The percentage of voids in cement is approximately
25 %
40 %
60 %
80 %
Correct Answer :
B. 40 %
Related Questions
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
Sands of zone I are:
Course
Medium
Medium to fine
Fine
The mixture of different ingredients of cement, is burnt at
1000°C
1200°C
1400°C
1600°C
A higher modular ratio shows
Higher compressive strength of concrete
Lower compressive strength of concrete
Higher tensile strength of steel
Lower tensile strength of steel
Minimum thickness of load bearing RCC wall should be
50 mm
100 mm
150 mm
200 mm
For a continuous slab of 3 m × 3.5 m size, the minimum overall depth of slab to satisfy vertical deflection limits is
50 mm
75 mm
100 mm
120 mm
According to ISI recommendations, the maximum depth of stress block for balanced section of a beam of effective depth d is
0.43 d
0.55 d
0.68 d
0.85 d
The following proportion of the ingredients of concrete mix, is not in conformation to arbitrary method of proportioning
1 : 1 : 2
1 : 2 : 4
1 : 3 : 6
1 : 4 : 10
Construction joints are generally provided in concrete
Roads
Retaining walls
Lining of canals
All the above
In a pile of length l, the points of suspension from ends for lifting it are located at
0.207 l
0.25 l
0.293 l
0.333 l
The condition not applicable to water cement ratio law, is
Internal moisture conditions on hydration continue till complete strength is gained
Concrete specimens may be tested at any temperature
Concrete specimens need be of same age
Concrete specimens need be of same size
The ratio of the diameter of reinforcing bars and the slab thickness is
1/4
1/5
1/6
1/8
Bulking of sand is
Mixing of different sizes of sand particles
Mixing of lime with sand
Maximum water with sand
Swelling of sand when wetted
Critical section for shear in case of flat slabs is at a distance of
Effective depth of slab from periphery of column/drop panel
d/2 from periphery of column/capital/ drop panel
At the drop panel of slab
At the periphery of column
Shrinkage of concrete depends upon
(i) Humidity of atmosphere
(ii) Passage of time
(iii) Stress The correct answer is
(i) and (ii)
(ii) and (iii)
Only (iii)
All (i), (ii) and (iii)
Assertion A : The load factor for live load is greater than that for dead load. Reason R : The live loads are more uncertain than dead loads. Select your answer based on the coding system given below:
Both A and R is true and R is the correct explanation of A
Both A and R is true but R is not the correct explanation of A
A is true but R is false
A is false but R is true
Cube strength of controlled concrete to be used for pre-tensioned and post-tensioned work respectively should not be less than
35 MPa and 42 MPa
42 MPa and 35 MPa
42 MPa and 53 MPa
53 MPa and 42 MPa
Segregation is responsible for
Honey-combed concrete
Porous layers in concrete
Surface scaling in concrete
All the above
The permissible diagonal tensile stress in reinforced brick work is
About 0.1 N/mm²
Zero
0.3 N/mm² to 0.7 N/mm²
About 1.0 N/mm²
The diameter of the Vicat plunger is 10 mm and its length varies from
20 mm to 30 mm
30 mm to 40 mm
40 mm to 50 mm
50 mm to 60 mm
The risk of segregation is more for
Wetter mix
Larger proportion of maximum size aggregate
Coarser grading
All the above
The limits of percentage p of the longitudinal reinforcement in a column is given by
0.15% to 2%
0.8% to 4%
0.8% to 6%
0.8% to 8%
Proper batching ensures
Economy
Durability
Workability
All the above
Air entrainment in the concrete increases
Workability
Strength
The effects of temperature variations
The unit weight
Workability of concrete is measured by
Vicat apparatus test
Slump test
Minimum void method
Talbot Richard test
Pozzolana cement is used with confidence for construction of
Dams
Massive foundations
R.C.C. structures
All the above
A continuous beam is deemed to be a deep beam when the ratio of effective span to overall depth (1/D) is less than
1.5
2.0
2.5
3.0
The effect of creep on modular ratio is
To decrease it
To increase it
Either to decrease or to increase it
To keep it unchanged
If the permissible stress in steel in tension is 140 N/mm², then the depth of neutral axis for a singly reinforced rectangular balanced section will be
0.35 d
0.40 d
0.45 d
Dependent on grade of concrete also
Slump test is done for
Clay
Sand
Lime
Concrete