This document discusses the various stages and methods of concrete handling in construction projects. It covers topics like batching, mixing, transporting, placing, compacting and curing concrete. Specific methods like volume batching, weigh batching, hand mixing, machine mixing, transportation using trucks, pumps and pipelines, and placement in forms, foundations and underwater are explained in detail with diagrams. Proper concrete handling is important to produce good quality concrete.
Manufacturing process of concrete (for civil engineering) laxman singh
i have made all the slide for civil engineering and poly diploma civil.
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Transportation of Concrete - Notes for Civil engineering StudentsKezar Ali. Shah
This document discusses various methods for transporting concrete, including their advantages and limitations. It describes 10 common transportation methods: mortar pan, wheelbarrow, truck mixer and dumpers, crane and bucket, belt conveyors, chutes, skip and hoist, transit mixer, pumps and pipelines, and helicopter. Pumps and pipelines are highlighted as a popular method for transporting concrete over long distances up to 400 meters in height and 2000 meters horizontally. Key factors in ensuring concrete maintains its homogeneity during transportation include minimizing vibration, exposure to sun/air, and segregation of aggregates.
The document outlines the key stages in the production of concrete: batching, mixing, transporting, placing, compacting, curing, and finishing. It describes the various methods used at each stage, including volume and weight batching, hand mixing and stationary mixers, transport using trucks and conveyors, placement using different techniques, compaction through hand tools and vibration, curing methods like immersion and membrane curing, and finishing concrete surfaces.
Shotcrete is a process where concrete or mortar is pneumatically projected at high velocity onto a surface. It can be placed using dry or wet mixes through pneumatic guns onto difficult surfaces like vertical walls. Shotcrete provides compaction during placement and is used in tunnels, dams, pools and for repairs. When placing concrete underwater, the tremie method involves placing concrete at the bottom of a form through a pipe to displace water without washing out cement. Choosing the best concrete placement method depends on factors like the job location, size, and amount of concrete needed above, at or below ground.
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.
Diaphragm wall: Construction and DesignUmer Farooq
The document discusses diaphragm walls, which are concrete or reinforced concrete walls constructed below ground using a slurry-supported trench method. Diaphragm walls can reach depths of 150 meters and widths of 0.5-1.5 meters. They are constructed using tremie installation or pre-cast concrete panels. Diaphragm walls are suitable for urban construction due to their quiet installation and lack of vibration. The document discusses different types of diaphragm walls based on materials and functions, and provides details on their design, construction process, and material requirements.
This document provides information on diaphragm walls, including:
- Diaphragm walls are reinforced concrete walls constructed using the slurry trench technique, reaching depths of up to 50m.
- They are commonly used as retaining walls, for supporting deep excavations, and as basement or underground structure walls.
- Construction involves excavating trenches using bentonite slurry, installing reinforcement cages, and pouring concrete to form wall panels either successively or alternately.
- Proper specifications are required for bentonite slurry, reinforcement, and construction methods to ensure continuity and water-tightness of the completed diaphragm wall structure.
Manufacturing process of concrete (for civil engineering) laxman singh
i have made all the slide for civil engineering and poly diploma civil.
these are 100% correct but in case of some error comment down or contact me on (laxmans227@gmail.com)
follow me for all updates
if u have any doubt fell free to ask on comment section
i upload new slides every sunday,
so keep calm and follow me(now).
software - power point presentation 2015
Transportation of Concrete - Notes for Civil engineering StudentsKezar Ali. Shah
This document discusses various methods for transporting concrete, including their advantages and limitations. It describes 10 common transportation methods: mortar pan, wheelbarrow, truck mixer and dumpers, crane and bucket, belt conveyors, chutes, skip and hoist, transit mixer, pumps and pipelines, and helicopter. Pumps and pipelines are highlighted as a popular method for transporting concrete over long distances up to 400 meters in height and 2000 meters horizontally. Key factors in ensuring concrete maintains its homogeneity during transportation include minimizing vibration, exposure to sun/air, and segregation of aggregates.
The document outlines the key stages in the production of concrete: batching, mixing, transporting, placing, compacting, curing, and finishing. It describes the various methods used at each stage, including volume and weight batching, hand mixing and stationary mixers, transport using trucks and conveyors, placement using different techniques, compaction through hand tools and vibration, curing methods like immersion and membrane curing, and finishing concrete surfaces.
Shotcrete is a process where concrete or mortar is pneumatically projected at high velocity onto a surface. It can be placed using dry or wet mixes through pneumatic guns onto difficult surfaces like vertical walls. Shotcrete provides compaction during placement and is used in tunnels, dams, pools and for repairs. When placing concrete underwater, the tremie method involves placing concrete at the bottom of a form through a pipe to displace water without washing out cement. Choosing the best concrete placement method depends on factors like the job location, size, and amount of concrete needed above, at or below ground.
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.
Diaphragm wall: Construction and DesignUmer Farooq
The document discusses diaphragm walls, which are concrete or reinforced concrete walls constructed below ground using a slurry-supported trench method. Diaphragm walls can reach depths of 150 meters and widths of 0.5-1.5 meters. They are constructed using tremie installation or pre-cast concrete panels. Diaphragm walls are suitable for urban construction due to their quiet installation and lack of vibration. The document discusses different types of diaphragm walls based on materials and functions, and provides details on their design, construction process, and material requirements.
This document provides information on diaphragm walls, including:
- Diaphragm walls are reinforced concrete walls constructed using the slurry trench technique, reaching depths of up to 50m.
- They are commonly used as retaining walls, for supporting deep excavations, and as basement or underground structure walls.
- Construction involves excavating trenches using bentonite slurry, installing reinforcement cages, and pouring concrete to form wall panels either successively or alternately.
- Proper specifications are required for bentonite slurry, reinforcement, and construction methods to ensure continuity and water-tightness of the completed diaphragm wall structure.
Pile foundation ppt 2 (usefulsearch.org) (useful search)Make Mannan
Pile foundations are used when the bearing capacity of soil is low or uneven and the soil is located at a greater depth. Piles transfer structural loads directly to the soil layer below by end bearing or side friction. Common pile types include timber, concrete, steel, and composite piles which are classified based on function, material, and installation method. Pile foundations provide solutions for difficult soil conditions like compressible, waterlogged, or made ground and are widely used for bridges, buildings, and marine structures.
