Placing
Wetting
Curing
Compacting
C. Curing
Chemically inert
Sufficiently strong
Hard and durable
All the above
One cantilever
Two cantilevers
Three cantilevers
Four cantilevers
50 mm
100 mm
150 mm
200 mm
1000°C
1200°C
1400°C
1600°C
Decreases workability
Increases strength
Increases heat of hydration
None of these
Ordinary Portland cement
Rapid hardening cement
Low heat cement
Blast furnace slag cement
1500 bags
2000 bags
2500 bags
3000 bags
A horizontal line
A vertical line
N.W. inclined line
N.E. inclined line
Magnesium oxide
Iron oxide
Silica
Lime
The weight of ingredients of concrete mix, is taken in kilograms
Water and aggregates are measured in litres
20 bags of cement make one tonne
All the above
2.0 to 3.5
3.5 to 5.0
5.0 to 7.0
6.0 to 8.5
Aggregates should be hard and durable
Water should be free from organic materials
Cement should be sufficient to produce the required strength
All the above
Reacts fast with water
Generates less heat of hydration
Causes initial setting and early strength of cement
Does not contribute to develop ultimate strength
Depends upon the amount of water used in the mix
Does not depend upon the quality of cement mixed with aggregates
Does not depend upon the quantity of cement mixed with aggregates
All the above
20 mm to 30 mm
30 mm to 40 mm
40 mm to 50 mm
50 mm to 60 mm
150 × 150 × 500 mm
100 × 100 × 700 mm
150 × 150 × 700 mm
100 × 100 × 500 mm
Lime stone and clay
Gypsum and lime
Pozzolana
Lime, pozzolana and clay
1.5
2.0
2.5
3.0
Single sized aggregates
Two sized aggregate
Graded aggregates
Coarse aggregates
Cement and standard sand mortar are used in the ratio of 1 : 3
Water is added at the rate of (P/4) + 3.0 percentage of water where P is the percentage of water for standard consistency
A cube mould of 10 cm × 10 cm × 10 cm is used
The prepared moulds are kept in a atmosphere of 50% relative humidity
Between 150 to 300 kg/cm2
Between 350 to 600 kg/cm2
Between 150 to 500 kg/cm2
Below 200 kg/cm2
Directly proportional to compressive strength
Inversely proportional to compressive strength
Directly proportional to square root of compressive strength
Inversely proportional to square root of compressive strength
Only (i)
(i) and (ii)
(i) and (iii)
All (i), (ii) and (iii)
Proportions of the material and water should be the same as to be used at the work site
Cement should be mixed by hand in order to maintain uniformity
Concrete mix should be stored in air-tight containers
Concrete ingredients should be kept at a temperature of 37° ± 2°C
1 : 3 : 6 mix
1 : 1 : 2 mix
1 : 2 : 4 mix
1 : 1.5 : 3 mix
25 %
40 %
60 %
80 %
7 days for beam soffits
14 days for bottom slabs of spans 4.6 m and more
21 days for bottom beams over 6 m spans
All the above
Fly ash
Hydrated lime
Calcium chloride
All the above
Greatest surface area for the given cement and aggregates
Least surface area for the given cement and aggregates
Least weight for the given cement and aggregates
Greatest weight for the given cement and aggregates
Increases workability
Decreases workability
Decreases resistance to weathering
Increases strength