Concrete is a versatile building material that is strong, durable, and resistant to fire and corrosion. It is made by mixing cement, aggregates like sand and gravel, and water. As the cement hydrates, it hardens and binds the aggregates together. The document discusses the properties of concrete's constituent materials and how they affect the properties of hardened concrete, such as strength, permeability, thermal properties, and cracking. It also covers quality assurance measures like quality control plans, testing, and audits to ensure high quality concrete construction.
Deterioration of concrete structures can occur through various chemical, physical, and mechanical processes over time. Scaling and disintegration are forms of physical deterioration where the concrete's surface layers break down from freezing and thawing or weathering. Corrosion of reinforcement rebar can develop due to penetration of chloride ions or carbonation reducing the pH. Other causes include sulfate attack, alkali-aggregate reactions, abrasion, high temperatures, and erosion. Proper mix design and concrete quality can increase durability and prevent deterioration.
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 on various tests conducted on aggregates that are used in construction. It describes the aggregate abrasion value test, which determines the abrasion resistance and hardness of aggregates. It also summarizes the aggregate impact value test, which evaluates the resistance of aggregates to shocks and impacts, and the aggregate crushing value test, which determines the resistance of aggregates to crushing under gradually applied compressive loads. Finally, it outlines the procedure to determine the specific gravity and water absorption of aggregates.
This document discusses repairs, rehabilitation, and retrofitting of structures. It begins by defining repair, rehabilitation, and retrofitting. Repair returns a structure to its previous condition without improving strength. Rehabilitation considers strength by repairing damage. Retrofitting modifies existing structures to increase resistance to hazards like earthquakes. It provides examples of each process. The document outlines evaluation and quality control methods for repairs. It also discusses materials and techniques used for crack repair in structures, including epoxy injection grouting. Overall, the document provides an overview of restoring and upgrading structures through various repair, rehabilitation, and retrofitting methods.
Cracks in concrete and its remedial measures kamariya keyur
Cracks in concrete can be caused by various factors like plastic shrinkage, drying shrinkage, thermal variations, chemical reactions, errors in design and construction practices, structural overloads, foundation movement, and vegetation. The document classifies cracks as structural or non-structural and describes different types of cracks that can occur before or after concrete hardening. It provides details on the causes and prevention measures for different types of cracks like plastic shrinkage, drying shrinkage, crazing, thermal cracks, cracks due to chemical reactions, and those arising from poor construction practices. The summary focuses on the key information around classification, types, causes and remedies of cracks in concrete structures.
Pre-stressed concrete uses tensioned steel strands or bars to place concrete in compression and improve its tensile strength. There are two main methods - pre-tensioning and post-tensioning. Pre-tensioning tensions the strands before the concrete is poured, while post-tensioning tensions strands inside ducts after the concrete has cured. This compression counteracts tensile and flexural stresses from loads to reduce cracking and increase strength, allowing pre-stressed concrete to be lighter and more durable than reinforced concrete. It is commonly used in bridges, buildings, tanks, and other structures.
Self-compacting concrete was developed in Japan in the 1980s to solve problems with inadequate compaction of traditional concrete. It uses a high paste content and superplasticizers to create a concrete that can flow and consolidate under its own weight without vibration. Tests were developed to evaluate properties like filling ability, passing ability, and segregation resistance. Self-compacting concrete provides benefits like easier placement, faster construction, better surface finish, and improved durability. However, it also has higher costs associated with materials and mix design development.
Deterioration of concrete structures can occur through various chemical, physical, and mechanical processes over time. Scaling and disintegration are forms of physical deterioration where the concrete's surface layers break down from freezing and thawing or weathering. Corrosion of reinforcement rebar can develop due to penetration of chloride ions or carbonation reducing the pH. Other causes include sulfate attack, alkali-aggregate reactions, abrasion, high temperatures, and erosion. Proper mix design and concrete quality can increase durability and prevent deterioration.
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 on various tests conducted on aggregates that are used in construction. It describes the aggregate abrasion value test, which determines the abrasion resistance and hardness of aggregates. It also summarizes the aggregate impact value test, which evaluates the resistance of aggregates to shocks and impacts, and the aggregate crushing value test, which determines the resistance of aggregates to crushing under gradually applied compressive loads. Finally, it outlines the procedure to determine the specific gravity and water absorption of aggregates.
This document discusses repairs, rehabilitation, and retrofitting of structures. It begins by defining repair, rehabilitation, and retrofitting. Repair returns a structure to its previous condition without improving strength. Rehabilitation considers strength by repairing damage. Retrofitting modifies existing structures to increase resistance to hazards like earthquakes. It provides examples of each process. The document outlines evaluation and quality control methods for repairs. It also discusses materials and techniques used for crack repair in structures, including epoxy injection grouting. Overall, the document provides an overview of restoring and upgrading structures through various repair, rehabilitation, and retrofitting methods.
Cracks in concrete and its remedial measures kamariya keyur
Cracks in concrete can be caused by various factors like plastic shrinkage, drying shrinkage, thermal variations, chemical reactions, errors in design and construction practices, structural overloads, foundation movement, and vegetation. The document classifies cracks as structural or non-structural and describes different types of cracks that can occur before or after concrete hardening. It provides details on the causes and prevention measures for different types of cracks like plastic shrinkage, drying shrinkage, crazing, thermal cracks, cracks due to chemical reactions, and those arising from poor construction practices. The summary focuses on the key information around classification, types, causes and remedies of cracks in concrete structures.
Pre-stressed concrete uses tensioned steel strands or bars to place concrete in compression and improve its tensile strength. There are two main methods - pre-tensioning and post-tensioning. Pre-tensioning tensions the strands before the concrete is poured, while post-tensioning tensions strands inside ducts after the concrete has cured. This compression counteracts tensile and flexural stresses from loads to reduce cracking and increase strength, allowing pre-stressed concrete to be lighter and more durable than reinforced concrete. It is commonly used in bridges, buildings, tanks, and other structures.
Self-compacting concrete was developed in Japan in the 1980s to solve problems with inadequate compaction of traditional concrete. It uses a high paste content and superplasticizers to create a concrete that can flow and consolidate under its own weight without vibration. Tests were developed to evaluate properties like filling ability, passing ability, and segregation resistance. Self-compacting concrete provides benefits like easier placement, faster construction, better surface finish, and improved durability. However, it also has higher costs associated with materials and mix design development.
The document discusses repair and rehabilitation of concrete structures. It describes various causes of distress in concrete structures including structural causes, errors in design/construction, chemical reactions, and weathering. It then outlines the evaluation process for repair projects, including visual inspection, non-destructive testing, and laboratory testing to determine the extent of damage and appropriate repair methods. Specific causes of reinforcement corrosion like cracks, moisture, and concrete permeability are explained along with remedial measures.
Causes of deterioration of concrete structuresKarthi Kavya
The document discusses types of deterioration that can occur in concrete structures. It identifies three main types: distress in concrete, permeability of concrete, and aggressive deterioration agents. Distress can be physical, chemical, or mechanical due to issues like high water-cement ratio, inadequate curing, poor aggregates, overloading, or design deficiencies. Permeability is increased by porosity, microcracks, and dampness/seepage, allowing chemicals to enter. Major agents are chlorides, sulfates, and alkali-silica reaction, which can cause corrosion, cracking, or expansion through carbonation, sulfate attack, or silica gel formation.
This document discusses concrete distress, its causes, and concrete repair systems. It defines distress as damage to concrete that can occur during production or service life due to varying conditions. Common causes of distress include structural loads, errors in design and construction, drying shrinkage, corrosion, and deterioration over time from chemical reactions, freezing/thawing, or weathering. Proper concrete repair requires determining the cause of damage, evaluating its extent, selecting repair methods, preparing the surface, applying repair materials, and curing. Durable repairs depend on high quality workmanship and materials to ensure the repair is well-bonded and resistant to future distress.
this presentation deals with the different types of cracks generated in concrete during its usage and after its application and also methods to retrofit these cracks
This document provides an overview of concrete, including its history and types. It focuses on high-strength concrete (HSC), describing how it is made with a low water-cement ratio and additives. Guidelines are given for selecting materials for HSC to achieve different compressive strengths. The differences between normal strength concrete and HSC are outlined. Applications of HSC include reducing column sizes in buildings and bridges and increasing floor area in high-rise buildings. Examples are given of bridges that used HSC to decrease volume and increase spans.
This document is a study on recycled aggregate concrete conducted by Neelanjan Sarkar from Murshidabad College of Engineering & Technology. It discusses what recycled aggregate concrete is, its characteristics, classification, production process, uses, applications, and benefits. Recycled aggregate concrete is produced using crushed waste concrete as a substitute for natural aggregates. It has properties like lower strength, density and higher water absorption compared to normal concrete. However, using recycled materials reduces waste and saves on costs and natural resource usage, making it a more sustainable construction material.
Distress of concrete structures & their repair techniquesZaid Ansari
This document discusses concrete distress and repair techniques. It begins by explaining that concrete structures may need repair after 25-30 years of service without maintenance. It then lists common causes of concrete distress like weathering, environmental effects, poor design/construction, and water leakage leading to corrosion. The document outlines expected service lives for different structure types. It also describes common concrete failure modes and causes of early deterioration. The remainder of the document discusses techniques for identifying distressed concrete, various repair materials and methods, and the need for trained concrete workers.
This document discusses retrofitting of structures. Retrofitting is required when structures are damaged or do not meet current seismic standards. It summarizes various retrofitting techniques such as adding shear walls, infill walls, steel bracing, wall thickening, wing walls, mass reduction, base isolation, and jacketing structural elements. It provides examples of existing retrofitted structures in Gujarat. Retrofitting increases strength and ductility but can reduce space and increase foundation loads. Materials discussed include steel, fiber reinforced polymer, and reinforced concrete.
This document discusses structural analysis methods for statically indeterminate structures. It defines key terms like degree of static indeterminacy, internal and external redundancy, and methods for analyzing indeterminate structures. Specific methods discussed include the flexibility matrix method, consistent deformation method, and unit load method. Examples of statically indeterminate beams and frames are also provided.
This document provides information on aggregates used in traditional building materials. It defines aggregates as fillers used with binding materials that are derived from rocks. Aggregates make up 70-80% of concrete's volume and influence its properties. Aggregates are broadly classified into fine aggregates smaller than 4.75mm and coarse aggregates larger than 4.75mm. The document discusses various types of coarse aggregates based on geological origin, size, shape, and unit weight. It also covers properties of aggregates like strength, shape, specific gravity, moisture content and tests conducted on aggregates. Alkali aggregate reaction and measures to prevent it are summarized.
