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Concrete Mix Design With Different Mixes Of Asbestos

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By
Osama Ahmed
Moaazhussaini
Sohailhussaini
Syed Nizam Uddin
Syed Jaffer Ali

Abstract
In this constructed environment, the rising prizes of building construction materials are the factor of great worry. The coarse aggregates are the main ingredients used in concrete. We all want that our buildings must be strong, stable and should build with the construction material of reasonable prizes. Every construction industry totally relies on cement, aggregates whether it is coarse or fine for the production of concrete.In this research, we have replaced the coarse aggregate partially by using asbestos cement sheet waste. It is a waste material so by using asbestos cement sheet waste as a replacement we can solve the problems of price rising. Therefore, we have planned to prepared some number of cubes using asbestos cement sheet waste at various proportions like 0%, 5%, 10%,15%, 20% and 25% by weight of coarse aggregate.The properties for fresh concrete are tested for compressive strength at the age of 7, 14 and 28 days. It is found that with the increase in the percentage replacement of coarse aggregate with AC sheet waste there is increase in Compressive Strength upto 10 % replacement after that there is decrease in Compressive Strength with further replacement of coarse aggregate with AC sheet waste. It can also observed that 28 days compressive strength is increased by 3.33%, 6.41% upto 10 % replacement of coarse aggregate with AC sheet waste as compared to conventional concrete

CHAPTER 1
Introduction

Almost in all countries in the world various experiments are done aimed at reducing the use of primary aggregates and escalating reuse and recycling have been introduced, which is economically,technically or environmentally acceptable.As a result, in developing countries like India, the informal sector and secondary industries recycle 15–20% of solid wastes in various building materials and components. Asbestos products manufacturing industries are located in fifteen industrial states of India strategically important from raw materials and energy availability view point and also from consumption pattern view point. The pattern of asbestos industries can be predicted from the state wise asbestos consumption in India Maharashtra, Madhya Pradesh and Gujarat consume more than 75 % of the asbestos in India.

History of asbestos
A naturally-occurring mineral now known to cause asbestos cancer, asbestos has long been considered a miracle material. Boasting excellent heat- and fire-resistant properties, asbestos has a history that dates back to the ancient Greek island of Ewoia—what is believed to be the site of the first asbestos mine. As a matter of fact, the word “asbestos” comes from a Greek word meaning “inextinguishable.”

Even centuries ago, people were awed by this mineral for which they found many uses. Asbestos has long been used as a building material, even as far back as during the Holy Roman Empire. It was also utilized to produce fabric that would be used in clothing and a variety of other textiles. Legend has it that an early Roman emperor used to marvel at the fact that he could throw his asbestos tablecloth into the fire after meals and it would emerge clean and unscathed! Early Egyptians used cloths made of asbestos to wrap their dead, believing it would last for centuries to come.

Asbestos found use not only in factories, but also in oil and chemical refineries, on railroad cars, and in shipyards. Asbestos materials were used to insulate pipes and boilers in steam locomotives, to line tanks and ovens in refineries, and could be found literally everywhere aboard the nation’s ships, from engine rooms to galleys. Tens of thousands of workers would soon be exposed on a daily basis and many would later begin to experience the same problems as those from centuries past who worked in the asbestos mines.

As the twentieth century progressed, more and more uses for asbestos were found. It was used in the brakes and clutches of new-fangled automobiles, insulated America’s new skyscrapers, and especially found much popularity in the construction industry, where it was used in items like cement, roof shingles, floor and ceiling tiles, siding, stucco, plaster, and much more.

By the middle of the 1900s, it was once again becoming apparent that asbestos was causing health problems. Those who were especially susceptible to developing asbestos-related diseases and disorders were individuals who were exposed to the mineral when it was enjoying abundant use – mostly from the 1940s through the 1970s. Navy veterans and shipyard employees were among those most likely to develop asbestosis and mesothelioma cancer but others who worked with asbestos regularly were certainly not exempt.

