adequate for prediction of the sensitivities
of pozzolanic activity of GHA-RHA in acidic environment.
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.
STUDY ON BEHAVIOR OF ALKALI ACTIVATED FLYASH BASED GEOPOLYMER CONCRETEIAEME Publication
Objectives: This study is to identify the effect of parameter such as Activator ratio that affects the properties of alkali activated fly ash-based geopolymer concrete.
Methodology: To achieve the above objectives, the present investigation is adopted a technology that is currently in use to manufacture and to test the conventional concrete. The main aim of this activity was to facilitate promotion of new materials later on to the concrete industry. Research variable included activator ratio (1:2, 1:2.5, and 1:3). The trial mix is prepared for the molarity of 16 M. Concrete specimens were cured at room temperature. The response variables are Flexural strength, Compressive strength and Split tensile strength.
Findings: Test data are used to identify the variation of Geopolymer concrete properties which are affected by using of various activator ratios and curing period. At all ages, the activator ratio 1:3 gives maximum strength and also economical when compared to other two activator ratios. There is substantial gain in compressive strength of fly ash based geopolymer concrete with age.
Improvements: This work can be enhanced for various molarities under various temperatures and various activator ratios.
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.
This paper presents the findings of an investigation on the compressive strength of concrete containing
Groundnut Husk Ash (GHA) blended with Rice Husk Ash (RHA) and its resistance to acid aggression, as well
as regression models of the concrete resistance in acidic environment. The GHA and RHA used were obtained
by controlled burning of groundnut husk and rice husk, respectively in a kiln to a temperature of 600 oC, and
after allowing cooling, sieved through sieve 75 µm and characterized. The compressive strength of GHA-RHAConcrete
was investigated at replacement levels of 0, 10, 20, 30 and 40 %, respectively by weight of cement. A
total of seventy five 150 mm cubes of GHA-RHA-Concrete grade 20 were tested for compressive strength at 3,
7, 28, 60 and 90 days of curing. Also, thirty 100 mm cubes were exposed to attack from 10 % concentration of
diluted solution of sulphuric acid (H2SO4) and nitric acid (HNO3), respectively and the concrete resistance was
also modeled using Minitab statistical software to establish regression models. The result of the investigations
showed that the compressive strength of the concrete decreased with increase in GHA-RHA content. However
15 % replacement with GHA-RHA was considered as optimum for structural concrete. The use of GHA
admixed with 10 % RHA in concrete improved its resistance against sulphuric and nitric acids aggression. The
average weight loss of GHA-RHA- concrete after 28 days of exposure in sulphuric acid and nitric acid were
11.6 % and 11.7 %, respectively as opposed to 22.4 % and 15.1 %, respectively for plain Portland cement
concrete. The regression models of GHA-RHA-Concrete for resistance against sulphuric and nitric acids were
developed with R2
values of 0.668 and 0.655, respectively and were adequate for prediction of the sensitivities
of pozzolanic activity of GHA-RHA in acidic environment.
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.
STUDY ON BEHAVIOR OF ALKALI ACTIVATED FLYASH BASED GEOPOLYMER CONCRETEIAEME Publication
Objectives: This study is to identify the effect of parameter such as Activator ratio that affects the properties of alkali activated fly ash-based geopolymer concrete.
Methodology: To achieve the above objectives, the present investigation is adopted a technology that is currently in use to manufacture and to test the conventional concrete. The main aim of this activity was to facilitate promotion of new materials later on to the concrete industry. Research variable included activator ratio (1:2, 1:2.5, and 1:3). The trial mix is prepared for the molarity of 16 M. Concrete specimens were cured at room temperature. The response variables are Flexural strength, Compressive strength and Split tensile strength.
Findings: Test data are used to identify the variation of Geopolymer concrete properties which are affected by using of various activator ratios and curing period. At all ages, the activator ratio 1:3 gives maximum strength and also economical when compared to other two activator ratios. There is substantial gain in compressive strength of fly ash based geopolymer concrete with age.
Improvements: This work can be enhanced for various molarities under various temperatures and various activator ratios.
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.
STRENGTH AND DURABILITY STUDY OF GROUND GRANULATED BLAST FURNACE SLAG BASED G...Shoaib Wani
Ordinary Portland cement is recognized as a major construction material.
GGBS can improve the durability of a concrete structure by reducing the water permeability, increasing the corrosion resistance and sulphate resistance.
The improved properties can extend the service life of structures and reduce the overall maintenance costs.
