This document provides information on the key ingredients and composition of concrete. It discusses the main components of concrete including cement, aggregates, water, and admixtures. It describes the function of each component and how they contribute to the properties of hardened concrete. It also summarizes the manufacturing process of cement and discusses Bogue's compounds which form due to chemical reactions during cement production.
Aggregates make up 70-80% of concrete by volume and can be classified by source, size, shape, and other properties. Their properties affect the workability, strength, and economics of concrete. Igneous, sedimentary, and metamorphic rocks are common sources. Aggregate size, shape, texture, strength, and durability all impact the performance of concrete. Tests are used to evaluate aggregate crushing strength, impact resistance, and abrasion characteristics important for different concreting applications. Proper aggregate selection and testing are essential for producing high quality concrete.
Mineral admixtures are added to concrete to make it more economical and durable. Common mineral admixtures include pozzolanas such as fly ash, ground granulated blast furnace slag, silica fume, and metakaoline. These admixtures improve concrete properties such as workability, permeability, chemical resistance, and strength through pozzolanic reactions. Fly ash is the most widely used pozzolanic material worldwide due to its ability to reduce the environmental pollution caused by coal combustion in thermal power plants. Ground granulated blast furnace slag reduces heat generation during curing and improves permeability and chemical resistance of hardened concrete. Metakaoline and silica fume are highly reactive pozzolanas
This document discusses water and admixtures used in concrete. It describes how the quality of water can impact concrete strength, durability and corrosion. It outlines acceptable limits for impurities in water and discusses the effects of seawater. It also categorizes and explains the purpose and effects of different types of admixtures (A-F) including water reducers, retarders, accelerators and superplasticizers. Specialty admixtures like air-entraining and waterproofing are also briefly covered.
Admixtures are materials added to concrete mixes to modify properties. There are two main types - chemical and mineral. Chemical admixtures include plasticizers, superplasticizers, retarders, accelerators, and air-entraining agents. Mineral admixtures include fly ash, slag, and silica fume. Admixtures are used to increase workability, strength, and durability while decreasing water demand and permeability. Common admixtures like plasticizers and superplasticizers work by dispersing cement particles and lubricating the mix to increase flowability.
This document summarizes the classification and properties of aggregates used in construction. It defines aggregates as inert materials mixed with cement or lime for mortar or concrete. Aggregates are classified as fine or coarse based on particle size. Common fine aggregates include sand from various sources, while coarse aggregates include crushed stone and gravel. Key properties discussed include size, shape, composition and performance in tests such as crushing value, impact value and abrasion value. Sieve analysis is also described to determine particle size distribution. An ideal aggregate is characterized as hard, strong, dense and free of impurities to provide durable concrete.
Concrete Construction: Batching of mixes; casting process, compaction and curing;
requirement of mix design and casting of test cubes – removing cubes from moulds and
curing for strength tests; bar-bending equipments and preparation of reinforcement for
R C C works
Special concrete is used when special properties are more important than normal concrete properties. It is produced using chemical and mineral admixtures added to conventional concrete mixes. There are several types of special concrete including lightweight concrete, high strength concrete, fibre reinforced concrete, ferrocement, ready mix concrete, and others. Each type has specific properties and uses in construction where standard concrete is not suitable.
This document provides information on the key ingredients and composition of concrete. It discusses the main components of concrete including cement, aggregates, water, and admixtures. It describes the function of each component and how they contribute to the properties of hardened concrete. It also summarizes the manufacturing process of cement and discusses Bogue's compounds which form due to chemical reactions during cement production.
Aggregates make up 70-80% of concrete by volume and can be classified by source, size, shape, and other properties. Their properties affect the workability, strength, and economics of concrete. Igneous, sedimentary, and metamorphic rocks are common sources. Aggregate size, shape, texture, strength, and durability all impact the performance of concrete. Tests are used to evaluate aggregate crushing strength, impact resistance, and abrasion characteristics important for different concreting applications. Proper aggregate selection and testing are essential for producing high quality concrete.
Mineral admixtures are added to concrete to make it more economical and durable. Common mineral admixtures include pozzolanas such as fly ash, ground granulated blast furnace slag, silica fume, and metakaoline. These admixtures improve concrete properties such as workability, permeability, chemical resistance, and strength through pozzolanic reactions. Fly ash is the most widely used pozzolanic material worldwide due to its ability to reduce the environmental pollution caused by coal combustion in thermal power plants. Ground granulated blast furnace slag reduces heat generation during curing and improves permeability and chemical resistance of hardened concrete. Metakaoline and silica fume are highly reactive pozzolanas
This document discusses water and admixtures used in concrete. It describes how the quality of water can impact concrete strength, durability and corrosion. It outlines acceptable limits for impurities in water and discusses the effects of seawater. It also categorizes and explains the purpose and effects of different types of admixtures (A-F) including water reducers, retarders, accelerators and superplasticizers. Specialty admixtures like air-entraining and waterproofing are also briefly covered.
Admixtures are materials added to concrete mixes to modify properties. There are two main types - chemical and mineral. Chemical admixtures include plasticizers, superplasticizers, retarders, accelerators, and air-entraining agents. Mineral admixtures include fly ash, slag, and silica fume. Admixtures are used to increase workability, strength, and durability while decreasing water demand and permeability. Common admixtures like plasticizers and superplasticizers work by dispersing cement particles and lubricating the mix to increase flowability.
This document summarizes the classification and properties of aggregates used in construction. It defines aggregates as inert materials mixed with cement or lime for mortar or concrete. Aggregates are classified as fine or coarse based on particle size. Common fine aggregates include sand from various sources, while coarse aggregates include crushed stone and gravel. Key properties discussed include size, shape, composition and performance in tests such as crushing value, impact value and abrasion value. Sieve analysis is also described to determine particle size distribution. An ideal aggregate is characterized as hard, strong, dense and free of impurities to provide durable concrete.
Concrete Construction: Batching of mixes; casting process, compaction and curing;
requirement of mix design and casting of test cubes – removing cubes from moulds and
curing for strength tests; bar-bending equipments and preparation of reinforcement for
R C C works
Special concrete is used when special properties are more important than normal concrete properties. It is produced using chemical and mineral admixtures added to conventional concrete mixes. There are several types of special concrete including lightweight concrete, high strength concrete, fibre reinforced concrete, ferrocement, ready mix concrete, and others. Each type has specific properties and uses in construction where standard concrete is not suitable.