This presentation gives a brief introduction on FRC's history, definition and why is it used. Types of FRC's and it's applications is explained in detail in later stages.Also, it covers various properties that affects FRC and a Case study in end.
Introduction about Repair & Rehabilitation of Structures
Repair of Structures
Rehabilitation of Structures
Maintenance of Structures
Various Methods of Maintenance
This document outlines 8 techniques for repairing cracks in concrete structures: 1) Sealing with epoxies, 2) Routing and sealing, 3) Stitching, 4) External stressing, 5) Overlays, 6) Grouting, 7) Blanketing, and 8) Autogenous healing. Sealing with epoxies involves injecting epoxy compounds into cracks at high pressure. Routing and sealing enlarges cracks and fills them with sealants. Stitching reestablishes tensile strength across major cracks using metal units drilled into crack walls. External stressing closes cracks by applying compression to overcome tensile stresses. Overlays provide a sealed surface for multiple cracks. Grouting is an alternative
This power point presentation gives you information about the various chemicals, admixtures used to repair members and improve the properties of concrete. it gives you information about the various types of concrete. it gives you information about the various methods of repair.
This presentation has been prepared by civil engineering students of Tolani Foundation Gandhidham Polytechnic:
DHAWANI LAVISH
GAYAKWAD TEJAS
GORASIYA MAYUR
HIRANI YATIN
KATARMAL DARSHAN
LALWANI PIYUSH
MALI VISHNU
PATEL PARTH
PRAJAPATI JAYESH
PRAJAPATI KALPESH
Thank You!!
This document discusses self-compacting concrete (SCC), which does not require vibration for compaction. It can be designed to have good filling ability, passing ability, and segregation resistance. The document outlines the objectives, specifications, advantages, applications, characteristics, and test methods for SCC. It also reviews literature on using fibers or fly ash to improve properties of hardened SCC and its alkaline resistance.
This document discusses quality control in concrete construction. It explains that concrete is made by mixing cement, fine aggregate, coarse aggregate, water, and admixtures. Quality control is important to ensure the concrete has strength, durability, and aesthetics. Quality control involves testing the materials used, the fresh concrete mix, and the hardened concrete. Tests on fresh concrete include slump and compacting factor tests, while tests on hardened concrete include compression, tensile, and flexural strength tests. The document outlines the quality control process from the production of materials to placement and curing of the concrete.
Highway maintenance is the routine work needed to keep highways in safe and usable condition, and includes physical activities like sealing cracks and patching potholes as well as traffic services like removing snow and painting lines. Highway maintenance programs are designed to counteract the effects of weather, vandalism, plant growth, traffic wear, aging, material failures, and design flaws in order to protect investments in roads and maintain safety and economic benefits. Regular maintenance is required for all pavements as stresses from temperature, moisture, traffic, and earth movements constantly impact the road surface over time.
This document provides information on concrete mix design, including objectives, basic considerations, and the IS (Indian Standards) method for mix design. The objectives of mix design are to achieve the desired workability, strength, durability, and cost. Basic considerations include cost, specifications, workability, strength, durability, and aggregate grading. The IS method is then described in steps, including selecting target strength, water-cement ratio, air content, water and sand contents, cement content, and aggregate contents. An example application of the IS method is also provided.
The document discusses various topics related to concrete works at construction sites, including factors that cause material segregation and bleeding in fresh concrete; methods of preparing, transporting, casting, placing, and compacting concrete; and criteria for determining when concrete has hardened, such as achieving sufficient compression and tensile strength. It also describes common tests to evaluate the workability and strength of fresh and hardened concrete, as well as standard procedures for conducting these tests.
Effect of Magnetized Water on Mechanical Properties of Foam ConcreteIRJET Journal
1. The document investigates the effect of using magnetized water on the properties of foam concrete.
2. Tests were conducted on foam concrete mixes using water passed through a magnetic field 2-15 times, finding that magnetized water improved foam stability, workability, strength, shrinkage resistance, and durability compared to regular water.
3. Compressive strengths were found to be 61%, 50%, and 39% higher at 7, 14, and 28 days for magnetized water mixes. Water absorption and shrinkage also decreased, while acid resistance, thermal insulation, and sound absorption increased with more magnetization.
The document discusses repair and rehabilitation of concrete structures. It describes various causes of distress in concrete structures including structural causes, errors in design/construction, chemical reactions, and weathering. It then outlines the evaluation process for repair projects, including visual inspection, non-destructive testing, and laboratory testing to determine the extent of damage and appropriate repair methods. Specific causes of reinforcement corrosion like cracks, moisture, and concrete permeability are explained along with remedial measures.
Causes of deterioration of concrete structuresKarthi Kavya
The document discusses types of deterioration that can occur in concrete structures. It identifies three main types: distress in concrete, permeability of concrete, and aggressive deterioration agents. Distress can be physical, chemical, or mechanical due to issues like high water-cement ratio, inadequate curing, poor aggregates, overloading, or design deficiencies. Permeability is increased by porosity, microcracks, and dampness/seepage, allowing chemicals to enter. Major agents are chlorides, sulfates, and alkali-silica reaction, which can cause corrosion, cracking, or expansion through carbonation, sulfate attack, or silica gel formation.