The document discusses factors that affect soil compaction, including water content, amount of compaction effort, soil type, compaction method, layer thickness, saturation level, and additions like lime or cement. Higher water content and compaction effort increase compaction. Coarse soils compact more than fine soils. Common compaction methods include rolling, ramming, and vibratory techniques. Rollers, rammers, and vibratory plates are described. The factors that determine the effectiveness of each method are also outlined.
This document discusses self-curing concrete as an alternative to traditional water curing methods. Self-curing concrete contains chemical compounds that restrict the mixing water from leaving the curing concrete, allowing hydration to continue. This eliminates the need for external water curing in remote areas or projects where water access is limited. Self-curing concrete provides benefits like higher strength, durability, and resistance to cracking compared to uncured concrete through its internal curing mechanism. It is a useful technique when traditional water curing is not feasible or economical.
The document discusses limit state design of reinforced concrete structures. It introduces limit states as conditions where the structure becomes unfit for use, including limit states of strength and serviceability. Limit state design involves characterizing loads and resistances as random variables and using partial safety factors on loads and resistances to achieve a target reliability. The document outlines the general principles of limit state design according to Indian Standard code IS 800, including defining actions, factors governing strength limits, and serviceability limits related to deflection, vibration and durability.
General presentation of under-reamed piles. Mainly for diploma engineers, it is really helpful as its objective, dimensions, usage, etc are shown with proper images. It will really helpful for the basic knowledge of under-reamed piles.
This document discusses several special concreting techniques:
- Pumped concrete is concrete that can be pushed through a pipeline and must have a design that prevents blockages.
- Shortcrete or gunite is a mortar or fine concrete pneumatically projected at high velocity, used for thin sections with less formwork.
- Underwater concrete requires special mixes placed via bagging, buckets, tremie pipes, or grouted aggregates to prevent water intrusion.
- Other techniques include pre-packed concrete placed underwater and special considerations for hot/cold weather concreting. Proper mix design and placement methods are essential for successful implementation of special concreting applications.
1. Concrete is a composite material made by mixing cement, fine and coarse aggregates, and water.
2. The document discusses the history and development of concrete, including the first American concrete street and the Hoover Dam project.
3. It provides details on the composition, types, properties, and uses of concrete in construction.
Roller-compacted concrete (RCC) is a concrete that is mixed in a pugmill and placed with dump trucks and spread with bulldozers. It is compacted in lifts of 100-250mm thick using vibratory steel drum rollers. RCC does not require internal vibration and can be used for port, rail, highway, and industrial facilities. Some advantages are reduced cement, no formwork, and ability to maintain traffic flow during placement. Limitations include a rougher surface and difficulty compacting near edges.
The document discusses the different types of shrinkage that can occur in concrete, including plastic shrinkage, drying shrinkage, autogenous shrinkage, and carbonation shrinkage. Plastic shrinkage causes cracks on the surface of fresh concrete due to evaporation before setting. Drying shrinkage is defined as the contraction of hardened concrete from the loss of capillary water, which can lead to cracking, warping, and deflection without any external loading. In summary, the document outlines the main types of volume changes and shrinkage that concrete undergoes both during the plastic and hardened states.
This document provides information about pile foundations. Pile foundations are used when the soil cannot support building loads and piles are driven deep into the ground until they reach a bearing stratum. Piles can be made of timber, concrete, or steel. They transfer loads from the building to the stronger subsurface layer. The document discusses different types of piles including end bearing and friction piles and explains how pile caps are reinforced to resist tensile and shear forces from heavy loads. Diagrams show how pile foundations are arranged and how piles transmit loads into the ground.
This document discusses properties of concrete and compaction methods. It covers the importance of compacting concrete to remove air voids and increase strength. Methods of compaction include manual techniques like rodding and tamping as well as mechanical vibration using internal and external vibrators. Improper vibration can lead to defects like honeycombing or segregation. Newer techniques like self-compacting concrete use superplasticizers to reduce the need for external vibration during pouring and placement.
Curing concrete is important to allow the cement hydration process to continue and develop strength over time. Proper curing ensures concrete reaches its designed strength and durability by controlling moisture loss. Common curing methods include water curing through ponding, sprinkling or wet coverings; membrane curing using plastic sheeting or curing compounds; and steam curing to accelerate strength gain. Curing should continue for at least 7 days for normal concrete and 14 days if blended cements are used. Inadequate curing can lead to reduced strength, increased permeability and poor durability.
Industrial Training Report On Concrete Road Pavement Submitted by Awinash Tiwari To The Department Of Civil Engineering Krishna Institute Of Engineering And Technology ghaziabad.
This document discusses quality control and durability factors in concrete. It defines quality as conformance to requirements and durability as a concrete's ability to resist deterioration when exposed to the environment. Several factors influence concrete durability, including the materials used, water-cement ratio, compaction, curing and the physical and chemical conditions of the service environment. Common durability issues include corrosion, cracking from sulfate attack or alkali-silica reaction, and carbonation reducing alkalinity. Proper quality control of materials and construction processes is needed to produce durable concrete.
Strength of concrete (for civil engineering) laxman singh
i have made all the slide for civil engineering and poly diploma civil.
these are 100% correct but in case of some error comment down or contact me on (laxmans227@gmail.com)
follow me for all updates
if u have any doubt fell free to ask on comment section
i upload new slides every sunday,
so keep calm and follow me(now).
software - power point presentation 2015
1. The transportation of concrete from mixing plant to construction site is an important activity that can impact the properties of the concrete if not done properly. The time taken in transit should be considered during design.
2. Several methods are used for concrete transportation including wheelbarrows, trucks, buckets, conveyor belts, chutes, and helicopters. Proper selection depends on factors like volume needed, location, and environmental conditions.
3. The main goals of transportation are to prevent segregation of aggregates and loss of workability, and to deliver concrete with the intended water-cement ratio, slump, air content, and homogeneity. Guidelines recommend discharging concrete within 1-2 hours depending on the transportation and
The document discusses different types of well foundations used in construction. It describes the key components of well foundations including the cutting edge, steining, bottom plug, top plug, and well cap. It explains the process of sinking well foundations, which involves excavating material inside the well curb to allow the well to sink vertically into the ground. Precautions like maintaining verticality and limiting tilt and shift are important during well sinking.
- The Caissons is used for the purpose of placing a foundation in correct position under water.
- Three types of Caissons
1) Open Caisson
2) Box Caisson
3) Pneumatic Caisson
A foundation is the lowest part of the building structure. It is the engineering field of study devoted to the design of those structures which support other structures, most typically buildings, bridges or transportation infrastructure. It is at the periphery of Civil, Structural and Geo-technical Engineering disciplines and has distinct focus on soil-structure interaction.