Cement is tested through laboratory and field tests to evaluate its properties and suitability. Key laboratory tests described in the document include:
- Fineness tests which measure particle size and surface area to determine reactivity.
- Setting time tests which ensure cement sets within specified time limits.
- Compressive strength tests where cement mortar cubes are crushed to determine strength over time.
- Soundness and loss of ignition tests which evaluate volume stability and carbon/moisture content.
Results of laboratory tests help ensure cement meets standards before use in construction projects.
This document discusses fresh concrete and factors that affect its workability. It describes workability as the ease with which concrete can be mixed, placed, and compacted. Key factors that influence workability include water content, aggregate size and shape, admixtures, aggregate surface texture, and aggregate grading. Common tests to measure workability are the slump test, compacting factor test, and VeeBee consistometer test. The document also covers segregation and bleeding of concrete, their causes, and methods to prevent them.
Cement is a binding material made of calcareous, siliceous, and argillaceous substances. There are various types of cement used for different purposes, including ordinary Portland cement, rapid hardening cement, extra rapid hardening cement, sulphate resisting cement, quick setting cement, low heat cement, Portland pozzolana cement, Portland slag cement, high alumina cement, air entraining cement, supersulphated cement, masonry cement, expansive cement, colored cement, and white cement. The document discusses the chemical composition and functions of cement constituents and manufacturing processes.
This document provides information on bitumen, which is used as a binding material in pavements. It discusses the types of bitumen including paving grade, modified, cutback and emulsion. Cutback bitumen has solvents added to increase fluidity while bitumen emulsion uses water. Modified bitumen has additives added to improve properties. The document also describes various tests conducted on bitumen like penetration, ductility, softening point and viscosity to determine hardness and grading. Bitumen requirements include adequate viscosity and adhesion properties. The grading of bitumen depends on the results of penetration tests.
Water plays a key role in cement concrete as it acts as a reactant in the chemical process of hydration that provides concrete its strength over time. The water-cement ratio is an important factor, with lower ratios producing higher strength concrete. Water used for mixing must meet requirements for quality and impurities. Admixtures can be used to improve workability or reduce the water content. Proper curing is also important for achieving design strength and durability of the concrete. Sprayed concrete has advantages over poured concrete such as lower permeability and faster strength gain.
Cracks in concrete and its remedial measures kamariya keyur
Cracks in concrete can be caused by various factors like plastic shrinkage, drying shrinkage, thermal variations, chemical reactions, errors in design and construction practices, structural overloads, foundation movement, and vegetation. The document classifies cracks as structural or non-structural and describes different types of cracks that can occur before or after concrete hardening. It provides details on the causes and prevention measures for different types of cracks like plastic shrinkage, drying shrinkage, crazing, thermal cracks, cracks due to chemical reactions, and those arising from poor construction practices. The summary focuses on the key information around classification, types, causes and remedies of cracks in concrete structures.
Properties of fresh and Hardened ConcreteVijay RAWAT
The document discusses various properties of fresh and hardened concrete. It describes workability, consistency, segregation, bleeding, mixing, placing, consolidating, and curing of fresh concrete. It also discusses compressive strength, tensile strength, modulus of elasticity, permeability, and durability of hardened concrete. The key properties of fresh concrete include workability, consistency, segregation, bleeding, setting time, and uniformity. Compressive strength is identified as the most important property of hardened concrete.
This document discusses Ordinary Portland Cement and Rapid Hardening Cement. It defines cement and describes its main types. Ordinary Portland Cement (OPC) is the most widely used type and comprises calcium, silica, alumina, and iron. The production process involves crushing raw materials, mixing them, heating the mixture in a kiln to form clinker, grinding the clinker, and adding gypsum. OPC is used in construction where special properties are not required. Rapid Hardening Cement gains strength more quickly than OPC and is used when early strength or cold weather work is needed.
This document discusses ground granulated blast furnace slag (GGBFS), a byproduct of steel production that can be used in concrete production. It has several benefits over traditional Portland cement concrete including greater strength, durability, and sustainability. GGBFS concrete exhibits improved sulfate and chloride resistance, reduces temperatures in large pours, and results in a lighter colored, smoother finish. It also enhances workability and pumpability while requiring less water. Overall, incorporating GGBFS in concrete delivers higher performance while reducing costs and environmental impact.
Marsh cone test is reliable and simple method to study the rheological properties of cements and mortars.
Flow time of cement/mortar through marsh cone is indicator of viscosity, which depends upon cement super plasticizer compatibility.
High volume fly ash concrete is a concrete where a replacement of about 35% or more of cement is made with the usage of fly ash.
Fly ash concrete is an eco-friendly construction material in which fly ash replaces a part of Portland cement.
MEANING OF MIX DESIGN
GRADE OF CONCRETE.
FACTORS INFLUCING THE CHOICE OF MIX DESIGN.
MATHODS OF CONCRETE MIX DESIGN
MIX DESIGN BY INDIAN STANDARD METHOD.
Concrete permeability is a key factor in its durability. Permeability is affected by water-cement ratio, with lower ratios producing less permeable concrete. Curing also impacts permeability. Proper curing, including moist curing, produces less permeable concrete. Permeability testing involves measuring water flow through a sample over time under pressure. Sulfate attack can occur when sulfates penetrate permeable concrete and form expansive compounds that crack the material. Resistance to sulfates is improved with lower permeability concrete.
The document provides information on aggregates used in concrete, including their definition, classification, properties, grading, and tests. It defines aggregates as materials such as sand and gravel used to make concrete and mortar. Aggregates are classified by their geological origin, size, and shape. Their properties including strength, absorption, and density are described. The importance of proper grading of aggregates for density and strength of concrete is discussed. Common tests on aggregates like crushing value, impact value, and abrasion value are outlined.
The document discusses the benefits of meditation for reducing stress and anxiety. Regular meditation practice can help calm the mind and body by lowering heart rate and blood pressure. Making meditation a part of a daily routine, even if just 10-15 minutes per day, can have mental and physical health benefits over time by reducing stress levels and promoting relaxation.
