This report discusses different types of lightweight concrete, including no-fines concrete, lightweight aggregate concrete, and aerated concrete. It describes their key characteristics and composition. The report also examines the mechanical properties and compressive strengths of structural lightweight concrete specimens at various curing ages and temperatures. The main findings are that compressive strength decreases with higher water-cement ratios, increases with curing age, and decreases significantly as temperature rises. Reinforcement and mineral admixtures can improve the flexural, tensile and compressive strengths of lightweight concrete.
This document presents a phase 2 project on lightweight concrete submitted by 5 civil engineering students. It defines lightweight concrete and discusses its types, advantages, durability, applications, mix design, and tests. Lightweight concrete has lower density than normal concrete and is made with lightweight aggregates. It offers benefits like reduced dead load, faster construction, and lower transportation costs. The document examines the durability and typical uses of lightweight concrete, provides steps for mix design, and notes that compression, split tensile, and slump tests were performed to determine the strength of lightweight concrete mixes containing expanded polystyrene spheres.
reinforced cement Concrete structures failures,repair and mixing typessurya teja
There are two main types of concrete mixers: batch mixers that mix concrete in batches that must be fully emptied and cleaned between batches, and continuous mixers that continuously produce concrete. Batch mixers can be horizontal drum mixers or vertical pan mixers. Drum mixers have fixed blades inside a rotating drum while pan mixers have either a rotating pan or blades. Continuous mixers are non-tilting drums with rotating screw-type blades that continuously feed and discharge concrete.
This document provides information about concrete, its ingredients, properties, types of cement, and methods of placing and curing concrete. It discusses that concrete is composed of cement, fine aggregates (sand), coarse aggregates, and water. The main ingredients are cement (usually Portland cement), water, fine aggregates, and coarse aggregates. It also outlines some key properties of good concrete including being strong, durable, water tight, workable, and able to resist wear and tear. The document then discusses reinforced concrete and factors affecting the workability and durability of concrete. It concludes with descriptions of different cement types and methods for placing and curing concrete.
CONCRETE
CONSTITUENTS OF CONCRETE
LIGHTWEIGHT CONCRETE
ADVANTAGES
DISADVANTAGES
APPLICATIONS
PRINCIPLE TECHNIQUES BEHIND LIGHTWEIGHT CONCRETE
LIGHTWEIGHT AGGREGATE CONCRETE
PRODUCTION OF LIGHTWEIGHT AGGREGATE CONCRETE
CLASSIFICATION OF LIGHTWEIGHT AGGREGATE CONCRETE
NATURAL AGGREGATE
ARTIFICIAL AGGREGATE
LOW-DENSITY CONCRETES
STRUCTURAL LIGHTWEIGHT CONCRETE
MODERATE-STRENGTH LIGHTWEIGHT CONCRETE
PROPERTIES OF LIGHTWEIGHT AGGREGATE CONCRETE
AERATED OR FOAMED CONCRETE
MANUFACTURING OF FOAMED CONCRETE
PROPERTIES OF FOAMED CONCRETE
APPLICATIONS OF FOAMED CONCRETE
NO FINES CONCRETE
PROPERTIES NO FINES CONCRETE
APPLICATIONS NO FINES CONCRETE
HIGH DENSITY CONCRETE
Man-made (Synthetic) Aggregates
ADMIXTURE
High Strength Concrete
SPECIAL METHODS OF MAKING HIGH STRENGTH CONCRETE
This document discusses the materials and design considerations for plain and reinforced concrete structures according to the National Building Code of India. It outlines the types of cement, aggregates, water, admixtures, and reinforcement that can be used. It also covers mix design and proportioning, durability requirements, and factors to consider when selecting reinforced concrete as a construction material such as its economy, suitability for structural and architectural functions, low maintenance needs, availability of materials, rigidity, and fire resistance.
This document provides an overview of light weight concrete, including its definition, types of aggregates used, mix design, properties, applications, and advantages/disadvantages. Light weight concrete uses expanded aggregates that create an internal cellular structure, resulting in lower density than conventional concrete. It has benefits such as reduced dead load, faster construction, and lower transport costs. Common uses include structural elements, floor slabs, roof decks, and insulation. While offering weight savings, light weight concrete can be more difficult to place and finish than standard concrete.
Building Materials assignment 1 (Concrete)Syafiq Zariful
This document provides information on five types of building materials: ferrocement, fiber reinforced concrete, gypsum concrete, stamped concrete, and translucent concrete. It discusses the constituents, properties, advantages, disadvantages and applications of each material. Ferrocement is a reinforced cement mortar with wire mesh. It has high tensile strength and is lightweight but labor intensive. Fiber reinforced concrete includes fibers to increase toughness. Gypsum concrete uses gypsum as a binder and is used for partitions and ceilings. Stamped concrete is colored and textured to resemble other materials. Translucent concrete allows light transmission and is used for ceilings and facades.
This document presents a phase 2 project on lightweight concrete submitted by 5 civil engineering students. It defines lightweight concrete and discusses its types, advantages, durability, applications, mix design, and tests. Lightweight concrete has lower density than normal concrete and is made with lightweight aggregates. It offers benefits like reduced dead load, faster construction, and lower transportation costs. The document examines the durability and typical uses of lightweight concrete, provides steps for mix design, and notes that compression, split tensile, and slump tests were performed to determine the strength of lightweight concrete mixes containing expanded polystyrene spheres.
reinforced cement Concrete structures failures,repair and mixing typessurya teja
There are two main types of concrete mixers: batch mixers that mix concrete in batches that must be fully emptied and cleaned between batches, and continuous mixers that continuously produce concrete. Batch mixers can be horizontal drum mixers or vertical pan mixers. Drum mixers have fixed blades inside a rotating drum while pan mixers have either a rotating pan or blades. Continuous mixers are non-tilting drums with rotating screw-type blades that continuously feed and discharge concrete.
This document provides information about concrete, its ingredients, properties, types of cement, and methods of placing and curing concrete. It discusses that concrete is composed of cement, fine aggregates (sand), coarse aggregates, and water. The main ingredients are cement (usually Portland cement), water, fine aggregates, and coarse aggregates. It also outlines some key properties of good concrete including being strong, durable, water tight, workable, and able to resist wear and tear. The document then discusses reinforced concrete and factors affecting the workability and durability of concrete. It concludes with descriptions of different cement types and methods for placing and curing concrete.
CONCRETE
CONSTITUENTS OF CONCRETE
LIGHTWEIGHT CONCRETE
ADVANTAGES
DISADVANTAGES
APPLICATIONS
PRINCIPLE TECHNIQUES BEHIND LIGHTWEIGHT CONCRETE
LIGHTWEIGHT AGGREGATE CONCRETE
PRODUCTION OF LIGHTWEIGHT AGGREGATE CONCRETE
CLASSIFICATION OF LIGHTWEIGHT AGGREGATE CONCRETE
NATURAL AGGREGATE
ARTIFICIAL AGGREGATE
LOW-DENSITY CONCRETES
STRUCTURAL LIGHTWEIGHT CONCRETE
MODERATE-STRENGTH LIGHTWEIGHT CONCRETE
PROPERTIES OF LIGHTWEIGHT AGGREGATE CONCRETE
AERATED OR FOAMED CONCRETE
MANUFACTURING OF FOAMED CONCRETE
PROPERTIES OF FOAMED CONCRETE
APPLICATIONS OF FOAMED CONCRETE
NO FINES CONCRETE
PROPERTIES NO FINES CONCRETE
APPLICATIONS NO FINES CONCRETE
HIGH DENSITY CONCRETE
Man-made (Synthetic) Aggregates
ADMIXTURE
High Strength Concrete
SPECIAL METHODS OF MAKING HIGH STRENGTH CONCRETE
This document discusses the materials and design considerations for plain and reinforced concrete structures according to the National Building Code of India. It outlines the types of cement, aggregates, water, admixtures, and reinforcement that can be used. It also covers mix design and proportioning, durability requirements, and factors to consider when selecting reinforced concrete as a construction material such as its economy, suitability for structural and architectural functions, low maintenance needs, availability of materials, rigidity, and fire resistance.
