Pozzolanic properties exist in
Shales
Fly ash
Pumicite
All the above
Correct Answer :
D. All the above
Related Questions
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
Pick up the correct statement from the following:
Calcium chloride acts as a retarder
Calcium chloride acts as an accelerator
Gypsum (calcium sulphate) acts as a retarder
Both (b) and (c)
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
The risk of segregation is more for
Wetter mix
Larger proportion of maximum size aggregate
Coarser grading
All the above
Permissible compressive strength of M 150 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2
In case of hand mixing of concrete, the extra cement to be added is
5 %
10 %
15 %
20 %
The rock which is not calcareous, is:
Lime stone
Chalk
Laterite
None of these
According to the recommendations of IS : 456-1978, the expansion joints
Are provided where plane changes abruptly
Are provided to ensure minimum resistance
Do not carry reinforcement across them
All the above
The bulk density of aggregates, is generally expressed as
Tonnes/cubic metre
kg/cubic metre
kg/litre
g/cm3
For a good concrete
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
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 correct statement from the following:
Insufficient quantity of water makes the concrete mix harsh
Insufficient quantity of water makes the concrete unworkable
Excess quantity of water makes the concrete segregated
All the above
Proper proportioning of concrete, ensures
Desired strength and workability
Desired durability
Water tightness of the structure
All the above
Pick up the correct statement from the following:
Higher workability indicates unexpected increase in the moisture content
Higher workability indicates deficiency of sand
If the concrete mix is dry, the slump is zero
All the above
Ordinary concrete is not used for concrete grade
M 100
M 150
M 250
M 400
The operation of removing humps and hollows of uniform concrete surface, is known as
Floating
Screeding
Trowelling
Finishing
If the average compressive strength is 4000 kg/cm2 and standard deviation is 500, the co-efficient of variation is
10 %
12.5 %
15 %
18.5 %
In a spherical dome the hoop stress due to a concentrated load at crown is
Compressive everywhere
Tensile everywhere
Partly compressive and partly tensile
Zero
If a grading curve is horizontal between the portions of 20 mm I.S. Sieve and 4.75 mm I.S. Sieve, the graded aggregates do not contain
20 mm particles
10 mm particles
4.75 mm particles
All the above
Workability of concrete is measured by
Vicat apparatus test
Slump test
Minimum void method
Talbot Richard test
Workability of concrete mix with low water cement ratio is determined by
Tensile strength test
Slump test
Compaction factor test
Flexural strength test
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
For the construction of cement concrete dams, the maximum permissible size of the aggregates, is
40 mm
50 mm
60 mm
70 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 aggregate impact value of the aggregate used in
Building concrete is less than 45
Road pavement concrete is less than 30
Runway concrete is less than 30
All the above
Pick up the correct statement from the following:
Water cement paste hardens due to hydration
During hardening cement binds the aggregates together
Cement provides strength, durability and water tightness to the concrete
All the above
For the construction of cement concrete floor, the maximum permissible size of aggregate, is
4 mm
6 mm
8 mm
10 mm
High carbon content in the steel causes
Decrease in tensile strength but increase in ductility
Increase in tensile strength but decrease in ductility
Decrease in both tensile strength and ductility
Increase in both tensile strength and ductility
For a longitudinal reinforcing bar in a column, the minimum cover shall neither be less than the diameter of bar nor less than
15 mm
25 mm
30 mm
40 mm
The grade of concrete not recommended by I.S. : 456, is
M 100
M 200
M 300
M 500