Approximate value of shrinkage strain in concrete, is
0.003
0.0003
0.00003
0.03
Correct Answer :
B. 0.0003
Related Questions
Setting time of cement increases by adding
Gypsum
Hydrogen peroxide
Calcium chloride
Sodium oxide
Shrinkage in concrete can be reduced by using
Low water cement ratio
Less cement in the concrete
Proper concrete mix
All the above
Hardening of cement occurs at
Rapid rate during the first few days and afterwards it continues to increase at a decreased rate
Slow rate during the first few days and afterwards it continues to increase at a rapid rate
Uniform rate throughout its age
None of these
The minimum cover in a slab should neither be less than the diameter of bar nor less than
10 mm
15 mm
25 mm
13 mm
For a reinforced concrete section, the shape of shear stress diagram is
Wholly parabolic
Wholly rectangular
Parabolic above neutral axis and rectangular below neutral axis
Rectangular above neutral axis and parabolic below neutral axis
The minimum diameter of longitudinal bars in a column is
6 mm
8 mm
12 mm
16 mm
After casting, an ordinary cement concrete on drying
Expands
Mix
Shrinks
None of these
If 1500 g of water is required to have a cement paste 1875 g of normal consistency, the percentage of water is,
20 %
25 %
30 %
35 %
The ratio of various ingredients (cement, sand, aggregates) in concrete of grade M 200, is
1 : 2 : 4
1 : 3 : 6
1 : 1 ½ : 3
1 : 1 : 2
Separation of water or water sand cement from a freshly concrete, is known
Bleeding
Creeping
Segregation
Flooding
Workability improved by adding
Air-entraining agent
Foaming agent
Oily-agent
All the above
For ensuring quality of concrete, use
Single sized aggregates
Two sized aggregate
Graded aggregates
Coarse aggregates
The most useless aggregate is one whose surface texture is
Smooth
Granular
Glassy
Honey combed and porous
If the engineer-in-charge approves, the 10 cm cubes may be used for the work test of concrete provided maximum nominal size of aggregate, does not exceed
10 cm
15 cm
20 cm
25 cm
Pick up the incorrect statement from the following:
A rich mix of concrete possesses higher strength than that a lean mix of desired workability with excessive quantity of water
The strength of concrete decreases as the water cement ratio increases
Good compaction by mechanical vibrations, increases the strength of concrete
None of these
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
Pick up the incorrect statement from the following:
In properly graded aggregates, bulk density is more
In single size aggregates, bulk density is least
In single size aggregates, bulk density is maximum
None of these
Water cement ratio is generally expressed in volume of water required per
10 kg
20 kg
30 kg
50 kg
Internal friction between the ingredients of concrete, is decreased by using
Less water
Fine aggregates
Rich mix
More water and coarse aggregates
Air entrainment in the concrete increases
Workability
Strength
The effects of temperature variations
The unit weight
The compaction of concrete, improves
Density
Strength
Durability
All the above
Concrete containing
Siliceous aggregates, has higher co-efficient of expansion
Igneous aggregates, has intermediate coefficient of expansion
Lime stones, has lowest co-efficient of expansion
All the above
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
Particles of 0.002 mm size are that of
Clay
Sand
Gravel
None of these
Workability of concrete is inversely proportional to
Time of transit
Water-cement ratio
The air in the mix
Size of aggregate
If the effective working time is 7 hours and per batch time of concrete is 3 minutes, the output of a concrete mixer of 150 litre capacity, is
15,900 litres
16,900 litres
17,900 litres
18,900 litres
The main reason for providing number of reinforcing bars at a support in a simply supported beam is to resist in that zone
Compressive stress
Shear stress
Bond stress
Tensile stress
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
Sand requiring a high water cement ratio, belongs to
Zone I
Zone II
Zone III
Zone IV
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