Self-compacting concrete was developed in Japan in the 1980s to solve problems with inadequate compaction of traditional concrete. It uses a high paste content and superplasticizers to create a concrete that can flow and consolidate under its own weight without vibration. Tests were developed to evaluate properties like filling ability, passing ability, and segregation resistance. Self-compacting concrete provides benefits like easier placement, faster construction, better surface finish, and improved durability. However, it also has higher costs associated with materials and mix design development.
This document discusses the principles and classification of triangulation, which is a surveying method used to determine distances based on geometry. It describes three orders or classifications of triangulation: primary, secondary, and tertiary. Primary triangulation establishes the most precise control points over large areas. Secondary triangulation uses smaller triangles within the primary framework, while tertiary triangulation establishes intermediate control for detailed surveys using even smaller triangles. Specifications for each order are provided, such as average triangle size, expected errors, and instrumentation precision.
The document discusses various tests used to evaluate the properties of fresh and hardened concrete, including slump tests, compaction factor tests, Vee-Bee consistometer tests, flow tests, and Kelly ball tests for fresh concrete workability. Hardened concrete is evaluated using rebound hammer tests to estimate compressive strength and ultrasonic pulse velocity tests to assess quality. A case study describes a reinforced concrete structure collapse due to design flaws in accounting for beam-column joint forces, inadequate reinforcement detailing, and omitted column links.
Cement is tested through laboratory and field tests to evaluate its properties and suitability. Key laboratory tests described in the document include:
- Fineness tests which measure particle size and surface area to determine reactivity.
- Setting time tests which ensure cement sets within specified time limits.
- Compressive strength tests where cement mortar cubes are crushed to determine strength over time.
- Soundness and loss of ignition tests which evaluate volume stability and carbon/moisture content.
Results of laboratory tests help ensure cement meets standards before use in construction projects.
This document discusses fresh concrete and factors that affect its workability. It describes workability as the ease with which concrete can be mixed, placed, and compacted. Key factors that influence workability include water content, aggregate size and shape, admixtures, aggregate surface texture, and aggregate grading. Common tests to measure workability are the slump test, compacting factor test, and VeeBee consistometer test. The document also covers segregation and bleeding of concrete, their causes, and methods to prevent them.
Cement is a binding material made of calcareous, siliceous, and argillaceous substances. There are various types of cement used for different purposes, including ordinary Portland cement, rapid hardening cement, extra rapid hardening cement, sulphate resisting cement, quick setting cement, low heat cement, Portland pozzolana cement, Portland slag cement, high alumina cement, air entraining cement, supersulphated cement, masonry cement, expansive cement, colored cement, and white cement. The document discusses the chemical composition and functions of cement constituents and manufacturing processes.
This document provides information on bitumen, which is used as a binding material in pavements. It discusses the types of bitumen including paving grade, modified, cutback and emulsion. Cutback bitumen has solvents added to increase fluidity while bitumen emulsion uses water. Modified bitumen has additives added to improve properties. The document also describes various tests conducted on bitumen like penetration, ductility, softening point and viscosity to determine hardness and grading. Bitumen requirements include adequate viscosity and adhesion properties. The grading of bitumen depends on the results of penetration tests.
Water plays a key role in cement concrete as it acts as a reactant in the chemical process of hydration that provides concrete its strength over time. The water-cement ratio is an important factor, with lower ratios producing higher strength concrete. Water used for mixing must meet requirements for quality and impurities. Admixtures can be used to improve workability or reduce the water content. Proper curing is also important for achieving design strength and durability of the concrete. Sprayed concrete has advantages over poured concrete such as lower permeability and faster strength gain.
Cracks in concrete and its remedial measures kamariya keyur
Cracks in concrete can be caused by various factors like plastic shrinkage, drying shrinkage, thermal variations, chemical reactions, errors in design and construction practices, structural overloads, foundation movement, and vegetation. The document classifies cracks as structural or non-structural and describes different types of cracks that can occur before or after concrete hardening. It provides details on the causes and prevention measures for different types of cracks like plastic shrinkage, drying shrinkage, crazing, thermal cracks, cracks due to chemical reactions, and those arising from poor construction practices. The summary focuses on the key information around classification, types, causes and remedies of cracks in concrete structures.
Properties of fresh and Hardened ConcreteVijay RAWAT
The document discusses various properties of fresh and hardened concrete. It describes workability, consistency, segregation, bleeding, mixing, placing, consolidating, and curing of fresh concrete. It also discusses compressive strength, tensile strength, modulus of elasticity, permeability, and durability of hardened concrete. The key properties of fresh concrete include workability, consistency, segregation, bleeding, setting time, and uniformity. Compressive strength is identified as the most important property of hardened concrete.
This document discusses Ordinary Portland Cement and Rapid Hardening Cement. It defines cement and describes its main types. Ordinary Portland Cement (OPC) is the most widely used type and comprises calcium, silica, alumina, and iron. The production process involves crushing raw materials, mixing them, heating the mixture in a kiln to form clinker, grinding the clinker, and adding gypsum. OPC is used in construction where special properties are not required. Rapid Hardening Cement gains strength more quickly than OPC and is used when early strength or cold weather work is needed.
This document discusses ground granulated blast furnace slag (GGBFS), a byproduct of steel production that can be used in concrete production. It has several benefits over traditional Portland cement concrete including greater strength, durability, and sustainability. GGBFS concrete exhibits improved sulfate and chloride resistance, reduces temperatures in large pours, and results in a lighter colored, smoother finish. It also enhances workability and pumpability while requiring less water. Overall, incorporating GGBFS in concrete delivers higher performance while reducing costs and environmental impact.
Marsh cone test is reliable and simple method to study the rheological properties of cements and mortars.
Flow time of cement/mortar through marsh cone is indicator of viscosity, which depends upon cement super plasticizer compatibility.
High volume fly ash concrete is a concrete where a replacement of about 35% or more of cement is made with the usage of fly ash.
Fly ash concrete is an eco-friendly construction material in which fly ash replaces a part of Portland cement.
MEANING OF MIX DESIGN
GRADE OF CONCRETE.
FACTORS INFLUCING THE CHOICE OF MIX DESIGN.
MATHODS OF CONCRETE MIX DESIGN
MIX DESIGN BY INDIAN STANDARD METHOD.