Unfortunately, records have shown that many business owners who employed the use of asbestos in their facilities knew that the material was dangerous yet continued to allow its use. Eventually, stories of sick employees became commonplace, causing the American government to consider imposing laws about the use of asbestos

Some countries still mine asbestos – mostly the “white” chrysotile form – and it is still exported from these locations to other countries around the world. However, more than 40 countries have totally banned the use of asbestos, recognizing its toxicity.

In this constructed environment, the rising prizes of building construction materials are the factor of great worry. The coarse aggregates are the main ingredients used in concrete. We all want that our buildings must be strong, stable and should build with the construction material of reasonable prizes. Every construction industry totally relies on cement, aggregates whether it is coarse or fine for the production of concrete.In this research, I have replaced the coarse aggregate partially by using asbestos cement sheet waste. It is a waste material so by using asbestos cement sheet waste as a replacement we can solve the problems of price rising.Therefore, we have planned to prepare some number of cubes using asbestos cement sheet waste at various proportions like 0%, 5%, 10,15%, 20% and 25% by weight of coarse aggregate.The properties for fresh concrete are tested for compressive strength at the age of 7, 14 and 28 days. It is found that with the increase in the percentage replacement of coarse aggregate with AC sheet waste there is increase in Compressive Strength upto 10 % replacement after that there is decrease in Compressive Strength with further replacement of coarse aggregate with AC sheet waste. It can also observed that 28 days compressive strength is increased by 3.33%, 6.41% upto 10 % replacement of coarse aggregate with AC sheet waste as compared to conventional concrete.

Asbestos
Asbestos is a set of six naturally occurring silicate minerals which all have in common their eponymous asbestiform habit: long, thin fibrous crystals, with each visible fiber composed of millions of microscopic “fibrils” that can be released by abrasion and other processes. [2] They are commonly known by their colors, as blue asbestos, brown asbestos, white asbestos, and green asbestos.

Asbestos mining existed more than 4,000 years ago, but large-scale mining began at the end of the 19th century, when manufacturers and builders began using asbestos for its desirable physical properties:sound absorption, average tensile strength,resistance to fire, heat, electricity, and affordability. It was used in such applications as electrical insulation for hotplate wiring and in building insulation. When asbestos is used for its resistance to fire or heat, the fibers are often mixed with cement or woven into fabric or mats. These desirable properties made asbestos very widely used. Asbestos use continued to grow through most of the 20th century until public knowledge (acting through courts and legislatures) of the health hazards of asbestos dust outlawed asbestos in mainstream construction and fireproofing in most countries

Coarse aggregate
Coarse aggregate, or simply “aggregate”, is a broad category of coarse particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates. Aggregates are the most mined materials in the world. Aggregates are a component of composite materials such as concrete and asphalt concrete; the aggregate serves as reinforcement to add strength to the overall composite material. Due to the relatively high hydraulic conductivity value as compared to most soils, aggregates are widely used in drainage applications such as foundation and French drains, septic drain fields, retaining wall drains, and road side edge drains. Aggregates are also used as base material under foundations, roads, and railroads. In other words, aggregates are used as a stable foundation or road/rail base with predictable, uniform properties (e.g. to help prevent differential settling under the road or building), or as a low-cost extender that binds with more expensive cement or asphalt to form concrete.

coarse aggregate
Coarse Aggregates

fine aggregate
Fine Aggregates

Preferred bituminous aggregate sizes for road construction are given in EN 13043 as d/D (where the range shows the smallest and largest square mesh grating that the particles can pass). The same classification sizing is used for larger armor stone sizes in EN 13383, EN 12620 for concrete aggregate, EN 13242 for base layers of road construction and EN 13450 for railway ballast.

The American Society for Testing and Materials (ASTM) publishes an exhaustive listing of specifications including ASTM D 692 and ASTM D 1073 for various construction aggregate products, which, by their individual design, are suitable for specific construction purposes. These products include specific types of coarse and fine aggregate designed for such uses as additives to asphalt and concrete mixes, as well as other construction uses. Sources for these basic materials can be grouped into three main areas: Mining of mineral aggregate deposits, including sand, gravel, and stone; use of waste slag from the manufacture of iron and steel; and recycling of concrete, which is itself chiefly manufactured from mineral aggregates.