This document provides an overview of light weight concrete, including its definition, types of aggregates used, mix design, properties, applications, and advantages/disadvantages. Light weight concrete uses expanded aggregates that create an internal cellular structure, resulting in lower density than conventional concrete. It has benefits such as reduced dead load, faster construction, and lower transport costs. Common uses include structural elements, floor slabs, roof decks, and insulation. While offering weight savings, light weight concrete can be more difficult to place and finish than standard concrete.
Building Materials assignment 1 (Concrete)Syafiq Zariful
This document provides information on five types of building materials: ferrocement, fiber reinforced concrete, gypsum concrete, stamped concrete, and translucent concrete. It discusses the constituents, properties, advantages, disadvantages and applications of each material. Ferrocement is a reinforced cement mortar with wire mesh. It has high tensile strength and is lightweight but labor intensive. Fiber reinforced concrete includes fibers to increase toughness. Gypsum concrete uses gypsum as a binder and is used for partitions and ceilings. Stamped concrete is colored and textured to resemble other materials. Translucent concrete allows light transmission and is used for ceilings and facades.
This document discusses and defines various types of concrete. It describes 17 different types including normal strength concrete, plain concrete, reinforced concrete, prestressed concrete, precast concrete, lightweight concrete, high-density concrete, air entrained concrete, ready mix concrete, polymer concrete, high-strength concrete, high-performance concrete, self-consolidating concrete, shotcrete concrete, pervious concrete, vacuum concrete, and pumped concrete. For each type, it briefly explains the key properties and typical uses.
The document describes a study on transparent concrete. Transparent concrete is made by adding glass rods to a concrete mix. The study aims to design translucent concrete blocks with 1-5% glass rods by weight and analyze the blocks' physical and engineering properties compared to conventional concrete blocks. The results show the transparent concrete blocks have 5-10% higher initial compressive strength at 7 days and 10-15% higher at 28 days for mixes up to 3% glass rods. Strength decreases with glass rod content above 3%. The document provides details on the materials, methodology, tests conducted and results obtained in the study.
This document discusses structural lightweight concrete. It begins by defining lightweight concrete and noting its lighter weight compared to conventional concrete. It then discusses properties like compressive strength and water absorption tested at different densities, foam percentages, and water-cement ratios. Applications include construction, vessels, and roof decks. Advantages include reduced weight and transportation costs, while disadvantages include sensitivity to water and difficulty in placement. A case study examines the Wellington Stadium project in New Zealand, where lightweight concrete allowed rapid construction in a seismic area with poor foundation conditions.
Thanx to see our report again and here we talked about concrete just like a roadway but enough information to understand about it. things we talked about are advantages and disadvantages, manufacturing, types, test. Here in every point we compared to asphalt. So if you have any questions or if you have noticed anything you can send a message to me to this email
Alirizgar234@gmail.com
The document presents research on cellular lightweight concrete (CLC), which has a lower density than normal concrete. It discusses three types of CLC production, advantages like reduced weight and costs, and applications for roofs, walls, and insulation. A case study is described that partially replaced coarse aggregate with pumice aggregate in concrete mixes. Testing showed compressive strength was highest at 60% replacement, making CLC a viable alternative to normal concrete for some non-load-bearing applications.
The document discusses different types of concrete and their uses. It describes concrete as a composite material made of a binding agent like cement or lime, and fine and coarse aggregates. It classifies concrete into types based on the binding material (cement or lime concrete), design (plain, reinforced, or pre-stressed cement concrete), and purpose. Cement concrete is commonly used in buildings due to its strength and durability, while lime concrete is used where cement availability is limited. Reinforced concrete can withstand tensile, compressive, and shear stresses.
Lightweight concrete has a lower density than normal concrete, ranging from 300-1850 kg/m3. There are three main types: lightweight aggregate concrete uses expanded aggregates; aerated concrete is produced by incorporating air bubbles; and no-fines concrete omits fine aggregates. Lightweight concrete provides benefits like improved thermal insulation, soundproofing, and fire resistance compared to normal concrete.
The document discusses building maintenance, common defects, and remedial methods for RCC structures. It describes three main common defects: foundations, walls, and concrete/RCC frames. For foundations, common issues include differential settlement, uplift of shrinkage soil, and dampness. For walls, issues include cracking, dampness penetration, and failure during cyclones. For concrete frames, common problems discussed are seepage/leakage, spalling of concrete, and corrosion of steel reinforcement. The document provides detailed remedial methods for addressing each of these defects.
CELLULAR LIGHT WEIGHT CONCRETE BLOCKS WITH DIFFERENT MIX PROPORTIONSIjripublishers Ijri
Burnt Clay Brick is the predominant construction material in the country. The CO2 emissions in the brick manufacture
process have been acknowledged as a significant factor to global warming. Now-a-days there are so many technologies
involved in the recent development of concrete. Cellular Lightweight Concrete (CLC) is one of the recent emerging technology
in making concrete. The usage of Cellular Light-weight Concrete (CLC) gives a prospective solution to building
construction industry along with environmental preservation. By using this type of concrete, we have found so many
advantages when compared to the burnt clay bricks.
Study on property of concrete using light weight aggregate.RAZMOHAMMADKHAN1
1) The document discusses a seminar on studying the properties of lightweight concrete using lightweight aggregate. It aims to reduce the dead load and seismic load of structures.
2) Lightweight concrete has a density of 300-1850 kg/m3 compared to normal concrete which has 2200-2600 kg/m3. This lower density is achieved by replacing normal aggregate with porous lightweight aggregate or adding gas bubbles.
3) The advantages of lightweight concrete include reducing structural loads, providing similar mechanical properties to normal concrete, and having improved workability. It allows for thinner slabs and lighter structures.
This document discusses fly ash concrete and the effects of fly ash on concrete properties. It begins with an introduction to concrete and its typical ingredients. It then defines fly ash, describing its chemical and physical properties. Fly ash is classified and standards from BIS and ASTM for fly ash quality are reviewed. The effects of fly ash on the workability, setting time, heat of hydration, and compressive strength of concrete are summarized. Specifically, fly ash is shown to improve workability, reduce heat of hydration, and increase long-term compressive strength while decreasing early strength. Finally, the benefits of using fly ash in concrete are listed as improved durability, strength, workability, cost, and reduced density and heat
This document describes high-strength lightweight cellular concrete, also called high-performance cellular concrete. It is made through a process that injects a foam solution into a cement mixture, creating microscopic air bubbles throughout the concrete. This results in a concrete that is much lighter in weight but can achieve compressive strengths comparable to regular concrete. It has benefits like better insulation, freeze-thaw resistance, and fire resistance. The document discusses the history of cellular concrete and how this new process allows for structural uses by controlling the concrete's density and strengths.
This document discusses different types of concrete. It begins by explaining that concrete is composed of cement, fine aggregates like sand, and coarse aggregates mixed with water. It then describes several types of concrete including ordinary concrete, self-compacting concrete, reinforced cement concrete, precast concrete, prestressed concrete, and pervious concrete. For each type, it provides a brief definition and some of the key characteristics. The document focuses on explaining the composition and properties of different concretes used in construction.
Lightweight concrete has a lower density than ordinary concrete due to the use of lightweight aggregates. It has strengths between 7-40 MPa, improved workability, thermal insulation, and water absorption. Lightweight concrete exhibits higher moisture movement and fire resistance compared to ordinary concrete. It is used in prestressed concrete, high-rise buildings, and to reduce dead load. While more expensive, it allows for rapid, simple construction and reduced transportation costs.
The document discusses reinforced cement concrete (RCC), including its history, materials, specifications, and advantages/disadvantages. RCC uses steel reinforcement embedded in concrete to resist tensile, shear, and sometimes compressive stresses. François Coignet is considered a pioneer of RCC, building the first reinforced concrete structure in 1853. Proper proportions and mixing of cement, aggregates like sand and gravel, and water are needed to produce durable concrete. Precast concrete involves casting pieces off-site then transporting them for assembly.
Concrete is one of the most durable building materials. It provides superior fire resistance compared with wooden construction and gains strength over time. Structures made of concrete can have a long service life. Concrete is used more than any other manmade material in the world. As of 2006, about 7.5 billion cubic meters of concrete are made each year, more than one cubic meter for every person on Earth.
Module on light and heavy weight concreteErankajKumar
Lightweight concrete has lower density than normal weight concrete, ranging from 90-115 lb/ft3 compared to 140-150 lb/ft3. It uses lightweight aggregates that are expanded or porous, like shale, clay or slag. Lightweight concrete can be classified based on density and strength, including low density concrete for insulation, moderate strength concrete, and structural concrete. Structural lightweight concrete has compressive strengths over 17.0 MPa and is used in construction where weight needs to be reduced. It has benefits like high strength to weight ratio, thermal insulation, fire resistance, and ease of construction using prefabricated units.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
The document summarizes different types of specialized concretes discussed in a civil engineering seminar. It describes translucent concrete made with optical fibers, green concrete using recycled materials, geo-polymer concrete made from industrial wastes, bacterial self-healing concrete, bendable engineered cementitious composite, pervious concrete without fine aggregates, vacuum concrete where excess water is removed, and cellular lightweight concrete made with a foam agent. Each type is defined and its composition, properties, advantages, and applications are outlined.
Lightweight concrete has a lower density than normal concrete, ranging from 300-1850 kg/m3 compared to 2200-2600 kg/m3. There are three main types: lightweight aggregate concrete uses porous aggregates; aerated concrete is produced by incorporating air bubbles; and no-fines concrete omits fine aggregates. Lightweight concrete reduces building dead load, improves workability, has better insulation and durability, and allows for use of industrial wastes. Its lower density offers applications in construction elements like pre-stressed concrete and high-rise buildings.
This document provides information about light weight concrete, including its definition, types of aggregates used, mix design, properties, advantages, applications, and conclusions. Light weight concrete is a type of concrete that uses an expanding agent to increase its volume while reducing weight compared to conventional concrete. It has benefits such as reduced dead load, faster construction, and lower transport costs. The document discusses various types of lightweight aggregates, mix design considerations, compressive strengths associated with cement contents, and applications of light weight concrete in construction.
This document discusses different types of lightweight concrete, including structural lightweight concrete, ultra-lightweight concrete, and autoclave aerated concrete. It provides details on the composition, properties, uses, and advantages of each type. Structural lightweight concrete has a density between 1450-1850 kg/m3, compared to normal concrete's 2400 kg/m3. Ultra-lightweight concrete can have a density as low as 600-1000 kg/m3 when using expanded glass or polystyrene beads. Autoclave aerated concrete is produced by introducing gas into a cement mixture, creating millions of tiny air pockets that reduce the density to 300-1000 kg/m3.
This document discusses and defines various types of concrete. It describes 17 different types including normal strength concrete, plain concrete, reinforced concrete, prestressed concrete, precast concrete, lightweight concrete, high-density concrete, air entrained concrete, ready mix concrete, polymer concrete, high-strength concrete, high-performance concrete, self-consolidating concrete, shotcrete concrete, pervious concrete, vacuum concrete, and pumped concrete. For each type, it briefly explains the key properties and typical uses.
The document describes a study on transparent concrete. Transparent concrete is made by adding glass rods to a concrete mix. The study aims to design translucent concrete blocks with 1-5% glass rods by weight and analyze the blocks' physical and engineering properties compared to conventional concrete blocks. The results show the transparent concrete blocks have 5-10% higher initial compressive strength at 7 days and 10-15% higher at 28 days for mixes up to 3% glass rods. Strength decreases with glass rod content above 3%. The document provides details on the materials, methodology, tests conducted and results obtained in the study.
This document discusses structural lightweight concrete. It begins by defining lightweight concrete and noting its lighter weight compared to conventional concrete. It then discusses properties like compressive strength and water absorption tested at different densities, foam percentages, and water-cement ratios. Applications include construction, vessels, and roof decks. Advantages include reduced weight and transportation costs, while disadvantages include sensitivity to water and difficulty in placement. A case study examines the Wellington Stadium project in New Zealand, where lightweight concrete allowed rapid construction in a seismic area with poor foundation conditions.
Thanx to see our report again and here we talked about concrete just like a roadway but enough information to understand about it. things we talked about are advantages and disadvantages, manufacturing, types, test. Here in every point we compared to asphalt. So if you have any questions or if you have noticed anything you can send a message to me to this email
Alirizgar234@gmail.com
The document presents research on cellular lightweight concrete (CLC), which has a lower density than normal concrete. It discusses three types of CLC production, advantages like reduced weight and costs, and applications for roofs, walls, and insulation. A case study is described that partially replaced coarse aggregate with pumice aggregate in concrete mixes. Testing showed compressive strength was highest at 60% replacement, making CLC a viable alternative to normal concrete for some non-load-bearing applications.
The document discusses different types of concrete and their uses. It describes concrete as a composite material made of a binding agent like cement or lime, and fine and coarse aggregates. It classifies concrete into types based on the binding material (cement or lime concrete), design (plain, reinforced, or pre-stressed cement concrete), and purpose. Cement concrete is commonly used in buildings due to its strength and durability, while lime concrete is used where cement availability is limited. Reinforced concrete can withstand tensile, compressive, and shear stresses.
Lightweight concrete has a lower density than normal concrete, ranging from 300-1850 kg/m3. There are three main types: lightweight aggregate concrete uses expanded aggregates; aerated concrete is produced by incorporating air bubbles; and no-fines concrete omits fine aggregates. Lightweight concrete provides benefits like improved thermal insulation, soundproofing, and fire resistance compared to normal concrete.
The document discusses building maintenance, common defects, and remedial methods for RCC structures. It describes three main common defects: foundations, walls, and concrete/RCC frames. For foundations, common issues include differential settlement, uplift of shrinkage soil, and dampness. For walls, issues include cracking, dampness penetration, and failure during cyclones. For concrete frames, common problems discussed are seepage/leakage, spalling of concrete, and corrosion of steel reinforcement. The document provides detailed remedial methods for addressing each of these defects.
