The document provides guidelines on the four main types of concrete admixtures:
1) Accelerating admixtures which increase the rate of hydration and strength gain.
2) Retarding admixtures which decrease the initial reaction rate to delay setting.
3) Water-reducing admixtures which increase workability or strength at a reduced water-cement ratio.
4) Air-entraining admixtures which introduce tiny air bubbles to increase frost resistance.
For each type, the document discusses chemical composition, advantages, effects on concrete properties, and recommended dosages. The goal is to optimize concrete performance through judicious use of admixtures.
This document summarizes research on the durability of fibre reinforced concrete. It discusses how fibres can improve the properties of concrete, including increased tensile strength and resistance to cracking. It outlines the methodology of the research, which involves testing concrete reinforced with different types and amounts of fibres, including steel, glass, natural and artificial fibres. The research examines the effect of fibres on the compressive and flexural strength of concrete beams. It also evaluates the durability of fibre reinforced concrete exposed to chloride and sulfate attacks. The results indicate that natural fibre reinforced concrete has the highest tensile strength and best durability. The research concludes that fibre reinforcement improves concrete properties and durability.
1. The document discusses various types of special concretes including lightweight concrete, foam concrete, self-compacting concrete, vacuum concrete, fibre reinforced concrete, ferrocement, ready mix concrete, slurry infiltrated fibre concrete (SIFCON), and shotcrete.
2. Lightweight concrete uses lightweight aggregates like shale, clay, or slate to reduce density while maintaining strength. Foam concrete is made by injecting air or gas into the mix to create a cellular structure.
3. Self-compacting concrete can be placed without vibration due to its fluidity. Vacuum concrete has water removed using vacuum mats to increase strength.
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.
This document discusses using plastic bottle strips to stabilize soil. Unstable expansive soils like black cotton soil cause problems for foundations due to swelling, shrinkage, and unequal settlement. Soil stabilization is done to improve strength and prevent erosion. Plastic is a good stabilizer as it is flexible, water resistant, and provides thermal resistance. Tests on lateritic soil mixed with plastic strips at 0.6% found increased CBR values and reduced settlement under loading compared to unmixed soil, demonstrating plastic's effectiveness as a stabilizer. Using waste plastic bottles in this way provides an economical solution while reducing plastic waste.
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.
Aggregates make up 65-80% of concrete's volume and are inert fillers that float in the cement paste. Their characteristics impact the performance of fresh and hardened concrete. Aggregates are classified based on size, specific gravity, availability, shape, and texture. Proper aggregate grading leads to a dense, strong concrete mixture. The fineness modulus is a number that indicates an aggregate's grading, and the flakiness index measures elongated particles. Well-graded aggregates with low elongation produce high quality concrete.
The document discusses water-cement ratio and its effect on concrete strength. It provides examples of calculating water and cement amounts given a ratio. It also discusses determining the design and batched water-cement ratios for a given mix, accounting for cement, fly ash, water amounts. Calculating percent solids and voids in aggregates based on dry rodded unit weight is also covered.
This document summarizes research on geopolymer concrete as an alternative to traditional Portland cement concrete. Geopolymer concrete is made through a chemical reaction of aluminosilicate materials like fly ash with an alkaline solution, forming a three dimensional polymeric chain structure. It offers benefits over Portland cement like lower CO2 emissions in production, higher strength and durability, and the ability to utilize industrial waste materials. Some potential applications highlighted include use in coastal and cold weather construction for its chloride resistance, as well as airport runways and highways due to its heat resistance.
This document summarizes research on the durability of fibre reinforced concrete. It discusses how fibres can improve the properties of concrete, including increased tensile strength and resistance to cracking. It outlines the methodology of the research, which involves testing concrete reinforced with different types and amounts of fibres, including steel, glass, natural and artificial fibres. The research examines the effect of fibres on the compressive and flexural strength of concrete beams. It also evaluates the durability of fibre reinforced concrete exposed to chloride and sulfate attacks. The results indicate that natural fibre reinforced concrete has the highest tensile strength and best durability. The research concludes that fibre reinforcement improves concrete properties and durability.
1. The document discusses various types of special concretes including lightweight concrete, foam concrete, self-compacting concrete, vacuum concrete, fibre reinforced concrete, ferrocement, ready mix concrete, slurry infiltrated fibre concrete (SIFCON), and shotcrete.
2. Lightweight concrete uses lightweight aggregates like shale, clay, or slate to reduce density while maintaining strength. Foam concrete is made by injecting air or gas into the mix to create a cellular structure.
3. Self-compacting concrete can be placed without vibration due to its fluidity. Vacuum concrete has water removed using vacuum mats to increase strength.
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.
This document discusses using plastic bottle strips to stabilize soil. Unstable expansive soils like black cotton soil cause problems for foundations due to swelling, shrinkage, and unequal settlement. Soil stabilization is done to improve strength and prevent erosion. Plastic is a good stabilizer as it is flexible, water resistant, and provides thermal resistance. Tests on lateritic soil mixed with plastic strips at 0.6% found increased CBR values and reduced settlement under loading compared to unmixed soil, demonstrating plastic's effectiveness as a stabilizer. Using waste plastic bottles in this way provides an economical solution while reducing plastic waste.
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.
