Addition of gypsum to cement:
reduces setting time of cement
produces very light colour cement
increases setting time of cement
shining surface is formed
Answer is Right!
Answer is Wrong!
This question was previously asked in
UPSC NDA-2 – 2015
– Gypsum (calcium sulfate dihydrate) is added to the cement clinker during grinding to act as a retarder.
– Gypsum reacts with C₃A to form ettringite, which precipitates on the surface of the C₃A particles, forming a barrier that slows down the rapid hydration of C₃A.
– This allows sufficient time for the cement paste or concrete to be mixed, transported, placed, and finished before it begins to harden.