Question

In curing cement plasters, water is sprinkled from-time to time. This helps in :

• A. Developing interlocking needle like crystals of hydrate silicates
• B. Hydrated sand gravel mixed with cement
• C. Converting sand into silicic acid
• D. Keeping it cool

Answer 1

Answer: (A)

Developing interlocking needle like crystals of hydrate silicates

Answer 2

Setting of cement is an exothermic process, Hence cement structures have to be cooled during setting to develops interlocking needle like structure crystals of hydrate silicates.

2CaO.SiO2+ xH2O $\overset{\quad Hydration\quad}{\rightarrow}$2CaO.SiO2.xH2O