Aggregates make up 65-80% of concrete's volume and are inert fillers that float in the cement paste. Their characteristics impact the performance of fresh and hardened concrete. Aggregates are classified based on size, specific gravity, availability, shape, and texture. Proper aggregate grading leads to a dense, strong concrete mixture. The fineness modulus is a number that indicates an aggregate's grading, and the flakiness index measures elongated particles. Well-graded aggregates with low elongation produce high quality concrete.
The document discusses water-cement ratio and its effect on concrete strength. It provides examples of calculating water and cement amounts given a ratio. It also discusses determining the design and batched water-cement ratios for a given mix, accounting for cement, fly ash, water amounts. Calculating percent solids and voids in aggregates based on dry rodded unit weight is also covered.
This document summarizes research on geopolymer concrete as an alternative to traditional Portland cement concrete. Geopolymer concrete is made through a chemical reaction of aluminosilicate materials like fly ash with an alkaline solution, forming a three dimensional polymeric chain structure. It offers benefits over Portland cement like lower CO2 emissions in production, higher strength and durability, and the ability to utilize industrial waste materials. Some potential applications highlighted include use in coastal and cold weather construction for its chloride resistance, as well as airport runways and highways due to its heat resistance.
The document discusses the fresh and hardened properties of concrete. It describes workability, segregation, and bleeding as important fresh properties. Workability is affected by water content, mix proportions, aggregate size and shape. The slump cone test and compaction factor test are described for measuring workability. Hardened properties discussed include compressive strength, flexural strength, and modulus of elasticity. The compression test, flexural strength test, and stress-strain relationship determination are described for evaluating hardened properties.
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.
Soil stabilization can be done in many ways. But the stabilization using waste plastic fibers is an economic method since the stabilizer used here is waste plastic materials, which are easily available. A plastic material is any of a wide range of synthetic or semi-synthetic organic solids that are moldable.
soil stabilizers for sale
soil stabilizer products
spray on soil stabilizer
soil stabilizer equipment
liquid soil stabilizer
soil binder and stabilizer
soil stabilizer polymer
enzyme soil stabilizers
Plastic as a soil stabilizer ppt
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Durability is the ability of concrete to resist weathering actions, chemical attacks, and abrasion while maintaining its desired engineering properties. A durable concrete structure withstands deterioration over its design life through exposure to the environment. Factors that influence durability include the water-cement ratio, cement content, cover thickness, type of aggregates used, and curing of the concrete. Permeability is an important indicator of durability, with lower permeability reducing susceptibility to chemical attacks. Proper compaction and curing help reduce the permeability of concrete.
Concrete is one of the most versatile materials used in infrastructural development. It plays a critical role in in construction industry and making it sustainable is of paramount importance. How do we do it? Let us look here!!
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.
The reduced CO2 emissions of Geopolymer cements make them a good alternative to Ordinary Portland Cement.
Produces a substance that is comparable to or better than traditional cements with respect to most properties.
Geopolymer concrete has excellent properties within both acid and salt environments
Low-calcium fly ash-based geopolymer concrete has excellent compressive strength and is suitable for Structural applications.
The document discusses the durability of concrete and the factors that affect it. It defines durability as the ability of concrete to resist weathering, chemical attack, and abrasion while maintaining its desired properties. The main factors discussed are abrasion, biological factors, temperature effects, freezing and thawing, and various types of chemical attacks including carbonation, chloride attack, acid attack, and sulfate attack. Prevention and mitigation methods are provided for each factor.
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.
This document summarizes information presented at a conference on asphalt emulsion basics. It discusses how asphalt emulsions are made by combining asphalt, water, and an emulsifying agent. The agent allows the asphalt and water to mix by surrounding the asphalt particles. Various tests are described that evaluate properties of both the emulsion and residual asphalt, such as viscosity, stability, sieve testing, and distillation residue properties. Advantages of emulsions over other asphalt application methods are their lower application temperatures and reduced emissions.
The document discusses the properties of fresh concrete, including workability, consistency, and factors that affect them. It defines workability as the effort required to manipulate fresh concrete with minimum segregation. Consistency refers to a concrete's ease of flow and cohesiveness. Tests are described for measuring properties like slump, ball penetration, density, and air content. Maintaining adequate workability and consistency is important for proper transport, placement, compaction and finishing of concrete.
1. What is Mix design.
2. Understand the different types of mix.
3. Design the mix proportion as per IS Method.
4. Design the mix proportion as per ACI Method.
production tests aging of bitumen and modified Bitumen Abhijeet Bhosale
This document provides information on bitumen through a presentation by several people. It defines bitumen as a viscous liquid or solid consisting of hydrocarbons that is soluble in trichloroethylene. Bitumen is black or brown in color and has waterproofing and adhesive properties. It is produced from crude oil through fractional distillation. Different types of bituminous materials include tar, pitch and asphalt. The document also describes various tests conducted on bitumen like penetration test, ductility test, softening point test, and viscosity test. It provides recommended values for different bitumen grades based on these 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.
A presentation on High Performance Concrete - High performance concrete is a concrete mixture, which possess high durability and high strength when compared to conventional concrete.
Permeability of concrete, chemical attack, acid attack, efflorescence, Corrosion in concrete. Thermal conductivity, thermal diffusivity, specific heat. Alkali Aggregate Reaction
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.