CELLULAR LIGHT WEIGHT CONCRETE BLOCKS WITH DIFFERENT MIX PROPORTIONSIjripublishers Ijri
Burnt Clay Brick is the predominant construction material in the country. The CO2 emissions in the brick manufacture
process have been acknowledged as a significant factor to global warming. Now-a-days there are so many technologies
involved in the recent development of concrete. Cellular Lightweight Concrete (CLC) is one of the recent emerging technology
in making concrete. The usage of Cellular Light-weight Concrete (CLC) gives a prospective solution to building
construction industry along with environmental preservation. By using this type of concrete, we have found so many
advantages when compared to the burnt clay bricks.
Study on property of concrete using light weight aggregate.RAZMOHAMMADKHAN1
1) The document discusses a seminar on studying the properties of lightweight concrete using lightweight aggregate. It aims to reduce the dead load and seismic load of structures.
2) Lightweight concrete has a density of 300-1850 kg/m3 compared to normal concrete which has 2200-2600 kg/m3. This lower density is achieved by replacing normal aggregate with porous lightweight aggregate or adding gas bubbles.
3) The advantages of lightweight concrete include reducing structural loads, providing similar mechanical properties to normal concrete, and having improved workability. It allows for thinner slabs and lighter structures.
This document discusses fly ash concrete and the effects of fly ash on concrete properties. It begins with an introduction to concrete and its typical ingredients. It then defines fly ash, describing its chemical and physical properties. Fly ash is classified and standards from BIS and ASTM for fly ash quality are reviewed. The effects of fly ash on the workability, setting time, heat of hydration, and compressive strength of concrete are summarized. Specifically, fly ash is shown to improve workability, reduce heat of hydration, and increase long-term compressive strength while decreasing early strength. Finally, the benefits of using fly ash in concrete are listed as improved durability, strength, workability, cost, and reduced density and heat
This document describes high-strength lightweight cellular concrete, also called high-performance cellular concrete. It is made through a process that injects a foam solution into a cement mixture, creating microscopic air bubbles throughout the concrete. This results in a concrete that is much lighter in weight but can achieve compressive strengths comparable to regular concrete. It has benefits like better insulation, freeze-thaw resistance, and fire resistance. The document discusses the history of cellular concrete and how this new process allows for structural uses by controlling the concrete's density and strengths.
This document discusses different types of concrete. It begins by explaining that concrete is composed of cement, fine aggregates like sand, and coarse aggregates mixed with water. It then describes several types of concrete including ordinary concrete, self-compacting concrete, reinforced cement concrete, precast concrete, prestressed concrete, and pervious concrete. For each type, it provides a brief definition and some of the key characteristics. The document focuses on explaining the composition and properties of different concretes used in construction.
Lightweight concrete has a lower density than ordinary concrete due to the use of lightweight aggregates. It has strengths between 7-40 MPa, improved workability, thermal insulation, and water absorption. Lightweight concrete exhibits higher moisture movement and fire resistance compared to ordinary concrete. It is used in prestressed concrete, high-rise buildings, and to reduce dead load. While more expensive, it allows for rapid, simple construction and reduced transportation costs.
The document discusses reinforced cement concrete (RCC), including its history, materials, specifications, and advantages/disadvantages. RCC uses steel reinforcement embedded in concrete to resist tensile, shear, and sometimes compressive stresses. François Coignet is considered a pioneer of RCC, building the first reinforced concrete structure in 1853. Proper proportions and mixing of cement, aggregates like sand and gravel, and water are needed to produce durable concrete. Precast concrete involves casting pieces off-site then transporting them for assembly.
Concrete is one of the most durable building materials. It provides superior fire resistance compared with wooden construction and gains strength over time. Structures made of concrete can have a long service life. Concrete is used more than any other manmade material in the world. As of 2006, about 7.5 billion cubic meters of concrete are made each year, more than one cubic meter for every person on Earth.
Module on light and heavy weight concreteErankajKumar
Lightweight concrete has lower density than normal weight concrete, ranging from 90-115 lb/ft3 compared to 140-150 lb/ft3. It uses lightweight aggregates that are expanded or porous, like shale, clay or slag. Lightweight concrete can be classified based on density and strength, including low density concrete for insulation, moderate strength concrete, and structural concrete. Structural lightweight concrete has compressive strengths over 17.0 MPa and is used in construction where weight needs to be reduced. It has benefits like high strength to weight ratio, thermal insulation, fire resistance, and ease of construction using prefabricated units.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
The document summarizes different types of specialized concretes discussed in a civil engineering seminar. It describes translucent concrete made with optical fibers, green concrete using recycled materials, geo-polymer concrete made from industrial wastes, bacterial self-healing concrete, bendable engineered cementitious composite, pervious concrete without fine aggregates, vacuum concrete where excess water is removed, and cellular lightweight concrete made with a foam agent. Each type is defined and its composition, properties, advantages, and applications are outlined.
Lightweight concrete has a lower density than normal concrete, ranging from 300-1850 kg/m3 compared to 2200-2600 kg/m3. There are three main types: lightweight aggregate concrete uses porous aggregates; aerated concrete is produced by incorporating air bubbles; and no-fines concrete omits fine aggregates. Lightweight concrete reduces building dead load, improves workability, has better insulation and durability, and allows for use of industrial wastes. Its lower density offers applications in construction elements like pre-stressed concrete and high-rise buildings.
This document provides information about light weight concrete, including its definition, types of aggregates used, mix design, properties, advantages, applications, and conclusions. Light weight concrete is a type of concrete that uses an expanding agent to increase its volume while reducing weight compared to conventional concrete. It has benefits such as reduced dead load, faster construction, and lower transport costs. The document discusses various types of lightweight aggregates, mix design considerations, compressive strengths associated with cement contents, and applications of light weight concrete in construction.
This document discusses different types of lightweight concrete, including structural lightweight concrete, ultra-lightweight concrete, and autoclave aerated concrete. It provides details on the composition, properties, uses, and advantages of each type. Structural lightweight concrete has a density between 1450-1850 kg/m3, compared to normal concrete's 2400 kg/m3. Ultra-lightweight concrete can have a density as low as 600-1000 kg/m3 when using expanded glass or polystyrene beads. Autoclave aerated concrete is produced by introducing gas into a cement mixture, creating millions of tiny air pockets that reduce the density to 300-1000 kg/m3.
The document discusses different types of concrete and their properties. It begins by listing the advantages of concrete such as high compressive strength, durability, fire resistance, and more. It then describes different types of concrete classified based on binding material (cement, lime) and design (plain, reinforced, prestressed). Key types discussed include normal strength concrete, reinforced concrete, precast concrete, lightweight concrete, and others. For each type, the document provides details on composition, properties, uses, and characteristics. It also covers mix design and factors that affect mix proportions such as required strength, workability, durability, aggregate size and quality control.
This document discusses cellular lightweight concrete (CLC), including its production process and properties. CLC is produced by mixing cement, fly ash, water and a stable foam to create lightweight, insulating concrete blocks. The production process involves preparing molds, mixing foam, charging the mixer with cement/fly ash and foam, pouring the mixture into molds, curing, and assembling blocks. Test results show that after 21 days, CLC blocks made with a protein-based foam had a compressive strength 8.96 N/mm2, higher than conventional clay bricks. CLC blocks use waste fly ash, are lighter than clay bricks, and can replace them in construction as a more sustainable building material. Rat-trap bonding is
Experimental study on strength properties of concrete using brick aggregates ...EditorIJAERD
This document presents the results of an experimental study on the strength properties of concrete using brick aggregates. Brick aggregates from over-burnt and normal burnt bricks were used to partially or fully replace conventional coarse aggregates in M20 grade concrete mixes. Cubes and cylinders were cast using different proportions of cement, fine aggregate, and brick aggregates. Compressive strength and split tensile tests were performed on the specimens at 7 and 28 days. The test results showed that concrete made with brick aggregates can achieve comparable strength to conventional concrete. Using brick aggregates can provide an economical and sustainable alternative to natural coarse aggregates for concrete production.
