The approximate value of the ratio between direct tensile strength and flexural strength is
0.33
0.5
0.75
1.0
Correct Answer :
B. 0.5
Related Questions
In order to obtain the best workability of concrete, the preferred shape of aggregate is
Rounded
Elongated
Angular
All of the above
Sinking of an intermediate support of a continuous beam (i) Reduces the negative moment at support (ii) Increases the negative moment at support (iii) Reduces the positive moment at center of span (iv) Increases the positive moment at center of span The correct answer is
(i) and (iii)
(i) and (iv)
(ii) and (iii)
(ii) and (iv)
If the storey height is equal to length of RCC wall, the percentage increase in strength is
0
10
20
30
M10 grade of concrete approximates
1 : 3 : 6 mix
1 : 1 : 2 mix
1 : 2 : 4 mix
1 : 1.5 : 3 mix
An ordinary Portland cement when tested for its fineness, should not leave any residue on I.S. sieve No. 9, more than
5 %
10 %
15 %
20 %
The design yield stress of steel according to IS: 4561978 is: (Where fy is the characteristic yield strength of steel)
0.37 fy
0.57 fy
0.67 fy
0.87 fy
Proper proportioning of concrete, ensures
Desired strength and workability
Desired durability
Water tightness of the structure
All the above
Proper batching ensures
Economy
Durability
Workability
All the above
You are asked to construct a massive dam, the type of cement you will use, is
Ordinary Portland cement
Rapid hardening cement
Low heat cement
Blast furnace slag cement
The factor which affects workability, is
Water content and its temperature
Shape and size of the aggregates
Air entraining agents
All the above
Pick up the correct statement from the following:
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
Which of the following statements is incorrect?
Minimum cross sectional area of longitudinal reinforcement in a column is 0.8%
Spacing of longitudinal bars measured along the periphery of column should not exceed 300 mm
Reinforcing bars in a column should not be less than 12 mm in diameter
The number of longitudinal bars provided in a circular column should not be less than four
The specifications of a cement bag for storage, are
Weight 50 kg
Height 18 cm
Plan area 3000 sq. cm
All the above
Segregation is responsible for
Honey-combed concrete
Porous layers in concrete
Surface scaling in concrete
All the above
If P, Y and Z are the weights of cement, fine aggregates and coarse aggregates respectively and W/C is the water cement ratio, the minimum quantity of water to be added to first batch, is obtained by the equation
0.1P + 0.3Y + 0.1Z = W/C × P
0.3P + 0.1Y + 0.01Z = W/C × P
0.4P + 0.2Y + 0.01Z = W/C × P
0.5P + 0.3Y + 0.01Z = W/C × P
Pick up the incorrect statement from the following. While performing preliminary test on concrete
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
The type of aggregates not suitable for high strength concrete and for pavements subjected to tension, is
Rounded aggregate
Irregular aggregate
Angular aggregate
Flaky aggregate
The rock which is not calcareous, is:
Lime stone
Chalk
Laterite
None of these
Workability improved by adding
Fly ash
Hydrated lime
Calcium chloride
All the above
For the construction of R.C.C. slabs, columns, beams, walls, etc. the grade of concrete mix used, is
1 : 3 : 6
1 : 1 ½ : 3
1 : 2 : 4
1 : 1 : 2
If 50 kg of fine aggregates and 100 kg of coarse aggregates are mixed in a concrete whose water cement ratio is 0.6, the weight of water required for harsh mix, is
8 kg
10 kg
12 kg
14 kg
Increase in the moisture content in concrete
Reduces the strength
Increases the strength
Does not change the strength
All of the above
If the effective plan area of a warehouse is 54 sq. m, and maximum height of piles permitted is 270 cm, the number of cement bags to be stored, is
2000 bags
2200 bags
2400 bags
2700 bags
For an ordinary Portland cement
Residual does not exceed 10% when sieved through IS Sieve No. 9
Soundness varies from 5 to 10 mm
Initial setting time is not less than 30 minutes
Compressive stress after 7 days, is not less than 175 kg/cm2
'Ware house pack' of cement means
Full capacity of the ware house
Pressure exertion of the bags of upper layers
Pressure compaction of the bags on lower layers
Packing the ware house
A concrete having a slump of 6.5 cm, is said to be
Dry
Earth moist
Semi-plastic
Plastic
For preparing ordinary concrete, the quantity of water used, is
5% by weight of aggregates plus 20% of weight of cement
10% by weight of aggregates plus 10% of weight of cement
5% by weight of aggregates plus 30% of weight of cement
30% by weight of aggregates plus 10% of weight of cement
For given water content, workability decreases if the concrete aggregates contain an excess of
Thin particles
Flat particles
Elongated particles
All the above
If the size of panel in a flat slab is 6 m × 6 m, then as per Indian Standard Code, the widths of column strip and middle strip are
3.0 m and 1.5 m
1.5 m and 3.0 m
3.0 m and 3.0 m
1.5 m and 1.5 m
The slab is designed as one way if the ratio of long span to short span is
Less than 1
Between 1 and 1.5
Between 1.5 and 2
Greater than 2