Mechanical and chemical stabilization can modify soil properties. Mechanical stabilization involves rearranging particles and improving gradation by adding aggregates. Chemical stabilization uses cementing agents like cement, lime, and calcium chloride to bond soil particles. Portland cement increases strength and reduces shrinkage by cementing particles. Lime also increases strength over time through chemical reactions. Bitumen or asphalt stabilizes soils by binding loose particles or waterproofing. Calcium chloride increases compaction and early strength by replacing sodium ions in the soil. Proper mixing, compaction, moisture content, and curing are important for effective stabilization.
Concrete is a widely used construction material consisting of cement, water, and aggregates. The strength of concrete is specified using its 28-day cube strength in N/sq.mm. Formwork is used to mold wet concrete into desired shapes and allow it to cure. Formwork design involves choosing traditional or systematic approaches using wood or steel components like props, beams, sheathing to form columns, walls, and beams until the concrete gains sufficient strength. Proper formwork is important for quality concrete finish and structural integrity.
Concrete durability is affected by many factors including the quality of materials used, water-cement ratio, compaction, and curing. Lack of durability can result in cracking, scaling, spalling, or disintegration of concrete. Environmental factors like abrasion, biological growth, freezing and thawing, or chemical attacks from carbonation, chlorides, acids, or sulfates can also damage concrete over time if not properly addressed. Proper concrete mix design, placement, and curing can improve durability.
Chemical admixtures are added to concrete to modify properties in either the fresh or hardened state. Common admixtures include air-entraining admixtures, which introduce tiny air bubbles that improve freeze-thaw resistance; water-reducing admixtures, which lower the water content needed for a given workability; and superplasticizers, also called high-range water reducers, which make very flowable, self-consolidating concrete. Admixtures function through adsorption, de-flocculation, or chemical interaction with hydrating cement. They are used to reduce construction costs, achieve desired concrete properties, and maintain quality in adverse conditions.
International Journal of Engineering Research and DevelopmentIJERD Editor
This document presents the results of a study comparing the hardened concrete properties of mixes containing micro silica or alccofine as supplementary cementitious materials. Concrete cubes, beams, and cylinders were cast with micro silica or alccofine added to cement at increments of 0%, 3.34%, 6.68%, 10.02%, 13.36%, and 16.7%. The hardened properties tested included compressive strength, flexural strength, splitting tensile strength, and impact resistance. Test results showed that the concretes with micro silica and alccofine additions generally exhibited higher strength properties compared to the control mix without additions.
The document discusses the fresh and hardened properties of concrete. It describes workability, segregation, and bleeding as important fresh properties. Workability is affected by water content, mix proportions, aggregate size and shape. The slump cone test and compaction factor test are described for measuring workability. Hardened properties discussed include compressive strength, flexural strength, and modulus of elasticity. The compression test, flexural strength test, and stress-strain relationship determination are described for evaluating hardened properties.
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.
Soil stabilization can be done in many ways. But the stabilization using waste plastic fibers is an economic method since the stabilizer used here is waste plastic materials, which are easily available. A plastic material is any of a wide range of synthetic or semi-synthetic organic solids that are moldable.
soil stabilizers for sale
soil stabilizer products
spray on soil stabilizer
soil stabilizer equipment
liquid soil stabilizer
soil binder and stabilizer
soil stabilizer polymer
enzyme soil stabilizers
Plastic as a soil stabilizer ppt
interesting civil engineering topics
seminar topics pdf
civil engineering topics for presentation
civil seminar topics ppt
best seminar topics for civil engineering
seminar topics for mechanical engineers
civil engineering ppt
latest civil engineering seminar topics
Durability is the ability of concrete to resist weathering actions, chemical attacks, and abrasion while maintaining its desired engineering properties. A durable concrete structure withstands deterioration over its design life through exposure to the environment. Factors that influence durability include the water-cement ratio, cement content, cover thickness, type of aggregates used, and curing of the concrete. Permeability is an important indicator of durability, with lower permeability reducing susceptibility to chemical attacks. Proper compaction and curing help reduce the permeability of concrete.
Concrete is one of the most versatile materials used in infrastructural development. It plays a critical role in in construction industry and making it sustainable is of paramount importance. How do we do it? Let us look here!!
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.
The reduced CO2 emissions of Geopolymer cements make them a good alternative to Ordinary Portland Cement.
Produces a substance that is comparable to or better than traditional cements with respect to most properties.
Geopolymer concrete has excellent properties within both acid and salt environments
Low-calcium fly ash-based geopolymer concrete has excellent compressive strength and is suitable for Structural applications.
The document discusses the durability of concrete and the factors that affect it. It defines durability as the ability of concrete to resist weathering, chemical attack, and abrasion while maintaining its desired properties. The main factors discussed are abrasion, biological factors, temperature effects, freezing and thawing, and various types of chemical attacks including carbonation, chloride attack, acid attack, and sulfate attack. Prevention and mitigation methods are provided for each factor.
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.
This document summarizes information presented at a conference on asphalt emulsion basics. It discusses how asphalt emulsions are made by combining asphalt, water, and an emulsifying agent. The agent allows the asphalt and water to mix by surrounding the asphalt particles. Various tests are described that evaluate properties of both the emulsion and residual asphalt, such as viscosity, stability, sieve testing, and distillation residue properties. Advantages of emulsions over other asphalt application methods are their lower application temperatures and reduced emissions.
The document discusses the properties of fresh concrete, including workability, consistency, and factors that affect them. It defines workability as the effort required to manipulate fresh concrete with minimum segregation. Consistency refers to a concrete's ease of flow and cohesiveness. Tests are described for measuring properties like slump, ball penetration, density, and air content. Maintaining adequate workability and consistency is important for proper transport, placement, compaction and finishing of concrete.