The document discusses different types of lightweight and heavyweight concrete. It defines lightweight concrete as having a density less than 1850 kg/m3 and a compressive strength over 17 MPa. Lightweight concrete uses porous lightweight aggregates like expanded shale, clay or slate to reduce weight. Heavyweight concrete uses dense aggregates like barites or magnetite to increase density for radiation shielding. The document provides details on the composition, properties and uses of different types of lightweight and heavyweight concrete.
Effect of Admixture on Properties of ConcreteIRJET Journal
This document discusses the effect of admixtures on the properties of concrete. It begins by defining concrete and its main components of cement, water, aggregates, and sometimes admixtures. It then discusses different types of admixtures including their physical and chemical functions. The document also examines how admixtures can be used to increase properties like strength and decrease weaknesses in concrete like brittleness. Finally, it analyzes how admixtures like silica fume can improve properties of lightweight concrete by increasing its strength.
Experimental Studies on Cellular Light Weight Concrete Based On Foam, Fly Ash...IRJET Journal
- The document discusses experimental studies on cellular lightweight concrete (CLWC) made using foam, fly ash, and silica fume. CLWC is a cementitious material that is lighter in weight than conventional concrete, weighing 400-1950 kg/m3.
- Due to its lower strength compared to conventional concrete, CLWC is suitable for non-load bearing applications like walls. Additions like fly ash and silica fume are used to improve the properties of CLWC.
- The document provides details on the production of CLWC including the typical constituents of cement, aggregates, admixtures, and the role of fly ash. Compressive strength, water absorption and density are some key properties examined.
This document provides an overview of concrete, including its composition, properties, types, and testing. It discusses the ingredients of concrete including cement, sand, gravel, and water. It describes types of concrete such as plain cement concrete, reinforced cement concrete, and pre-stressed concrete. It also summarizes different types of cement and tests used to evaluate concrete, including slump and compaction factor tests.
IRJET- Utilization of Various Industrial Waste Materials as Filler in Aerated...IRJET Journal
This document reviews the utilization of various industrial waste materials as fillers in aerated concrete. Aerated concrete, or foam concrete, is a lightweight concrete made by mixing cement, sand, and an aerating agent that creates air pockets. Using industrial wastes as partial replacements for fine aggregates can further reduce the density of aerated concrete while providing strength benefits and reducing non-recyclable waste. The document discusses the production of aerated concrete and examines literature on using waste materials like quarry dust, rubber crumbs, and plastic granules in aerated concrete mixes. Strength testing shows these materials can improve compressive strength when used as partial substitutes for fine aggregates.
Concrete is a composite material made of cement, aggregate (rock, sand or gravel), and water. It is widely used in construction due to its durability and ability to be cast into any shape. Concrete derives its strength through a process called hydration where the cement and water bind the aggregates. There are various grades of concrete suitable for different purposes based on their proportions and aggregate sizes. Proper mixing, placing, compacting and curing of concrete are required to produce high quality concrete with the desired properties and strengths.
This document discusses special concretes and defects in concrete. It describes 8 types of special concrete - lightweight, high strength, fiber reinforced, ferrocement, shotcrete, polymer, high performance, and geopolymer concrete. Lightweight concrete has a density of 300-1850kg/m3 and is used to reduce weight while maintaining load capacity. Special concreting techniques for underwater, cold weather, and hot weather conditions are also outlined. Common concrete defects include permeability, freezing/thawing, sulfate attack, carbonation, creep/shrinkage, leaching, and corrosion of reinforcement.
Segregation in Concrete
The main explanation of this report of Segregation in concrete in terms of
concrete and self-compacting. The aim was to find an analytical relation to
estimating the risk of sedimentation, using the characteristics of the particles
and those of the mortars. The prediction of surface effect segregation (i.e.
transportation of different particle size fractions during heap formation) has
been the subject of a significant level of study.
Explanation of the type of segregation in term size, dry, wet, and water separate
and effect segregation in concrete in term strength and cracks, and
Prevention of Segregation in Concrete.
I brought up an example that supports segregation in concrete which is used
in Kurdistan Region, and explaining the example in term caused segregation
the effect in concrete.
This document summarizes a study on the workability and strength characteristics of fly ash concrete. Fly ash is a byproduct of coal combustion that is commonly used as a supplementary cementitious material (SCM) in concrete. The study investigated different dosages of fly ash from 0-30% replacement of cement, along with dosages of 0-1% of a superplasticizer. Tests were conducted on fresh and hardened concrete to evaluate the effects on workability, compressive strength, and the SCM properties of fly ash. The results were analyzed to better understand how fly ash influences the properties of concrete.
This document summarizes a study on the workability and strength characteristics of fly ash concrete. Fly ash is a byproduct of coal combustion that is commonly used as a supplementary cementitious material (SCM) in concrete. The study investigated different dosages of fly ash from 0-30% replacement of cement, along with dosages of 0-1% of a superplasticizer. Tests were conducted on fresh and hardened concrete to evaluate the effects on workability, compressive strength, and the SCM properties of fly ash. The results were analyzed to better understand how fly ash influences the properties of concrete.
Lightweight Concrete by using Thermocol and Fly AshIRJET Journal
1. The study investigated using thermocol and fly ash as aggregates in concrete to produce a lighter, more economical, and environmentally friendly alternative to normal concrete.
2. Tests found that replacing cement with 30-40% fly ash and adding 0.25-0.3% thermocol produced lightweight concrete with slightly improved compressive strength compared to normal concrete.
3. Using industrial waste fly ash and thermocol helped address issues of natural resource depletion and fly ash disposal, while achieving the goal of lightweight concrete suitable for uses like partition walls.
This document discusses different types of light weight concrete, including light weight aggregate concrete, aerated concrete, and no-fines concrete. Light weight concrete has lower density than normal concrete, ranging from 300-1850 kg/m3 compared to 2200-2600 kg/m3. It has advantages like reduced dead load, improved workability, and applications in pre-stressed concrete and high-rise buildings. The main methods to produce light weight concrete are using porous aggregates, incorporating air bubbles, or omitting fine aggregates. Properties depend on the type and density, with compressive strengths ranging from 0.3-40 MPa.
