What is hydration of cement ? Discuss the reactions that take place between cement compounds and water.
Hydration Of Cement :- Anhydrous cement does not bind fine and coarse aggregate it acquires adhesive property only when mixed with water. The chemical reaction that takes place between cement and water is referred to as hydration of cement.
C₃S + H₂O 
– C - S – H + Ca(OH)₂
Hydrated calcium silicate
Gel structure
(more gel structure results in more strength)
The cement compound when mixed with water forms (C – S – H)( Gel structure) which leads to stiffening of paste. More gel structure results in rapid evolution of heat and early stiffening of paste cause early strength of concrete.
Short notes on :
What are flaky and elongated aggregates? How can the shape of aggregate influence strength of concrete? Following is the result of a sieve analysis of 500 gm aggregate:
| IS sieve size | 10 mm | 4.75 mm | 2·36 mm | 1·18 mm | 600 micron | 300 micron | 150 micron | lower than 150 micron |
| Weight retained in gm | 0 | 10 | 50 | 50 | 95 | 175 | 85 | 35 |
Find out the 'Fineness Modulus' of the sample
Differentiate between creep and shrinkage of concrete.
Write notes on Mixing and Mixer machines of concrete.