This document discusses concrete distress, its causes, and concrete repair systems. It defines distress as damage to concrete that can occur during production or service life due to varying conditions. Common causes of distress include structural loads, errors in design and construction, drying shrinkage, corrosion, and deterioration over time from chemical reactions, freezing/thawing, or weathering. Proper concrete repair requires determining the cause of damage, evaluating its extent, selecting repair methods, preparing the surface, applying repair materials, and curing. Durable repairs depend on high quality workmanship and materials to ensure the repair is well-bonded and resistant to future distress.
this presentation deals with the different types of cracks generated in concrete during its usage and after its application and also methods to retrofit these cracks
This document provides an overview of concrete, including its history and types. It focuses on high-strength concrete (HSC), describing how it is made with a low water-cement ratio and additives. Guidelines are given for selecting materials for HSC to achieve different compressive strengths. The differences between normal strength concrete and HSC are outlined. Applications of HSC include reducing column sizes in buildings and bridges and increasing floor area in high-rise buildings. Examples are given of bridges that used HSC to decrease volume and increase spans.
This document is a study on recycled aggregate concrete conducted by Neelanjan Sarkar from Murshidabad College of Engineering & Technology. It discusses what recycled aggregate concrete is, its characteristics, classification, production process, uses, applications, and benefits. Recycled aggregate concrete is produced using crushed waste concrete as a substitute for natural aggregates. It has properties like lower strength, density and higher water absorption compared to normal concrete. However, using recycled materials reduces waste and saves on costs and natural resource usage, making it a more sustainable construction material.
Distress of concrete structures & their repair techniquesZaid Ansari
This document discusses concrete distress and repair techniques. It begins by explaining that concrete structures may need repair after 25-30 years of service without maintenance. It then lists common causes of concrete distress like weathering, environmental effects, poor design/construction, and water leakage leading to corrosion. The document outlines expected service lives for different structure types. It also describes common concrete failure modes and causes of early deterioration. The remainder of the document discusses techniques for identifying distressed concrete, various repair materials and methods, and the need for trained concrete workers.
This document discusses retrofitting of structures. Retrofitting is required when structures are damaged or do not meet current seismic standards. It summarizes various retrofitting techniques such as adding shear walls, infill walls, steel bracing, wall thickening, wing walls, mass reduction, base isolation, and jacketing structural elements. It provides examples of existing retrofitted structures in Gujarat. Retrofitting increases strength and ductility but can reduce space and increase foundation loads. Materials discussed include steel, fiber reinforced polymer, and reinforced concrete.
This document discusses structural analysis methods for statically indeterminate structures. It defines key terms like degree of static indeterminacy, internal and external redundancy, and methods for analyzing indeterminate structures. Specific methods discussed include the flexibility matrix method, consistent deformation method, and unit load method. Examples of statically indeterminate beams and frames are also provided.
This document provides information on aggregates used in traditional building materials. It defines aggregates as fillers used with binding materials that are derived from rocks. Aggregates make up 70-80% of concrete's volume and influence its properties. Aggregates are broadly classified into fine aggregates smaller than 4.75mm and coarse aggregates larger than 4.75mm. The document discusses various types of coarse aggregates based on geological origin, size, shape, and unit weight. It also covers properties of aggregates like strength, shape, specific gravity, moisture content and tests conducted on aggregates. Alkali aggregate reaction and measures to prevent it are summarized.
This presentation gives a brief introduction on FRC's history, definition and why is it used. Types of FRC's and it's applications is explained in detail in later stages.Also, it covers various properties that affects FRC and a Case study in end.
Introduction about Repair & Rehabilitation of Structures
Repair of Structures
Rehabilitation of Structures
Maintenance of Structures
Various Methods of Maintenance
This document outlines 8 techniques for repairing cracks in concrete structures: 1) Sealing with epoxies, 2) Routing and sealing, 3) Stitching, 4) External stressing, 5) Overlays, 6) Grouting, 7) Blanketing, and 8) Autogenous healing. Sealing with epoxies involves injecting epoxy compounds into cracks at high pressure. Routing and sealing enlarges cracks and fills them with sealants. Stitching reestablishes tensile strength across major cracks using metal units drilled into crack walls. External stressing closes cracks by applying compression to overcome tensile stresses. Overlays provide a sealed surface for multiple cracks. Grouting is an alternative
This power point presentation gives you information about the various chemicals, admixtures used to repair members and improve the properties of concrete. it gives you information about the various types of concrete. it gives you information about the various methods of repair.
This presentation has been prepared by civil engineering students of Tolani Foundation Gandhidham Polytechnic:
DHAWANI LAVISH
GAYAKWAD TEJAS
GORASIYA MAYUR
HIRANI YATIN
KATARMAL DARSHAN
LALWANI PIYUSH
MALI VISHNU
PATEL PARTH
PRAJAPATI JAYESH
PRAJAPATI KALPESH
Thank You!!
This document discusses self-compacting concrete (SCC), which does not require vibration for compaction. It can be designed to have good filling ability, passing ability, and segregation resistance. The document outlines the objectives, specifications, advantages, applications, characteristics, and test methods for SCC. It also reviews literature on using fibers or fly ash to improve properties of hardened SCC and its alkaline resistance.
This document discusses quality control in concrete construction. It explains that concrete is made by mixing cement, fine aggregate, coarse aggregate, water, and admixtures. Quality control is important to ensure the concrete has strength, durability, and aesthetics. Quality control involves testing the materials used, the fresh concrete mix, and the hardened concrete. Tests on fresh concrete include slump and compacting factor tests, while tests on hardened concrete include compression, tensile, and flexural strength tests. The document outlines the quality control process from the production of materials to placement and curing of the concrete.