1. What is Mix design.
2. Understand the different types of mix.
3. Design the mix proportion as per IS Method.
4. Design the mix proportion as per ACI Method.
production tests aging of bitumen and modified Bitumen Abhijeet Bhosale
This document provides information on bitumen through a presentation by several people. It defines bitumen as a viscous liquid or solid consisting of hydrocarbons that is soluble in trichloroethylene. Bitumen is black or brown in color and has waterproofing and adhesive properties. It is produced from crude oil through fractional distillation. Different types of bituminous materials include tar, pitch and asphalt. The document also describes various tests conducted on bitumen like penetration test, ductility test, softening point test, and viscosity test. It provides recommended values for different bitumen grades based on these 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.
A presentation on High Performance Concrete - High performance concrete is a concrete mixture, which possess high durability and high strength when compared to conventional concrete.
Permeability of concrete, chemical attack, acid attack, efflorescence, Corrosion in concrete. Thermal conductivity, thermal diffusivity, specific heat. Alkali Aggregate Reaction
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.
Mechanical and chemical stabilization can modify soil properties. Mechanical stabilization involves rearranging particles and improving gradation by adding aggregates. Chemical stabilization uses cementing agents like cement, lime, and calcium chloride to bond soil particles. Portland cement increases strength and reduces shrinkage by cementing particles. Lime also increases strength over time through chemical reactions. Bitumen or asphalt stabilizes soils by binding loose particles or waterproofing. Calcium chloride increases compaction and early strength by replacing sodium ions in the soil. Proper mixing, compaction, moisture content, and curing are important for effective stabilization.
Concrete is a widely used construction material consisting of cement, water, and aggregates. The strength of concrete is specified using its 28-day cube strength in N/sq.mm. Formwork is used to mold wet concrete into desired shapes and allow it to cure. Formwork design involves choosing traditional or systematic approaches using wood or steel components like props, beams, sheathing to form columns, walls, and beams until the concrete gains sufficient strength. Proper formwork is important for quality concrete finish and structural integrity.
Concrete durability is affected by many factors including the quality of materials used, water-cement ratio, compaction, and curing. Lack of durability can result in cracking, scaling, spalling, or disintegration of concrete. Environmental factors like abrasion, biological growth, freezing and thawing, or chemical attacks from carbonation, chlorides, acids, or sulfates can also damage concrete over time if not properly addressed. Proper concrete mix design, placement, and curing can improve durability.
Chemical admixtures are added to concrete to modify properties in either the fresh or hardened state. Common admixtures include air-entraining admixtures, which introduce tiny air bubbles that improve freeze-thaw resistance; water-reducing admixtures, which lower the water content needed for a given workability; and superplasticizers, also called high-range water reducers, which make very flowable, self-consolidating concrete. Admixtures function through adsorption, de-flocculation, or chemical interaction with hydrating cement. They are used to reduce construction costs, achieve desired concrete properties, and maintain quality in adverse conditions.
International Journal of Engineering Research and DevelopmentIJERD Editor
This document presents the results of a study comparing the hardened concrete properties of mixes containing micro silica or alccofine as supplementary cementitious materials. Concrete cubes, beams, and cylinders were cast with micro silica or alccofine added to cement at increments of 0%, 3.34%, 6.68%, 10.02%, 13.36%, and 16.7%. The hardened properties tested included compressive strength, flexural strength, splitting tensile strength, and impact resistance. Test results showed that the concretes with micro silica and alccofine additions generally exhibited higher strength properties compared to the control mix without additions.
PMC-S waterproofing system is a 8 years innovative R&D effort by Jiazhou New Waterproofing Co., Ltd. and Southwest Jiaotong University.This system is a specialized waterproofing solution for tunnels and underground projects.(If applied to exposed sites like roof,etc,2cm thickness protective layer is required).
This system won China's highest honor National Science and Technology Progress Award in 2011 and also won 6 Invention Patents and 8 Utility-Model Patents.
PMC-S is successfully applied in Munigou Highway Tunnels(over 3000 meters altitude,extreme conditions),Shenzhen LNG Terminal(China's first LNG Terminal),Najing Youth Olympic Axis Underground Project(the biggest underground project),Langzhong Railway Station Underpass,Pengzhou Petrochemical Tanks Bottom Waterproofing projects,etc.
The main Benefits of PMC-S:
1.Fast curing:the membrane forms within 3 to 8 seconds after spraying on by instant oxidantion and deoxidantion chemical change in the spray gun.
2.30% Self-recovering:the membrane absorb the moisture to self-recover from the wound by construction operation
3.Long existing with the building:Unlike other waterproofing work,there will be a reparing after 3-5 years.With PMC-S applied projects,the endless and huge amount of budget for repairing is no longer a problem.
4.Fully bonded system provides excellent watertightness, preventing development of
water migration in both concrete membrane interfaces
5.Eco-friendly,non toxic component
6.Efficient Operation,fast installation,shorten the construction period time
7.Fireproof: A1 Grade
Concrete and its types and properties and admixtures used in concreteZeeshan Afzal
Its free..use it and like it and share it if you think its best:
Concrete
Introduction.
2. Ingredients.
3.Manufacturing.
4. Classification On Installation Bases.
5.Terminologies.
6.Admixtures And Their Types.
7.Types Of Concrete.
