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.
Quality Control in Concrete and Durability factors : An overviewbybyRAJESH PRASAD,IRSE, CPM/M, RVNL. KOLKATA. An interesting and informative presentation....
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
Quality Control in Concrete and Durability factors : An overviewbybyRAJESH PRASAD,IRSE, CPM/M, RVNL. KOLKATA. An interesting and informative presentation....
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 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!!
A crack is a complete or incomplete separation of concrete into two or more parts produced by breaking or fracturing.
Cracks are one kind of universal problems of concrete construction as it affects the building artistic and it also destroys the wall’s integrity, affects the structure safety and even reduce the durability of structure
Carbon dioxide penetrates into the concrete through the cracks and speed up carbonation around the cracks, thus shortening the structure usage.
The cracks in the concrete wall would cause the leakage of the building; it reduces the stiffness, durability and seismic performance of buildings.
Cracks on the wall surface damage to the later rendering, will affect to the appearance.
Workability of concrete is defined as the ease and homogeneity with which a freshly mixed concrete or mortar can be mixed, placed, compacted and finished. Strictly, it is the amount of useful internal work necessary to produce 100% compaction.
non destructive concrete testing equipment
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non destructive test Penetration method
Rebound hammer method
Pull out test method
Ultrasonic pulse velocity method
Radioactive methods
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Vacuum concrete is the type of concrete in which the excess water is removed for improving concrete strength.
The water is removed by use of vacuum mats connected to a vacuum pump.
The main aim of this technique is to extract extra water from concrete surface using vacuum dewatering.
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!!
A crack is a complete or incomplete separation of concrete into two or more parts produced by breaking or fracturing.
Cracks are one kind of universal problems of concrete construction as it affects the building artistic and it also destroys the wall’s integrity, affects the structure safety and even reduce the durability of structure
Carbon dioxide penetrates into the concrete through the cracks and speed up carbonation around the cracks, thus shortening the structure usage.
The cracks in the concrete wall would cause the leakage of the building; it reduces the stiffness, durability and seismic performance of buildings.
Cracks on the wall surface damage to the later rendering, will affect to the appearance.
Workability of concrete is defined as the ease and homogeneity with which a freshly mixed concrete or mortar can be mixed, placed, compacted and finished. Strictly, it is the amount of useful internal work necessary to produce 100% compaction.
non destructive concrete testing equipment
non destructive concrete testing methods
non destructive test Penetration method
Rebound hammer method
Pull out test method
Ultrasonic pulse velocity method
Radioactive methods
methods of testing concrete
concrete strength testing methods
types of non destructive testing
non destructive concrete testing equipment
concrete tests pdf
destructive and non destructive testing
concrete testing procedures
non destructive test for concrete
destructive and non destructive testing
non destructive testing pdf
types of non destructive testing
non destructive testing methods
non destructive testing methods ppt
Vacuum concrete is the type of concrete in which the excess water is removed for improving concrete strength.
The water is removed by use of vacuum mats connected to a vacuum pump.
The main aim of this technique is to extract extra water from concrete surface using vacuum dewatering.
Building crack,types,causes & its repairingGAUTAMSWALA
This presentation is all about cracks occur in building.It includes all types of cracks,its major causes and repairing techniques and finally a conclusion from which viewers can fully understand
about building cracks.
In this PPT, you will come to know about how cracks form on the structure and what preventive measures should follow to overcome cracks and different types of cracks
Cosmetic shop management system project report.pdfKamal Acharya
Buying new cosmetic products is difficult. It can even be scary for those who have sensitive skin and are prone to skin trouble. The information needed to alleviate this problem is on the back of each product, but it's thought to interpret those ingredient lists unless you have a background in chemistry.
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Data file handling has been effectively used in the program.
The automated cosmetic shop management system should deal with the automation of general workflow and administration process of the shop. The main processes of the system focus on customer's request where the system is able to search the most appropriate products and deliver it to the customers. It should help the employees to quickly identify the list of cosmetic product that have reached the minimum quantity and also keep a track of expired date for each cosmetic product. It should help the employees to find the rack number in which the product is placed.It is also Faster and more efficient way.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
Democratizing Fuzzing at Scale by Abhishek Aryaabh.arya
Presented at NUS: Fuzzing and Software Security Summer School 2024
This keynote talks about the democratization of fuzzing at scale, highlighting the collaboration between open source communities, academia, and industry to advance the field of fuzzing. It delves into the history of fuzzing, the development of scalable fuzzing platforms, and the empowerment of community-driven research. The talk will further discuss recent advancements leveraging AI/ML and offer insights into the future evolution of the fuzzing landscape.