The primary objective is to study the strength and durability of geopolymer concrete
To study the strength and durability parameters of GGBS based geopolymer concrete.
use of fly ash and silica fume as a partial replacement of cement in concreteHIMANSHU KUMAR AGRAHARI
this project was done with help of few members, in this project, we have replaced cement partially with fly ash and silica fumes, and tested the cubes with different mix and at different time of curing period
COMPARATIVE STUDY OF COMPRESSIVE STRENGTH AND DURABILITY PROPERTIES ON GEOPOL...Journal For Research
The usage of practical advancement in structural building society has prompted the utilization of new materials with low environmental effects. One of the most commonly used construction material in the world is concrete, which is normally produced by OPC. However, the production of OPC has prompted ecological worries over the creation of CO2. Almost to create 1 ton of OPC 1 ton of CO2 is discharged to the atmosphere. With a specific end goal to diminish the utilization of OPC and CO2, the new concrete has been created, that is GEOPOLYMER CONCRETE. Latest research has demonstrated that it is conceivable to utilize fly ash or slag as a binder in concrete by activating them with alkali components through a polymerization procedure. This paper reports the point of interest of the test work that has been embraced to examine the strength and durability properties of ultra-fine slag and processed fly ash mortar mixes. At first specimens were casted for normal GGBS and fly ash in the ratio of 100:0, 75:25, 50:50, 25:75 and later for the best ratio (75:25), GGBS is replaced by ultra-fine GGBS by 7.5, 12 and 20%. Samples were compared with cured at ambient temperature and oven curing. The results showed that mix proportion of 20% replacement of ultra-fine GGBS gave the maximum strength for both oven and ambient curing (76.2 and 91.1 MPa). Even all the durability properties are within the permissible limits.
CHARACTERIZATION & DURABILITY PROPERTIES OF ULTRAFINE FLY ASH BASED GEOPOLYME...Journal For Research
Huge scale generation of cement is creating environmental issue on one hand and depletion of natural resources on the other hand. This danger to nature has prompted research being made of industrial byproducts as supplementary cementetious materials in making concrete for more green and durable. Fly ash and silica fume both are pozzolanic materials which have been broadly utilized for improving the properties like strength and durability in concrete. Silica fume demonstrates the greater pozzolanic activity then fly ash because of its finer particle size distribution, the pozzolanic activity of fly ash also can be enhanced by decreasing the particle size distribution. Geopolymer is a class of aluminosilicate binding materials integrated by thermal action of solid aluminosilicate based materials such as metakoaline, GGBFS, fly ash. Geopolymer get activated with the alkaline solution and heat. Sodium hydroxide and sodium silicate were utilized as an alkaline solution with a steady ratio of 2.5 and the mix is designed for molarity 10 for the work carried out. In the present study, an attempt has been made to explore the geopolymer concrete by utilizing ultrafine fly ash (UFFA) produced by air classification and processed GGBFS with varied proportions. Discusses on the properties of geopolymer concrete has also been mentioned. Compressive strength and durability tests like Permeability, Abrasion, Sorptivity, Acid and sulphate attack, Drying shrinkage were conducted. In this work geopolymer concrete was prepared with varying proportions of GGBS and UFFA in the ratio of 92.5:7.5 and 88:12 and 80:20. The maximum strength was achieved for the ratio 92.5:7.5. The obtained compressive strength is in the range of 36.5MPa to 91.6MPa from 1st day to 28th day of hot curing.
Experimental Investigation on Ferro-Geopolymer Flat PanelsSuhail Shaikh
To find out the effective utilization of the abundant quantity of Indian fly ash polluting the environment.
To find out the suitability of quarry sand as a fine aggregate.
To determine the suitability of Geopolymer mortar in practical application of the Civil Engineering Field.
This paper presents an experimental result on the behavior of fly ash and slag based geopolymer concrete exposed to 5% sulphate solutions for 3.5 months of G30 and G50 which are equivalent to M30 and M50 grades respectively. The test specimens were cast and after one day rest period, half of the specimens were cured in an oven at 60°C for 24 hours and the remaining period cured in sun light until the testing is done and remaining half of the specimens were ambient cured. After 28 days the specimens were immersed in sulphates such as Na2SO4 and MgSO4 for 15, 45, 75 and 105 days then tested on 15th, 45th, 75th and 105th day according to codal procedures and the results are compared with the controlled concrete. From the test results, it is observed that the geopolymer concrete has better resistance to sulphates attack than controlled concrete.