8.Properties Of Concrete.
9.Uses Of Concrete.
Objective:
To know more about “concrete”.
How you can prevent corrosion?
How you can give strength to your structure using concrete?
What kind of admixtures you can use to get the required result?
What are the terminologies that are associated with concrete?
What are the tests that can be performed to check the quality?
Who Invented The Concrete ?
A “composite material” that consists essentially of a binding medium, such as a mixture of Portland cement and water, within which are embedded particles or fragments of aggregate, usually a combination of fine and coarse aggregate.
Cement
In concrete, the most commonly used is
Portland cement, a hydraulic cement which
sets and hardens by chemical reaction with
water and is capable of doing so under water.
Cement is the “glue” that binds the
concrete ingredients together & instrumental
for the strength of the composite
Aggregate
The Aggregate is a granular material, such as sand, gravel, crushed stone, or in iron-blast furnace slag. The aggregate constitutes typically 75% of the concrete volume, or more, and therefore its properties largely determine the properties of the concrete.
Proportion of ingredients
A mix is about 10 to 15 percent cement, 60 to 75 percent aggregate and 15 to 20 percent water. Entrained air in many concrete mixes may also take up another 5 to 8 percent.
Classification of concrete on basis of
installation method
Types
4.1 Ready-Mix Concrete.
4.2 Reinforced Concrete.
4.3 Fresh Concrete.
4.4 Pre-cast Concrete.
4.5 Shrink-Mix Concrete.
Ready/Pre Mix Concrete
Reinforced Concrete
Fresh Concrete
pre cast Concrete
properties of fresh concrete
properties of harden concrete
green concrete
mineral admixture
retarding admixture
accelarating admixture
color admixture
pozolon
water reducing admixture
air entraining admixture
chemical admixture
pigments
cement
cement paste
aggregates
terminologies in concrete
Effective use of crystalline waterproofing technology will reduce the
porosity and permeability of conventional concrete, and provide the high performance
advantages and benefits that building owners and design professionals have come to rely
upon in design and construction projects.
1. Concrete strength is tested using cubes or cylinders according to standardized methods like ASTM C470. Compressive strength increases with lower water-cement ratio and full compaction.
2. Factors that affect concrete strength include water-cement ratio, degree of compaction, curing time, cement composition and fineness, aggregate properties like size and texture.
3. Common failure modes for cubes are non-explosive or explosive, while cylinders typically fail via splitting, shearing, or a combination. Tensile strength is about 10% of compressive strength.
The document discusses intravenous (IV) admixtures and preparations. Some key points:
- IV admixtures involve preparing mixtures of two or more drugs into an IV fluid bag or bottle, done under doctor's orders by a trained pharmacist to avoid errors.
- Characteristics like solubility, osmolality, and pH must be considered and adjusted to match blood levels.
- IV sets include spikes, drip chambers, clamps, tubing, and needles to administer fluids and drugs via IV. Proper sterile technique is crucial when preparing IVs.
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.
Use of chemical admixtures and mineral additives in various kinds of high performance and high strength concrete is essential. I have explained how it works.
Waterproofing prevents the passage of liquid water through structures and is important to apply where hydrostatic pressure may occur. It can be applied to the positive or negative side of structures. Common types include sheet membranes, liquid waterproofing, and bentonite or cementitious waterproofing. The document discusses definitions of waterproofing versus damp-proofing, why waterproofing is necessary to prevent structural damage, where and how water can enter structures, and appropriate locations and types of waterproofing applications.
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 discusses concrete permeability and durability. It defines concrete and its composition, noting that concrete is made up of cement paste and aggregates. The cement paste binds the aggregates but is also porous, allowing water and chemicals to pass through. Several degradation mechanisms are described, all of which involve the penetration of water or other substances into the concrete. The document emphasizes that permeability determines a concrete's vulnerability, and that reducing permeability is key to improving durability. It describes different transport mechanisms by which substances can move through concrete, including diffusion, capillary action, and permeation.
1) The document presents a study on the mix design parameters of high strength concrete using iso-strength lines.
2) Sixteen concrete mixes were designed with water-binder ratios ranging from 0.30 to 0.42 and silica fume replacements ranging from 0 to 15%.
3) Regression analysis was used to develop relationships between slump, water content, and compressive strength at various ages for the different mixes. Iso-strength lines were plotted to predict strength based on water-binder ratio and silica fume content.
EFFECT OF SILICA FUME ON RHEOLOGY AND MECHANICAL PROPERTY OF SELF COMPACTING ...IAEME Publication
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Development of normal strength and high strength self curing concrete using s...eSAT Journals
Abstract
As water is becoming a scarce material day-by-day, there is an urgent need to do research work pertaining to saving of water in making concrete and in constructions. Curing of concrete is maintaining satisfactory moisture content in concrete during its early stages in order to develop the desired properties. However, good curing is not always practical in many cases. Curing of concrete plays a major role in developing the concrete microstructure and pore structure and hence improves its durability and performance. Keeping importance to this, an attempt has been made to develop self curing concrete by using Super Absorbing Polymers as self curing agents. Compressive strength of concrete containing self curing agents is investigated and compared with conventionally cured concrete. Self curing agent increases the water retention capacity of the concrete by reducing evaporation of water from concrete.
