71.  The compound of Portland cement which reacts immediately with water and also sets first is
A. Tr-calcium silicate
B. Di-calcium silicate
C. Tr-calcium aluminate
D. Tetra calcium alumino ferrite.

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72.  The commonly used raw material in the manufacture of cement, is
A. slate
B. sand stone
C. lime stone
D. basalt,

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73. The compound of Portland cement which contributes to the strength after two to three years is
A. Tricalcium silicate
B. Di-calcium silicate
C. Tricalcium aluminate
D. Tetracalcium alumino ferrite.

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74. Rapid hardening cement attains early strength due to
A. larger proportion of lime grounded finer than normal cement
B. lesser proportion of lime grounded coarser than normal cement
C. lesser proportion of lime grounded finer than normal cement
D. larger proportion of lime grounded coarser than normacement

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75. Quick setting cement is produced by adding
A. less amount of gypsum in very fine powdered form
B. more amount of gypsum in very fine powdered form
C. aluminium sulphate in very fine powdered form
D. pozzolana in very fine powdered form

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76.  Portland cement manufactured from pure white chalt. and clay but free from iron-oxide, is known as
A. quick setting cement
B. rapid hardening cement
C. white cement
D. all the above.

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77. Portland pozzolana cement possesses
A. higher resistance to chemical attack
B. lower heat of hydration
C. lower shrinkage on drying
D. all the above.

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