Chapter 2
Literature review:

Asbestos is a naturally occurring fibrous material which is widely used in construction field ,so we used asbestos in replacement of coarse aggregate, partially in varying percentages of 5%, 10%, 15%, 20%, 25%. so we referred various materials and other journals by

“STUDY OF COMPRESSIVE STRENGTH OF CONCRETE WITH ASBESTOS” BY MANU CHAUDHARY, R.D. PATEL who have a lot of journal under their name,they are the masters in the field of construction materials. This journal helped us to know the insight of the asbestos and its properties like compressive strength of the mix concrete. the above journal gives the various aspects of compressive strength of concrete  mixed with asbestos.

we did refer the book of concrete technology by M.S. SHETTY who is renowned author in this field of construction materials and technology from this we came to know the properties of concrete,cement,asbestos and its physical, chemical properties, compressive strength and its tensile strength and the other aspects of the construction materials. We got to know the procedure of the various methods of carrying out the process.

2.1 Physical Properties:

  • Bulk chrysotile has a hardness similar to human finger nail.
  • Naturally occurring fiber bundles range in length from several millimeters to more than 10cm.
  • Chrysotile fiber has considerable tensile strength, and may be spun into thread and woven into a cloth.
  • They are also resistant to heat and are excellent thermal electrical and acoustic insulators.
  • Asbestos binds with better insulating materials to create the ultimate construction materials.
  • Asbestos fibers have no detectible odor or taste.
  • They are all solids that do not move through soil and are insoluble in water.
  • Its color will vary according to type, and metallic composition.
  • Crocidolite, which has iron and sodium as its only metallic elements, is the most colorful, adorned in a range of colors including shades of lavender, blue and green.

Chapter 3
Materials

3.1 ASBESTOS:
Asbestos refers to a set of six naturally occurring fibrous minerals. Asbestos has six primary sub-classifications: chrysotile, crocidolite, amosite, anthophyllite, tremolite, and actinolite. Among these, chrysotile and amosite asbestos are the most common.

Sl no Physical properties Test result
1 Maximum size(mm) 20
2 Fineness modulus 7.34
3 Specific gravity 1.61
4 Water adsorption % 4.401%
5 Aggregate crushing value % 14.531%
6 Aggregate impact value % 9.841%

 

3.2 TYPES OF ASBESTOS:
1.CHRYSOTILE ASBESTOS
Many studies have proven that exposure to chrysotile asbestos, commonly referred to as white asbestos, can cause a number of serious health conditions. While most commercial uses of asbestos in the United States have been of the chrysotile type, the use of this toxic mineral has declined significantly during the last few decades.

Naturally occurring deposits of chrysotile are often accompanied by trace amounts of tremolite (amphibole) asbestos, which is considered more toxic than chrysotile. However, several reports have indicated that exposure to solely chrysotile asbestos fibers can occur and such exposure can be equally hazardous as exposure to amphibole asbestos types.

Scientists from the National Institute for Occupational Safety and Health concluded that chrysotile asbestos should be treated with virtually the same level of concern as the amphibole forms of asbestos.

   1) AMPHIBOLE ASBESTOS
The other five types of asbestos are classified in the amphibole category. Amosite (brown asbestos) and crocidolite (blue asbestos) are considered the most commercially valuable types. Anthophyllite, tremolite and actinolite are the other non-commercial forms of amphibole asbestos. All amphibole fibers are straight and longer than chrysotile fibers, and studies suggest it may take less exposure to amphibole asbestos to cause mesothelioma than chrysotile asbestos.

   2)AMOSITE ASBESTOS
According to the American Cancer Society, exposure to amosite asbestos creates a higher risk of cancer in comparison with other types of asbestos. Several asbestos studies suggest exposure to amosite can cause lung cancer, mesothelioma and asbestosis.

Amosite Asbestos
In its natural state, amosite is known as the mineral grunerite. Commercially, grunerite is referred to as amosite or brown asbestos. Approximately 80,000 tons of amosite were mined in the Transvaal province of South Africa by 1970.