IRJET- Experimental Study of Compressive Strength on Foam Concrete with Q...IRJET Journal
This document presents an experimental study on the compressive strength of foam concrete with quarry dust and fly ash. Foam concrete is a type of lightweight concrete with lower density and strength compared to conventional concrete. It is created by uniformly distributing air bubbles throughout the concrete mass. The study investigates the influence of varying foam concrete densities (800-1800 kg/m3) on compressive strength. Quarry dust is used as a partial replacement for sand. Sodium lauryl sulphate foam is used to vary the concrete density. Three mix designs are used with different cementitious material contents and replacements of sand with quarry dust. The results are discussed to determine the optimum foam content for decreased density and compressive strength
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Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
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Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
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The aquaponic system of planting is a method that does not require soil usage. It is a method that only needs water, fish, lava rocks (a substitute for soil), and plants. Aquaponic systems are sustainable and environmentally friendly. Its use not only helps to plant in small spaces but also helps reduce artificial chemical use and minimizes excess water use, as aquaponics consumes 90% less water than soil-based gardening. The study applied a descriptive and experimental design to assess and compare conventional and reconstructed aquaponic methods for reproducing tomatoes. The researchers created an observation checklist to determine the significant factors of the study. The study aims to determine the significant difference between traditional aquaponics and reconstructed aquaponics systems propagating tomatoes in terms of height, weight, girth, and number of fruits. The reconstructed aquaponics system’s higher growth yield results in a much more nourished crop than the traditional aquaponics system. It is superior in its number of fruits, height, weight, and girth measurement. Moreover, the reconstructed aquaponics system is proven to eliminate all the hindrances present in the traditional aquaponics system, which are overcrowding of fish, algae growth, pest problems, contaminated water, and dead fish.
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2. 2
Table of Contents
List of tables…………………………………………………………………………………………………………………….3
List of figures …………………………………………….…………............................................................4
1.Introduc on........................................................................................................................... 5
2.TYPES OF LIGHTWEIGHT CONCRETE ..........................................................................................6
. 2.1. NO-FINES CONCRETE .......................................................................................................6
2.2. LIGHTWEIGHT AGGREGATE CONCRETE……………………………….…………………………………………….….6
2.3. AERATED CONCRETE …………………….………………………………………………………………………………….….7
3.ADVANTAGES AND DISADVANTAGES OF LIGHTWEIGHT CONCRETE …………………………………….……….8
4.Mechanical Properties of Structural Lightweight Concrete ……………………………….…………………………..9
4.1. Compressive strength (unheated specimens) ……………………………………………………………..9
4.2. Compressive strengths (heated specimens) ……………………………………………………………………..10
5.Effect of reinforcement on behavior of lightweight concrete ………………………………………………………13
5.1.Compressive Strength…………………………………………………………………………………………………...…. 13
5.2.Flexural Strength…………………………………………………………………………………………………………………14
5.3. Splitting Tensile Strength………………………………………………………………………………………….………..16
6.Effect of mineral admixture on properties of lightweight concrete ………………………………………..……17
References…………………………………………………………………………………………………………………….……18
3. 3
List of Tables:
Table 3.1: Advantages and Disadvantages of Lightweight Concrete ……………………………….8
Table 4.1 Average Compressive Strength of Unheated Test Specimens ……………………..…...9
Table 5.1. Compressive Strength at 7 and 28 days ………………………………………………………..……13
Table 5.2. Flexural Strength at 28 days ………………………………………………………………………..……...15
Table 5.3. Spli ng tensile at 28 days………………………………………………………………………………………………16
4. 4
List of Figures:
Figure 2.1 No-fines concrete……………………………………………….……………….………….…….6
Figure 2.2 Lightweight Aggregate Concrete………………………………………………….………..7
Figure 2.3. Aerated Concrete………………………………………………………………………………...8
Figure 4.1. Varia on of Strength with Age at Ambient Temperature……………………………....10
Fig. 4.2.Varia on of Strength with Temperature for Different Mix Ra os. …………..11 ,12
Figure 5.1 Compressive Strength at 7 and 28 days………………………………………………….13
Figure 5.1.2 Show the shape of concrete crush with Fibers and without Fibers……..13
Figure 5.2.1 Flexural Strength at 28 days……………………………………………………………………………14
Figure 5.2.2 Show the shape of concrete failure with Fibers and without Fibers…...14
Figure 5.3.1 Spli ng tensile strength at 28 days………………………………………………………………….16
Figure 5.3.2 Rela onship between the steel fibers content and increasing in tensile splitting
strength………………………………………………………………………………………………………………………………..16
5. 5
1.Introduction
In concrete construction, the concrete represents a very large proportion of the total
load on the structure, and there are clearly considerable advantages in reducing its density.
One of the ways to reduce the weight of a structure is the use of lightweight aggregate
concrete (LWAC)(Mouli and Khelafi, 2008)
Lightweight concrete (LWC) has been used for more than 2,000 years (ACI 213R) (American
Concrete Ins tute [ACI], 2003). Early notable LWC structures include the Port of Cosa, the Pantheon
Dome, and the Coliseum.
Lightweight concrete can be defined as a type of concrete which includes an expanding agent in
that it increases the volume of the mixture while giving additional qualities such as nailibility and
lessened the dead weight [1].
. It is lighter than the conven onal concrete with a dry density of 300kg/m3up to 1840 kg/m3; 87
to 23% lighter. It was first introduced by the Romans in the second century where ‘The Pantheon’
has been constructed using pumice ,the most common type of aggregate used in that particular year
[2]. From there on, the use of lightweight concrete has been widely spread across other countries
such as USA, United Kingdom and Sweden.
The lower density and higher insulating capacity are the most obvious characteristics of
Lightweight Aggregate Concrete (LWAC) by which it distinguishes itself from ‘ordinary’ Normal
Weight Concrete (NWC). However, these are by no means the only characteristics, which justify the
increasing attention for this (construction) material. If that were the case most of the design,
production and execution rules would apply for LWAC as for normal weight concrete, without any
amendments. Lightweight Aggregate (LWA) and Lightweight Aggregate Concrete are not new
materials.
In recent years, more attention has been paid to the development of lightweight aggregate
concrete (Lo et al.,2007). The specific gravity of concrete can be lowered either by using porous,
therefore lightweight aggregates instead of ordinary ones, or introducing air into the mortar,
or removing the fine fractions of aggregate and compacting concrete only partially. In all cases,
the main goal is to introduce voids into the aggregate and the mortar or between mortar and
aggregate. A combination of these methods can also be made in order to reduce further the
weight of concrete. The use of lightweight aggregates is by far the simplest and most commonly
used method of making a lightweight concrete (Gündüz and Ugur, 2005).
6. 6
2. TYPES OF LIGHTWEIGHT CONCRETE
Lightweight concrete can be prepared either by injecting air in its composition or it can be
achieved by omitting the finer sizes of the aggregate or even replacing them by a hollow, cellular or
porous aggregate. Particularly, lightweight concrete can be categorized into three groups:
i) No-fines concrete
ii) Lightweight aggregate concrete
iii) Aerated/Foamed concrete
2.1. NO-FINES CONCRETE
No-fines concrete can be defined as a lightweight concrete composed of cement and fine
aggregate. Uniformly distributed voids are formed throughout its mass. The main characteristics of
this type of lightweight concrete is it maintains its large voids and not forming laitance layers or
cement film when placed on the wall. Figure 2.1 shows one example of No-fines concrete.
Figure 2.1 No-fines concrete
No-fines concrete usually used for both load bearing and non-load bearing for external walls
and partitions. The strength of no-fines concrete increases as the cement content is increased.
However, it is sensitive to the water composition. Insufficient water can cause lack of cohesion
between the particles and therefore, subsequent loss in strength of the concrete. Likewise too much
water can cause cement film to run off the aggregate to form laitance layers, leaving the bulk of the
concrete deficient in cement and thus weakens the strength.
2.2. LIGHTWEIGHT AGGREGATE CONCRETE
Porous lightweight aggregate of low specific gravity is used in this lightweight concrete instead
of ordinary concrete. The lightweight aggregate can be natural aggregate such as pumice, scoria and
all of those of volcanic origin and the artificial aggregate such as expanded blast-furnace slag,
7. 7
vermiculite and clinker aggregate. The main characteristic of this lightweight aggregate is its high
porosity which results in a low specific gravity [4].