Concrete permeability is a key factor in its durability. Permeability is affected by water-cement ratio, with lower ratios producing less permeable concrete. Curing also impacts permeability. Proper curing, including moist curing, produces less permeable concrete. Permeability testing involves measuring water flow through a sample over time under pressure. Sulfate attack can occur when sulfates penetrate permeable concrete and form expansive compounds that crack the material. Resistance to sulfates is improved with lower permeability concrete.
The document provides information on aggregates used in concrete, including their definition, classification, properties, grading, and tests. It defines aggregates as materials such as sand and gravel used to make concrete and mortar. Aggregates are classified by their geological origin, size, and shape. Their properties including strength, absorption, and density are described. The importance of proper grading of aggregates for density and strength of concrete is discussed. Common tests on aggregates like crushing value, impact value, and abrasion value are outlined.
The document discusses the benefits of meditation for reducing stress and anxiety. Regular meditation practice can help calm the mind and body by lowering heart rate and blood pressure. Making meditation a part of a daily routine, even if just 10-15 minutes per day, can have mental and physical health benefits over time by reducing stress levels and promoting relaxation.
Self-compacting concrete was developed in Japan in the 1980s to solve problems with inadequate compaction of traditional concrete. It uses a high paste content and superplasticizers to create a concrete that can flow and consolidate under its own weight without vibration. Tests were developed to evaluate properties like filling ability, passing ability, and segregation resistance. Self-compacting concrete provides benefits like easier placement, faster construction, better surface finish, and improved durability. However, it also has higher costs associated with materials and mix design development.
This document discusses the principles and classification of triangulation, which is a surveying method used to determine distances based on geometry. It describes three orders or classifications of triangulation: primary, secondary, and tertiary. Primary triangulation establishes the most precise control points over large areas. Secondary triangulation uses smaller triangles within the primary framework, while tertiary triangulation establishes intermediate control for detailed surveys using even smaller triangles. Specifications for each order are provided, such as average triangle size, expected errors, and instrumentation precision.
The document discusses various tests used to evaluate the properties of fresh and hardened concrete, including slump tests, compaction factor tests, Vee-Bee consistometer tests, flow tests, and Kelly ball tests for fresh concrete workability. Hardened concrete is evaluated using rebound hammer tests to estimate compressive strength and ultrasonic pulse velocity tests to assess quality. A case study describes a reinforced concrete structure collapse due to design flaws in accounting for beam-column joint forces, inadequate reinforcement detailing, and omitted column links.
This document summarizes three common concrete tests: compression, split tension, and flexure strength. The compression test uses cylindrical specimens to determine the compressive strength of concrete, which typically ranges from 21 to 34 MPa. The split tension test measures tensile strength by applying a compressive load along the cylinder's diameter until failure, and the flexure strength test uses a three-point loading apparatus on beam specimens to calculate the modulus of rupture. Both the split tension and flexure strength tests help evaluate properties important for concrete pavements and structures.
Field tests are carried out on cement at construction sites to assess quality. Some key field tests include checking for lumps, color, texture when rubbed between fingers, and reaction when mixed with water. Additional tests involve making a cement paste block, curing it for 24 hours underwater and checking for cracks, as well as casting a cement block, curing it for 7 days underwater, and loading it to check for failure. While field tests are lower cost and more convenient than laboratory tests, they only provide a rough assessment of quality and cannot measure all engineering properties.
The document discusses two tests used to measure the workability of concrete: the slump test and VEBE test. The slump test measures how much a sample of freshly mixed concrete sags or "slumps" due to gravity. The VEBE test also measures workability but uses vibration and timing to determine how long it takes for the sample to be remolded by the vibration. Both tests are affected by the amount of water in the concrete mix, with too much or too little water impacting the workability. The slump test is commonly used in the field while the VEBE test is better for dry mixes but less practical for field use.
Tests on fresh concrete SLUMP TEST VEE BEE TEST COMPACTION FACTOR TESTNisarg Mistry
THIS PDF IS ABOUT TESTS ON FRESH CONCRETE USED ON FIELD AND IN LABS.
IT INCLUDES TEST METHODOLOGY
TEST DATA INTERPRETATION AND PICTURES OF APPRATUS USED
The document describes 7 different tests conducted on cement:
1. Field testing examines the cement's appearance, texture, and behavior when mixed with water.
2. The standard consistency test determines the percentage of water needed to achieve a standardized consistency for cement paste.
3. The fineness test evaluates the particle size distribution of cement, with finer particles offering a greater surface area for hydration.
4. The soundness test ensures cement does not expand after setting, which could indicate excess lime causing unsoundness.
5. The strength test measures the compressive strength of cement mortar mixtures at various ages (3, 7, 28 days).
6. The heat of hydration test examines the heat released
The document discusses the properties of aggregates used in road construction. It describes the types of aggregates derived from igneous, sedimentary and metamorphic rocks. Several tests are used to evaluate aggregates including crushing value, impact value, Los Angeles abrasion and shape tests. The results of these tests are used to determine whether aggregates meet requirements for sub-base, base or surfacing layers. Requirements include maximum values for impact value, flakiness index and water absorption.
Lesson: Concrete Technology - Building Materials
The quality of aggregate affect the durability and strength of concrete. Since about 3/4 of the volume of concrete is occupied by aggregate.
The document summarizes various tests conducted on cement, including:
1. Field testing to check for lumps, color, texture and consistency.
2. Standard consistency tests to determine the percentage of water required for a cement paste.
3. Fineness tests using sieving or air permeability methods to check particle size.
4. Soundness tests using a Le Chatelier apparatus to ensure cement does not expand after setting.
5. Strength tests involving casting cement-sand mortar cubes and breaking them to measure compressive strength after curing.
This document discusses various types of admixtures used in concrete construction. It describes plasticizers as materials that reduce the water content needed for a given workability or provide higher workability at the same water content. Superplasticizers are an improved version that can reduce water content by 30% without reducing workability. Retarders slow the hydration process to allow for longer workability. Accelerators increase early strength. Air-entraining admixtures incorporate tiny air bubbles that improve freeze-thaw resistance and workability. Waterproofing admixtures fill pores or make concrete water-repellent. Pozzolans like fly ash react with calcium hydroxide to improve properties such as strength and permeability.
