To prevent segregation, the maximum height for placing concrete, is
100 cm
125 cm
150 cm
200 cm
Correct Answer :
A. 100 cm
Related Questions
Maximum distance between expansion joints in structures as per IS: 456 1978 is
20 m
30 m
45 m
60 m
A construction joint is provided where
Bending moment is small
Shear force is small
The member is supported by other member
All the above
If the storey height is equal to length of RCC wall, the percentage increase in strength is
0
10
20
30
Pick up the correct statement from the following:
The maximum size of a coarse aggregate, is 75 mm and minimum 4.75 mm
The maximum size of the fine aggregate, is 4.75 mm and minimum 0.075 mm
The material having particles of size varying from 0.06 mm to 0.002 mm, is known as silt
All the above
Tricalcium aluminate (C3A)
Reacts fast with water
Generates less heat of hydration
Causes initial setting and early strength of cement
Does not contribute to develop ultimate strength
The recommended value of modular ratio for reinforced brick work is
18
30
40
58
Particles of 0.002 mm size are that of
Clay
Sand
Gravel
None of these
For a concrete mix 1:3:6 and water cement ratio 0.6 both by weight, the quantity of water required per bag, is
10 kg
12 kg
14 kg
16 kg
The internal dimensions of a ware house are 15 m × 5.6 m, and the maximum height of piles is 2.70 m, the maximum number of bags to be stored in two piles, are
1500 bags
2000 bags
2500 bags
3000 bags
According to IS: 4561978, the column or the strut is the member whose effective length is greater than
The least lateral dimension
2 times the least lateral dimension
3 times the least lateral dimension
4 times the least lateral dimension
Pre-stress loss due to friction occurs
Only in post-tensioned beams
Only in pre-tensioned beams
In both post-tensioned and pre-tensioned beams
None of the above
Under normal conditions using an ordinary cement, the period of removal of the form work, is:
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
Select the incorrect statement
The loss of pre-stress is more in pre-tensioning system than in posttensioning system.
Pre-tensioning system has greater certainty about its durability.
For heavy loads and large spans in buildings or bridges, posttensioning system is cheaper than pre-tensioning system
None of the above
Permissible compressive strength of M 200 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2
The high strength of rapid hardening cement at early stage, is due to its
Finer grinding
Burning at high temperature
Increased lime cement
Higher content of tricalcium
If a beam fails in bond, then its bond strength can be increased most economically by
Increasing the depth of beam
Using thinner bars but more in number
Using thicker bars but less in number
Providing vertical stirrups
C.R.R.I. charts are used to obtain a relationship between strength of concrete and
Water cement ratio
Workability
Grading of aggregate
Fineness modulus
For a simply supported beam of span 15 m, the minimum effective depth to satisfy the vertical deflection limits should be
600 mm
750 mm
900 mm
More than 1 m
Segregation is responsible for
Honey-combed concrete
Porous layers in concrete
Surface scaling in concrete
All the above
If the foundations of all the columns of a structure are designed on the total live and dead load basis, then
There will be no settlement of columns
There will be no differential settlement
The settlement of exterior columns will be more than interior columns
The settlement of interior columns will be more than exterior columns
After casting, an ordinary cement concrete on drying
Expands
Mix
Shrinks
None of these
In a ring beam subjected to uniformly distributed load (i) Shear force at mid span is zero (ii) Shear force at mid span is maximum (iii) Torsion at mid span is zero (iv) Torsion at mid span is maximum The correct answer is
(i) and (iii)
(i) and (iv)
(ii) and (iii)
(ii) and (iv)
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
In pre-stressed concrete
Forces of tension and compression change but lever arm remains unchanged
Forces of tension and compressions remain unchanged but lever arm changes with the moment
Both forces of tension and compression as well as lever arm change
Both forces of tension and compression as well as lever arm remain unchanged
The process of proper and accurate measurement of concrete ingredients for uniformity of proportion, is known
Grading
Curing
Mixing
Batching
The cement becomes useless if its absorbed moisture content exceeds
1 %
2 %
3 %
5 %
If 20 kg of coarse aggregate is sieved through 80 mm, 40 mm, 20 mm, 10 mm, 4.75 mm, 2.36 mm, 1.18 mm, 600 micron, 300 micron and 150 micron standard sieves and the weights retained are 0 kg, 2 kg, 8 kg, 6 kg, 4 kg respectively, the fineness modulus of the aggregate, is
7.30
7.35
7.40
7.45
The main reinforcement in the heel of a T-shaped R.C. retaining wall is provided on
Top face perpendicular to wall
Bottom face perpendicular to wall
Both top and bottom faces perpendicular to wall
None of the above
Permissible compressive strength of M 200 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2
The purpose of reinforcement in pre-stressed concrete is
To provide adequate bond stress
To resist tensile stresses
To impart initial compressive stress in concrete
All of the above