1. How many principal thermal properties are there for aggregates?
a) 1
b) 2
c) 3
d) 4
Explanation: There are 3 principal thermal properties for aggregates: coefficient of thermal expansion, specific heat, thermal conductivity.
2. Coefficient of thermal expansion of concrete is __________ coefficient of thermal expansion in aggregates.
a) Directly proportional
b) Inversely proportional
c) Equal
d) More than
Explanation: Coefficient of thermal expansion of concrete increases with the increase in coefficient of thermal expansion of aggregates and vice-versa.
3. If the coefficient of thermal expansion of coarse aggregates and cement paste differs too much, then what happen?
a) A small change in temperature may introduce
b) No change
c) A large change in temperature may introduce
d) A small change in pressure may introduce
Explanation: If it happens then a large change in temperature may introduce differential movement which may break the bond between the aggregates and the paste.
4. If the coefficient of the two materials differ by more than 5.4 * 10-6 per oC, then?
a) Workability of concrete may freeze
b) Durability of concrete subjected to freezing
c) Durability of concrete subjected to boiling
d) Workability of concrete subjected to boiling
Explanation: If the coefficient of the two materials differ by more than 5.4 * 10-6 per oC, then the Durability of concrete subjected to freezing and thawing may be affected.
5. For majority of aggregates, the coefficient of thermal expansion lies between approximately ____________
a) 5.4 * 10-6 and 12.6 * 10-6 per oC
b) 10.8 * 10-6 and 16.2 * 10-6 per oC
c) 5.4 * 10-6 and 10.8 * 10-6 per oC
d) 10.8 * 10-6 and 12.6 * 10-6 per oC
Explanation: The coefficient of thermal expansion lies between approximately 5.4 * 10-6 and 12.6 * 10-6 per oC.
6. For hydrated Portland cement, the coefficient of thermal expansion lies between approximately ____________
a) 5.4 * 10-6 and 12.6 * 10-6 per oC
b) 10.8 * 10-6 and 16.2 * 10-6 per oC
c) 5.4 * 10-6 and 10.8 * 10-6 per oC
d) 10.8 * 10-6 and 12.6 * 10-6 per oC
Explanation: The coefficient of thermal expansion for hydrated Portland cement lies between approximately 10.8 * 10-6 and 16.2 * 10-6 per oC.
7. The linear thermal coefficient of expansion lies between approximately ____________
a) 5.4 * 10-6 and 12.6 * 10-6 per oC
b) 10.8 * 10-6 and 16.2 * 10-6 per oC
c) 5.8 * 10-6 and 14 * 10-6 per oC
d) 10.8 * 10-6 and 12.6 * 10-6 per oC
Explanation: The linear thermal coefficient of expansion lies between approximately 5.8 * 10-6 and 14 * 10-6 per oC depending upon the type of aggregates.
8. The specific heat of the aggregates is _____________
a) The ability to conduct the heat
b) The ability to insulate the heat
c) Is a measure of its heat capacity
d) Same as thermal conductivity
Explanation: The specific heat of the aggregates is a measure of its heat capacity and thermal conductivity is to conduct the heat.
9. The thermal conductivity of the aggregates is ______________
a) The ability to conduct the heat
b) The ability to insulate the heat
c) Is a measure of its heat capacity
d) Same as thermal conductivity
Explanation: Thermal conductivity is the ability of the aggregates to conduct the heat.
10. The coefficient of thermal expansion affects the heat resistance.
a) True
b) False
Explanation: Coefficient of thermal expansion and fire resistance both are related to the heat content.