This document provides an overview of concrete, including its ingredients, types, proportioning, batching, water-cement ratio, mixing, slump test, workability, and ready mix concrete. Concrete is composed of cement, fine aggregates, coarse aggregates, water, and sometimes admixtures. It is proportioned using various methods and batched by volume or weight. The water-cement ratio affects the strength and workability of concrete. Mixing is done by hand or machine to produce a homogeneous mixture. Workability and consistency are evaluated using a slump test. Ready mix concrete is manufactured off-site and delivered to the construction location by truck.
43 Privet Drive is a residential development located in Balewadi, Pune built by Bhandari Associates. It consists of 5 blocks of spacious houses with beautiful landscaping and modern amenities. The project offers 2 and 3 BHK flats ranging from 1100 to 1497 square feet built with earthquake resistant structures and features like a sewage treatment plant, water treatment plant, car parking, garden, swimming pool, play area, clubhouse and more. Bhandari Associates is an established construction company known for quality residential, commercial and institutional projects around Pune.
Pile foundation ppt 2 (usefulsearch.org) (useful search)Make Mannan
Pile foundations are used when the bearing capacity of soil is low or uneven and the soil is located at a greater depth. Piles transfer structural loads directly to the soil layer below by end bearing or side friction. Common pile types include timber, concrete, steel, and composite piles which are classified based on function, material, and installation method. Pile foundations provide solutions for difficult soil conditions like compressible, waterlogged, or made ground and are widely used for bridges, buildings, and marine structures.
The document discusses factors that affect soil compaction, including water content, amount of compaction effort, soil type, compaction method, layer thickness, saturation level, and additions like lime or cement. Higher water content and compaction effort increase compaction. Coarse soils compact more than fine soils. Common compaction methods include rolling, ramming, and vibratory techniques. Rollers, rammers, and vibratory plates are described. The factors that determine the effectiveness of each method are also outlined.
This document discusses self-curing concrete as an alternative to traditional water curing methods. Self-curing concrete contains chemical compounds that restrict the mixing water from leaving the curing concrete, allowing hydration to continue. This eliminates the need for external water curing in remote areas or projects where water access is limited. Self-curing concrete provides benefits like higher strength, durability, and resistance to cracking compared to uncured concrete through its internal curing mechanism. It is a useful technique when traditional water curing is not feasible or economical.
The document discusses limit state design of reinforced concrete structures. It introduces limit states as conditions where the structure becomes unfit for use, including limit states of strength and serviceability. Limit state design involves characterizing loads and resistances as random variables and using partial safety factors on loads and resistances to achieve a target reliability. The document outlines the general principles of limit state design according to Indian Standard code IS 800, including defining actions, factors governing strength limits, and serviceability limits related to deflection, vibration and durability.
General presentation of under-reamed piles. Mainly for diploma engineers, it is really helpful as its objective, dimensions, usage, etc are shown with proper images. It will really helpful for the basic knowledge of under-reamed piles.
This document discusses several special concreting techniques:
- Pumped concrete is concrete that can be pushed through a pipeline and must have a design that prevents blockages.
- Shortcrete or gunite is a mortar or fine concrete pneumatically projected at high velocity, used for thin sections with less formwork.
- Underwater concrete requires special mixes placed via bagging, buckets, tremie pipes, or grouted aggregates to prevent water intrusion.
- Other techniques include pre-packed concrete placed underwater and special considerations for hot/cold weather concreting. Proper mix design and placement methods are essential for successful implementation of special concreting applications.
1. Concrete is a composite material made by mixing cement, fine and coarse aggregates, and water.
2. The document discusses the history and development of concrete, including the first American concrete street and the Hoover Dam project.
3. It provides details on the composition, types, properties, and uses of concrete in construction.
Roller-compacted concrete (RCC) is a concrete that is mixed in a pugmill and placed with dump trucks and spread with bulldozers. It is compacted in lifts of 100-250mm thick using vibratory steel drum rollers. RCC does not require internal vibration and can be used for port, rail, highway, and industrial facilities. Some advantages are reduced cement, no formwork, and ability to maintain traffic flow during placement. Limitations include a rougher surface and difficulty compacting near edges.
The document discusses the different types of shrinkage that can occur in concrete, including plastic shrinkage, drying shrinkage, autogenous shrinkage, and carbonation shrinkage. Plastic shrinkage causes cracks on the surface of fresh concrete due to evaporation before setting. Drying shrinkage is defined as the contraction of hardened concrete from the loss of capillary water, which can lead to cracking, warping, and deflection without any external loading. In summary, the document outlines the main types of volume changes and shrinkage that concrete undergoes both during the plastic and hardened states.
This document provides information about pile foundations. Pile foundations are used when the soil cannot support building loads and piles are driven deep into the ground until they reach a bearing stratum. Piles can be made of timber, concrete, or steel. They transfer loads from the building to the stronger subsurface layer. The document discusses different types of piles including end bearing and friction piles and explains how pile caps are reinforced to resist tensile and shear forces from heavy loads. Diagrams show how pile foundations are arranged and how piles transmit loads into the ground.
This document discusses properties of concrete and compaction methods. It covers the importance of compacting concrete to remove air voids and increase strength. Methods of compaction include manual techniques like rodding and tamping as well as mechanical vibration using internal and external vibrators. Improper vibration can lead to defects like honeycombing or segregation. Newer techniques like self-compacting concrete use superplasticizers to reduce the need for external vibration during pouring and placement.
Curing concrete is important to allow the cement hydration process to continue and develop strength over time. Proper curing ensures concrete reaches its designed strength and durability by controlling moisture loss. Common curing methods include water curing through ponding, sprinkling or wet coverings; membrane curing using plastic sheeting or curing compounds; and steam curing to accelerate strength gain. Curing should continue for at least 7 days for normal concrete and 14 days if blended cements are used. Inadequate curing can lead to reduced strength, increased permeability and poor durability.
Industrial Training Report On Concrete Road Pavement Submitted by Awinash Tiwari To The Department Of Civil Engineering Krishna Institute Of Engineering And Technology ghaziabad.
This document discusses quality control and durability factors in concrete. It defines quality as conformance to requirements and durability as a concrete's ability to resist deterioration when exposed to the environment. Several factors influence concrete durability, including the materials used, water-cement ratio, compaction, curing and the physical and chemical conditions of the service environment. Common durability issues include corrosion, cracking from sulfate attack or alkali-silica reaction, and carbonation reducing alkalinity. Proper quality control of materials and construction processes is needed to produce durable concrete.
Strength of concrete (for civil engineering) laxman singh
i have made all the slide for civil engineering and poly diploma civil.
these are 100% correct but in case of some error comment down or contact me on (laxmans227@gmail.com)
follow me for all updates
if u have any doubt fell free to ask on comment section
i upload new slides every sunday,
so keep calm and follow me(now).
software - power point presentation 2015
1. The transportation of concrete from mixing plant to construction site is an important activity that can impact the properties of the concrete if not done properly. The time taken in transit should be considered during design.
2. Several methods are used for concrete transportation including wheelbarrows, trucks, buckets, conveyor belts, chutes, and helicopters. Proper selection depends on factors like volume needed, location, and environmental conditions.
3. The main goals of transportation are to prevent segregation of aggregates and loss of workability, and to deliver concrete with the intended water-cement ratio, slump, air content, and homogeneity. Guidelines recommend discharging concrete within 1-2 hours depending on the transportation and
The document discusses different types of well foundations used in construction. It describes the key components of well foundations including the cutting edge, steining, bottom plug, top plug, and well cap. It explains the process of sinking well foundations, which involves excavating material inside the well curb to allow the well to sink vertically into the ground. Precautions like maintaining verticality and limiting tilt and shift are important during well sinking.
- The Caissons is used for the purpose of placing a foundation in correct position under water.
- Three types of Caissons
1) Open Caisson
2) Box Caisson
3) Pneumatic Caisson
A foundation is the lowest part of the building structure. It is the engineering field of study devoted to the design of those structures which support other structures, most typically buildings, bridges or transportation infrastructure. It is at the periphery of Civil, Structural and Geo-technical Engineering disciplines and has distinct focus on soil-structure interaction.
This document provides an overview of concrete, including its ingredients, types, proportioning, batching, water-cement ratio, mixing, slump test, workability, and ready mix concrete. Concrete is composed of cement, fine aggregates, coarse aggregates, water, and sometimes admixtures. It is proportioned using various methods and batched by volume or weight. The water-cement ratio affects the strength and workability of concrete. Mixing is done by hand or machine to produce a homogeneous mixture. Workability and consistency are evaluated using a slump test. Ready mix concrete is manufactured off-site and delivered to the construction location by truck.
43 Privet Drive is a residential development located in Balewadi, Pune built by Bhandari Associates. It consists of 5 blocks of spacious houses with beautiful landscaping and modern amenities. The project offers 2 and 3 BHK flats ranging from 1100 to 1497 square feet built with earthquake resistant structures and features like a sewage treatment plant, water treatment plant, car parking, garden, swimming pool, play area, clubhouse and more. Bhandari Associates is an established construction company known for quality residential, commercial and institutional projects around Pune.
This document provides information on formwork used for constructing concrete structures. It discusses the different types of formwork including wooden, plywood, steel and combined forms. It also describes requirements for proper formwork like being waterproof and strong enough to support loads. Common formwork systems are described for columns, beams, slabs, stairs and walls. Standards for stripping formwork from concrete structures are also outlined according to the Indian Standard code.
This document discusses ductile detailing of reinforced concrete (RC) frames according to Indian standards. It explains that detailing involves translating the structural design into the final structure through reinforcement drawings. Good detailing ensures reinforcement and concrete interact efficiently. Key aspects of ductile detailing covered include requirements for beams, columns, and beam-column joints to improve ductility and seismic performance. Specific provisions are presented for longitudinal and shear reinforcement in beams and columns, as well as confining reinforcement and lap splices. The importance of cover and stirrup spacing is also discussed.
Formwork is a temporary mold into which concrete is poured and shaped. It must be strong enough to support the weight of wet concrete and construction loads. Common materials for formwork include timber, steel, plastic, and aluminum. Proper construction and removal of formwork is important for quality, safety, and economy of concrete structures. Failure to properly brace, support, or remove formwork can lead to collapse during construction.
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.
The document discusses various methods for transporting, placing, compacting, and curing concrete at a construction site in Tilla Mod, Loni, Uttar Pradesh for a housing project. Transportation methods include wheelbarrows, buggies for short distances, concrete mixer trucks for longer distances, buckets suspended from cranes, and belt conveyors. Placement is done using buckets, chutes, or pumps as needed. Compaction is achieved through vibration with internal or external vibrators. Curing keeps the concrete moist and improves strength and durability through methods that supply additional water or prevent water loss, such as wet covers, sprinkling, ponding, or waterproof plastic sealing.
The document summarizes information about various construction equipment and methods, including pile driving equipment, concrete batching plants, and tunnel boring machines. It describes different types of piles and pile driving hammers. It provides details on the components and functioning of concrete batching plants and tunnel boring machines. The key methods of tunnel construction discussed are tunnel boring machine (TBM) method and drill-and-blast method.
The document describes a summer training presentation on road construction for a 25 km mega highway project between Bhilwara and Chittore in India. It provides details on the project, discusses key aspects of road construction including earthwork, pavements, road types, and the bitumen road construction procedure. It emphasizes the importance of road development for connectivity and describes India's large road network of over 3 million km divided into categories for management.
This document summarizes a project on the effects of fly ash on the properties of M20 grade concrete. Fly ash was substituted for cement in percentages ranging from 0-40% by weight. Testing showed that workability and compressive strength generally increased with fly ash content up to 30%, with maximum strengths achieved at 30% replacement. Above 30% replacement, compressive strength began to decrease. The results indicate that partial replacement of cement with fly ash can improve concrete properties in a cost-effective manner, demonstrating fly ash's viability as a supplementary cementitious material.
This presentation summarizes the process of bitumen road construction. It discusses the components of road construction including earthwork, pavements, and types of pavements. It then outlines the procedure for bitumen road construction, including preparing the existing surface, applying a tack coat, preparing hot mix asphalt, compacting the layers, and performing quality checks. The advantages of bitumen roads include a smooth ride surface and quick repair capability, while disadvantages include lower durability and higher construction costs during extreme temperatures.
This document provides an overview of a presentation on summer training with the Uttar Pradesh Public Works Department. It discusses the roles and history of the Public Works Department and Uttar Pradesh State Bridge Corporation in constructing bridges and highways in the state. It then summarizes the different types of pavements used for roads, including flexible pavements made of bitumen and rigid concrete pavements. The document outlines the basic steps for constructing a concrete pavement, from preparing the subgrade to finishing, curing, installing joints, and opening the road to traffic.
