The

Mas

terb

uild

er |

Sept

embe

r 20

14 |

ww

w.m

aste

rbui

lder

.co.

in90

STUDENT RESEARCH: CONCRETE

Mix Design for M40 Grade of Concreteas per IS 10262:2009N. Raj & D. IlakkiyaFinal Year Civil Engineering, Nehru Institute of Technology, Coimbatore

Abstract: The main aim of this project is to provide the gen-eral mix design for any grade of concrete, so that, this proj-ect contains the mix design for M40 grade of concrete, as per IS 10262:2009. In this project, the mix shall be designed to produce the required grade of concrete having the desig-nated workability, and characteristic compressive strength, which will not be less then the appropriate values as per IS 10262:2009.by this project, the required mix design will be obtained by changing the corresponding values with respec-tive areas. Then we can obtain the required mix design for different grades of concrete.

In this project, general mix proportion is providing us the general procedure for nay grade of concrete. In the field of construction, concrete is the main material made up of dif-ferent type of materials. The concrete is of different grades and each grade of concrete is useful for different properties and place. Generally these are two type of concrete,

1. By Designing 2. By Adopting

1. By designing the concrete mix, concrete is called as Desing Mix Concrete.

2. By adopting the concrete mix, concrete is called as Nominal Mix Concrete.

From the above two type of concrete, design mix con-crete procedure is applied in this project. The mix design pro-cedure shall be selected to ensure the workability of fresh concrete. As per IS 456:2000, several information should be provided for design mix concrete pg.no 22.

Design Mix Concrete

Design mix concrete is the type of concrete used in con-struction, to produce the grade of concrete having the re-quired workability and characteristic strength nominal mix, will reduce the cement content which is used in concrete reduce the water cement ratio also will increase the strength. In this project, general procedure has been given for the concrete of grades very from this procedure of M40grade of concrete the different grades such as M40 to M40 has been obtained by changing the values as per Indian standard 10dis. so it is much easier to design the mix ratio for grade of concrete up to M40.

Required Data:

Characteristics compressive strength (fck) = 40 MpaMaximum cement content = 450kg/mDegree of workability = 0.8 compacting factor

Grade of cement = OPC 53Specific gravity of cement = 3.15Specific gravity of sand = 2.6Specific gravity of aggregate = 2.6Maximum size of aggregate = 20mm

1. Target mean strength for mix design

The target mean compressive strength at 28 days is given by,

fck = fck+ts

= 40+1.65*5 (t= 1.65 and s = 5) from IS 10262:2009 = 48.25 N/mm²

2. Selection of water cement ratio

W/c ratio = 40% from IS 456:2000 table no: 5

3. Selection of water content

Maximum water content for 20mm aggregate = 180 Kg.

4. Estimation of entrapped air

Entrapped air = 2% for 20mm aggregate (from IS 10262:1982 table3)

5. Determination of cement content

Cement content = mass of water/ (w/c ratio) = 180/0.4 = 450 kg/m³

6. Determination of coarse and fine aggregate:

fa = 623.63 kg/m³

The

Mas

terb

uild

er |

Sept

embe

r 20

14 |

ww

w.m

aste

rbui

lder

.co.

in92

= 1084.95 kg/m³

Material Cement Sand Aggregate Water

Kg/ m3 450 624 1085 180

Experimental Work:

Initial test:

For the design mix concrete, it is necessary to do the ini-tial test for all materials which are going to be used in con-crete. Like wise the result of the initial test are equal to the appropriate values provided in the Indian standards. So it is noted that, the materials can be used in the concrete for de-sign mix concrete.

Laboratory test

To check out the theoretical results as per Indian stan-dard with the practical results. The cubes will casted and cured and tested.

Compressive strength test

From the design mix concrete, the results are neces-sary to be equal, for that the cubes of size 50mmX150mmx 150mm have been casted. The casted cubes are to be tested for 3rd day, 7day and 28th day. The result of this will be com-pared with the target mean strength of theoretical values which are obtained.

Before test

Result

After test

Akcknowledgement:

The authors are thank full to Mr.M.Vadivel and Mr.M.PraveenKumar professor of Civil Engineering Depart-ment at Nehru Institute of Technology, Coimbatore.

Conclusion

From this project it is concluded that, the comparison be-tween the theoretical results and laboratory test results are compared, which are almost equal, so we concluded that the design mix concrete is better than nominal mix concrete.

Reference

1 Concrete mix proportioning-guidelines IS 10262:2009

2 Recommended guidelines for concrete mix design IS 10262:1982

3 Plain reinforced concrete-code of practice IS 456:2000

4 SP 23 (1982): Handbook on concrete mixes [CED 2: Cement and Concrete].

5 IS 516 (1959): Method of test for strength of concrete [CED 2: Ce-ment and concrete] w

STUDENT RESEARCH: CONCRETE