The lightweight aggregate concrete can be divided into two types according to its application.
One is partially compacted lightweight aggregate concrete and the other is the structural lightweight
aggregate concrete. The partially compacted lightweight aggregate concrete is mainly used for two
purposes that is for precast concrete blocks or panels and cast in-situ roofs and walls. The main
requirement for this type of concrete is that it should have adequate strength and a low density to
obtain the best thermal insulation and a low drying shrinkage to avoid cracking [2].
Structurally lightweight aggregate concrete is fully compacted similar to that of the normal
reinforced concrete of dense aggregate. It can be used with steel reinforcement as to have a good
bond between the steel and the concrete. The concrete should provide adequate protection against
the corrosion of the steel. The shape and the texture of the aggregate particles and the coarse
nature of the fine aggregate tend to produce harsh concrete mixes. Only the denser varieties of
lightweight aggregate are suitable for use in structural concrete [2].
. Figure 2.2 shows the feature of lightweight aggregate concrete.
Figure 2.2 Lightweight Aggregate Concrete.
2.3. AERATED CONCRETE
Aerated concrete does not contain coarse aggregate, and can be regarded as an aerated
mortar. Typically, aerated concrete is made by introducing air or other gas into a cement slurry and
fine sand. IN commercial practice, the sand is replaced by pulverized fuel ash or other siliceous
material, and lime maybe used instead of cement [2].
8. 8
There are two methods to prepare the aerated concrete. The first method is to inject the gas
into the mixing during its plastic condition by means of a chemical reaction.
The second method, air is introduced either by mixing-in stable foam or by whipping-in air, using an
air-entraining agent. The first method is usually used in precast concrete factories where the precast
units are subsequently autoclaved in order to produce concrete with a reasonable high strength and
low drying shrinkage. The second method is mainly used for in-situ concrete, suitable for insulation
roof screeds or pipe lagging. Figure 2.3 shows the aerated concrete.
Figure 2.3. Aerated Concrete
3. ADVANTAGES AND DISADVANTAGES OF LIGHTWEIGHT CONCRETE
Table 2 shows the advantages and disadvantages of using lightweight concrete as structure [2].
Table 3.1: Advantages and Disadvantages of Lightweight Concrete
Advantages Disadvantages
i) rapid and relatively simple construction.
ii) Economical in terms of transportation as well
as reduction in manpower.
iii) Significant reduction of overall weight results
in saving structural frames, footing or piles.
iv) Most of lightweight concrete have better
nailing and sawing properties than heavier and
stronger conventional concrete.
i) Very sensitive with water content in the
mixtures.
ii) Difficult to place and finish because of the
porosity and angularity of the aggregate. In some
mixes the cement mortar may separate the
aggregate and float towards the surface.
iii) Mixing time is longer than
conventional concrete to assure
proper mixing.
9. 9
The use of lightweight aggregate in concrete has many advantages. These include:
(a) Reduction of dead load that may result in reduced footings sizes and lighter and smaller
upper structure. This may result in reduction in cement quantity and possible reduction in
reinforcement.
(b) Lighter and smaller pre-cast elements needing smaller and less expensive handling and
transporting equipment.
(c) Reductions in the sizes of columns and slab and beam dimensions that result in larger space
availability.
(d) High thermal insulation.
(e) Enhanced fire resistance (Kayali, 2007; ACI 213,2003).
4. Mechanical Properties of Structural Lightweight Concrete
4.1. Compressive strength (unheated specimens)
Table 4.1 shows summary of average compressive strength of unheated test specimens. It is
observed that at 7-day curing age, the compressive strength values of the unheated concrete
specimens with 1:2:2 mix and w/c ra os of 0.6 and 0.8 were 2.85 and 2.60
N/mm2
respectively. At 21-day curing age, average compressive strength of specimens with w/c
ra o of 0.6 and 0.8 were 4.46 and 3.65 N/mm2
respec vely. At 90-day curing age, concrete with
1:2:2 mix and water/cement ra o of 0.6 showed an average compressive strength value of 4.69
N/mm2
while for 1:2:2 mix and at 0.8 water/cement ra o, the average strength was 4.56 N/mm2
.
( 3)
Table 4.1 Average Compressive Strength of Unheated Test Specimens ( N/mm2
)
Curing Age (days)
w/c Ratio Mix Ra o 1:2:2 Mix Ra o 1:2.5:2
0.6
0.8
7
2.85
2.6
21
4.46
3.95
90
4.69
4.56
7
5.34
4.88
21
6.00
5.62
90
7.34
6.52
Compressive Strength
(N/mm2
)
In all test cases, the average compressive strengths of test specimens with w/c of 0.6 were
higher than the corresponding values for test specimens with 0.8 w/c ra o. The decrease in
strength of test specimens with w/c = 0.8 rela ve to test specimens prepared with w/c = 0.6
could be attributed to presence of excess moisture for hydration process in the specimens
prepared with 0.8 w/c ra o. ( 3)
The results of strength variation with curing age for different mixes at 21o
C laboratory
temperature (unheated specimens) are presented in Fig. 4.1. The figure indicates that the test
10. 10
specimens for 1:2 ½:2 mix at w/c ra o of 0.6 have the highest compressive strength values. At
7-day curing age, the average values for compressive strength are 5.34N/mm2
and 4.88 N/mm2for
0.6 and 0.8 w/c ra os respec vely. This indicates a 9.20% more than the strength of the specimens
with 0.8 w/c ra o. At 90 day curing age, the strength values are7.34 N/mm2
and 6.52 N/mm2 at w/c
ra o of 0.6 and 0.8. This indicates a difference of 12.42% in strength values an indica on that the
smaller the w/c ratio value, the higher the strength of the mixes provided the mix were prepared
under the same condition. ( 3)
Also, for test specimens prepared from 1:2:2 mix with w/c ra o of 0.6, the average
compressive strength at 7-day curing age was 2.85 N/mm2
as against 2.60 N/mm2
for specimens with
0.8 w/c ra o. This indicates a reduc on of 8.77% of compressive strength of test specimens with 0.6
w/c ratio. This trend of decrease in strength values for mix with 0.6 w/c ratio when compared with
the mix with 0.8 w/c ratio was also observed at 21- and 90-day curing ages. ( 3)
Figure 4.1. Varia on of Strength with Age at Ambient Temperature.
4.2. Compressive strengths (heated specimens)
Figures 4.2 present results of compressive strengths with increase in temperature. It is
observed that the compressive strengths of test specimens reduced with increase in temperature. At
7-day curing age, the 1:2½:2 mix test specimens cast with 0.6 w/c ra o have average compressive
strength of 5.34 N/mm2
at ambient (21o
C) temperature while at 800o
C temperature, the average
compressive strength of test specimens reduced to 3.67N/mm2
at the same age. This shows 31.27%
reduc on in strength. An average of 3.48% reduc on in compressive strength with every 50o
C
increase in temperature was recorded. At 21-day curing age, between 21o
C and 800o
C temperature
range, the compressive strength values are 5.90 N/mm2
and 4.21 N/mm2
respectively. This gives a
11. 11
reduction in strength values of 28.64%. An average of 3.18% reduc on in compressive strength with
every 50o
C increase in temperature was recorded. ( 3)
At 90-day curing age a reduc on in strength value of 35.10% corresponding to an average loss in
strength of 3.9% for every 50o
C increase in temperature was observed. The investigation further
showed that at 8000
C/hour, in most specimens the periwinkle shells disintegrated considerably and
had all broken into pieces.