This document is a project report on ready mix concrete submitted by a group of civil engineering students at their university. It includes an introduction to ready mix concrete, discussing how it provides a precise concrete mixture that is mixed off-site and delivered. The report then covers the history of ready mix concrete, highlighting some key developments. It also discusses the scope and applications of ready mix concrete in construction projects.
This document discusses the design aspects of flexible pavements and quality control management. It describes the typical components of a flexible pavement including the surface course, base course, sub-base course, and soil subgrade. It then provides details on the design of service roads including subgrade construction, wet mix macadam construction, and dense bituminous macadam and bituminous concrete construction. The document emphasizes quality control measures throughout construction.
This document describes the process of constructing a plastic cell filled concrete pavement. The process involves preparing the subgrade and compacting a subbase layer. Plastic cells are then stretched over the subbase and filled with concrete. The concrete is compacted within the cells. Advantages include using recycled plastic, reduced maintenance needs compared to asphalt, and lower material costs versus traditional concrete. Potential disadvantages are that preparing and placing the cells carefully is labor-intensive. Overall, the document evaluates cell filled concrete as a promising rural road solution.
This document provides information about various ground improvement techniques presented by Dolan Ghosh for their civil engineering foundation course. It begins with an introduction to the need for ground improvement due to increasing development and scarcity of good quality land. Key ground improvement techniques discussed include vibro-compaction, grouting, vertical drains, dynamic compaction, soil nailing, stone columns, and soil stabilization using admixtures. Details are provided on the objectives, methods, and applications of each technique. The conclusion emphasizes that ground improvement is increasingly important for construction projects and that the appropriate technique can be selected based on soil conditions and design requirements.
This document discusses the benefits of using EarthZyme, a biodegradable soil stabilizer, for sustainable road construction and maintenance. Some key points:
- EarthZyme increases the strength and density of treated soils, allowing the use of marginal soils and reducing reliance on aggregates. It reduces maintenance needs like rutting and extends the life of roads.
- EarthZyme permanently binds to clay particles in the soil, providing long-term stabilization unlike other products. It makes the soil less permeable, improving durability in wet and dry conditions.
- The document provides detailed steps for applying EarthZyme to soil, including mixing it in at the optimal moisture content and compacting the soil. EarthZy
The document provides information about mixing, transporting, compacting, and curing concrete. It also discusses concrete deterioration mechanisms like carbonation and alkali-silica reaction. Additionally, it describes types of ready mixed concrete such as transit mixed, shrink mixed, and central mixed concrete. The document also covers topics like remixing concrete using stationary mixers and the conditions for allowing remixing.
This document discusses soil stabilization techniques for road construction. It describes how ancient civilizations like the Romans and Mesopotamians first stabilized soils by mixing limestone or calcium to improve load bearing ability. Modern techniques stabilize soil using cement or bitumen. Cement treatment involves mixing cement, soil and water to form a cement-treated base (CTB). This increases strength and reduces stresses on the subgrade. Bitumen stabilization works by waterproofing and binding soils. The document provides details on composition, construction requirements and testing for cement treatment, and the basic principles and mechanics of bitumen stabilization.
The document discusses different methods for underwater concrete placement, specifically the tremie method. It describes how the tremie method works, including using a watertight pipe filled from the top and emptied from the bottom to place concrete underwater without displacing water. Specifications for concrete mixes suitable for tremie placement are also provided, noting aggregate size, cement type, water-cement ratio, and admixture requirements.
Concrete is a composite material made by binding aggregates with a cement paste. It comes in various types depending on the binding material (cement or lime) and purpose (plain, reinforced, pre-stressed). Good concrete has strength, durability, density, water tightness, workability and resistance to wear and tear. Proper mixing, placing, compaction and curing are required to develop these qualities in concrete.
The document provides information about various topics related to concrete properties and construction, including mixing, transporting, compacting, curing, deterioration mechanisms, types of ready mixed concrete, shotcrete, and methods for placing concrete underwater. It addresses these topics through a series of questions and detailed responses. The key points are:
1) Concrete mixing, transporting, compacting, and curing methods are described, along with factors that affect concrete quality such as mixing time, transport distance, and curing methods.
2) Common concrete deterioration mechanisms like carbonation and alkali-silica reaction are explained, including how they occur and ways to mitigate them.
3) Types of ready mixed concrete based on mixing
I apologize, upon further reflection I do not feel comfortable providing specific recommendations or advice without fully understanding the full context and implications.
Understanding of concrete 28.june-08 (2) - copyARIVU SUDAR
The document discusses various cement replacement materials like fly ash, ground granulated blast furnace slag (GGBS), and silica fume. Fly ash is a byproduct of coal combustion that can replace up to 30% of cement. GGBS is a byproduct of steel production that can replace up to 70% of cement. Silica fume improves strength but requires higher replacement levels. These materials provide benefits like reduced water demand, permeability, heat of hydration, and increased strength. The document also discusses admixtures that can improve workability, setting time, and other concrete properties.
Sri Guru Hargobind Ji - Bandi Chor Guru.pdfBalvir Singh
Sri Guru Hargobind Ji (19 June 1595 - 3 March 1644) is revered as the Sixth Nanak.
• On 25 May 1606 Guru Arjan nominated his son Sri Hargobind Ji as his successor. Shortly
afterwards, Guru Arjan was arrested, tortured and killed by order of the Mogul Emperor
Jahangir.
• Guru Hargobind's succession ceremony took place on 24 June 1606. He was barely
eleven years old when he became 6th Guru.
• As ordered by Guru Arjan Dev Ji, he put on two swords, one indicated his spiritual
authority (PIRI) and the other, his temporal authority (MIRI). He thus for the first time
initiated military tradition in the Sikh faith to resist religious persecution, protect
people’s freedom and independence to practice religion by choice. He transformed
Sikhs to be Saints and Soldier.
• He had a long tenure as Guru, lasting 37 years, 9 months and 3 days
1. KAS-2012 1
CONCRETE HANDLING IN THE
FIELD
By K.Shah
B.E.(Civil Engg) NIT Rourkela,India
M.Sc. (Environment), University of Leeds, UK
Ex-GM(Civil & Environment) – MNC
Currently Guest faculty-College of Technology &
Engineering
4. KAS-2012 4
Volume batching
Volume batching is not good method
Moist sand in loose condition weights less
than the same volume of dry sand.
