1.In concrete masonry, hollow concrete units are used for _________ walls.
a) Either load-bearing or non-load bearing
b) Only load-bearing
c) Only non-load bearing
d) Neither load-bearing nor non-load bearing
Explanation: Concrete masonry uses two types of cement concrete blocks for the construction of walls – hollow concrete block and solid concrete block. Solid concrete blocks are used only in load-bearing walls whereas hollow concrete blocks can be used for either load-bearing or non-load bearing walls.
2. The cores in the blocks used in concrete masonry should be _________ shaped.
a) Oval
b) Square
c) Triangular
d) Circular
Explanation: The Concrete Association of India recommends that the shape of the cores in the blocks used in concrete masonry should be oval. There should be at least two cores in the blocks.
3. Which of the following surface finishes is a rough finish?
a) Glazed finish
b) Colored finish
c) Specially faced finish
d) Slumped finish
Explanation: Slumped finish is obtained by preparing a concrete of the desired slump. It is a rough finish. Glazed finish is used to give a shiny appearance. Colored finish is obtained by adding various colored pigments to the concrete mix to impart different colors whereas in the specially faced finish, finishing material such as marble, is used on the facing side of the block.
4. In hollow clay blocks masonry, the load bearing main walls should be constructed in __________ (cement, lime, sand) mix.
a) 1:2:6
b) 1:1:6
c) 1:2:9
d) 1:1:9
Explanation: In hollow clay blocks masonry, the load bearing main walls should be constructed in 1:1:6 (cement, lime, sand). And non-load bearing main walls should be constructed in 1:2:9 mix.
5. Thermal insulation of hollow clay blocks is good because of ____________
a) Air within the cells of blocks
b) Air outside the cells of blocks
c) Resistance to water
d) Resistance to air
Explanation: Hollow clay blocks are fireproof and thermally insulated. The reason behind their good thermal insulation is the presence of a huge amount of air within the cells of these blocks.
6.Which of the following is not a type of structural clay unit in hollow clay blocks masonry?
a) Partition block
b) Fixing block
c) Load bearing block
d) Cavity block
Explanation: Hollow clay blocks are available in various shapes and sizes. Various types are partition block, fixing block, load-bearing block, rug faced block, conduit block, etc.
7.In grooved tiles, the area covered by the grooves should not exceed _________ of the area of cored faces.
a) 20%
b) 30%
c) 40%
d) 50%
Explanation: Tiles used in hollow clay blocks masonry may have grooves on their faces. While manufacturing grooved tiles, it is to be kept in mind that the area covered by the grooves should not exceed 50% of the area of the cored faces.
8. In hollow clay blocks masonry _________ act as partitions between the cells.
a) Webs
b) Shells
c) Grooves
d) Blocks
Explanation: In hollow clay blocks masonry, a shell surrounds the hollow interior. The role of a web is to serve as partitions between the cells.
9. What should be the least overall average thickness of the shells used in hollow clay blocks masonry?
a) 1 cm
b) 2 cm
c) 3 cm
d) 4 cm
Explanation: The shell of a clay block surrounds the hollow interior while a web acts as a partition between the cells. The least overall average thickness of a shell should be 2 cm.
10. Grooved tiles are used only in those cases where plastering is to be done.
a) True
b) False
Explanation: Grooved tiles are used only in those cases where plastering is to be done. In all other cases, smooth tiles should be used.