Highway maintenance is the routine work needed to keep highways in safe and usable condition, and includes physical activities like sealing cracks and patching potholes as well as traffic services like removing snow and painting lines. Highway maintenance programs are designed to counteract the effects of weather, vandalism, plant growth, traffic wear, aging, material failures, and design flaws in order to protect investments in roads and maintain safety and economic benefits. Regular maintenance is required for all pavements as stresses from temperature, moisture, traffic, and earth movements constantly impact the road surface over time.
This document provides information on concrete mix design, including objectives, basic considerations, and the IS (Indian Standards) method for mix design. The objectives of mix design are to achieve the desired workability, strength, durability, and cost. Basic considerations include cost, specifications, workability, strength, durability, and aggregate grading. The IS method is then described in steps, including selecting target strength, water-cement ratio, air content, water and sand contents, cement content, and aggregate contents. An example application of the IS method is also provided.
The document discusses various topics related to concrete works at construction sites, including factors that cause material segregation and bleeding in fresh concrete; methods of preparing, transporting, casting, placing, and compacting concrete; and criteria for determining when concrete has hardened, such as achieving sufficient compression and tensile strength. It also describes common tests to evaluate the workability and strength of fresh and hardened concrete, as well as standard procedures for conducting these tests.
Effect of Magnetized Water on Mechanical Properties of Foam ConcreteIRJET Journal
1. The document investigates the effect of using magnetized water on the properties of foam concrete.
2. Tests were conducted on foam concrete mixes using water passed through a magnetic field 2-15 times, finding that magnetized water improved foam stability, workability, strength, shrinkage resistance, and durability compared to regular water.
3. Compressive strengths were found to be 61%, 50%, and 39% higher at 7, 14, and 28 days for magnetized water mixes. Water absorption and shrinkage also decreased, while acid resistance, thermal insulation, and sound absorption increased with more magnetization.
This document discusses concrete mix design. It defines mix design as determining the relative proportions of concrete ingredients to achieve desired properties economically. The key materials used are cement, fine and coarse aggregates, water, and admixtures. Mix designs can be nominal, standard, or designed. Factors that define mix proportions include compressive strength, workability, durability, aggregate type and size, water-cement ratio, and quality control. Common mix design methods are the IS, ACI, Road Note 4, and IRC 44 methods.
This document discusses quality assurance for concrete construction. It covers ensuring concrete meets requirements for strength, permeability, thermal properties and cracking resistance. Factors like climate, temperature, chemicals and construction errors can affect concrete properties. Quality assurance involves proper design, materials, workmanship and maintenance. It outlines developing a quality assurance plan to define tasks, responsibilities, control procedures and documentation to ensure the structure performs satisfactorily over its lifespan.
This document discusses quality assurance for concrete construction. It covers ensuring concrete meets requirements for strength, permeability, thermal properties and cracking resistance. Factors like climate, temperature, chemicals and construction errors can affect concrete properties over time. Quality assurance involves proper design, materials selection, workmanship and documentation. It outlines responsibilities and ensures the structure will perform satisfactorily. The document also discusses concrete strength testing, permeability, thermal properties like conductivity and cracking classification. It examines how climate, temperature, chemicals can impact concrete durability.
This document discusses quality assurance for concrete structures. It defines quality assurance as ensuring all components of a structure perform as intended over the structure's lifetime. It identifies key parties that benefit from quality assurance, including clients, designers, material producers, contractors, and users. The document then describes the three main components of a quality management system: quality assurance plans, quality control processes, and quality audits. It provides details on what should be addressed in quality assurance plans and quality control processes. Finally, it discusses how quality audits are used to monitor and document quality assurance and control programs throughout the design and construction phases.
This document summarizes different methods of curing concrete and their effectiveness. It discusses that proper curing is crucial to obtaining design strength and maximum durability in concrete. Various curing methods are described, including ponding, fogging, wet coverings using burlap or impervious paper, membrane-forming compounds, internal curing using lightweight aggregates, leaving forms in place, and steam curing. Ponding and wet coverings using saturated materials are identified as most effective at maintaining moisture, while membrane compounds are more practical. The document concludes that curing method has a fundamental effect on concrete's mechanical properties and strengths. Immersion curing generally provides the best results.
IRJET- Effect of Different Curing on Strength of ConcreteIRJET Journal
This document analyzes the effect of different curing methods on the compressive strength of concrete. Concrete cubes were cured using three methods - immersion (water curing), sprinkling, and plastic sheeting. Testing at 7 and 28 days found that water curing and sprinkling provided higher compressive strengths than plastic sheeting. Plastic sheeting allowed more drying, hindering the hydration process and reducing strength. Overall, water curing is recommended to achieve better compressive strength.
what is polymer concrete, types, properties, material used in manufacturing process , manufacturing process, applications and their advantages. case study on polymer composite concrete.
Cement concrete is a composite material consisting of a binding material (cement or lime), aggregates (fine and coarse), water, and admixtures. The cement and water form a paste that coats the aggregates and binds them together. Concrete can be classified based on its constituents, method of production, place of casting, and bulk density. Proper curing is important for concrete to gain strength and hardness through hydration. Common curing methods include water curing, membrane curing, and steam curing. The water-cement ratio significantly impacts concrete strength, with lower ratios producing stronger concrete.
