CONCRETE TECHNNOLOGY

Sample Set I

1. a) What are accelerators and mention its purpose (4M)

b) Define workability of concrete (3M)

c) What is the affect of Water / Cement ratio on workability and strength (4M)

d) Define shrinkage and creep of concrete (3M)

e) What is carbonation of concrete (4M)

f) What is polymer concrete (4M)

2. a) what are the properties of good aggregates for making concrete and discuss in brief various tests carried out on aggregates (7M)

b) Explain about the different tests conducted on cement in the laboratory to check its suitability (7M)

3. a) What is segregation and bleeding of concrete why they occur, discuss how to prevent them (7M)

b) Discuss bout the Flow table test to measure the workability and its significance (7M)

4. a) i. Discuss about the maturity concept of concrete, ii. The strength of sample of fully matured concrete is found to be 40Mpa. Find the strength of identical concrete at the age of 7 days when cured at an average temperature during day time at 200C and night time at 100C (7M)

b) Discuss about the rebound hammer test method on concrete structures and its limitations (7M)

5. a) What is Shrinkage of concrete and types and discuss about the factors affecting the shrinkage of concrete. (7M)

b) Discuss in detail about the relation between creep and time (7M)

6. Design M25 grade concrete mix using IS method for mild exposure and good quality control. The workability required is 0.9 CF. Maximum size of coarse aggregate is 20mm and fine aggregate confirmed to Zone.III. The specific gravity of cement is 3.05, specific gravity of coarse aggregate and fine aggregate is 2.77. Cement is OPC 53 grade. Water absorption by CA is 1.5% and moisture content in FA is 3%. Assume any other suitable data if necessary (14M)

7. a) Discuss about the development of Polymer concrete and its Properties (7M)

b) What are the fresh properties of SCC to be checked and discuss about any two methods to verify fresh properties of SCC (7M)

Sample Set II

1. a) What are the retarders and accelerators? 4M

b) What is the setting time of concrete? 3M

c) How water cement ratio is useful for mix design? 3M

d) What is Poisson’s ratio in concrete? 4M

e) What is an acceptance criteria? 4M

f) What is self compacting concrete? 4M

2. a) What is sieve analysis of fine aggregate? 8M

b) What is the quality of water mixed in concrete? 8M

3. a) What are different tests for measurement of workability? 12M

b) Write about shotcrete. 4M

4. a) What are the factors affecting the strength of hardened concrete? 8M

b) What are the different non destructive testing equipment? 8M

5. What is creep? What are the factors influencing creep? 16M

6. a) What are the factors for choosing mix proportions? 8M

b) Write about durability of concrete. 8M

7. Write about i) high density concrete ii) high performance concrete iii) light weight aggregate concrete. 16M