In this investigation, workability and strength characteristics of Normal Strength and High Strength Concrete, cast with the self curing agents have been studied and compared with the corresponding conventionally cured concrete. For the Normal Strength Self Curing Concrete of grade M20, M30 and M40, IS method of mix design was adopted. Mix proportions of High Strength Self Curing concrete of grade M60, M70 and M80 were obtained based on the guidelines given in modified ACI 211 method suggested by P.C.AITCIN. Super plasticizer dosage was varied with grade of concrete. Trial dosages of 0.8%, 1% and 1.2% of the weight of cement were used for M60, M70 and M80 grades of concrete respectively. Two self curing agents have been tried, out of which one has been found to be very effective. Trial dosage of 0.25% and 0.3% of the weight of cement was used for normal strength concrete and trial dosage of 0.4% of the weight of cement was used for High Strength Concrete. From the workability test results, it was found that the self curing agent has improved workability. It is found that concrete with this self curing agent gives more strength than that of the conventionally cured concrete. Also the percentage saving in cost of water has been found out and hence Self Curing Concrete holds economical.
Keywords: Self curing concrete, Self curing agents, Normal strength concrete, High strength concrete, Polyethylene Glycol (PEG), Super plasticizers.
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The document presents the results of an experimental study investigating the use of silica fume as a partial replacement for cement in high performance concrete. Various mix proportions were tested with silica fume replacement levels ranging from 0% to 12.5%. Specimens including cubes, beams, and cylinders were cast and tested at 7, 14, and 28 days to evaluate the compressive strength, flexural strength, and split tensile strength of the concrete mixtures. The study found that replacing 7.5% of the cement with silica fume produced concrete with sufficient strength for construction purposes while also reducing the amount of cement used, providing economic and sustainability benefits.
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Admixtures in concrete
1. Guidelines on use of Admixtures in Concrete
3 Types of Admixtures
IS: 9103 covers the following types of admixtures:
(a) Accelerating admixtures
(b) Retarding admixtures
(c) Water reducing admixtures , and
(d) Air entraining admixtures
Following paras describe above admixtures in brief.
Accelerating Admixtures:
These admixtures when added to concrete, mortar or grout
increases the rate of hydration of hydraulic cement, shortens the time
of set, accelerates the hardening or development of strength of
concrete/ mortar.
These admixtures function by interaction with C3S (Tri-calcium
silicate) component of the cement thus increasing the reaction
between cement and water.
Chemical Composition:
Many substances are known to act as accelerators for concrete. They
include Alkali Hydroxides, Silicates, Fluoro-Silicates, Organic
Compounds, Calcium Formates, Calcium Nitrates, Calcium Thio
Sulphates, Aluminium Chlorides, Potassium Carbonates, Sodium
Chlorides & Calcium Chlorides.
Of these calcium chlorides are most widely used because of its ready
availability, low cost, predictable performance characteristics. Non-
chloride Admixtures are preferred as chloride containing ones are
believed to accelerate corrosion of reinforcement. For chloride free
admixture also see para 8.1
Advantages :
i) Shortens the setting time of cement and therefore increases
the rate of gain of strength.
ii) Enables earlier release from precast moulds thus speeding
2. Guidelines on use of Admixtures in Concrete
production.
iii) Reduces segregation and increase density and compressive
strength.
iv) Cures concrete faster and therefore uniform curing in winter
and summer can be achieved.
v) Early use of concrete floors by accelerating the setting of
concrete.
vi) Reduces water requirements, bleeding, shrinkage and time
required for initial set.
Effect of use of Accelerator.
Table-1 below shows typical test results provided by M/S. Asian
laboratories ,New Delhi.
Mix details: OPC 350 kg/cum., Zone 2 sand 26%, 5-20 mm crushed
aggregates 74%, Dosage: 1% by weight of cement.
Table-1
Compressive Strength (Kg/cm2
)Cement
Kg/m3
Water
Kg/m3
Reduction
in unit
water
content
(%)
W/C
Rati
o
Slump
in mm
1day 3days 7days 28days
Reference
concrete
350 210 Nil 0.6 55 30.25 88.5 163.45 253
Concrete
with
CEMWET-
ACC
350 178.5 15.0 0.51 60 51.0 135.0 216.0 304
From the results of above table it is seen that by the use of
accelerator in concrete mix of same slump and cement content, the
increased strength at early and final stage with better workability can
be achieved even at reduced water cement ratio.
Dosage ranging from 0.06 to 3% by wt. of cement, for different
products are recommended by different manufactures but it shall be
fixed as per design requirement and site trials (see para 8.4)
3. Guidelines on use of Admixtures in Concrete
Retarding Admixtures:
This type of chemical admixtures decreases the initial rate of reaction
between cement and water and thereby retards the setting of
concrete. It functions by coating the surface of C3S (Tri calcium
silicate) components, thus, delaying this reaction with the water.
Reaction products are slow to form as such the setting and
hardening of concrete are delayed reducing early compressive
strengths. Since the rate of stiffening of concrete can be too fast in
our tropical climatic conditions, sufficient time for the concrete is
required for transportation and placement before setting. In such
conditions retarding admixtures can be very useful. Retardation in
setting time up to 8-10 hours is possible by suitable use of retarders.
The delay in hardening caused by the retarders can be exploited to
obtain an architectural finish of exposed aggregate: the retarder is
applied to the interior surface of the formwork so that the hardening
of the adjacent cement is delayed. This cement can be brushed off
after the formwork has been struck so that an exposed aggregate
surface is obtained.