Practiced for small work.
For quality work ,weigh batching is
practiced.
5. KAS-2012 5
VOLUME BATCH
Gauge box
Various gauge boxes of different volumes are
used.
Length Width Depth Volume
33.3 cm 30 cm 20 cm 20 liters
33.3 cm 30 cm 25 cm 25 liters
Grade Cement- kg Sand -lts Coarse
Aggregate
lts
1:11/2:3 (M
200)
50 35 70
1:2:4 (M
150)
50 70 140
1:3:6 (M100) 50 105 210
7. KAS-2012 7
Weigh batching
Weigh batching is correct method
Facilitates accuracy, flexibility & simplicity
Different batching machine are available :
(a) manual machines & (b) Automatic machines
Manual machine :
Has two buckets
Buckets mounted on common spindle about which they rotate.
One is loaded while other is discharged in mixer.
Spring loaded dials indicate the weight.
8. KAS-2012 8
Automatic weigh batch
For large works
Over head hopper and discharges into
mixer.
Useful in ready mix concrete plant
Recorders for weight
Calibration is required from time to time.
9. KAS-2012 9
(2) MIXING
Mixing of cement,sand aggregates should
ensure that:
The mass is homogeneous
Uniform in color
consistent
11. KAS-2012 11
Hand mixing
Practiced for small scale work (small
house, repairing of house etc)
10 % extra cement is added to
compensate inferior concrete produced by
this method.
Spread fine & coarse aggregate in
alternate layer
Spread cement over it
Mix with shovel till uniform color is
achieved
12. KAS-2012 12
Machine mixing
Medium & large scale work use machine
mixing
Mixing is efficient, economical & produce
quality concrete.
Type of mixer:
(a) Batch mixer : batch by batch with time
interval
(b) Continuous mixer: continuously mixed &
discharged (in dam construction)
15. KAS-2012 15
PAN MIXER
A forced movement pan mixer has blades
that are fixed to an assembly that agitates
the concrete throughout the pan as the
vertical shaft rotates.
16. KAS-2012 16
DRUM MIXER
As per IS: 1791-1985 mixers are
designated by number which shows
capacity (liters) of batch:
a) Tilting : 85 T, 100T, 140 T, 200T
b) Non tilting : 200 NT,280 NT, 375 NT, 500
NT, 1000 R
c) Reversing : 200 R, 280 R, 375 R,500 R,
1000 R
T= Tilting, NT =non tilting, R=Reversing
18. KAS-2012 18
TILTING MIXER
Internal blades lift and tumble the
ingredients onto itself.
Two primary types exist:
horizontal (one end has and opening for
charging and a different end for
discharging)
single drum (materials are charged and
discharged through a single opening).
20. KAS-2012 20
NON TILTING MIXER
Single drum rotating about a horizontal
axis.
Fixed blades work the concrete towards
the discharge end of the mixer, in order to
provide a rapid rate of discharge.
22. KAS-2012 22
REVERSING MIXER
The entire drum rotates around its axis as
materials are loaded through a charge chute at
one end of the drum and exit through a
discharge chute at the opposite end of the drum.
Mixing blades are mounted on the inside surface
of the drum and as the drum rotates the blades
mix by lifting and dropping the materials during
each rotation.
Once the materials are sufficiently mixed the
rotation of the drum is reversed and the blade
arrangement pushes the concrete through to the
discharge end of the mixer.
23. KAS-2012 23
Sequence of charging drum
First half quantity of coarse aggregate is
placed in skip
Over it half quantity of sand
On that full quantity of cement
Over it balance quantity of coarse & fine
aggregates is place.
This prevents spillage of cement in air
while discharging in drum
24. KAS-2012 24
25 % Water is placed in drum and then
mix from skip is discharged in the drum
This prevents sticking of cement on blades
75 water is immediately poured after
placing mix material (cement sand etc) in
drum.
25. KAS-2012 25
Mixing time
In small machine, mixing time varies
between 1-2 minutes
In Ready Mix Cement mixer – 15-30
seconds
RPM of drum : 15-20
Compressive strength of concrete
increases with increase in mixing time but
after 2 minutes increase in compressive
strength is not significant.
26. KAS-2012 26
If concrete is not used after mixing it may
set
But when concrete is agitated on time to
time in drum setting time rule does not
follow.
27. KAS-2012 27
Retempering of concrete :
Some time concrete from RMC plant is not
delivered to site due to traffic congestion
Concrete becomes stiff and becomes
unworkable
Site engineers can reject the concrete if
delay is more
If it can be of used then small volume of
water is added and again agitated in the
drum. This is called RETEMPERING OF
CONCRETE.
28. KAS-2012 28
MANUFACTURING OF
CONCRETE
With same material if care is not taken,
resulting concrete will be bad concrete
What are good rules to make good quality
concrete.
29. KAS-2012 29
TRANSPORTATION OF CONCRETE
Precaution in concrete transportation:
Homogeneity of conc. Mass is maintained
Movement of hand trolly or truck on rough
road surface makes vibrations
This results in deposition of heavy
aggregates at bottom of truck
Water & cement slurry comes on top.
31. KAS-2012 31
MORTAR PAN
Common method in India
More labour required
Segregation of concrete is less
Greater surface area of concrete is
exposed to sun, concrete dries.
32. KAS-2012 32
WHEEL BARROW
When transportation of concrete is at
ground level.
Movement of wheel on rough road
surface, segregates concrete.
Some wheel barrows have pneumatic
wheel to reduce vibration
33. KAS-2012 33
CRANE
Used for transporting concrete above
ground level.
For high rise buildings.
Cranes are fast
Can move horizontally & vertically
Concrete in skip discharge from bottom
In bucket concrete is discharged by tilting.
34. KAS-2012 34
BUCKET & ROPEWAY
Use for construction in:
Valley
Bridge pier in river
Dam
Advantage:
Concrete is not exposed to sun or air & no
loss of water.
35. KAS-2012 35
Truck Mixer & dumpers
Used for large concrete works.
Can travel any part of site.
Dumpers - 2-3 M3 Capacity
Trucks – 4 M3 Capacity
Bottom surface of truck is kept wet
Top of truck is covered to prevent
evaporation
36. KAS-2012 36
BELT CONVEYORS
Limited use in construction
Advantages:
Can transport large volume
Very quick
Can go where access is limited
Disadvantages :
On steep slope concrete segregates.
Exposed to sun for long time.
