Concrete Technology — Winter 2023

Explain the precautions to be taken in storing cement.

Explain the role of each Bogue’s compound in the process of hydration of cement.

Briefly explain the wet process of manufacture of cement.

Write a brief note on: (a) Natural aggregates (b) Artificial aggregates (c) Recycled aggregates.

Distinguish between OPC and PPC.

How does strength of aggregate influence the strength of concrete? With a typical stress-strain curve for aggregate, concrete and cement paste illustrate the influence.

Determine the fineness modulus of the sand for which sieve result is as shown below: I.S. sieve 10 4.75 2.36 1.18 0.600 0.300 0.150 0.075 size mm mm mm mm mm mm mm mm Percentage 100 90 78 56 28 10 8 passing

Explain the terms ‘flakiness index’ and ‘elongation index’ as applied to coarse aggregates.

Explain the test to determine crushing value of aggregates.

What are mineral admixtures? Why are they generally used? List various mineral admixtures used with concrete.

State the functions of water in making concrete.

Differentiate between high-strength concrete and high-performance concrete.

In a mix design, the following proportion (in kg per m3 of concrete) is arrived at: Water: Cement: FA: CA = 185: 370: 778: 1024. If fine aggregate at site is found to contain 2% moisture and coarse aggregate contains 1% moisture, determine the correct proportion to be used at site.

After designing concrete mix for first trial, how do you proceed to finalize the mix with further trial?

Write explanatory notes on no-fines concrete.

State factors affecting compressive strength of concrete and explain any one in detail.

What precautions will you take, if concreting is to be done above 40°C?

Explain segregation of concrete in detail.

List various methods of concreting under water and explain ‘tremie’ method.1

What is shrinkage? Give the classification of shrinkage.

Define workability and discuss factors affecting workability.

What is self-compacting concrete? And what are the advantages and disadvantages of using it?

Explain mechanism of sulphate attack on concrete.

Discuss the effect of freezing and thawing on concrete.

Explain the basic principle on which rebound hammer works. What are its limitations?