Chemical Composition:
These admixtures can be divided in several categories based on their
chemical composition. The main ingredients of retarders are as
follows:
i) Lignosulphonic acids and their salts. e.g. Na, Ca or NH4,
ii) Hydro-carboxylic acids and their salts.
iii) Carbohydrates including sugar.
iv) Inorganic salts based on flourates, phosphates, oxides, borax
and magnesium salts.
Advantages:
i) Improves workability, cohesion and extends setting time,
provides protection against delays and stoppages and facilitates
keeping workable concrete for extended period ..
ii) In the large construction, good workability of the concrete
throughout the placing period and prevention of cold joints is
ensured by adding retarders in the concrete.
4. Guidelines on use of Admixtures in Concrete
iii) Extended setting time minimise risks of long distance delivery in
hot weather, improves pumpability of concrete by extended
setting period and improved workability of concrete.
iv) Reduces bleeding and segregation where poor sand grading
are unavoidable.
v) Reduces adverse environmental effects of various nature on
concrete and embedded steel by considerable reduction in
permeability.
Effect of use of Retarder:
Retarding admixture forms a film around the cement grain that
prevent or delays the reaction with water. After some times, this film
breaks and normal hydration takes place. Table below shows typical
test results provided by M/s FOSROC chemicals (I) Ltd., Bangalore.
Mix: Sand zone 2(IS:383)- 35%, Aggregate 20-5mm (IS:383)
65%
Cement OPC(IS:269)
Table-2
Compressive Strength
Kg/cm2
S.
No.
Test Dosage of
conplast-RP 264
lit/50kg cement
W/C
ratio
Slump
in mm
3days 7days 28days
Density
Kg/m3
1. Control Nil 0.65 60 102 131 167 2368
2. Workability
increased
0.15 0.65 130 105 135 171 2384
3. Strength
increased
0.15 0.572 65 161 193 257 2390
From the results of above table it is found that by use of retarder in
concrete as an admixture, due to increase in slump, the workability
can be increased maintaining same water cement ratio and strength
of concrete. With reduction of water cement ratio, the strength of
concrete can be increased without loss of workability.
Dosage ranging from0.05 to 1% by wt. of cement, for different
products are recommended by different manufactures. However, it
shall be fixed as per design requirement and after site trials (see
5. Guidelines on use of Admixtures in Concrete
para 8.4).
Plasticizer (Water Reducer) Admixtures
A material, which either increases workability of freshly mixed
concrete without increasing water cement ratio or maintains
workability with a reduced amount of water, is termed as water
reducing admixture.
As their name implies, the function of water reducing admixture is to
reduce the water content of the mix, usually by 5 to 10%, sometimes
(in concrete of very high workability) upto 15%. Thus, the purpose of
using a water reducing admixture in a concrete mix is to allow a
reduction in the water cement ratio while retaining the desired
workability or, alternatively, to improve its workability at a given water
cement ratio. The actual reduction in water depends on dose of
admixtures, cement content, type of aggregate used, ratio of cement,
fine and coarse aggregate etc. Therefore, the trial mixes containing
an actual material to be used on the job are essential to achieve
optimum properties.
Chemical Composition:
The chemicals used as plasticizer (water reducing admixtures) are
as follows:
i) Lignosulfonic acids, derivatives and their salts.
ii) Hydroxylated carboxylic acids, their salts and derivatives.
iii) Nepthalene sulphonic acid based
iv) Sulfonated melamine polycondensation products
v) Blends of above
vi) Inorganic material like borates, phosphates, amines and their
derivatives, carbohydrates, sugar and certain polymeric
compounds like cellulose, ethers etc.
Advantages:
i) They increase the workability of the concrete without reducing
the compressive strength or without changing water-cement
ratio. This is particularly useful when concrete pores are
restricted either due to congested reinforcement or due to thin
sections.
6. Guidelines on use of Admixtures in Concrete
ii) High strength can be obtained with the same cement content by
reducing water cement ratio.
iii) A saving in the quantity of cement (approx. upto 10%) can be
achieved keeping the same water/ cement ratio and workability.
Effect of use of Plasticizers:
Typical test results provided by M/s. M.C.Bauchemie(I) Pvt. Ltd.,
Mumbai, showing increase in workability and increase in strength are
given below in table-3.
Table-3
Compressive strength N/mm2
Description
of mix
Dosage
%
cement
wt.
Cement
kg/m3
W/C
Ratio
Slump
cm
1 day 3 days 7 days 28 days
Reference -- 300 0.6 7 7 18 26 34
0.2% 300 0.6 10 7 18 28 37Plasticizes
0.3% 300 0.6 12 6 17 27 35
0.2% 300 0.56 7 7 21 32 41Strength
increase
0.3% 300 0.54 7 8 23 33 44
0.2% 280 0.6 7 7 19 28 36Cement
saving
0.3% 270 0.6 7 6 19 27 35
From the above table it is seen that one of the following advantages
can be gained at a time:
i) Reduced cement content keeping same water-cement ratio
and workability. This will lead to economy.
ii) Reduced water-cement ratio keeping same water content and
same workability. This will lead to increase in strength.
iii) Increased workability keeping same water-cement ratio and
cement content. This is specially required when workability
retention for pumping etc. is needed.
Dosage ranging from 0.15 to 0.6% by weight of cement (different
doses for different products) are recommended by manufacturers,
7. Guidelines on use of Admixtures in Concrete
however, it shall be fixed as per design requirements and after site
trials.(see para 8.4).
Superplasticizer Admixtures
Normal water reducers are well established admixtures called
plasticizers in concrete technology. A normal water reducer is capable
of reducing water requirements by 10 to 15%. Higher water
reductions, by incorporating larger amounts of these admixtures,
result in undesirable effects on concrete like bleeding, segregation
and hardening . So, a new class of water reducers, chemically
different from the normal water reducer and capable of reducing
water content by about 30% has been developed. The admixtures
belonging to this class are known as super plasticizers.
Superplasticisers are infact the extended version of plasticisers.
At a given water /cement ratio and water content in the mix, the
dispersing action of superplasticizer increases the workability of
concrete, typically by raising the slump from 75mm to 200 mm, the
mix remaining cohesive. The resulting concrete can be placed with
little or no compaction and is not subject to excessive bleeding or
segregation. Such concrete is termed as flowing concrete and is
useful for placing in very heavily reinforced sections, in inaccessible
areas, in floor or road slabs, and also where very rapid placing is
desired. The principal mode of action of superplastcizers is their
ability to disperse cement particles very efficiently. As they do not
entrain air, they can be used at high dosage rates without affecting
strength.
Chemical Composition:
There exist four main categories of superplasticizers based on their
chemical composition:
(i) Sulfonated melamine formaldehyde condensates
(ii) Sulfonated naphthalene formaldehyde condensates
(iii) Modified lignosulfonates
(iv) Others such as sulfonic acid esters and carbohydrate esters
Advantages:
i) Cement content can be reduced to a greater extent keeping
8. Guidelines on use of Admixtures in Concrete
the same water/cement ratio. This will lead to economy.
ii) Water-cement ratio can be reduced significantly keeping same
cement content and workability. This will lead to increase in
strength.
iii) Higher workability at very low water cement ratio like casting
concrete with heavy reinforcement..
iv) Reduction in permeability
v) Where early strength development is required in prestressed
concrete or casting of floor, where early access for finishing
equipment is required.
Effect of use of Superplasticizers:
For increasing the workability of the mix, the normal dosages of
superplasticizers is 1 to 3 litre per cum. of concrete of the liquid
superplasticizer containing about 40% of active material. When
superplasticizers are used for large water reduction and for high
strength, their dosage is much higher: 5 to 20 litre per cubic metre of
concrete. Generally, the dosage recommended by the manufacturer
should be taken as guidelines and the correct dosage be decided
based on site trials. The typical test results showing the increase in
workability and increase in strength due to use of superplasticizer,
given in tables 4-6 have been taken from the literature provided by
CICO structural water proofing Pvt. Ltd., New Delhi.
Table-4
SN Dosage in Lt/50
kg of cement
W/C ration Cement content
kg/m3
Slump in mm
I Control Mix 0.55 350 50
II 0.2 0.55 350 80
III 0.4 0.55 350 150
IV 0.6 0.55 350 200
The test results given in the above table-4 indicates that by use of
different dosage of superplasticizer, the slump is increased resulting
into better workability of concrete.
9. Guidelines on use of Admixtures in Concrete
Table-5
Compressive strength in
kg/cm2
SN Dosage in
Lt/50 kg of
cement
W/C
ration
Cement
content kg/m3
7 days 28 days
I Control Mix 0.55 350 175 270
II 0.2 0.50 350 255 343
III 0.6 0.46 350 325 410
From the above table-5, it is found that by use of different dosage of
superplasticizer, the better strength can be achieved by reduced
water cement ratio.
Table-6
Compressive strength in kg/cm2
S.N. Dosage in
Lt/50 kg of
cement
% of
cement
saving
Cement
content
in
kg/m3
3 Days 7 Days 28Days 1Yr 3Yrs
I Control mix - 400 125 175 285 310 325
II 0.2 8.5% 366 130 185 293 321 340
III 0.6 14% 344 130 195 310 325 340
IV 1.0 20% 320 45 203 315 326 345
Saving of cement up to 20% can be achieved by different dosage of
superplasticizer in the concrete at constant water cement ratio (0.55)
and workability (80-90) slump.
Air Entraining Admixture:
This is an admixture for concrete or mortar which causes air to be
incorporated in the form of minute bubbles in the concrete or mortar
during mixing, usually to increase workability and resistance to
freezing and thawing. Air entrained also breaks the continuity of
capillaries.
The dosages required are between 0.005 to 0.05% by mass of
10. Guidelines on use of Admixtures in Concrete
concrete and it is advisable to mix it with batching water for uniform
dispersion. As per department of Atomic Energy Practice, the air
content is controlled between 3 to 6%. Method of measuring air
content is given in IS 1190.
Chemical Composition
The major proportion of commercial products is based on the
following chemical materials, set out in order of probable decreasing
use;
i) Abietic and pimeric acid salts
ii) Fatty Acid salts
iii) Alkyl - aryl sulphonates
iv) Alkyl sulphonates
v) Phenol ethoxylates
Advantages:
i) Durability
ii) Reduced bleeding and segregation because of :
a) Attachment of air bubbles with cement particle and
linking them.
b) Increase in inter particle attraction caused by adsorption
of air entrainer.
c) Bubble acting as extra fine filler and increased total
surface area of constituents relative to water volume.
d) Water flow between cement particles is restricted.
iii) Workability increased due to action of air bubbles as ball
bearing which assist movement of particles each other.