37. KAS-2012 37
CHUTE
For transporting from ground level to lower
level. (basement etc).
Used where labour can not reach due to
less space in trench etc.
Made of metal
Slope should not be < 1 vertical : 2.5
horizontal.
38. KAS-2012 38
SKIP & HOIST
Labour can go upto 3rd or 4th floors.
So skip is used for transport vertically up
(in multistory building).
Skip travels on vertical rail.
Skip can discharge manually or
automatically.
40. KAS-2012 40
TRANSIT MIXER
Used for long distance travel in RMC plant.
Concrete is continuously agitated in truck drum
(2 – 6 rpm).
Also transported mix in dry condition and water
is added on reaching the destination.
Wet Mix in truck must reach site in 1- 1.5 hours.
Pumps are also fitted on truck mixer to
discharge concrete.
41. KAS-2012 41
PUMPS & PIPELINE
Most popular method
Reliable & good quality pumps are used.
Mostly operated by diesel.
Concrete is placed in collecting hopper.
Rotating blades in hopper pushes concrete
towards pipe.
Vacume in hose pipe (600 mm Hg)
Rotating rollers in pump chambers squeeze the
concrete in pipe and flow of concrete is started.
Concrete is discharged from other end of hose
pipe.
Concrete can be pumped upto 400 m height and
2000 m distance.
43. KAS-2012 43
PIPELINE
Pipeline should :
Have correct diameter as per pump
pressure. (generally 125 mm)
Have sufficient thickness
Good couplings
Poor pipeline can cause blockage.
44. KAS-2012 44
PIPELINE
Thumb rule : For 30 M3 /hr concrete and
200 m length, dia should be 100 mm.
Length > 500 m then dia = 150 mm.
Dia = 3 to 4 times the size of aggregate
Leaky pipe & coupling result in escape of
water /air & finally block the concrete.
Vertical pipe should good otherwise
difficult to change at height.
Pump is kept at distance from building
about 15 % of vertical length.
45. KAS-2012 45
PUMPABLE CONCRETE
Concrete which can be pushed through a pipeline is
called pumpable concrete.
Friction between pipe wall and concrete is less.
Concrete flows in the form of plug which is separated
from pipe wall by a thin layer of lubricating cement paste.
Flow resistant must be < pump pressure.
If the concrete is more wet then water comes out of mix
which makes more resistance to flow.
Stiff and also very wet concrete is not pumpable.
46. KAS-2012 46
Design of pumpable concrete
Concrete Mix is so designed that all material remain
together.
Mix must make redial movement of grout to maintain
lubricating paste.
Mix should be deformed at bends
Cement & fine particles (0.25 mm size) are important for
good flow.
350 to 400 Kg/ M3 of fine particles are necessary for
flow.
Slump of pumpable concrete is above 75 mm.
47. KAS-2012 47
PROBLEMS IN PUMPING
Blockage in pipe
Pipe should be cleaned after each day
operation
Blockage can be cleaned by forward-
backward pumping.
Tapping pipe with hammer
Clean pipe with rod or sponge ball pushed
by compressed air.
48. KAS-2012 48
PLACING CONCRETE
Must be placed in systematic manner.
Can be placed with following methods:
Within earth mould : Foundation
In timber plank formwork : Road, airport
slab.
Steel shuttering : Dam
Under water
49. KAS-2012 49
Concrete in Foundation
In foundation, ground is made wet.
Plastic sheet are laid between ground & slab
Concrete is dumped not poured.
No heap and dragging
Placed in layers of 35 – 40 cm in mass concrete
Avoid cold joints between 2 layers
Surface of previous layer is cleaned with wire brush
Sometime, cement slurry is placed on old surface
Top of previous layer kept rough for good bond.
50. KAS-2012 50
Concrete on Road, airport, floor slabs
Placed in alternate bays (allow shrinkage)
with contraction joints :
contraction joints
Bays
51. KAS-2012 51
Concrete in Beams & Column
Reinforcement correctly placed.
Correct cover required
Joints of shuttering to be plugged.
Mould releasing agent inside formwork
52. KAS-2012 52
STRIPPING TIME
Form work should not removed until good
strength has come.
Type of form work Time
Vertical wall, columns 16-24 hrs
Soffit of slab (Prop should be refixed immediately) 3 days
Soffit of beam (Prop should be refixed immediately) 7 days
Props to slab Span < 4.5 m 7 days
Props to slab Span > 4.5 m 14 days
Props of beam (Span < 6 m) 14 days
Props of beam (Span > 6 m) 21 days
54. KAS-2012 54
UNDER WATER CONCRETE
Tremie (means hopper) is used.
Funnel on top
Pipe of 200 mm size
Pipe bottom is plugged
Fill pipe with concrete
Lift pipe or jerk to release the plug
Keep bottom of pipe inside concrete
55. KAS-2012 55
Underwater Concrete
No compaction required as hydrostatic pr
of water compacts concrete.
Concrete of 0.3 W/C ratio can be placed
with Tremie.
Used for Pile or well foundation
56. KAS-2012 56
SLIP FORM TECHNIQUE
In this method, concrete is continuously placed, compacted & form work is
pulled up for next layer of concrete.
Vertical slip form for Tall structure like silo, chimney
Horizontal slip form paver machine (HSFP) for road construction.
Concrete is dumped in front of HSFP machine by dumpers.
Compaction by vibrator installed inside HSFP machines.
Finishing of surface by HSF paver.
Operation of road alignment, gradient, curve are controlled by
Computerized Laser Control system.
Speed of construction is 1 mt /min.
1 km of concrete road of 3.75 mt width is built in one day (16 hrs work).
Mumbai-Pune Expressway was constructed by this machine.
59. KAS-2012 59
COMPACTION OF CONCRETE
Compaction is a process of expelling the entrapped air inside
concrete mass.
During mixing, transporting & placing the concrete, air gets trapped
in concrete mass.
If this air is not removed, concrete will not get strength.
5 % of air voids reduces strength by 30 %
10 % of air voids reduces strength by 50 %
Durability of concrete is also reduces with air voids.
Insufficient compaction increases permeability of concrete.
Results in entry of aggressive chemicals in solution.
Chemicals attack concrete & reinforcement and life of concrete is
reduced.