3)CROCIDOLITE ASBESTOS
Multiple asbestos studies suggest crocidolite may be responsible for more deaths than any other type of asbestos because its fibers are so thin — about the diameter of a strand of hair. When airborne, these fibers can be inhaled easily and become lodged in the lining of the lungs, more so than other forms of asbestos forms. Once inside the body, the fibers do not break down easily. This can lead to potentially life-threatening lung and abdominal conditions, including lung cancer, mesothelioma and asbestosis.

4)ANTHOPHYLLITE ASBESTOS
Anthophyllite asbestos is known to cause asbestos-related diseases, but most studies indicate the risk of developing mesothelioma from anthophyllite exposure is much less than it is from exposure to other types of asbestos.

3.3  CONCRETE
Concrete is a composite material composed of coarse aggregate bonded together with a fluid cement which hardens over time. Most concretes used are lime-based concretes such as Portland cement concrete or concretes made with other hydraulic cements, such ascement. However, asphalt concrete which is very frequently used for road surfaces is also a type of concrete, where the cement material is bitumen, and polymer concretes are sometimes used where the cementing material is a polymer.
In Portland cement concrete (and other hydraulic cement concretes), when the aggregate is mixed together with the dry cement and water, they form a fluid mass that is easily molded into shape. The cement reacts chemically with the water and other ingredients to form a hard matrix which binds all the materials together into a durable stone-like material that has many uses.Often, additives (such aspozzolans or superplasticizers) are included in the mixture to improve the physical properties of the wet mix or the finished material. Most concrete is poured with reinforcing materials (such as rebar) embedded to provide tensile strength, yielding reinforced concrete.

Famous concrete structures include the Hoover Dam, the Panama Canal and the Roman Pantheon. The earliest large-scale users of concrete technology were the ancient Romans, and concrete was widely used in the Roman Empire. The Colosseum in Rome was built largely of concrete, and the concrete dome of the Pantheon is the world’s largest unreinforced concrete dome. Today, large concrete structures (for example, dams and multi-storey car parks) are usually made with reinforced concrete.

3.4 COMPOSITION OF CONCRETE
CEMENT:

A cement is a binder, a substance used in construction that sets and hardens and can bind other materials together. The most important types of cement are used as a component in the production of mortar in masonry, and of concrete, which is a combination of cement and an aggregate to form a strong building material.

Cements used in construction can be characterized as being either hydraulic or non-hydraulic, depending upon the ability of the cement to set in the presence of water

Specific gravity = 3.15

WATER:
Water (chemical formula: H2O) is a transparent fluid which forms the world’s streams, lakes, oceans and rain, and is the major constituent of the fluids of organisms. As a chemical compound, a water molecule contains one oxygen and two hydrogen atoms that are connected by covalent bonds. Water is a liquid at standard ambient temperature and pressure, but it often co-exists on Earth with its solid state, ice; and gaseous state, steam (water vapor). It also exists as snow, fog, dew and cloud.

AGGREGATES:
Coarse aggregate or simply “aggregate”, is a broad category of coarse particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates. Aggregates are the most mined materials in the world. Aggregates are a component of composite materials such as concrete and asphalt concrete; the aggregate serves as reinforcement to add strength to the overall composite material. Due to the relatively high hydraulic conductivity value as compared to most soils, aggregates are widely used in drainage applications such as foundation and French drains, septic drain fields, retaining wall drains, and road side edge drains. Aggregates are also used as base material under foundations, roads, and railroads. In other words, aggregates are used as a stable foundation or road/rail base with predictable, uniform properties (e.g. to help prevent differential settling under the road or building), or as a low-cost extender that binds with more expensive cement or asphalt to form concrete

Preferred bitumenous aggregate sizes for road construction are given in EN 13043 as d/D (where the range shows the smallest and largest square mesh grating that the particles can pass). The same classification sizing is used for larger armour stone sizes in EN 13383, EN 12620 for concrete aggregate, EN 13242 for base layers of road construction and EN 13450 for railway ballast.

