Concrete Technology - June 2015

VTU Civil Engineering (Semester 4)

Total marks: --
Total time: -- INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary 1 (a) What are the various laboratory tests conducted on cement? 5 marks

1 (b) Explain the importance of conducting the soundness test on cement and the procedure of conducting the soundness test. 5 marks

1 (c) Explain with the flow chart the manufacture of cement by wet process. 5 marks

2 (a) Explain the importance of shape and texture of aggregate used in concrete. 5 marks

2 (b) Which are various tests conducted on coarse aggregates for determining its strength? 5 marks

2 (c) Explain bulking of aggregates. 5 marks

3 (a) What is an admixture? What is the effect of air entrainment on the properties of concrete? 5 marks

3 (b) Write short notes on accelerators and retarders. 5 marks

4 (a) Define workability and list the factors affecting workability. 5 marks

4 (b) List the various tests to measure workability and explain KEE BEE consistometer test. 5 marks

5 (a) What are factors affecting the strength of concrete? 5 marks

5 (b) Explain the accelerated curing test on concrete cubes. 5 marks

5 (c) Write short notes on Bond strength of concrete. 5 marks

6 (a) Explain briefly the factors affecting modulus of elasticity of concrete. 5 marks

6 (b) Discuss the factors affecting creep. 5 marks

7 (a) Explain the different methods of controlling sulphate attack on concrete. 5 marks

7 (b) Discuss the durability of concrete in sea water. 5 marks

8 Design a concrete mix by IS method for M30 grade concrete as per IS 10262-2009.
a) Grade: M30
b) Cement: OPC-43 Grade
c) Maximum Nominal size of aggregate: 20mm
d) Minimize cement content: 320 Kg/m³
e) Max, w/c Ratio: 0.45
f) Workability: 100mm slump
g) Exposure condition: Severe (Reinforced concrete)
h) Method of concrete placing: pumping
i) Degree of super vision: Good
j) Type of aggregate: Crushed Angular
k) Max. Cement content: 450 K'g/m³
l) Chemical admixture: Super plasticizer
Test Data for materials:
i) Specific Gravity of cement: 3.15
ii) Specific Gravity of C.A. :2.74
iii) Specific Gravity of F.A.: 2.74
iv) Water Absorption for
     1) C.A.: 0.5%
     2) F.A: 1.0%
v) Free surface moisture
     1) C.A.: NIL (Absorbed moistrure also NIL)
     2) F.A.: NIL
vi) Fine Aggregate conforms to grading zone-I
     1) of table 4 of IS 383
     2) Coarse Aggregate