Experimental study on geopolymer concrete by using ggbseSAT Journals
Abstract
The demand of concrete is increasing day by day and Cement is used for satisfying the need of development of infrastructure facilities, 1 tone cement production generates 1 tone CO2, which adversely affect the environment . In order to reduce the use of OPC and CO2 generation, the new generation concrete has been developed such as GEOPOLYMER CONCRETE. It uses Fly ash and Alkaline Solution as their Binding Materials. Geopolymer requires Oven Curing in the varying range of 60C to 100C for a period of 24 to 96 hours.
The objective of the present work is to study the effect of GGBS in fly ash based Geopolymer concrete and to study the Effect of Oven Curing and Ambient room temperature curing on them. And By replacing fly ash from 0 to 100% with GGBS and inspecting the Fresh Properties and Hardened Concrete properties at 7 days. The casted cube will be cured at normal room temperature and at 700C Oven heat provision for 24 hours and to ascertain the behavior of concrete mixed with GGBS, thereby examining the changes of properties like Strength and Durability.
Keywords: Fly ash, GGBS, Alkaline Solution, strength, durability, utilization
Crimson Publishers-In vitro Bioactivity Assessment of Novel Composites Based ...CrimsonPublishersRDMS
In vitro Bioactivity Assessment of Novel Composites Based on Calcium Aluminate Cement by Cortés-Hernández DA in Research & Development in Material Science
The influence of Rolling process on the porosity and wear behavior of Spray-f...IOSR Journals
Spray forming, also called spray casting or spray deposition, is the inert gas atomization of a liquid metal stream into variously sized droplets. These droplets are interrupted by a substrate which collects and solidifies the droplets into coherent, near fully dense perform. The present work concerns with this techniques. This technology was applied to produce Al-6%Si-20%Pb alloys. The spray droplets were deposited over a copper substrate to achieve a disc shape perform. After spray deposition samples were rolled at room temperature on two high rolling mills and total porosity and wear characteristic of spray deposits were studies. The total porosity decreases with the increase in the percentage of reduction in thickness of the samples. Thickness of the samples in both middle and peripheral region. Wear testing of spray formed and rolled Al-Si-Pb alloy were investigated on a pin on disc type wear machine. Wear rate behavior with applied load and increase in percentage of reduction in thickness of samples was observed. Wear rate increased with increasing the load and decreased with increase in percentage of reduction in thickness of the sample.
STRENGTH AND DURABILITY STUDY OF GROUND GRANULATED BLAST FURNACE SLAG BASED G...Shoaib Wani
Ordinary Portland cement is recognized as a major construction material.
GGBS can improve the durability of a concrete structure by reducing the water permeability, increasing the corrosion resistance and sulphate resistance.
The improved properties can extend the service life of structures and reduce the overall maintenance costs.
The primary objective is to study the strength and durability of geopolymer concrete
To study the strength and durability parameters of GGBS based geopolymer concrete.
use of fly ash and silica fume as a partial replacement of cement in concreteHIMANSHU KUMAR AGRAHARI
this project was done with help of few members, in this project, we have replaced cement partially with fly ash and silica fumes, and tested the cubes with different mix and at different time of curing period
COMPARATIVE STUDY OF COMPRESSIVE STRENGTH AND DURABILITY PROPERTIES ON GEOPOL...Journal For Research
The usage of practical advancement in structural building society has prompted the utilization of new materials with low environmental effects. One of the most commonly used construction material in the world is concrete, which is normally produced by OPC. However, the production of OPC has prompted ecological worries over the creation of CO2. Almost to create 1 ton of OPC 1 ton of CO2 is discharged to the atmosphere. With a specific end goal to diminish the utilization of OPC and CO2, the new concrete has been created, that is GEOPOLYMER CONCRETE. Latest research has demonstrated that it is conceivable to utilize fly ash or slag as a binder in concrete by activating them with alkali components through a polymerization procedure. This paper reports the point of interest of the test work that has been embraced to examine the strength and durability properties of ultra-fine slag and processed fly ash mortar mixes. At first specimens were casted for normal GGBS and fly ash in the ratio of 100:0, 75:25, 50:50, 25:75 and later for the best ratio (75:25), GGBS is replaced by ultra-fine GGBS by 7.5, 12 and 20%. Samples were compared with cured at ambient temperature and oven curing. The results showed that mix proportion of 20% replacement of ultra-fine GGBS gave the maximum strength for both oven and ambient curing (76.2 and 91.1 MPa). Even all the durability properties are within the permissible limits.