Civil engineering student Muhammad Awais submitted a report on concrete admixtures. The report defines admixtures as materials other than cement, water and aggregates that are added to concrete to give it special properties. It explains that admixtures are used to improve workability, strength, durability and other qualities of concrete. The main types of admixtures discussed are plasticizers, superplasticizers, accelerators, retarders and air-entraining agents. Mineral admixtures like fly ash and ground granulated blast furnace slag are also outlined. The report provides details on the purpose, composition and effects of various admixtures.
Chemical admixtures are ingredients added to concrete to modify its properties. Common admixtures include plasticizers, superplasticizers, retarders, accelerators, air-entraining agents, and damp-proofing/waterproofing agents. Plasticizers and superplasticizers reduce the water content needed for a given workability or increase workability at the same water content. Retarders slow hydration to increase workability time while accelerators increase early strength. Air-entraining agents create tiny air bubbles that increase frost and wear resistance. Damp-proofing agents fill pores or make concrete water-repellent. Factors like dosage, cement properties, temperature, and mixing methods affect admixture performance.
Module on admixture , polymer and exposy resinsErankajKumar
The document discusses admixtures, polymers, and epoxy resins used in construction materials. It begins by defining admixtures as chemical compounds added to concrete mixes to modify properties such as workability, hydration rate, and strength. Common admixtures include accelerators, retarders, air-entrainers, and water reducers. The document then classifies and describes various admixture types and discusses their functions, advantages, and disadvantages. It provides details on specific admixture materials and how they affect concrete properties. The overall purpose is to educate civil engineering students on admixture fundamentals and applications in construction technology and management.
1. The document discusses various chemical and mineral admixtures that are used to modify the properties of concrete, making it more suitable for different applications.
2. Chemical admixtures include accelerators, retarders, plasticizers, and superplasticizers which can increase workability, strength, and durability.
3. Mineral admixtures discussed are fly ash, silica fume, ground granulated blast furnace slag, and metakaolin which provide economic and performance benefits such as reduced permeability and increased strength.
This document discusses various types of admixtures that are added to concrete to modify its properties. It describes 15 types of admixtures classified according to their function, including plasticizers, superplasticizers, retarders, accelerators, air-entraining agents, and pozzolanic materials. Common chemical admixtures are discussed in more detail, along with their effects on properties of fresh and hardened concrete. Mineral admixtures like fly ash, blast furnace slag, rice husk ash, and silica fume are also summarized in terms of their composition and impact on improving concrete quality and durability.
Admixtures are added to concrete mixes to improve performance properties. Common types include plasticizers, superplasticizers, retarders, accelerators, and air-entraining admixtures. They allow reductions in water content or increases in workability. Trial mixes should be done to determine appropriate dosage for a given mix, as effect depends on cement and aggregates used. Admixtures improve qualities like strength, permeability, bleeding resistance, and durability in freezing environments.
Admixture of concrete power point presentationARUNKUMARC39
Chemical admixtures and mineral additives are used in concrete construction to improve properties and performance. Common admixtures include plasticizers, superplasticizers, retarders, accelerators, and air-entraining agents. Mineral additives like fly ash, silica fume, and blast furnace slag are pozzolanic and can enhance strength and durability while also reducing costs. These admixtures and additives allow concrete to be placed more easily, provide targeted properties, and improve quality under difficult conditions.
Chemical admixtures are added to concrete mixes to modify properties like workability, setting time, strength, and durability. There are five main types of admixtures: retarders which slow setting; accelerators which speed setting; superplasticizers which increase workability; water reducers which decrease water needs; and air-entrainers which introduce tiny air bubbles that improve freeze-thaw resistance. Producers use admixtures to reduce costs, modify hardened concrete properties, and ensure quality during mixing and placement.
Design a suitable splice and bolted connection for extending a column of rolled steel cross section ISHB200@40 kg/m. The column is to support service axial compressive load, bending moment and shear force of 1000 KN, 50 KN and 90 KN respectively. The column ends are smooth finished. Ordinary bolts of M20 grade 4.6 are available for splicing.
hello everybody,
My name is Ashish Kumar pursuing the diploma in civil engineering(2016-19) from GLA UNIVERSITY, MATHURA
This is a powerpoint presentation on Concrete Admixtures(Department of Civil Engineering)
share and like this ppt if you learn something new from this.
Thank You.
Admixtures are ingredients added to concrete other than cement, water and aggregates to achieve desired properties. Common admixtures include air-entraining, plasticizers, retarding, accelerating, corrosion inhibiting, waterproofing and grouting admixtures. Air-entraining admixtures introduce tiny air bubbles that allow space for ice expansion and prevent cracking. Plasticizers improve workability while using less water. Retarders slow hydration for placing large pours over time. Accelerators speed strength gain. Corrosion inhibitors protect reinforcement. Waterproofers make concrete less permeable. Mineral admixtures like fly ash and slag improve properties and provide environmental benefits.
admixture
TYPES OF ADMIXTURE
CHEMICAL ADMIXTURE
AIR ENTERINERS
WATER REDUCERS
SET RETARDERS
SET ACCELERATORS
SUPERPLASTICIZER
MINERAL ADMIXTURE
FLY ASH
SILICA FLUMES
SLAG
FUNCTION OF ADMIXTURE
ADVANTAGES OF ADMIXTURE
vedio link
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This power point presentation gives you information about the various chemicals, admixtures used to repair members and improve the properties of concrete. it gives you information about the various types of concrete. it gives you information about the various methods of repair.
This presentation has been prepared by civil engineering students of Tolani Foundation Gandhidham Polytechnic:
DHAWANI LAVISH
GAYAKWAD TEJAS
GORASIYA MAYUR
HIRANI YATIN
KATARMAL DARSHAN
LALWANI PIYUSH
MALI VISHNU
PATEL PARTH
PRAJAPATI JAYESH
PRAJAPATI KALPESH
Thank You!!