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Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
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Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Water scarcity is the lack of fresh water resources to meet the standard water demand. There are two type of water scarcity. One is physical. The other is economic water scarcity.
2. CONTENT
SR. NO. DESCRIPTION
1. Introduction
2. Classification of cracks
3. Types of cracks
4. Causes of crack and its remedies
3. “Prevention is better than cure”; prevention of cracks in concrete is better than repair.
“
“Cracks can be treated as cancer in R.C.C structure, as cancer which in its primary stage
is curable to a certain extent but becomes danger to life in later stage; same happens with
cracks”
1
4. INTRODUCTION
• A crack is a complete or incomplete separation of concrete into two or more parts
produced by breaking or fracturing.
• Cracking are early indications of failure of structure. It is vital to note that concrete
does crack and this is usual. What is not normal is too much of cracks.
• Cracks affects the building artistic and it also destroys the wall’s integrity, affects
the structure’s safety, even reduces the durability of structure.
2
5. CLASSIFICATION OF CRACKS
STRUCTURAL CRACKS
NON STRUCTURAL
CRACKS
CRACKS
Due to :
- Incorrect design
- Faulty construction
- Overloading
Due to :
- Internal stress in building materials
3
6. TYPES OF CRACK BASED ON HARDENING OF
CONCRETE
Before hardening After hardening
Plastic
Constructional
movement
Physical
-Drying shrinkage
-crazing
Chemical
-Corrosion of reinforcement
-Alkali aggregate reactions
Thermal
-freeze/ thaws cycle
-Temperature variations
-Early thermal contradiction
Structural
-Creep
-overloading
4
7. CAUSES OF CRACKS AND ITS REMEDIES
• It arises when the rate of evaporation of water from top layer of freshly laid
concrete is greater than bleed water provided by underlying concrete, due to this
surface concrete contracts.
• Due to the restraint shown by the concrete below the drying surface concrete layer
the tensile stresses are develop in the weak and stiffening plastic concrete.
• These cracks usually are parallel to one another and are spaced 0.3m to 1m apart.
These cracks may be as much as 5cm to 10cm in depth and up to 3mm in width.
PLASTIC SHRINKAGE CRACKING
5
8. Plastic shrinkage cracking occur due to:
Preventive measures of plastic shrinkage include use of:
Temperature of air above concrete is high.
Low relative humidity .
Wind velocity above concrete is high.
Fog nozzles to saturate the air above concrete
Plastic sheeting to cover concrete
Windbreaks to decrease the wind velocity
6
Styrene Butadiene as bonding agent
latex co-plymer
9. • After hardening, concrete starts drying. The excess water leaves the system causing
contraction or shrinkage. This excess water, called water of convenience would
have been added to get adequate workability and finish.
• The loss of free water contained in hardened concrete, does not result in any
appreciable dimension change. It is the loss of water held in gel pores that causes
the change in the volume.
Smaller size of aggregate more shrinkage
finer gel
DRYING SHRINKAGE
7
10. PREVENTIVE MEASURES :
• Rigid formwork.
• Use of acrylic polymer for crack filling and tile joint filling by mixing along with
white cement.
• Leak proof formwork.
• Use of screed vibrator and float for surface finishing.
• Use of a ‘rich” concrete mix (400 kg/m³ binder, W/C = 0.4) should be encouraged.
8
11. • Crazing is the development of a network of fine random cracks or fissures on the
surface of concrete caused by shrinkage of the surface layer.
• These cracks are rarely more than 3mm deep, and are more noticeable on over
floated or steel-troweled surfaces.
CONCRETE CRAZING
9
12. CAUSES :
• Poor or inadequate curing.
• Intermittent wet curing and drying.
• Excessive floating
• Excessive laitance on surface.
• Finishing with float when bleed water is on the surface.
• Sprinkling cement on the surface to dry up the bleed water.
PREVENTIVE MEASURE :
• Proper and early start of curing.
• Use of curing compound on the surface.
• Never sprinkle dry cement or a mixture of cement and fine sand on the surface of
the plastic concrete.