CHARACTERIZATION & DURABILITY PROPERTIES OF ULTRAFINE FLY ASH BASED GEOPOLYME...Journal For Research
Huge scale generation of cement is creating environmental issue on one hand and depletion of natural resources on the other hand. This danger to nature has prompted research being made of industrial byproducts as supplementary cementetious materials in making concrete for more green and durable. Fly ash and silica fume both are pozzolanic materials which have been broadly utilized for improving the properties like strength and durability in concrete. Silica fume demonstrates the greater pozzolanic activity then fly ash because of its finer particle size distribution, the pozzolanic activity of fly ash also can be enhanced by decreasing the particle size distribution. Geopolymer is a class of aluminosilicate binding materials integrated by thermal action of solid aluminosilicate based materials such as metakoaline, GGBFS, fly ash. Geopolymer get activated with the alkaline solution and heat. Sodium hydroxide and sodium silicate were utilized as an alkaline solution with a steady ratio of 2.5 and the mix is designed for molarity 10 for the work carried out. In the present study, an attempt has been made to explore the geopolymer concrete by utilizing ultrafine fly ash (UFFA) produced by air classification and processed GGBFS with varied proportions. Discusses on the properties of geopolymer concrete has also been mentioned. Compressive strength and durability tests like Permeability, Abrasion, Sorptivity, Acid and sulphate attack, Drying shrinkage were conducted. In this work geopolymer concrete was prepared with varying proportions of GGBS and UFFA in the ratio of 92.5:7.5 and 88:12 and 80:20. The maximum strength was achieved for the ratio 92.5:7.5. The obtained compressive strength is in the range of 36.5MPa to 91.6MPa from 1st day to 28th day of hot curing.
Experimental Investigation on Ferro-Geopolymer Flat PanelsSuhail Shaikh
To find out the effective utilization of the abundant quantity of Indian fly ash polluting the environment.
To find out the suitability of quarry sand as a fine aggregate.
To determine the suitability of Geopolymer mortar in practical application of the Civil Engineering Field.
This paper presents an experimental result on the behavior of fly ash and slag based geopolymer concrete exposed to 5% sulphate solutions for 3.5 months of G30 and G50 which are equivalent to M30 and M50 grades respectively. The test specimens were cast and after one day rest period, half of the specimens were cured in an oven at 60°C for 24 hours and the remaining period cured in sun light until the testing is done and remaining half of the specimens were ambient cured. After 28 days the specimens were immersed in sulphates such as Na2SO4 and MgSO4 for 15, 45, 75 and 105 days then tested on 15th, 45th, 75th and 105th day according to codal procedures and the results are compared with the controlled concrete. From the test results, it is observed that the geopolymer concrete has better resistance to sulphates attack than controlled concrete.
Experimental study on geopolymer concrete by using ggbseSAT Journals
Abstract
The demand of concrete is increasing day by day and Cement is used for satisfying the need of development of infrastructure facilities, 1 tone cement production generates 1 tone CO2, which adversely affect the environment . In order to reduce the use of OPC and CO2 generation, the new generation concrete has been developed such as GEOPOLYMER CONCRETE. It uses Fly ash and Alkaline Solution as their Binding Materials. Geopolymer requires Oven Curing in the varying range of 60C to 100C for a period of 24 to 96 hours.
The objective of the present work is to study the effect of GGBS in fly ash based Geopolymer concrete and to study the Effect of Oven Curing and Ambient room temperature curing on them. And By replacing fly ash from 0 to 100% with GGBS and inspecting the Fresh Properties and Hardened Concrete properties at 7 days. The casted cube will be cured at normal room temperature and at 700C Oven heat provision for 24 hours and to ascertain the behavior of concrete mixed with GGBS, thereby examining the changes of properties like Strength and Durability.
Keywords: Fly ash, GGBS, Alkaline Solution, strength, durability, utilization
Crimson Publishers-In vitro Bioactivity Assessment of Novel Composites Based ...CrimsonPublishersRDMS
In vitro Bioactivity Assessment of Novel Composites Based on Calcium Aluminate Cement by Cortés-Hernández DA in Research & Development in Material Science
The influence of Rolling process on the porosity and wear behavior of Spray-f...IOSR Journals
Spray forming, also called spray casting or spray deposition, is the inert gas atomization of a liquid metal stream into variously sized droplets. These droplets are interrupted by a substrate which collects and solidifies the droplets into coherent, near fully dense perform. The present work concerns with this techniques. This technology was applied to produce Al-6%Si-20%Pb alloys. The spray droplets were deposited over a copper substrate to achieve a disc shape perform. After spray deposition samples were rolled at room temperature on two high rolling mills and total porosity and wear characteristic of spray deposits were studies. The total porosity decreases with the increase in the percentage of reduction in thickness of the samples. Thickness of the samples in both middle and peripheral region. Wear testing of spray formed and rolled Al-Si-Pb alloy were investigated on a pin on disc type wear machine. Wear rate behavior with applied load and increase in percentage of reduction in thickness of samples was observed. Wear rate increased with increasing the load and decreased with increase in percentage of reduction in thickness of the sample.