Experimental Investigation of High – Strength Characteristics of Self Curing ...IJMTST Journal
In concrete structures exposed to the ambient air at early ages, the moisture content in concrete
decreases due to moisture diffusion. In addition, self-desiccation due to hydration of cement causes an
additional decrease of moisture content in concrete at early ages, especially for high-strength concrete. In this
study, the internal relative humidity in drying concrete specimens was measured at early ages. Furthermore,
the variation of relative humidity due to self-desiccation in sealed specimen was measured. The moisture
distribution in low-strength concrete with high water/cement ratio was mostly influenced by moisture
diffusion due to drying rather than self-desiccation. In high-strength concrete with low water/cement ratio,
however, self-desiccation had a considerable influence on moisture distribution. The results obtained from
the moisture diffusion theory were in good agreement with experimental results.
The document discusses various properties of hardened concrete including strength, durability, impermeability and stability. It describes different types of strength such as compressive, tensile, flexural and bond strength. It also discusses factors that affect the strength of concrete such as water-cement ratio, cement quality, aggregate size and properties of the concrete ingredients. Various tests to determine the strength and other properties of hardened concrete are also summarized.
INVESTIGATION ON CHARACTERSTICS PROPERTIES OF POLYPROPYLENE FIBRE – MODIFIED ...AsuSingh2
The document presents a project investigating the properties of polypropylene fibre-modified bitumen for road applications. It discusses the objectives, work plan, literature review on previous studies, description of materials used including polypropylene fibre and bitumen, test methodology, results from aggregate and bitumen testing, and plans for further tests and analysis. The project aims to study how adding polypropylene fibres to bitumen affects its properties to enhance road pavement design and durability. Various tests were conducted on aggregates and bitumen samples with and without fibre addition, and results were presented and analyzed.
IRJET- Experimental Approach for Underwater Concrete FormulationsIRJET Journal
This document discusses experimental approaches for developing underwater concrete formulations. It begins with an introduction to underwater concreting and a literature review showing limited recent work in this area. It then outlines 15 experimental concrete mixes containing ordinary Portland cement, superplasticizers, mineral admixtures, and various natural and synthetic viscosity-enhancing admixtures. The document discusses the properties required for underwater concrete, including flowability, bleed resistance, and strength development. It also reviews methods for testing underwater concrete, including washout resistance. The goal of the experiments is to identify admixtures that provide effective washout resistance at low cost using available natural materials.
The document describes various steps in the production of aggregates for concrete:
1) Quarrying of raw materials
2) Hauling and stockpiling of raw materials
3) Crushing, screening, and washing to produce the final product
4) Stockpiling of finished aggregates to prevent mixing
5) Delivery of aggregates to construction sites
It also discusses testing aggregates to check for impurities and harmful substances, which can negatively impact the properties of concrete. Two methods described to test for alkali-aggregate reaction are petrographic analysis and following the risk assessment guidelines in CSA standard A23.2-27A.
Concrete is a composite material made of aggregates, sand, cement and water. It has many useful properties such as versatility, durability and fire resistance which make it widely used in construction. Fresh concrete must have adequate workability and consistency to be properly mixed, placed and consolidated. Proper curing is also important to allow the cement to fully hydrate and gain strength over time. While concrete has advantages, it also has disadvantages like low tensile strength and requires careful mixing to ensure uniformity.
IRJET- Analysis of Compressive Strength of Self Curing Concrete Made using Po...IRJET Journal
This document analyzes the compressive strength of self-curing concrete made using Polyethylene Glycol (PEG400). PEG400 is used as an internal curing compound to prevent moisture loss from concrete and allow for more complete hydration. Tests were conducted on M20 grade concrete with 0-1.5% PEG400 by weight of cement. Results found that 0.5-1% PEG400 concrete had higher 7 and 28-day compressive strengths than plain concrete, with less cracking. PEG400 improved workability and water retention, allowing for better strength development over time compared to traditional curing methods.
This document discusses the properties of fresh concrete and factors that affect its strength. It covers topics like workability, slump testing, batching, mixing, placing, and curing concrete. It also examines several factors that influence the strength of concrete, including water-cement ratio, aggregate type and content, cement content, concrete maturity/age, compaction, temperature, relative humidity, and curing methods. Maintaining a proper water-cement ratio, using well-graded aggregates, adequately compacting and curing the concrete can increase its strength.
Properties of fresh and Hardened ConcreteVijay RAWAT
The document discusses various properties of fresh and hardened concrete. It describes workability, consistency, segregation, bleeding, mixing, placing, consolidating, and curing of fresh concrete. It also discusses compressive strength, tensile strength, modulus of elasticity, permeability, and durability of hardened concrete. The key properties of fresh concrete include workability, consistency, segregation, bleeding, setting time, and uniformity. Compressive strength is identified as the most important property of hardened concrete.
This is an overview of my career in Aircraft Design and Structures, which I am still trying to post on LinkedIn. Includes my BAE Systems Structural Test roles/ my BAE Systems key design roles and my current work on academic projects.
Cricket management system ptoject report.pdfKamal Acharya
The aim of this project is to provide the complete information of the National and
International statistics. The information is available country wise and player wise. By
entering the data of eachmatch, we can get all type of reports instantly, which will be
useful to call back history of each player. Also the team performance in each match can
be obtained. We can get a report on number of matches, wins and lost.