10
13. • Temperature difference within a concrete structure may be caused by portions of the
structure losing heat of hydration at different rates at one portion of the structure to
a different degree or at a different rate than another portion of the structure.
• These temperature differences result in differential volume change, leading to
cracks.
• The more massive is the structure, the greater is the potential for temperature
differential and restraint. Hardened concrete has a coefficient of thermal expansion
that may range from 4 to 9 x 10-6 per deg. F.
THERMAL VARIATIONS
11
14. PREVENTIVE MEASURES:
• Controlling the rate at which the concrete cools by insulating the exposed concrete
surface during first 5 days.
• Increasing the tensile strength of concrete.
• Reducing the concrete temperature at placement up to say 32 ˚C.
• Using low heat of hydration cement or using fly ash replacement of part of cement.
• Keeping steel formwork warm by air heating during winter.
• Use of thermally insulating material as formwork.
• Low grade of cement, OPC 33 grade is the best.
12
15. • Deleterious chemical reactions may cause cracking of concrete, due to materials
used to make the concrete or materials that come into contact with the concrete
after it has hardened.
• Concrete may crack with time as the result of slowly developing expansive
reactions between aggregate containing active silica and alkalis derived from
cement hydration, admixtures or external sources.
CRACKING DUE TO CHEMICAL REACTION
13
16. Alkali – silica reaction Formation of gel pores Local expansion
PREVENTIVE MEASURES:
• Proper selection of aggregate – it should be innocuous to alkalinity.
• Cement with low alkalinity (preferably less than 0.5, IS:456 limit is 0.6).
• Use of Pozzolanas (like fly ash and blast furnace slag) which themselves contain very
fine highly active silicon.
14
17. • Poorly detailed re entrant corners in walls, precast members and slabs.
• Restraint to members subjects to volume changes caused by variations in
temperature and moisture.
• Lack of adequate contraction joints.
• Improper design of foundations resulting in differential movement within the
structure.
ERRORS IN DESIGN AND DETAILING
15
18. • It includes freezing and thawing, wetting and drying and heating and cooling.
• Damage due to freezing and thawing is the most common weather related to physical
deterioration.
• Damage in hardened cement paste from freezing is caused by the movement of water
to freezing sites and by hydraulic pressure generated by growth of ice crystal.
PREVENTIVE MEASURE :
• Use of lowest practical water cement ratio and total water content
• Durable aggregate
• Adequate air entrainment
• Allowing structure to dry after curing
WEATHERING
16
19. • Some poor construction practices that results in cracking are :
- Adding water to improve workability
- Lack of curing
- Inadequate formwork support
- Inadequate compaction
- Placement of construction joints at high stress
PREVENTIVE MEASURES:
• Proper monitoring and use of good quality of materials is required at the time of
construction
POOR CONSTRUCTION PRACTICE
17
20. • Concrete gets damaged due to structural overload which are very easy to detect.
Precast member like beam and are generally subjected to this type of load.
• Most unfortunate things about cracks is due to structural overload are that cracks
are detected at early stages.
PREVENTIVE MEASURE :
• These types of cracks can be prevented if designer limit the load on structure .
STRUCTURAL OVERLOADS
18
21. Shear cracks in buildings occur when there is large differential settlement of
foundation and it may be either due to the following reasons:
• Unequal bearing pressure under different parts of the structure
• Bearing pressure on soil being in excess of safe bearing strength of the soil
• Low factor of safety in the design of foundation
• Local variation in the nature of supporting soil
Preventative Measure:
• The design of foundation should be based on sound engineering principles and
good practice.
FOUNDATION MOVEMENT AND SETTLEMENT OF SOIL
19
22. • Fast growing trees in the area around the walls can sometimes cause cracks in walls
due to expansive action of roots growing under the foundation.
• The cracks occur in clay soil due to moisture contained by roots.
PREVENTIVE MEASURE:
• Do not grow trees too close to the building. Remove any saplings of trees as soon
as possible if they start growing in or near of walls.
VEGETATION
20
23. Concrete Technology Book By MS Shetty
Sciencedirect.com
UltraTech Tech mailer – Issue 05 shrinkage cracks
International Research Journal of Engineering and Technology (IRJET)
IS 456 :2000 Plain and Reinforced concrete – code of practice
21
REFRENCES