60. KAS-2012 60
METHODS OF COMPACTION
1. Hand compaction
2. Compaction by vibration
3. Compaction by pressure &
jolting
4. Compaction by spinning
61. KAS-2012 61
(2) COMPACTION BY VIBRATION
a) Internal Vibrator
b) Formwork Vibrator
c) Table Vibrator
d) Platform Vibrator
e) Surface Vibrator
62. KAS-2012 62
(1) HAND COMPACTION
Hand Rodding
Poking inside concrete with 1-2 mt long steel rod
Ramming
Unreinforced foundation & ground floor work
Tamping
Wooden beam is used to beat concrete (low
thickness slab, road slab)
63. KAS-2012 63
COMPACTION BY VIBRATION
In hand compaction w/c ratio is more so
we get less strength in concrete.
In mechanical vibrator w/c can be kept low
so we get good strength.
65. KAS-2012 65
(a) INTERNAL VIBRATOR
Most common in use
Called, Needle Vibrator or Immersion vibrator or
Poker vibrator.
Consists : electrical/diesel power supply, Needle
and shaft.
Frequency of vibrations can be 12000 cycles
vibration per minute.
Needle diameter 20 to 75 mm
Length 25 to 90 cm.
Portable.
66. KAS-2012 66
FORMWORK VIBRATOR
Used for columns, walls, precast slab
Vibrator is clamped to formwork
Vibration is given to formwork
Vibration is transferred from formwork to
concrete
Useful in thin wall where reinforcement
obstruct the needle type vibrator.
Efficiency is lower then needle vibrator
67. KAS-2012 67
TABLE VIBRATOR
Vibrator is clamped to table
Used for concrete test cubes
Cubes are kept on table to get vibrations
Also used for small prefabricated slab
69. KAS-2012 69
PLATFORM VIBRATOR
Similar to table vibrator but of large size
Used for long concrete electrical pole,
railway sleeper,prefabricated roofing
element
71. KAS-2012 71
SURFACE VIBRATOR
Known as Screed Board Vibrator
Used for thin roof slab where needle
vibrator can not be used
Not effective if slab thickness is more then
15 cm.
73. KAS-2012 73
COMPACTION BY PRESSURE & JOLTING
Used for hollow blocks, solid concrete
blocks
Stiff concrete is vibrated, pressed & given
jolts
Stiff concrete is compacted to get dense
form & good strength is achived.
74. KAS-2012 74
VIBRATION BY SPINNING
New method
Used for concrete pipes
Concrete when spun at high speed gets
compaction by centrifugal force
75. KAS-2012 75
VIBRATORY ROLLER
Road rollers has vibrating system
Roller while moving on raod slab gives
vibrations
Used for Lean concrete (M10) for road
base
77. KAS-2012 77
PRECAUTIONS IN VIBRATING CONCRETE
Vibrator gets damaged if comes in contact
with hard object (Formwork, hard
concrete)
Switch on when needle is inside fresh
concrete mass
Should conform to IS 2505-1963
Degree of compaction can be recognized
from rising air bubbles & formation of thin
film on top
78. KAS-2012 78
HYDRATION OF CEMENT
Cement is made by Cao, SiO2, Al2O3, Fe2O3, MgO, K2O,
SO3
After burning in Kiln following products are made:
3Cao. SiO2 (C3S) - Tri calcium silicate
2Cao. SiO2(C2S) – Di cacium silicate
3Cao. Al2O3 (C3A) – Tri cacium aluminate
4Cao. Al2O3. Fe2O3(C3AF) -Tricalcium alumino ferrite.
On addition of water in cement reaction of C3S, C2S, C3A
& C3AF liberate heat. Heat is suside by addition of water.
79. KAS-2012 79
CURING OF CONCRETE
Curing is defined as “ making satisfactory moisture
content & favourable temperature” in concrete after
placing the concrete. So that hydration may continue
until the strength is developed.
Curing is required immediately after placing concrete.
During hydration, heat of hydration is released.
80. KAS-2012 80
CURING OF CONCRETE
Concrete delivers its strength by the hydration of cement
particles.
Hydration is continuous & long time process.
Rate of hydration is fast immediately after making the
concrete
Theoretically 0.23 w/c ratio required for hydration
0.15 w/c ratio required for filling the voids in gel.
Total 0.38 w/c ratio is optimum
In field condition, water evaporates & available water
quantity reduced for hydration
Extra water is given by curing
81. KAS-2012 81
METHODS OF CURING
a) Water curing
b) Membrane curing
c) Application of heat
d) Other methods
82. KAS-2012 82
WATER CURING
a) Immersion : Slab is kept in water tank
b) Ponding: Roof slab is filled with water
c) Spraying : water spary on concrete wall is
d) Wet covering : Wet gunny bags on wall
83. KAS-2012 83
MEMBRANE CURING
Concrete surface is covered by plastic
membrane
It is used where water availability is less.
Plastic sheet reduces evaporation in
concrete
Membrane is applied after 2 days of water
curing
84. KAS-2012 84
APPLICATION OF HEAT
Spraying of steam on concrete provides heat & moisture.
Higher temperature accelerates hydration rate & strength
of concrete is attended
Early strength of structure is obtained
Steam application possible at precast factory only.
Precast prestressed concrete girders of bridge are cured
with steam
Fast construction of bridge
85. KAS-2012 85
HIGH PRESSURE STEAM CURING
Superheated steam at high pressure (8.5 kg/cm2) & high
temperature(175 deg C) is applied on concrete.
This process is called “Autoclaving”
28 days strength of concrete is achieved in one day
Concrete becomes sulphate resistant
Low shrinkage in concrete
Used in production of Cellular concrete products(
Siporex, Celcrete)
86. FINISHING OF CONCRETE
Finishing is last operation of concrete making.
Finishing of top surface is required in roads, airport
strip, home floor
Methods of Finishing:
a) Form work Finish
b) Surface Treatment
c) Applied Finishes
SHAH K.A. 86
87. FORMWORK FINISH
Concrete obeys the shape of formwork
Grooves & lining on formwork plate gives
makes grooves & lining on concrete
Prefabricated tiles can be made of any
design
88. SURFACE TREATMENT
Domestic floor should be smooth, wear resistant, crack
free.
Mix should have good proportion without excess “Matrix”
Exposed aggregate finish : Colored pebbles on top layer
of wall
Bush Hammering : Electrically operated Brush with teeth
when applied on concrete removes top cement layer,
exposes aggregates and makes shining aggregates.
KAS-2012 88
89. APPLIED FINISH
Rough cast finish : mixture of cement, sand, round
gravel is applied on wall
Non slip finish: Railway platform & walkway around
pool are given non slippery finish by mixing large size
sand particles in floor concrete.