The Leading manufacturers, Suppliers, importers and exporters of a varied range of Carbon Products Calcined Petroleum Coke, Petroleum Coke, Cement & Cement Clinker, Petroleum ProductsPetroleum Products
The presentation focuses on recycling air pollution control residue (APCr) via plasma arc technology. APCr is a fast growing hazardous waste of which the UK is expected to produce 500,000 tonnes a year. The presentation will help people understand how Tetronics’ ground breaking technology can help tackle this issue.
Challenges for Concrete. Presenterat av professor Karen Scrivener, vinnare av Swedish Concrete Award 2015, på Träffpunkt Betong 15 den 7 oktober i Stockholm.
Study on Strength of Fly Ash Based Geopolymer Concrete Under Heat Curingijsrd.com
fly ash is a noncombustible material obtained from the various thermal power plants. Since fly ash is available in large scale, it is disposed of in rivers and landfills and ponds by thermal industries which are posing danger to environment. Due to high pozzolanic activity of fly ash, efforts are being made to use it as a cement replacement material. GeoPolymer concrete makes 100 percent utilization of fly ash in concrete along with alkaline solutions, as a binder. The cube specimens and beams are casted for 2% and 4% super plasticizers and alkaline to fly ash ratio of 0.35. The compressive strength of cubes is compared to that of conventional cubes at 7, 14 and 28 days .it is observed that GeoPolymer concrete is economical as compared to normal concrete from compressive strength point of view.
As cement is been involved in various contrived effects to the environment, an alternative is necessary for its impacts reduction.Such alternative is done by completely replacing the cement with silicafume and flyash which are the by-products.
This paper reports an investigational study on the effect of calcium carbide kiln
dust (CCKD) in cement mortar and its resistance towards hydrochloric acid attack.
Mortar with various CCKD replacement levels from 5 to 40 percent by binder weight
were tested. The setting time, consistency, density, compressive strength and the
durability tests were evaluated to measure the effect of CCKD in mortar durability was assessed in terms of loss of density and strength when the specimen
were cured in 5% hydrochloric acid (HCL) solution. The results indicate that CCKD
replacement levels from 5 to 20 percent performed on par with control mix in terms of
compressive strength, the loss in density and strength were around 30% under acid
curing. However, 30% and above CCKD replacement percentage showed low density
and compressive strength in both conditions. It is concluded that CCKD can be used
as an effective replacement for cement up to 20 percent without affecting the
performance.
A Review On Development Of Flyash Based High Strength Geopolymer Concretecedmmantc5411
Geopolymer concrete is the latest development in the field of concrete technology and it is still
developing. Geopolymers are inorganic, stable, hard and non-inflammable binder. The application of
geopolymer binder are in fire resistance fiber composite, sealant industry, tooling aeronautics SPF aluminium,
foundry equipment’s, radioactive toxic waste, ceramic, bricks and other precast concrete. The current review is
aims to put forward the development in geopolymer concrete for the production high strength geopolymer
concrete having strength more than 90MPa. The development of high strength concrete is aimed to reduce
structural member sizes and for economical construction in case of long span bridges and tall buildings. Also
the use flyash in concrete to reduce green gas house emission into the atmosphere by reducing cement usage
Effects of Silica Fume and Fly Ash as Partial Replacement of Cement on Water ...idescitation
ndustrial byproducts such as Silica Fume (SF) and Fly Ash (FA) can be utilized
to enhance the strength and water permeability characteristics of High Performance
Concrete (HPC). The utilization of these industrial by products is becoming popular
throughout the world because of the minimization of their potential hazardous effects on
environment. This paper investigates the individual effects of Silica Fume and Fly Ash as a
partial replacement of Ordinary Portland Cement (OPC) on water permeability,
compressive strength, split tensile strength and flexural tensile strength of High
Performance Concrete (HPC). To investigate these properties of concrete, the total
investigation was categorized into two basic test groups - SF Group for Silica Fume and FA
Group for Fly Ash. Seven types of mix proportions were used to cast the test specimens for
both groups. The replacement levels of OPC by Silica Fume were 0%, 2.5%, 5%, 7.5%,
10%, 15% and 20% where replacement levels of OPC by Fly Ash were 0%, 5%, 10%, 15%,
20%, 25% and 30%. 1% super-plasticizer was used in all the test specimens for high
performance (i.e., high workability at lower water-binder ratio) and to identify the sharp
effects of Silica Fume and Fly Ash on the properties of concrete. Water-binder ratio was
kept 0.42 for all cases and the specimens were tested at ages of 7, 14 and 28 days.10% Silica
Fume and 20% Fly Ash showed the lowest water penetration depth of 11mm and 15 mm
respectively. 7.5% Silica Fume and 10% Fly Ash were found to be optimum for maximum
compressive strength, maximum split tensile strength as well as maximum flexural tensile
strength.