This document discusses different types of concrete admixtures, including their functions and benefits. It describes 11 categories of admixtures: 1) air-entraining, 2) water-reducing, 3) plasticizers, 4) accelerating, 5) retarding, 6) hydration-control, 7) corrosion inhibitors, 8) shrinkage reducers, 9) alkali-silica reactivity inhibitors, 10) coloring, and 11) miscellaneous. For each category, it provides a brief explanation of what the admixture does and why it is used to improve properties of concrete. The document emphasizes that admixtures are added to reduce costs, achieve specific properties, and maintain quality during mixing, transport,
Admixtures are ingredients added to concrete to modify its properties. They are classified as chemical or mineral admixtures. Common chemical admixtures include accelerators, retarders, air-entraining, water-reducing, and superplasticizing admixtures. Mineral admixtures include fly ash, silica fume, ground granulated blast furnace slag, and rice husk ash which have pozzolanic properties. Admixtures are used to improve workability, strength, and durability among other properties of fresh and hardened concrete.
This document discusses different types of admixtures that are added to concrete mixtures to improve their properties. It describes 10 main categories of admixtures including air-entraining, water-reducing, accelerating, retarding, and mineral admixtures. It provides details on the mechanisms and effects of various admixtures such as air-entrainers, superplasticizers, fly ash, and silica fume. The document focuses in particular on how these admixtures improve the workability, strength, and durability of hardened concrete.
This document discusses different types of admixtures for concrete and mortar. It defines admixtures and provides general information on their uses and benefits. It then classifies admixtures according to the Colombian standard NTC 1299 into Type A (water reducers), Type B (retarders), Type C (accelerators), and others. Each type is described in terms of its chemical composition, dosage, and effects on concrete properties. A brief history of admixture development is also provided.
This document provides information on concrete admixtures. It discusses the history of admixture use dating back to ancient Rome, China, Mesoamerica and Peru. Common types of chemical admixtures are then outlined, including air-entraining, water-reducing, retarding, accelerating, super plasticizers, and corrosion-inhibiting admixtures. Specific admixture products are also highlighted and their benefits described. The document concludes with definitions and purposes of chemical admixtures like super plasticizers and retarding admixtures.
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CE 6002 CONCRETE TECHNOLOGY UNIT II
1. DEPARTMENT OF CIVIL ENGINEERING
CE 6002 – CONCRETE TECHNOLOGY
G.GUNA S.R.V.E.C 1
2. Admixtures are the material, other than
Cement
Water
Aggregates
fiber reinforcement
Which are used as an ingredient of concrete and is added to
batch immediately before or during mixing.
G.GUNA S.R.V.E.C 2
3. Admixtures have long been recognized as important
components of concrete used to improve its performance.
The original use of admixtures in cementitious mixtures is not well documented.
G.GUNA S.R.V.E.C 3
4. G.GUNA S.R.V.E.C 4
The major reasons for using admixtures are:
To reduce the cost of concrete construction.
To achieve certain properties in concrete more effectively than by other means.
To maintain the quality of concrete during the stages of mixing, transporting,
placing, and curing in ad-verse weather conditions.
To overcome certain emergencies during concreting operations.
6. G.GUNA S.R.V.E.C
6
Each class of admixture is defined by its primary
function. It may have one or more secondary
functions, however, and its use may affect,
positively or negatively, concrete properties other
than those desired
9. 1. Plasticizers
2. Super plasticizers
3. Retarders and Retarding Plasticizers
4. Accelerators and Accelerating Plasticizers
5. Damp-proofing and Waterproofing Admixtures
G.GUNA S.R.V.E.C 9
10. In general, these chemicals act as dispersants for portland cement particles. By
separating and spreading out the cement particles, internal friction is reduced,
and slump and workability of the concrete is increased
Lowering w/cm is a key method for improving durability
G.GUNA S.R.V.E.C
10
11. The organic substances or combinations of organic and inorganic
substances, which allow a reduction in water content for the given
workability, or give a higher workability at the same water content, are
termed as plasticizing admixtures.
The basic products constituting plasticizers are as follows:
Anionic surfactants such as lignosulphonates and their modifications and
derivatives, salts of sulphonates hydrocarbons.
Non ionic surfactants, such as polyglycol esters, acid of hydroxylated
carboxylic acids and their modifications and derivatives.
Other products, such as carbohydrates etc.
G.GUNA S.R.V.E.C 11
12. 12G.GUNA S.R.V.E.C
Amount used
• A good plasticizer is one which does not
cause air-entrainment in concrete more
than 1 or 2%.
• At constant workability –
The reduction in mixing water is expected to be
of the order of 5% to 15%.
Naturally increases the strength.
• At constant w/c ratio –
Increased workability.
Slump of 30mm to 150 mm.
Results - effects
Limitations
• Plasticizers are used in the amount of
0.1% to 0.4% by weight of cement.
13. 13G.GUNA S.R.V.E.C
Used at
1. Thin walls of water retaining structures with high
percentage of steel reinforcement
2. Deep beams, column and beam junctions
3. Tremie concreting
4. Pumping of concrete
5. Hot weather concreting
6. Concrete to be conveyed for considerable
distance and in ready mixed concrete industries.
Where high degree of workability is
required
14. Superplasticizers constitute a relatively new category and improved
version of plasticizer, the use of which was developed in Japan and Germany
during 1960 and 1970 respectively. They are chemically different from
normal plasticisers.
Classification of Superplasticizers:
Sulphonated malanie-formaldehyde condensates (SMF)
Sulphonated naphthalene-formaldehyde condensates (SNF)
Modified lignosulphonates (MLS)
Other types
G.GUNA S.R.V.E.C 14
16. 16G.GUNA S.R.V.E.C
Amount used
Permits reduction of water content about 30%
without reducing the workability
It is possible to use w/c ratio as low as 0.25 or
even lower and yet to make flowing concrete to
obtain strength of order 120 Mpa or more.
Results - benefits
• Based on various types of superplasticizers
different amount is used.
• Lignosulphonates – not more than 0.25%
• Carboxylic acids – 0.1%
• Sulphonated malanie-formaldehyde
condensates (SMF) – 0.5 to 3%
• Sulphonated naphthalene-formaldehyde
condensates (SNF) – 0.5 to 3%
17. 17G.GUNA S.R.V.E.C
Used at
Production of flowing, self levelling, self
compacting concrete
Production of high strength and high
performance concrete.
Superplasticizer is practiced for
18. A retarder is an admixture that slows down the chemical process of hydration so that
concrete remains plastic and workable for a longer time than concrete without the retarder.
1. Retarders are used to overcome the accelerating effect of high temperature on setting
properties of concrete in hot weather concreting.
2. Very useful when concrete has to be place in very difficult conditions and delay may occur
in transporting and placing.
