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
Correct Answer :
C. Increased lime cement
Related Questions
Hydration of cement is due to chemical action of water with
Tricalcium silicate and dicalcium silicate
Dicalcium silicate and tricalcium aluminate
Tricalcium aluminate and tricalcium alumino ferrite
All the above
Workability improved by adding
Fly ash
Hydrated lime
Calcium chloride
All the above
Shrinkage in concrete can be reduced by using
Low water cement ratio
Less cement in the concrete
Proper concrete mix
All the above
Most common method of pre-stressing used for factory production is
Long line method
Freyssinet system
Magnel-Blaton system
Lee-Macall system
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
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
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
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
Particles of 0.002 mm size are that of
Clay
Sand
Gravel
None of these
The dimensions of a 35 litre forma for measuring aggregates by volume, are:
Length 30 cm, breadth 25 cm, height 30 cm
Length 39 cm, breadth 25 cm, height 32 cm
Length 27 cm, breadth 27 cm, height 48 cm
Length 220 cm, breadth 25 cm, height 40 cm
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
Curing
Reduces the shrinkage of concrete
Preserves the properties of concrete
Prevents the loss of water by evaporation
All of the above
In counterfort type retaining walls (i) The vertical slab is designed as a continuous slab (ii) The heel slab is designed as a continuous slab (iii) The vertical slab is designed as a cantilever (iv) The heel slab is designed as a cantilever The correct answer is
(i) and (ii)
(i)and(iv)
(ii) and (iii)
(iii) and (iv)
Water cement ratio is generally expressed in volume of water required per
10 kg
20 kg
30 kg
50 kg
The property of the ingredients to separate from each other while placing the concrete is called
Segregation
Compaction
Shrinkage
Bulking
An ideal ware house, is provided
Water proof masonry walls
Water proof roof
Few windows which remain generally closed
All the above
Concrete gains strength due to
Chemical reaction of cement with sand and coarse aggregates
Evaporation of water from concrete
Hydration of cement
All the above
Permissible compressive strength of M 200 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2
Pick up the correct statement from the following:
According to the petrological characteristics, concrete aggregates are classified as heavy weight, normal weight and light weight
According to the shape of the particles, concrete aggregates are classified as rounded irregular, angular and flaky
According to the surface texture of the particles, the concrete aggregates are classified as glassy, smooth, granular, rough, crystalline, honey combed and porous
All the above
The maximum thickness of concrete floor of a cement warehouse, is
10 cm
15 cm
20 cm
25 cm
The minimum cover to the ties or spirals should not be less than
15 mm
20 mm
25 mm
50 mm
Admixtures which cause early setting and hardening of concrete are called
Workability admixtures
Accelerators
Retarders
Air entraining agents
Permissible compressive strength of M 200 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2
The maximum amount of dust which may be permitted in aggregates is
5% of the total aggregates for low workability with a coarse grading
10% of the total aggregates for low workability with a fine grading
20% of the total aggregates for a mix having high workability with fine grading
All the above
If fineness modulus of sand is 2.5, it is graded as
Very fine sand
Fine sand
Medium sand
Coarse sand
Due to shrinkage stresses, a simply supported beam having reinforcement only at bottom tends to
Deflect downward
Deflect upward
Deflect downward or upward
None of the above
In slump test, each layer of concrete is compacted by a steel rod 60 cm long and of 16 mm diameter for
20 times
25 times
30 times
50 times
According to I.S. : 456, the number of grades of concrete mixes, is
3
4
5
7
The operation of removing humps and hollows of uniform concrete surface, is known as
Floating
Screeding
Trowelling
Finishing
Strength of concrete increases with
Increase in water-cement ratio
Increase in fineness of cement
Decrease in curing time
Decrease in size of aggregate