Structural Properties of Laterite - Quarry Dust Cement BlocksQUESTJOURNAL
ABSTRACT: The study investigated the compressive strength and static modulus of elasticity of building blocks with full replacement of river sand with a blend of laterite – quarry. Values of compressive strength and static modulus are very helpful in the analyses and design of structures as they help in avoiding unrealistic assumptions which may be misleading in design. The maximum value of compressive strength obtained from a blend of 70% quarry dust and 30% laterite was 2.56N/mm2 at water cement ratio of 0.58 while a static modulus of elasticity of 8.86 was obtained from a combination of 75% quarry dust and 25% laterite.
Effect of silica fume on the strength of cement mortareSAT Journals
Abstract
The replacement of sand/cement by certain percentage of silica fumes, resulted in the improvement in compressive strength of the mortar. Silica fumes to the highly pozzolanic materials because it consists essentially of silica in non- crystalline form with a high specific surface. It is used to improve the mechanical properties of the concrete. The main objective of this paper is to study the effect of silica fume on the compressive strength of mortar. Three proportions of mixes viz mix 1:3, mix 1:4 and mix 1:6 with different percentages of silica fumes replacement with sand/cement were used. The maximum increase in strength at the age of 28 days when sand is replaced by 15% of silica fume has been observed as 40% and in case of cement replaced with 15% of silica fume, the observed increase in compressive strength of mortar comes out to be 28%.
A quantitative cost analysis shows that with the replacement of cement and sand by silica fume, the in cost is more when sand is replaced and it is less when cement is replaced.
Keywords: pozzolanic, silica fumes, non- crystalline, compressive strength
Effects of Self Compacting Concrete Using the Discrete Models as Binary & Ter...theijes
The effect of using nanosized[4],[5] pozzolanic materials [1], [12], 14] like Fly ash(FA) [3], Metakeolin (MK) [8],Silica fume(SF)[6],Rise husk ash(RHA)[14],Ground granulated blust furnace slag (GGBFS)[2] etc. as partial replacement with dry weight of Ordinary Portland Cement(OPC) to enhance the strength, durability, workability of concrete. The test results of fresh and the hardened properties of Self compacting concrete (SCC)[8],[19] incorporating pozzolanic materials at various percentage by fixing the Water to Binder (i.e. powder)ratio(w/b) of 0.45. The effects of pozzolanic materials properties of SCC were investigated by comparing the test results. Various tests [4],[5],[9] were conducted on fresh SCC like the slump flow, L-box passing ability of the SCC mixtures and T500mm slump flow time were also done. Compressive strength test [9] along with the Initial surface absorption test(ISAT) and the Capillary suction test(CST)[7] were also performed on the hardened SCC[8]
2. 456 F.G. Collins, J.G. Sanjayan/Cement and Concrete Research 29 (1999) 455–458
The concrete mixture proportions are summarised in Table
2. The materials used for concrete making, the method of pre-
paring concrete mixes in the laboratory, and the tests for fresh
and mechanical concrete properties reported in this paper
were in accordance with the Australian standard AS1012.
Samples were made for subsequent laboratory testing as fol-
lows:
• Cylinders in accordance with AS1012, Parts 8 and 9
(100-mm diameter and 200-mm height) for compres-
sive strength testing in triplicate at 1, 3, 7, 28, 56, and
91 days (following demoulding, subject to “bath” cur-
ing at 23ЊC, “exposed” curing at 23ЊC and 50% RH,
and “sealed” curing involving storage in two polythene
bags and a sealed container at 23ЊC).