3. .Gypsum and Calcium Sulphate are well known retarders.
4. Other examples are: starches, cellulose products, sugars, acids or salts of acids
G.GUNA S.R.V.E.C 18
19. 19G.GUNA S.R.V.E.C
Limitations
amount. Access Retarders should be
used in proper amount will cause
indefinite setting time.
At normal temperatures addition of
sugar 0.05 to 0.10 percent have little
effect on the rate of hydration, but if
the quantity is increased to 0.2
percent, hydration can be retarded to
such an extent that final set may not
take place for 72 hours or more.
Casting and consolidating large
number of pours without the
formation of cold joints.
Grouting oil wells, where
temperature is about 200 °C, at a
depth of 6000 meters.
Used at
20. Accelerating admixtures are added to concrete to increase the rate of early
strength development
Why accelerators?
1. Permit earlier removal of formwork
2. Reduce the required period of curing
3. Advance the time that a structure can be placed in service
4. Partially compensate for the retarding effect of low temperature during cold weather
concreting
5. In the emergency repair work.
G.GUNA S.R.V.E.C 20
21. Commonly used materials as an accelerator:
Calcium chloride (Not used now)
Some of the soluble carbonates
Silicates fluosilicates (Expensive)
Some of the organic compounds such as triethenolamine (Expensive)
G.GUNA S.R.V.E.C 21
22. Accelerators are so powerful that it is possible to make the cement set
into stone hard in a matter of five minutes are less.
With the availability of such powerful accelerator, the under water
concreting has become easy.
Similarly, the repair work that would be carried out to the waterfront
structures in the region of tidal variations has become easy.
The use of such powerful accelerators have facilitated, the basement
waterproofing operations.
G.GUNA S.R.V.E.C 22
Benefits of Accelerators
23. In practice one of the most important requirements of concrete
is that it must be impervious to water under two conditions;
Firstly, when subjected to pressure of water on one side.
permeability-reducing admixture for hydrostatic conditions (PRAH)
Secondly, to the absorption of surface water by capillary action.
Permeabilityreducing admixture for non-hydrostatic conditions (PRAN).
G.GUNA S.R.V.E.C 23
24. Waterproofing admixtures are available in powder, paste or liquid
form and may consist of pore filling or water repellent materials.
Chemically active pore filling materials: silicate of soda, aluminium/zinc
sulphates and aluminium/calcium chloride.
Chemically inactive filling material: chalk, fullers earth and talc.
G.GUNA S.R.V.E.C 24
25. 25G.GUNA S.R.V.E.C
Amount used
Use of admixture should in no case be considered
as a substitute for bad materials, bad design or
workmanship.
In no case can an admixture be expected to
compensate for cracks or large voids in concrete
causing permeability.
Chemically active pore fillers accelerates the
setting of concrete and thus render the concrete
more impervious at early age.
Chemically inactive pore fillers improve the
workability and to facilitate the reduction of
water for given workability and to make dense
concrete which is basically impervious.
Water repelling materials like soda, potash soaps,
calcium soaps, waxes, fats, vegetable oils repel
water and make the concrete impervious
Results - effects
Limitations
Depends upon various damp-proofing and
water proofing admixtures.
26. Pozzolanic materials are:
Siliceous or siliceous-aluminous materials,
Little or no cementitious value,
In finely divided form and in the presence of moisture,
Chemically react with calcium hydroxide liberated on hydration, at
ordinary temperature, to form compounds, possessing cementitious properties.
They are also known as POZZOLANIC materials.
G.GUNA S.R.V.E.C 26
27. Improves many qualities of concrete, such as:
Lower the heat of hydration and thermal shrinkage;
Increase the water tightness;
Reduce the alkali-aggregate reaction;
Improve resistance to attack by sulphate soils and sea water;
Improve extensibility;
Lower susceptibility to dissolution and leaching;
Improve workability;
Lower costs.
G.GUNA S.R.V.E.C 27
29. G.GUNA S.R.V.E.C 29
Fly ash is finely divided residue resulting from the
combustion of powdered coal and transported by the flue
gases and collected by;
Electrostatic
Precipitator
Fly ash is the most widely used
pozzolanic material all over the world.
30. 30G.GUNA S.R.V.E.C
Class F
Fly ash normally produced by
burning anthracite or bituminous
coal, usually has less than 5% CaO.
Class F fly ash has pozzolanic
properties only.
Fly ash normally produced by
burning lignite or sub-bituminous
coal. Some class C fly ash may
have CaO content in excess of 10%.
In addition to pozzolanic
properties, class C fly ash also
possesses cementitious properties.
Class C
31. 31G.GUNA S.R.V.E.C
Amount used
Reduction of water demand for
desired slump. With the reduction of
unit water content, bleeding and
drying shrinkage will also be reduced.
fly ash is not highly reactive, the heat
of hydration can be reduced through
replacement of part of the cement
with fly ash.
Results - effects
• Up to 35% by mass of cement (According to
IS: 456 – 2000) & minimum shall not be less
than 15%.
32. .
• Use of fly ash is because of many factors such as:
a) Abundance of fly ash
b) Fly ashes from major TPP(Trans-Pacific Partnership) are of very high quality i.e. quality of fly
ash.
c) Economic factor i.e. Cost of fly ash with in 200 km from a TPP is as low as 10% to 20% of the
cost of cement.
d) Environmental factors i.e. reduction in CO2 emission.
HVFAC is a concrete where excess of 35%of fly-ash is
used as replacement
G.GUNA S.R.V.E.C 32
33. 33G.GUNA S.R.V.E.C
Effects of Fly Ash on Hardened
Concrete
contributes to the strength of
concrete due to its pozzolanic
reactivity.
continued pozzolanic reactivity
concrete develops greater strength
at later age not at initial stage.
contributes to making the texture
of concrete dense, resulting in
decrease of water permeability
and gas permeability.
34. 34G.GUNA S.R.V.E.C
Used at
Many high-rise buildings
Industrial structures
Water front structures
Concrete roads
Roller compacted concrete dams.
35. G.GUNA S.R.V.E.C 35
The transition zone is a thin layer between the
bulk hydrated cement paste and the aggregate
particles in concrete. This zone is the weakest
component in concrete, and it is also the most
permeable area. Silica fume plays a significant
role in the transition zone through both its
physical and chemical effects.
1. fine micro-crystalline
silica produced in electric
arc furnaces as a by
product.
2. Very fine non-crystalline
silica produced in electric
arc furnaces as a by
product.
36. It is a product resulting from reduction
of high purity quartz with coal in an electric
arc furnace in the manufacture of silicon or
ferrosilicon alloy.
1. Micro silica is initially produced as an ultrafine
undensified powder
2. At least 85% SiO2 content
3. Mean particle size between 0.1 and 0.2 micron
4. Minimum specific surface area is 15,000 m2/kg
5. Spherical particle shape
G.GUNA S.R.V.E.C 36
37. Micro silica is available in the following forms:
1. Undensified forms with bulk density of 200–300 kg/m3
2. Densified forms with bulk density of 500–600 kg/m3
3. Micro-pelletised forms with bulk density of 600–800 kg/m3
4. Slurry forms with density 1400 kg/m3
5. Admixtures and Construction Chemicals.
6. Slurry is produced by mixing undensified micro silica powder and water in equal
proportions by weight. Slurry is the easiest and most practical way to introduce
micro silica into the concrete mix.
7. Surface area 15–20 m2/g.
8. Standard grade slurry pH value 4.7, specific gravity 1.3 to 1.4, dry content of micro
silica 48 to 52%.
G.GUNA S.R.V.E.C 37
38. 38G.GUNA S.R.V.E.C
Effect on fresh concrete
The increase in water demand of concrete containing microsilica will be about
1% for every 1% of cement substituted.
lead to lower slump but more cohesive mix.
make the fresh concrete sticky in nature and hard to handle.
large reduction in bleeding and concrete with microsilica could be handled and
transported without segregation.
to plastic shrinkage cracking and, therefore, sheet or mat curing should be
considered.
produces more heat of hydration at the initial stage of hydration.
the total generation of heat will be less than that of reference concrete.
39. 39G.GUNA S.R.V.E.C
nano silica
The 2% nano silica is the optimum content
that exhibited highest compressive strength
at 7 and 28 days among all nano silica
contents
The rate of strength development indicates
that the mortars containing nano silica,
being more reactive and contributes more to
the compressive strength at 7 days than 28
days.
The addition of 2% NS increased the early
age compressive strength (i.e. 3 days) of
HVFA concrete containing 60% fly ash by
about 95%. However, no such improvement
is noticed at other ages.
The use mechanical dry mixing of nano
silica with cement, fly ash and sand
performed better than ultrasonic mixing of
NS with water and superplasticizer
BSE image analysis shows that the addition
of 2% nano silica significantly improves the
microstructure of the matrix of high volume
fly ash mortars. The XRD results also
confirm this result where the addition of 2%
nano silica reduces the calcium hydroxide by
about 58% and 50% in high volume fly ash
mortars containing 40% and 60% fly ash,
respectively
40. 40G.GUNA S.R.V.E.C
Backscattered electron (BSE) images of polished
surface of paste samples after 28 days of curing:
(a) cement paste, (b) paste containing 40% fly
ash, (c) paste containing
60% fly ash, (d) paste containing 2% NS, (e) paste
containing 38% fly ash and 2% NS and (f) paste
containing 58% fly ash and 2% NS.
41. 41G.GUNA S.R.V.E.C
Effect on hardened concrete
1. Modulus of elasticity of
microsilica concrete is less.
2. Improvement in durability of
concrete.
3. Resistance against frost damage.
4. Addition of silica fume in small
quantities actually increases the
expansion.
5. Conserve cement
6. Produce ultra high strength
concrete of the order of 70 to 120
Mpa.
7. Increase early strength of fly
concrete.
8. Control alkali-aggregate reaction.
9. Reduce sulfate attack & chloride
associated corrosion.
42. 42G.GUNA S.R.V.E.C
Rice husk ash is obtained by
Burning rice husk in a controlled manner
without causing environmental
pollution.
Material of future as mineral additives.
43. 43G.GUNA S.R.V.E.C
Amount used
10% by weight of cement.
It greatly enhances the workability
and impermeability of concrete.
Amorphous silica (90% SiO2) in
very high proportion when burnt
in controlled manner.
5% carbon.
2% K2O.
Contains
44. 44G.GUNA S.R.V.E.C
Effects
Reduces susceptible to acid attack
and improves resistance to
chloride penetration.
Reduces large pores and porosity
resulting very low permeability.
Reduces the free lime present in
the cement paste.
Decreases the permeability of the
system.
Improves overall resistance to
CO2 attack.
Enhances resistance to corrosion
of steel in concrete.
Reducing micro cracking and
improving freeze-thaw resistance.
Improves capillary suction and
accelerated chloride diffusivity.
45. G.GUNA S.R.V.E.C 45
Blast-furnace slag is a nonmetallic product
consisting essentially of silicates and
aluminates of calcium and other bases.
The molten slag is rapidly chilled by
quenching in water to form a glassy sand
like granulated material.
The granulated material when further
ground to less than 45 micron will have
specific surface of about 400 to 600 m2/ kg
(Blaine).
46. G.GUNA S.R.V.E.C 46
Highly reactive metakaolin is made by
water processing to remove unreactive
impurities to make100% reactive
pozzolan.
Such a product, white or cream in
colour, purified, thermally activated is
called High Reactive Metakaolin
(HRM).
47. G.GUNA S.R.V.E.C 47
the synergy of cement and metakaolin tends to
reduce the pore size to about a tenth of the
diameter within the first days. This is valid to a
replacement until the 20% level and about 27%
water in which most of the Portlandite formed
will have reacted to form additional CSH* or
CSAH** phases.
Through the formation of these phases the
pores will be filled by additional binding
material. Due to the lower pores diameter the
water uptake is reduced.
The total pore volume depends on the w/b
ratio***. With very high porosity the
advantages of metakaolin replacement will
decrease.
48. 48G.GUNA S.R.V.E.C
Effects of Metakaolin
High reactive metakaolin shows high
pozzolanic reactivity and reduction
in Ca(OH)2 even as early as one day.
The cement paste undergoes distinct
densification.
Densification includes an increase
in strength and decrease in
permeability.
The high reactive metakaolin is
having the potential to compete
with silica fume.
Use of Metakaolin