500 Best Concrete Technology- MCQ
Q129). The main object of proportioning concrete is to obtain
a).required strength and workability
b).desired durability
c).water tightness
d).all of these
Correct Answer:
all of these
Explanation:
Q130). M 25 means that the compressive strength of 15 cm cubes at 28 days after mixing is
a).15 N/mm2
b).20 N/mm2
c).25 N/mm2
d).30 N/mm2
Correct Answer:
25 N/mm2
Explanation:
Q131). The test conducted in the laboratory on the specimen made out of trial concrete mix is called
a).preliminary test
b).slump test
c).works test
d).none of these
Correct Answer:
preliminary test
Explanation:
Q132). In performing preliminary test
a).the moulds required for test specimens should be rigid
b).the mix should be stored in airtight containers
c).the aggregate should be dry
d).all of the above
Correct Answer:
all of the above
Explanation:
Q133). In order to prepare test specimen, it is necessary to
a).mix the cement and fine aggregate by dry hand
b).mix the coarse aggregate
c).mix water to the cement, fine aggregate and coarse aggregates
d).all of the above
Correct Answer:
all of the above
Explanation:
Q134). The ratio of different ingredients (cement, sand and aggregate) in concrete mix of grade M 20 is M 20 is
a). 1:1:2
b). 1:1.5:3
c). 1:2:4
d). 1:3:6
Correct Answer:
1:1.5:3
Explanation:
Q135). In preliminary test, the concrete is placed in the mould in ………. layers of equal volume.
a).two
b).three
c).four
d).five
Correct Answer:
three
Explanation:
Q136). The preliminary test should be repeated if the difference of compressive strength of three test specimens exceeds
a).0.5 N/mm2
b).1 N/mm2
c).1.5 N/mm2
d).2 N/mm2
Correct Answer:
1.5 N/mm2
Explanation: