WorksheetsDay 37-Oct 27-worksheet-PWD-Cement&Bricks
Total questions: 15
Worksheet time: 10mins
The compound in cement responsible for progressive (final) strength and resistance to freezing and thawing is
C3A
C3S
C2S
C4AF
The low heat cement contains
high C3A and low C2S
low C3A and high C2S
high C3S and low C2S
high C4AF and low C3A
In brick earth, excess alumina results in
brittle bricks
smooth and strong bricks
shrinkage and warping during drying
improved resistance to efflorescence
Hydrophobic cement becomes water resistant due to the addition of
aluminium sulphate
oleic acid
pozzolana
sodium silicate
Which brick manufacturing defect causes spongy, swollen mass due to excess carbonaceous matter and sulphur?
Black core
Bloating
Chuff
Efflorescence
The kiln which is permanent, has 12 chambers and a central chimney is
(a)
Excess alkalis in cement cause efflorescence on the finished surface.
True
False
In bricks, excess magnesia improves hardness without affecting durability.
True
False
Assertion (A): C3A in cement contributes to flash setting and releases the highest heat of hydration. Reason (R): C3A percentage in sulphate resisting cement is deliberately kept very high.
Both A and R are true, and R is the correct explanation
Both A and R are true, but R is not the correct explanation
A is true but R is false
A is false but R is true
The compound (a) in cement is responsible for early strength.
The chief constituent providing plasticity to brick earth is (a) .
Excess (a) in brick earth causes the brick to melt and lose its shape during burning.
Fire bricks are manufactured using ________ clay containing high ________ and ________.
Fire clay, Alumina, Silica
Kaolin clay, Iron, Lime
Ball clay, Magnesia, Potash
Fire clay, Calcium, Soda
In perforated bricks, the total area of perforation is limited to ________ % of the total area.
30–45%
10–20%
50–60%
70–80%
Name the equipment used to test initial setting time of cement
(a)