Chapter 4
METHODS

The process of testing the concrete was done by the following steps:

1. Collection of information
2. Calculation of required quantities of materials using IS 10262-2009
3. Collection of materials according to m30 grade.
4. Measuring of the materials.
5. Preparation of concrete
6. Testing of concrete by using (i) slump cone test and (ii) compaction factor test.
7. Casting of cubes.
8. Demoulding of cubes.
9. Curing.
10. Testing the compressive strength using universal testing machine (UTM).
11. Comparing of results with the normal concrete

Flow Chart for Experimental Procedure
Flow Chart for Experimental Procedure

1. Collection of information:
Referring the various textbooks pertaing to concrete technology, and referringdifferent journals of different authors and various publications.And after doing extensive research we selected the materials and its information.

2. Calculation of required materials
The required quantities are calculated by followingIS code 10242:2009 and using m30 grade mix ratio (1:1:1.5). Then the water cement ratio is calculated. And the measuring are done by volume, so the volume of the various coarse aggregate and fine aggregate and the asbestos is known.

3. Collection of material using M30 grade
The M30 mix ratio is 1:1:1.5 in which these relate to the cement, coarse aggregate, fine aggregate. So according to it and by volumetric measurement the quantities of the aggregates are known.

4. Measuring of materials
The materials are measured using volumetric measurement as the aggregates are measured in volume, the cement, fine aggregate, coarse aggregate are measured separately using a weighing scale and water is also measured which is to be added in it.

5. Preparation of concrete

The concrete is prepared using the M30 grade mix ratio, so according to the quantities of cement, fine aggregates, coarse aggregate are known. Then they are mixed on a sheet or over a clean place then water is added and using a spade its thoroughly mixed.

6. Testing of concrete for workability
They are various test to be done on concrete to check its workability, which is useful as it determines the concretes ability to mould in a shape as required easily.

The various tests done on concrete are

(i) slump cone test procedure  is shown below

Slumpcone test

Slump is a measurement of concrete’s workability, or fluidity.

It’s an indirect measurement of concrete consistency or stiffness

Principle
The slump test result is a measure of the behavior of a compacted inverted cone of concrete under the action of gravity. It measures the consistency or the wetness of concrete.

• Slump cone,
• Scale for measurement,
• Tamping rod (steel)

Types of Slump
The slumped concrete takes various shapes, and according to the profile of slumped concrete, the slump is termed as;

1. Collapse Slump
2. Shear Slump
3. True Slump

Types of Slump

Collapse Slump
In a collapse slump the concrete collapses completely. A collapse slump will generally mean that the mix is too wet or that it is a high workability mix, for which slump test is not appropriate.

Shear Slump
In a shear slump the top portion of the concrete shears off and slips sideways.

If one-half of the cone slides down an inclined plane, the slump is said to be a shear slump.
1. If a shear or collapse slump is achieved, a fresh sample should be taken and the test is repeated.
2. If the shear slump persists, as may the case with harsh mixes, this is an indication of lack of cohesion of the mix.

True Slump
In a true slump the concrete simply subsides, keeping more or less to shape
1. This is the only slump which is used in various tests.
2. Mixes of stiff consistence have a Zero slump, so that in the rather dry range no variation can be detected between mixes of different workability.

However , in a lean mix with a tendency to harshness, a true slump can easily change to the shear slump type or even to collapse, and widely different values of slump can be obtained in different samples from the same mix; thus, the slump test is unreliable for lean mixes.

Degree of workability Slump Compacting

Factor

Use for which concrete is suitable
mm In
Very low 0-25 0-1 0.78 Very dry mixes; used in road making. Roads vibrated by power operated machines.
Low 25-50 1-2 0.85 Low workability mixes; used for foundations with light reinforcement. Roads vibrated by hand operated Machines.
Medium 50-100 2-4 0.92 Medium workability mixes; manually compacted flat slabs using crushed aggregates. Normal reinforced concrete manually compacted and heavily reinforced sections with vibrations.
High 100-175 4-7 0.95 High workability concrete; for sections with congested reinforcement. Not normally suitable for vibration

 

(ii) Compaction factor test procedure.
The compaction factor test is used to test the workability of concrete. Work-ability of concrete is the ability/ease with which concrete can be mixed, transported and placed. This is a major factor which contributes to the other properties of concrete also. If concrete is workable enough then it can be compacted with less compacting effort. So there is a relation between the amount of work required to compact a given fresh concrete and the work-ability of the concrete. This relation is well suited for the concrete of the low water cement ratio. Slump cone test is also used to find out the work-ability of the concrete but only recommended for the concrete of higher work-ability. For less workable concrete(having less water cement ratio), compaction is standardized by various standards.

NOTE
The test is sufficiently sensitive to enable difference in work ability arising from the initial process in the hydration of cement to be measured. Each test, there for should be carried out at a constant time interval after the mixing is completed, if strictly comparable results are to be obtained. Convenient time for releasing the concrete from the upper hopper has been found to be two minutes after the completion of mixing.

7. Casting of cubes
The moulds of cubes are made of iron, with dimension of 15*15*15 cm. these cubes are oiled before the placing of concrete, the concrete when it is being placed, tamping is done after placing of about 25 mm of concrete, it is then kept for 24hrs for drying.

8. Demoulding of cubes
The cubes are to be opened by removing the bolts and keeping it in the open and dry place for some time before placing it in the curing tank.

9. Curing of cubes
The cubes which are demoulded are to be placed in a curing tank for 7 days, 14days, and 28days. Then after the curing time is done then they are removed and tested for its compressive strength.

10.Testing of compressive strength
The compressive strength of cubes are known by testing them in universal testing machine, this machine applies force gradually and then the reading are noted down.

Compressive strength:
The determination of compression strength of the prepared samples was carried out as per standard practice. The following table’s show the compressive and tensile strength of various samples after testing.

Compressive strength for 7 days for M-30

S.no Percentage of asbestos Compressive strength

(N/mm^2)

1 5 28.27
2 10 30.00
3 15 27.87
4 20 26.54
5 25 25.21

 

 

Compressive strength for 14 days for M-30

S.no Percentage of asbestos Compressive strength

(N/mm^2)

1 5 32.20
2 10 33.35
3 15 30.31
4 20 27.71
5 25 26.24

List of tables

Graph between Compressive Strength of Concrete and Age
Graph between Compressive Strength of Concrete and Age

Graph between Compressive Strength of Concrete and % age of A.C. Sheet Waste
Graph between Compressive Strength of Concrete and % age of A.C. Sheet Waste

List of figures:

Compaction factor test
Compaction factor test

True slump
True slump

Casting of cubes
Casting of cubes:

Demoulding of cubes
Demoulding

Universal testing machine
Universal testing machine

Curing of cubes
Curing of cubes

Chapter 5
Result

M30 grade of concrete

Mix proportions 1:1:1.5

Volume of cube= 15*15*15 cm

=3.375*10^-6 m^3

=0.003375 cubic meter

Density e=mass/volume

2400kg/m3=m/0.003375m3

m=8.1 kg

assuming wastage=50%

mass                 =12kg

For grade M30

1:1:1.5

1+1+1.5=3.5

Cement = 1/3.5 *12

=3.42kg

Fine aggregate=1/3.5*12

=3.42 kg

Coarse aggregate=1.5/3.5*12

=5.14kg

Water cement ration= 0.50

Water content =0.5*3.42

=1.71kg

For 1 cube of normal mix of M30 grade of concrete

Cement =3.42kg

Fine aggregate=3.42kg

Coarse aggregate=5.14kg

Water content =1.71kg

For 3 cubes of normal mix of M30 grade of concrete

Cement =10.26kg

Fine aggregate=10.26kg

Coarse aggregate=15.42kg

Water content =5.13kg

For 5% replacement of coarse aggregate with asbestos

Cement = 9.747kg

Fine aggregate=9.747kg

Coarse aggregate=14.649kg

Water content =4.87kg

For 10% replacement of coarse aggregate with asbestos

Cement =9.234kg

Fine aggregate=9.234kg

Coarse aggregate=13.878kg

Water content =4.617kg

For 15% replacement of coarse aggregate with asbestos

Cement =9.234kg

Fine aggregate=9.234kg

Coarse aggregate=13.107kg

Water content =4.617kg

For 20% replacement of coarse aggregate with asbestos

Cement =9.234kg

Fine aggregate=9.234kg

Coarse aggregate=12.336kg

Water content =4.104kg

For 25% replacement of coarse aggregate with asbestos

Cement =9.234kg

Fine aggregate=9.234kg

Coarse aggregate=11.565kg

Water content =3.84kg

For  1 cube with different proportions of asbestos

%of asbestos

 