An In-Depth Exploration of Natural Language Processing: Evolution, Applicatio...DharmaBanothu
Natural language processing (NLP) has
recently garnered significant interest for the
computational representation and analysis of human
language. Its applications span multiple domains such
as machine translation, email spam detection,
information extraction, summarization, healthcare,
and question answering. This paper first delineates
four phases by examining various levels of NLP and
components of Natural Language Generation,
followed by a review of the history and progression of
NLP. Subsequently, we delve into the current state of
the art by presenting diverse NLP applications,
contemporary trends, and challenges. Finally, we
discuss some available datasets, models, and
evaluation metrics in NLP.
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Data Communication and Computer Networks Management System Project Report.pdfKamal Acharya
Networking is a telecommunications network that allows computers to exchange data. In
computer networks, networked computing devices pass data to each other along data
connections. Data is transferred in the form of packets. The connections between nodes are
established using either cable media or wireless media.
2. CONTENTS
Quality assurance for concrete construction as
built concrete properties, strength,
permeability, thermal properties and cracking
3. Concrete Properties
◼ Versatile
◼ Pliable when mixed
◼ Strong & Durable
◼ Does not Rust or Rot
◼ Does Not Need a Coating
◼ Resists Fire
4. CONSTITUENT MATERIALS AND PROPERTIES
Setting, Hydration and Hardening
- When cement is mixed with sufficient water, it loses its plasticity and
slowly forms into a hard rock-type material; this whole process is
called setting.
- Initial set: Initially the paste loses its fluidity and within a few hours
a noticeable hardening occurs - Measured by Vicat’s apparatus
- Final set: Further to building up of hydration products is the
commencement of hardening process that is responsible for strength
of concrete - Measured by Vicat’s apparatus
- Gypsum retards the setting process
5. HYDRATION OF CEMENT
2(3CaO.SiO2) + 6H2O = 3CaO.2SiO2.3H2O + 3Ca(OH)2
(Tricalcium silicate) (Tobermerite gel)
2(2CaO.SiO2) + 4H2O = 3CaO.2SiO2.3H2O+Ca(OH)2
(Dicalcium silicate) (Tobermerite gel)
3CaO.Al2O3 + 12H2O + Ca(OH)2 = 3CaO.Al2O3. Ca(OH)2.12H2O
(Tricalcium aluminate) (Tetra-calcium aluminate hydrate)
4CaO.Al2O3..Fe2O3 + 10H2O + 2Ca(OH)2 = 6CaO.Al2O3. Fe2O3.12H2O
(Tetra-calcium alumino-ferrite) (Calcium alumino-ferrite hydrate)
3CaO.Al2O3+10H2O+ CaSO4.2H2O = 3CaO.Al2O3.CaSO4.12H2O
(Tricalcium aluminate) (Calcium sulphoaluminate hydrate)
- C3S hardens rapidly: responsible for early strength
- C2S hardens slowly and responsible for strength gain beyond one
week
- Heat of hydration: Hydration is always accompanied by release of
heat
- C3A liberates the most heat - C2S liberates the least
6. CONSTITUENT MATERIALS AND PROPERTIES
Properties of Aggregates, Water and Admixtures
- Aggregates make up up 59-75% of concrete volume; paste constitutes
25-40% of concrete volume. Volume of cement occupies 25-45% of the
paste and water makes up to 55-75%. It also contains air, which varies
from 2-8% by volume
- Strength of concrete is dependent on the strength of aggregate particles
and the strength of hardened paste
Properties of Aggregates
Voids: Represent the amount of air space between the aggregate particles -
Course aggregates contain 30-50% of voids and fine aggregate 35-40%
Moisture content represents the amount of water in aggregates: absorbed
and surface moisture - Course aggregates contain very little absorbed
water while fine aggregates contain 3-5% of absorbed water and 4-5%
surface moisture
7. CONSTITUENT MATERIALS AND PROPERTIES
Gradation: Grading refers to a process that determines the particle size
distribution of a representative sample of an aggregate - Measured in
term of fineness modulus - Sieve sizes for course aggregates are: 3/4”,
1/2”, 3/8”, #4 and #8 - Sieve sizes for fine aggregates are #4, #8 , #16, #30,
#50 and #100
Durability of concrete: Determined by abrasion resistance and toughness
Chemical reactivity: determined by the alkali-aggregate reaction
Properties of Water
Any drinkable water can be used for concrete making - Water containing
more than 2000 ppm of dissolved salts should be tested for its effect on
concrete
- Chloride ions not more than 1000 ppm - Sulphate ions not more than
3000 ppm
- Bicarbonate ions not more than 400 ppm
8. CONSTITUENT MATERIALS AND PROPERTIES
Need and types
Admixture are materials that are added to plastic concrete to change
one or more properties of fresh or hardened concrete.
To fresh concrete: Added to influence its workability, setting times
and heat of hydration
To hardened concrete : Added to influence the concrete’s durability
and strength
Types: Chemical admixtures and mineral admixtures
Chemical: Accelerators, retarders, water-reducing and air-
entraining
Mineral : Strength and durability
9. MAKING AND TESTING OF CONCRETE (Cont’d)
Curing of concrete : Process of maintaining enough moisture in
concrete to maintain the rate of hydration during its early stages
- The most important single step in developing concrete
strength, after proper mix design - If not properly carried out,
affects its strength, water tightness and durability
Methods of curing:
1. Ponding or immersion
2. spraying or fogging
3. wet coverings (with burlap, cotton mats or tugs)
4. Impervious paper (two sheets of Kraft paper cemented
together by bituminous adhesive with fiber reinforcements)
5. Plastic sheets (Polyethyelene films 0.10 mm thick)
6. membrane-forming curing compound; Steam curing
10. Top of Slab being protected during cold weather
11. Properties of Fresh Concrete
• Concrete should be such that it can be
transported, placed, compacted and finished
without harmful segregation
• The mix should maintain its uniformity and
not bleed excessively
13. CONCRETE STRENGTH
FRESH CONCRETE
• SLUMP TEST
• CONSISTANCY TEST
• COMPACTION FACTOR TEST
HARDENED CONCRETE
COMPRESSIVE STRENGTH
TENSILE STRENGTH
FLEXURAL STRENGTH
14. QUALITY ASSURANCES FOR
CONCRETE CONSTRUCTION
Quality is a measure of the degree of
excellence and is indeed related to
fulfillment enjoyed by the user. In concrete
construction, even if rigid quality is not
followed, the material performs for a short
while without loss of strength.
16. QUALITY ASSURANCE PLAN
- Organizational Set-up
- Responsibilities of personnel
- Coordinating personnel
- Quality control measure
- Control norms and limit
- Acceptance/rejection criteria
- Inspection program
- Sampling, testing and documentation
- Material specification and qualification
- Corrective measure for noncompliance
- Resolution of disputed/difficulties
- Preparation of maintenance record
17. Quality Control Plan
It is a system of procedures and standards by
which the contractor, the product manufacture
and the engineer monitor the properties of the
product.
Generally the contracting agency is responsible
for the QC process
A contractor responsible for quality control
incurs a cost for it, which is less than the
uncontrolled cost for correcting the defective
workmanship or replacing the defective material
18. PERMEABILITY
The rates at which liquids and
gases can move in the concrete
are determined by its
permeability.
19. FACTORS AFFECTING PERMEABILITY
a)Varying and continuing hydration of the specimen.
b) Incomplete and variable initial saturation.
c) Lack of absolute water cleanliness.
d) Chemical reaction of specimen with the test fluid
e) Effect of dissolved gases where high pressure air is used
to pressurize the water.
f) Silting due to movement of fines.
g) Micro structural collapse and macroscopic instability
when very high flow pressures are used.
h) Lack of attainment of steady state condition.
20. Quality Audit
This is the system of tracing and
documentation of quality assurance and
quality control program.
It is the responsibility of the process owner.
Both design and construction processes comes
under this process.
The concept of QA encompasses the project
as a whole.
Each element of the project comes under the
preview of quality audit.
21. THERMAL PROPERTIES
Thermal properties are important in
structures in which temperature differentials
occur including those due to solar radiation
during casting and the inherent heat of
hydration.
Thermal conductivity
Thermal diffusivity
Specific heat
Coefficient of thermal expansion
22. THERMAL CONDUCTIVITY
This measures the ability of material to
conduct heat.Thermal conductivity is
measured in joules per second per square
meter of area of body when the
temperature deference is 10C per meter
thickness of the body.
The conductivity of concrete depends on
type of aggregate, moisture content,
density and temperature of concrete.
23. Thermal Diffusivity
Diffusivity represents the rate at which
temperature changes within the concrete
mass.
Conductivity
Diffusivity = ---------------
C X P
Where C is the specified heat and P is the
density of concrete
24. Specific Heat
It is defined as the quantity of heat
required to raise the temperature
of a unit mass of a material by one
degree centigrade.T
he common range of values for
concrete is between 840 and 1170
j/kg per 0C.
25. Coefficient of thermal
expansion
Coefficient of thermal expansion is
defined as the change in length per degree
change of temperature.
In concrete it depends upon the mix
proportions.Type of aggregate and
content of aggregate influences the
coefficients of thermal expansion of
concrete
28. DEGRADATION MECHANISMS IN
CONCRETE STRUCTURES
1. Freeze-thaw damage (physical effects, weathering).
2. Alkali-aggregate reactions (chemical effects).
3. Sulphate attack(chemical effects).
4. Microbiological induced attack(chemical effects).
5. Corrosion of reinforcing steel embedded in concrete (chemical effects).
a)carbonation of concrete
b) chloride induced.
6. Abrasion (physical effects).
7. Mechanical loads(physical effects).
29. EFFECT OF FREEZING AND THAWING:
The most severe climate attack on concrete occurs
when concrete containing moisture is subjected to
cycles of freezing and thawing.
The capillary pores in the cement are of such a size
that water in them will freeze when the ambient
temperatures is below 00C.
30. Poor design details leads to
1. Leakage through joints
2. Inadequate drainage
3. Inefficient drainage slope
4. Unanticipated shear stresses in piers, column
and abutments etc..,
5. Incompatibility of materials of sections.
6. Neglect in design
7. Errors in design
8. Errors in earlier repairs
9. Overloading
10. External influences such as(a) Earthquake
(b) Wind(c) Fire(e) Cyclone(f) Flash floors etc..,
31. Cracking
• Plastic shrinkage cracks
• Water from fresh concrete can be lost by evaporation,
absorption of sub grade, formwork and in hydration
process. When the loss of water from the surface of
concrete is faster than the migration of water from interior
to the surface dries up. This creates moisture gradient
which results n surface cracking while concrete is still in
plastic condition. The magnitude of plastic shrinkage and
plastic shrinkage cracks are depending upon ambient
temperature, relative humidity and wind velocity.
• Rate of evaporation of water in excess of 1 kg/m2 per hour
is considered critical. In such a situation the following
measures could be taken to reduce or eliminate plastic
shrinkage cracks