• Shrinkage prisms tested in accordance with AS1012,
Part 13 (75 ϫ 75 ϫ 285 mm). The exposure conditions
following demoulding for a triplicate set of samples
were seven days of bath curing followed by exposed
curing at 23ЊC and 50% RH.
• Cylinders in accordance with AS1012, Part 8 (100-mm
diameter and 200-mm height) for creep testing in ac-
cordance with AS1012, Part 16. Following demould-
ing, a duplicate set of specimens were subject to seven
days of bath curing followed by 21 days of exposed
curing at 23ЊC and 50% RH prior to loading at 40% of
the 28-day compressive strength.
• Flexural strength prisms in accordance with AS1012,
Part 8 (150 ϫ 150 ϫ 500 mm). Following demoulding,
a triplicate set of specimens were subject to bath cur-
ing for 28 days. Flexural strength testing was con-
ducted in accordance with AS1012, Part 11.
• Cylinders in accordance with AS1012, Part 8 (100-mm
diameter and 200-mm height). Following demoulding,
a triplicate set of specimens were subject to bath cur-
ing for 28 days and tested for elastic modulus in accor-
dance with AS1012, Part 17.
Properties of the fresh concretes including slump and air
content were also determined in accordance with AS1012,
Parts 3 and 4, respectively.
2. Fresh concrete properties
Slump loss versus time is summarised in Fig. 1 Slag acti-
vated by powdered sodium silicate and lime slurry (AAS1)
demonstrates considerably better workability than the other
concrete mixes, including OPC. At 30 min, AAS1 demon-
strates better slump than the initial slump; this is most likely
due to further dissolution of the powdered sodium silicate
into the mixing water. At 120 min, the slump loss of the
AAS1 concrete is minimal compared with the other con-
cretes. This result contrasts with slag activated by liquid so-
dium silicate and lime slurry (AAS2), also reported elsewhere
[6–16], that were based on liquid rather than powdered so-
dium silicate activators. It is postulated that the powdered so-
dium silicate has a slower release of alkali into the cement
system (as opposed to liquid sodium silicates) and leads to a
slower rate of initial reaction. Similar to AAS2, H/C concrete
showed significant loss of workability, with minimal slump at
60 min. The activated slag concretes entrain more air than
OPC concrete, as shown in Table 2. The bleed of the acti-
Table 1
Properties of cementitious materials
Constituent /property Slag OPC
SiO2 (%) 35.04 19.9
Al2O3 (%) 13.91 4.62
Fe2O3 (%) 0.29 3.97
MgO (%) 6.13 1.73
CaO (%) 39.43 64.27
Na2O (%) 0.34
TiO2 (%) 0.42
K2O (%) 0.39 0.57
P2O5 (%) Ͻ0.1
MnO (%) 0.43
Total sulphur as SO3 (%) 2.43 2.56
Sulphide sulphur as S2Ϫ
0.44
Cl (p.p.m) 80
Fineness (m2
/kg) 460 342
Loss on ignition (%) 1.45 2.9
Time to initial set (h) N/A 2.0
Strength (MPa) of 75 ϫ 75 ϫ 75 mm
mortar cubes (MPa)
3 Days N/A 32.7
7 Days N/A 42.0
28 Days N/A 54.1
Table 2
Summary of concrete mixture proportions (kg/m3
)
Constituents OPC H/C AAS1 AAS2
OPC 360 — — —
Slag — 360 360 360
Free water* 180 180 180 180
w/b 0.5 0.5 0.5 0.5
Fine aggregate 830 830 830 830
Coarse aggregate
14 mm 1130 1130 1130 1130
Air content % 0.5 1.2 1.2 1.1
*Adjustments made for water in aggregates (to saturated surface dry
condition), NaOH, Na2CO3, lime slurry, and sodium silicate. Fig. 1. Slump loss versus time; w/b ϭ 0.5.
3. F.G. Collins, J.G. Sanjayan/Cement and Concrete Research 29 (1999) 455–458 457
vated slag concretes was measured as zero at 2 h from the
time of mixing. The OPC concrete had a bleed of 0.45% (ex-
pressed as % of mixing water). Due to rapid loss of workabil-
ity, further work with AAS2 was discontinued.
