1. Young’s modulus for dickite is ___________
a) 5.2 GPa
b) 6.2 GPa
c) 7.2 GPa
d) 8.2 GPa
Explanation: Young’s modulus on clay particles using atomic force acoustic microscopy is measured for dickite is 6.2 GPa.
2. The grain density of the clay powders was measured using _______
a) Hydrostatic pressure
b) Cylindrical cavity
c) Pycnometer
d) Helium porosimeter
Explanation: The grain density of the clay powders was measured using a pycnometer.
3. To avoid trapped air produced by clay flocculation, we used ___ in distilled water.
a) (NaPO3)6
b) Na4P2O7
c) Na5P3O10
d) PO4
Explanation: To avoid trapped air produced by clay flocculation, we used sodium hexametaphosphate in distilled water.
4. For the cold-pressed aggregate samples, porosity, bulk and grain densities were measured with __________
a) Hydrostatic pressure
b) Cylindrical cavity
c) Pycnometer
d) Helium porosimeter
Explanation: For the cold-pressed aggregate samples, porosity, bulk and grain densities were measured at room P–T conditions with a helium porosimeter.
5.IS 456 of 2000 gives the modulus of elasticity as _______
a) Ec = 5000 fck.5
b) Ec = 5000 fck2
c) Ec = 5000 fck3
d) Ec = 5000 fck1/3
Explanation: IS 456 of 2000 gives the modulus of elasticity as Ec = 5000 fck.5 where Ec is the modulus of elasticity in N/mm2.
6. What are elastic strains?
a) These are the instantaneous deformations that occur when an external stress is first applied
b) These deformations occur either on loss of moisture from the concrete on cooling of concrete
c) It is the time-dependent deformation that occurs on the prolonged application of stress
d) Any one or combinations of the above types of deformations in a hardened concrete leads to cracking
Explanation: Elastic strain in concrete, as defined above, depends on the externally applied stress and the modulus of elasticity of concrete.
7. Static modulus of elasticity of concrete has been related to its ________
a) Tensile strength
b) Compressive strength
c) External strength
d) Applied force
Explanation: Static modulus of elasticity of concrete has been related to its compressive strength by the various Standards.
8. If the value of fck is 100 then what will be the modulus of elasticity?
a) 5000
b) 500
c) 50000
d) 50
Explanation: The modulus of elasticity as Ec = 5000 fck.5 =000*100.5 =5000*10 = =50000.
9. The __________ the aggregate, the ________ is the magnitude of creep.
a) Stronger, more
b) Weaker, more
c) Stronger, less
d) Weaker, less
Explanation: The stronger the aggregate the more is the restraining effect and hence the less is the magnitude of creep.
10. The _________ the modulus of elasticity the _________ is the creep.
a) Higher, more
b) Lower, more
c) Higher, less
d) Lower, less
Explanation: It can be easily imagined that the higher the modulus of elasticity the less is the creep.