Question

1. As a materials engineer in charge of designing concrete mix, what would you do in each following case at job site? Explain as briefly (preferably in a single sentence) as possible.

1. The structure is subjected to freezing.

               Ans:

2. Concrete is to be around closely spaced reinforcing steel.

               Ans:

3. The required slump value was 75 mm, you have obtained 20 mm of slump.

               Ans:

4. The required slump value was 75 mm, you have obtained 100 mm of slump.

               Ans:

Answer 1

1. The structure is subjected to freezing.

               Ans: use accelerators in mix.

1. Concrete is to be around closely spaced reinforcing steel.

               Ans: results in cracking.

1. The required slump value was 75 mm, you have obtained 20 mm of slump.

               Ans: add admixtures like plasticizers and superplasticizers.

1. The required slump value was 75 mm, you have obtained 100 mm of slump.

               Ans: add powdered silica fume.