500 Best Concrete Technology- MCQ
Q33). Efflorescence in cement is caused due to the excess of
a).silica
b).lime
c).alkalies
d).iron oxide
Correct Answer:
alkalies
Explanation:
Q34). The presence of tri-calcium silicate in cement
a).hydrates the cement rapidly
b).generates less heat of hydration
c).offers high resistance to sulphate attack
d).all of these
Correct Answer:
hydrates the cement rapidly
Explanation:
Q35). The presence of di-calcium silicate in cement
a).hydrates the cement slowly
b).generate less heat of hydration
c).has more resistance to sulphate attack
d).all of these
Correct Answer:
all of these
Explanation:
Q36). The tri-calcium aluminate in cement has the property of
a).reacting fast with water
b).causing initial setting of cement
c).generating large amount of heat of hydration
d).all of these
Correct Answer:
all of these
Explanation:
Q37). High percentage of tri-calcium silicate and low percentage of di-calcium silicate in cement results in
a).rapid hardening
b).high early strength
c).high heat generation
d).all of these
Correct Answer:
all of these
Explanation:
Q38). Low percentage of tri-calcium silicate and high percentage of the calcium silicate in cement results in
a).rapid hardening
b).high early strength
c).high heat generation
d).none of these
Correct Answer:
none of these
Explanation:
Q39). The sum of the percentage of tri-calcium silicate and di-calcium silicate for portland cement varies from
a).50 to 60 %
b).60 to 70 %
c).70 to 80 %
d).80 to 90 %
Correct Answer:
70 to 80 %
Explanation:
Q40). Rapid hardening cement is used
a).where high early strength is desired
b).where form work is to be removed as early as possible
c).for constructing Road pavements
d).all of the above
Correct Answer:
all of the above
Explanation: