search
arrow-left Previous
Next arrow-right
Q: For under-water construction ............ cement is used.
  • A. expansive
  • B. ordinary portland
  • C. portland pozzolona
  • D. quick setting
Correct Answer: Option D - Quick Setting Cement– The quantity of gypsum is reduced and small percentage of aluminium sulphate is added. It is ground much finer than ordinary Portland Cement. Initial setting time = 5 minutes Final setting time = 30 minutes ∎ It is used when concrete is to be laid under water or in running water. Portland Pozzolana Cement (IS–1489)– It is manufacture by grinding Portland Cement clinker and pozzolana (usually fly ash 10–25% by mass of PPC) or by intimately and uniformly blending Portland Cement and fine pozzolana. Initial setting time = 30 minutes Final setting time = 600 minutes It is use in the place of mass concrete such as Dams and in places of high temperature.
D. Quick Setting Cement– The quantity of gypsum is reduced and small percentage of aluminium sulphate is added. It is ground much finer than ordinary Portland Cement. Initial setting time = 5 minutes Final setting time = 30 minutes ∎ It is used when concrete is to be laid under water or in running water. Portland Pozzolana Cement (IS–1489)– It is manufacture by grinding Portland Cement clinker and pozzolana (usually fly ash 10–25% by mass of PPC) or by intimately and uniformly blending Portland Cement and fine pozzolana. Initial setting time = 30 minutes Final setting time = 600 minutes It is use in the place of mass concrete such as Dams and in places of high temperature.

Explanations:

Quick Setting Cement– The quantity of gypsum is reduced and small percentage of aluminium sulphate is added. It is ground much finer than ordinary Portland Cement. Initial setting time = 5 minutes Final setting time = 30 minutes ∎ It is used when concrete is to be laid under water or in running water. Portland Pozzolana Cement (IS–1489)– It is manufacture by grinding Portland Cement clinker and pozzolana (usually fly ash 10–25% by mass of PPC) or by intimately and uniformly blending Portland Cement and fine pozzolana. Initial setting time = 30 minutes Final setting time = 600 minutes It is use in the place of mass concrete such as Dams and in places of high temperature.