3. Compressive strength
Fig. 2 shows strength development with time following
bath curing. All concrete types show almost identical one-
day strength. The H/C concrete show rapid early strength de-
velopment, followed by lower strength than AAS1 and OPC
concrete at later ages. AAS1 concrete shows higher strength
than OPC concrete at all ages. Between 56 and 91 days, the
strength of OPC concrete levels out, whereas AAS1 concrete
continues to gain strength. Fig. 3 and Fig. 4 show the effects
of various curing environments on the development of com-
pressive strength. There is a significant difference in strength
between samples subjected to exposed curing and sealed/
bath curing, with AAS1 showing greater sensitivity to lack
of curing.
Beyond 28 days, AAS1-exposed concrete strength levels
out. Further work is currently underway to assess the longer
term strength of AAS concrete subjected to exposed curing.
4. Drying shrinkage
Results of drying shrinkage is summarised in Fig. 5. AAS1
concrete shows a minor expansion during the first seven days
bath curing followed by a considerably higher rate of drying
shrinkage when exposed, as compared with OPC concrete.
The implications of higher drying shrinkage are that under re-
strained conditions, it may lead to a higher incidence of crack-
ing. Adequate provision for joints and minimization of re-
straints should be allowed, although this is not always
practical. Drying shrinkage of H/C concrete is similar to OPC
concrete up to 56 days; however, it is considerably greater be-
yond 56 days. It is worth noting that the Australian Standard
for determination of drying shrinkage is based on 56-day test
results; this would lead to a false indication of drying shrink-
age in the case of H/C concrete. Further investigation is under-
way on AAS1 concrete to compare drying shrinkage of prisms
with that measured in larger structural members and also to de-
termine appropriate means of mitigation of drying shrinkage.
5. Flexural strength, elastic modulus, and creep
The 28-day flexural strength and elastic moduli of vari-
ous concretes are shown in Table 3. Overall strain due to
creep following 112 days loading is shown in Fig. 6. OPC
concrete shows higher initial creep than AAS1 concrete
during the first three days. However, after 112 days loading
AAS1 shows a slightly higher creep strain (42 microstrain/
MPa compared with 36.7 microstrain/MPa). The net effect
of greater creep, greater flexural strength, and lower elastic
modulus of AAS1 may be reduction of the risk of cracking
Fig. 2. Compressive strength development of concrete subject to bath cur-
ing, w/b ϭ 0.5.
Fig. 3. OPC concrete subject to different curing, w/b ϭ 0.5.
Fig. 4. AAS1 concrete subject to different curing, w/b ϭ 0.5.
Fig. 5. Drying shrinkage of various concretes.
4. 458 F.G. Collins, J.G. Sanjayan/Cement and Concrete Research 29 (1999) 455–458
due to drying shrinkage under restrained conditions and this
is currently being investigated.
6. Conclusions
The results of this investigation indicate:
1. At w/b ϭ 0.5, concrete containing slag activated by
powdered sodium silicate showed minimal slump loss
over 2 h, whereas concrete containing slag activated by
liquid sodium silicate shows considerably less initial
workability and demonstrates significant slump loss. H/
C concrete also showed significant slump loss over 2 h.
2. Activated slag concrete shows similar one-day strength
to OPC concrete, with AAS1 showing superior strength
at later ages. The H/C concrete had modest strength gain
beyond three days.
3. AAS1 concrete shows a greater strength difference
between bath/sealed cured cylinders to exposed cylin-
ders when compared with OPC concrete.
4. AAS1 and H/C concrete show greater drying shrinkage
than OPC concrete. However, the net effect of higher
flexural strength, lower elastic modulus, and greater
creep of AAS1 concrete may be reduction of the risk of
cracking due to drying shrinkage under restrained con-
ditions and this is currently being investigated.
Acknowledgments
The financial support for this project is jointly provided
by Independent Cement and Lime Pty Ltd, Blue Circle
Southern Cement Ltd, and Australian Steel Mill Services.
The authors thank the sponsors, especially Alan Dow, Tom
Wauer, Katherine Turner, Paul Ratcliff, John Ashby, and
Dr. Ihor Hinczak for the guidance and support. The enthusi-
astic participation of final-year students Soon Keat Lim and
Eric Tan in this project is very much appreciated. The ef-
forts and assistance with the laboratory work provided by
Jeff Doddrell, Roger Doulis, and Peter Dunbar are also
gratefully acknowledged.
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Fig. 6. Creep of OPC and AAS1 concretes.
Table 3
28-Day flexural strength and elastic modulus of various concretes
Parameter OPC H/C AAS1
Flexural strength
(MPa) 5.57 4.77 7.18
Flexural strength/
compressive strength 0.12 0.14 0.15
Elastic modulus
(ϫ1000 MPa) 41.7 36.5 36.7