Question No. 01
How did street originate in the plumbing term street ell?
Answer: A “street ell” may have gotten its name because it describes a 90 fitting particularly useful in tight, street ditches. When installing water pipes under a street, or from a water service, again under the street, into a home or business, this street ell allows one to change pipe direction with one less fitting, and in less space, than with a standard ell.
Question No. 02
In General Specification for Civil Engineering Works (1992 Edition), it specifies the temperature requirements for bituminous material during and after mixing. What is the reason behind this?
Answer: Temperature is one of the factors that govern the compaction of bituminous material and the air void content is found to decrease with an increase in compaction temperature. This phenomenon is explained by the viscosity-temperature relations: the higher is the viscosity of binders, the greater is the resistance to compaction. Therefore, in normal contract for bituminous laying, the temperature requirements for bituminous material during and after mixing are specified.
Question No. 03
What is diversion tunnel in a dam?
Answer: When a dam is to be built, a diversion tunnel is usually bored through solid rock next to the dam site to bypass the dam construction site. The dam is built while the river flows through the diversion tunnel.
Question No. 04
What is the function of a separation membrane between concrete pavement slab and sub-base?
Answer: The separation membrane between concrete pavement slab and sub-base has the
(i) It aids in reducing the frictional forces between concrete slab and sub-base and helps to
movement of concrete slab with respect to sub-base owing to changes in temperature and moisture.
(ii) It prevents the loss of cement and water in immature concrete which significantly affects the strength and durability of hardened concrete.
(iii) It avoids the mixing up of sub-base materials and freshly placed concrete.
Polythene sheeting, which is a waterproof material, is commonly used as separation membrane.
Question No. 05
Why was the Empire State Building made of steel?
Answer: Strength – Steel is very strong
Flexibility – Ability to flex in the wind
Cost – Inexpensive and fast to build: Prefab construction,
Concrete, a possible alternative, has less compressive strength than steel. The bottom support structure of the empire state building would consist of a large percentage of solid concrete simply to support the weight of the building.
Question No. 06
Why is sulphate-resisting cement not used in marine concrete?
Answer: The main components of Portland cement are tricalcium silicate, dicalcium silicate, tricalcium aluminate and tetracalcium aluminoferrite. In sulphate-resisting cement, it contains a low amount of tricalcium aluminate in order to avoid sulphate attack. Otherwise, tricalcium aluminate would react with sulphates to form calcium sulphoaluminate and gypsum that cause expansion and crack the concrete structure. However, for marine concrete sulphate-resisting cement should not be used because tricalcium aluminate has high affinity for chloride ions. This is based on the possible reaction of chloride ions and tricalcium aluminate to form calcium chloroaluminate hydrate as suggested by P. Kumar Mehta (1991) and the reduction of which may increase the rate of chloride attack to the concrete marine structure and result in faster corrosion of steel reinforcement in marine structures.
Question No. 07
What black man invented the clothes dryer?
Answer: George T. Sampson
Question No. 08
Would you cause a 55 gallon drum of water to weigh more by climbing in?
Answer: A person will sink in water if he is not holding enough air in his lungs to keep him floating. Therefore, the person weighs more than the amount of water that he will displace.
Question No. 09
Is it worthwhile to carry out tests on particle density of soil particles for geotechnical design?
Answer: Particle density of soils is defined by the ratio of soil particle mass and soil particle volume. Depending on soil types, the range of variation of soil particle density varies not significantly, i.e. by 4%. Therefore, it may not be worthwhile to order laboratory tests and incur additional expenditure just to determine the particles density by recognizing that the variation of particles density is not significant.
Question No. 10
What is the withdrawal force of steel nails?
Answer: In engineering, the code allowable withdrawal force is zero, because the wood expands and contracts over time and the nail pullout force can reduce to zero.