5% 10% 15% 20% 25%
Cement 3.249 3.078 2.907 2.736 2.565
Fine  aggregate 3.249 3.078 2.907 2.736 2.565
Coarse aggregate 4.883 4.262 4.369 4.112 3.855
Water content 1.62 1.539 1.45 1.368 1.28

List of Tables:

Compressive Strength of A.C. Sheet Waste Concrete
  Compressive Strength of A.C. Sheet Waste Concrete

Age Strength per cent
1 day 16%
3 days 40%
7 days 65%
14 days 90%
28 days 99%

Compressive strength of concrete at various ages:
The strength of concrete increases with age. Table shows the strength of concrete at

Chapter 6
Conclusion

It is observed from the experimental results and its analysis, that the compressive strength of concrete initially increases with replacement of coarse aggregate with asbestos sheet waste and after that, there is decrease in compressive strength of concrete with further replacement of coarse aggregate with asbestos sheet waste. From the experimental test result we can conclude that

1. In case of replacement of coarse aggregate, 10% asbestos cement sheet waste content can be taken as the optimum dosage for compressive strength, which can be used for giving maximum possible compressive strength at any age for the mixed design of asbestos cement sheet waste and coarse aggregate concrete.

2. In case of replacement of coarse aggregate, the percentage increase of compressive strength of asbestos cement sheet waste and coarse aggregate concrete compared with compressive strength of controlled mix is observed from 0.96 % to 7.14% at 7 days.

The percentage increase of compressive strength of asbestos cement sheet waste and coarse aggregate concrete compared with compressive strength of controlled mix is observed from 3.87% to 7.58% at 14 days.

3. One can reduce the overall cost considerably.
• Cost of coarse aggregate = R.s 500/ton
• Cost of fine aggregate = R.s 1900/ton
• Cost of cement = R.s 6.2 kg

4. for 1 cubic meter of concrete
• Cost of cement = R.s 6.2
• Cost of coarse aggregate = R.s 1,202.4
• Cost of fine aggregate = R.s 4,525

5.For 1 cubic meter of concrete replaced with 10% of asbestos
• Cost of cement = R.s 6.2
• Cost of coarse aggregate = R.s 1,082.4
• Cost of fine aggregate = R.s 4,525

6. hence from the above calculations we observe that the replacing of coarse aggregate with asbestos helps in reducing the overall cost considerably

For 1 cubic meter if replaced with asbestos helps in saving about 200 R.s

References
CONCRETE TECHNOLOGY THEORY AND PRACTICE AUTHOR : M S SHETTY (BE, ME, FICI, FIIBE, FIE, MACCE) PUBLISHERS : S. CHAND & COMPANY LTD.

International Journal of Science, Engineering and Technology Research (IJSETR), Volume 4, Issue 8, August-2015 2909 ISSN: 2278 – 7798

STUDIES ON COMPRESSIVE STRENGTH OF CEMENT CONCRETE BY USE OF ASBESTOS CEMENT SHEET WASTE MANU CHAUDHARY1 , R.D. PATEL2 1 PG Scholar, Department of Civil Engineering, M.M.M.U.T, Gorakhpur, U.P. 2Associate Professor, Department of Civil Engineering, M.M.M.U.T, Gorakhpur U.P.

en.wikipedia.org/wiki/Asbestos

en.wikipedia.org/wiki/Aggregate

We at engineeringcivil.com are thankful to Er Osama Ahmed for submitting this prjoect report to us. We are sure this would be of great help to other students who wish to know more about “Concrete Mix Design With Different Mixes Of Asbestos.”

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