The rate of loss of strength by the test specimens was higher at the early stages of drying as the
periwinkle shells tend to experience change in their structure due to temperature increase. This
perceived structural change as a result of heat effect is responsible for rapid loss of compressive
strength of the test specimens. As the temperature increased, the effect reached its peak, hence,
the rate of influence on the compressive strength reduced.
This trend in loss of compressive strength by test specimens with increase in temperature
is also observed for all other mixes as indicated in Figs. 4.2.(ii), (iii) and (iv).In all cases, as the
temperature increases, there is a gradual loss in strength of the specimens. At the temperature of
800o
C/hr, heated specimens lost between 26% and 40% of initial strength values before the heating
process commenced. ( 3)
Also, the rate of loss in strength evaluated by the slope of Figs. 4.2(i), (ii), (iii) and (iv) curves tends
to be higher in 1:2.5:2 mixes when compared to 1:2:2 mixes, irrespec ve of the water/cement
ratio and the curing age. The compressive strengths of the test specimens were reasonably
maintained up to 300o
C, there after as temperature increases there is a severe and
progressive decrease in strength. This is attributed to the formation of cracks in the specimens,
coupled with poor bonding of the concrete matrix. The loss in strength is considerably lower before
a ainment of 400o
C temperature level, but at 600o
C most of the periwinkle shells (aggregate) in the
test specimens were fractured. This accounts for higher strength loss at higher temperatures.( 3)
12. 12
Fig. 4.2.Variation of Strength with Temperature for Different Mix Ratios.
(i) 1:2.5:2 mix with w/c ra o = 0.6, (ii) 1:2:2 mix with w/c= 0.6,
Fig.4.2. Variation of Strength with Temperature for Different Mix Ratios.
(iii) 1:2.5:2 mix with w/c ra o = 0.8, (iv) 1:2:2 mix with w/c= 0.8.
13. 13
5. Effect of reinforcement on behavior of lightweight concrete :
5.1. Compressive Strength
Values of compressive strength for all mixes are shown in Table (5.1) and Figure (5.1) at 7 and
28 days, results demonstrated that in general, all concrete specimens exhibited an increase in
compressive strength with increase the percent of steel fibers. The percent of increasing in
compressive strength at 7 days about (27.18%, 43%, 30.32%, and 17.48%) for (1%, 0.75%,
0.5%, and 0.25%) steel fibers respec vely. While in 28 days, adding (1%, 0.75%, 0.5%, and
0.25%) steel fibers lead to increasing in compressive strength by about (30.33%, 51.73%, 33.79%,
and 21.26%) respec vely. It can be seen that the increase in compressive strength of light weight
steel fiber concrete at 28 days was greater than their corresponding compressive strength at 7 days.
Such increase in compressive strength was attributed to the intensive product of hydration process
around the steel fibers and in voids of concrete [5].
From Figure (5.1) it may also be concluded that the addi on of steel fibers up to 0.75% of
concrete volume improved the compressive strength of light weight concrete due to the better
mechanical bond strength between the fibers and the cement matrix which delays micro-
cracks formation [6].
However, Adding more steel fibers up to 1% of concrete volume reduces the increasing in
the compressive strength as compared with 0.75% but it remain higher than the reference mix
and this is attributed to the voids introduction in the mix due to excessive fiber content that may
lead to reduction in bonding and disintegration[7].
Table 5.1. Compressive Strength at 7 and 28 days
Mix Compressive strength
MPa-7 days
%Increase in compressive
Strength -7 days
Compressive strength
MPa-28 days
%Increase in compressive
Strength -28 days
A-0.00%S.F 22.66
28.82
32.41
29.53
26.32
……….
27.18
43.00
30.32
17.48
29.77
38.8
45.17
39.83
36.1
………..
30.33
51.73
33.79
21.26
B-1.00%S.F
C-0.75%S.F
D-0.50%S.F
E-0.25%S.F
14. 14
Figure 5.1 Compressive Strength at 7 and 28 days.
Figure 5.1.2 Show the shape of concrete crush with Fibers and without Fibers
5.2. Flexural Strength
The test results of the flexural strength are reported in Table (5.2) and Figure (5.2.1). The
results indicated that in general, all types of concrete specimens exhibited continued increase
in flexural strength with increasing in steel fibers. The increase in flexural strength for light
weight concrete with steel fiber rela ve to reference concrete mix were 20.91%, 29.25%, 41.67%
and 54.24% for light weight concrete with 0.25%, 0.5%, 0.75% and 1% steel fiber by volume of
concrete respectively. This behavior is mainly attributed to the role of steel fiber in releasing
fracture energy around crack tips which is required to extent crack growing by transferring stress
from one side to another side. Also this behavior is due to the increase in crack resistance of
the composite and the ability of fibers to resist forces after the concrete matrix has cracked [5].
15. 15
Table 5.2. Flexural Strength at 28 days
Mix Flexural strength
MPa-28 days
%Increase in flexural
Strength
A-0.00%S.F
B-1.00%S.F
C-0.75%S.F
D-0.50%S.F
E-0.25%S.F
6.60
10.18
9.35
8.53
7.98
……….
54.24
42.67
29.24
20.91
Figure 5.2.1 Flexural Strength at 28 days.
Figure 5.2.2 Show the shape of concrete failure with Fibers and without Fibers.
16. 16
5.3. Splitting Tensile Strength
The results of splitting tensile strength for the lightweight concrete mixes are shown in Table
(5.3) and plotted in Figure (5.3.1). It can be concluded that the inclusion of steel fibers in concrete
mix cause a considerable increase in splitting tensile strength relative to reference mix (without
fibers). Splitting tensile strength increases as the fiber volume fraction increases. However, The
increasing in splitting tensile strength of light weight steel fiber concrete (LWSFC) relative to
reference concrete at 28 days were 62.62%, 33.76% , 17.27% and 5.93% for LWSFC with 1%,
0.75%, 0.5% and 0.25% steel fiber by volume of concrete respec vely, Figure (5.3.2). This increasing
may be due to the excellent mechanical anchorage of steel fibers at their surface which leads to
high bond strength between the fibers and the matrix.[5]
Table 5.3. Splitting tensile at 28 days
Figure 5.3.2 Rela onship between the steel
Figure 5.3.1 Spli ng tensile strength at 28 days Fibers content and increasing in splitting
. tensile strength.
17. 17
6. Effect of mineral admixture on properties of lightweight concrete:
The use of mineral admixtures in concrete such as fly ash, silica fume, natural pozzolan,
metakaolin and calcined clay has become widespread due to their pozzolanic reaction and
environmental friendliness (Erdogan,1997; Mehta, 1986; Neville, 2003).These pozzolanic
admixtures are used for reducing the cement content in mortar and concrete production (Gleize
and Cyr, 2007;Sabir et al., 2001). Also, the use of pozzolanic materials such as silica fume and fly
ash are necessary for producing high performance concrete. These materials, when used as mineral
admixtures in high performance concrete, can improve both the strength and durability properties
of the concrete (Poon et al., 2006; Parande et al., 2008).
18. 18
References
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[3] . Balogun, L.A. (1986). Effect of temperature on the residual compressive strength of laterized
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[4] . Liew Chung Meng, Introduction to Lightweight Concrete.www.maxpages.com.
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Proper es of high Performance Concrete” 2005 Al-Rafidain Engineering Vol.13 No.4.
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