Que- Does Water damage concrete?
Plain concrete is not affected or damaged by water but Reinforced Concrete (RCC) can be damaged due to water. This is because the water may seep into the concrete and corrode the steel reinforcement inside.
Que- What is the initial and final setting time of ideal cement mix?
Initial setting time for ideal cement mix is around 30 minutes for almost all kind of cements. For masonry cement it can be 90minutes. Final setting time of ideal cement mix should be 10 hours at max. For masonry cement it shouldn’t exceed 24hours.
Que- What are common methods of curing the concrete?
- Spraying
- Wet covering of Surface
- Ponding
- Application of curing chemicals
- Steam curing
Que- What is the formula for weight of steel?
Weight of steel in kg can be calculate by formula (D2*L)/162; where D is diameter of steel bar in millimeter and L is total length of steel bar in meter.
Que- What do you know about “TMT”?
TMT stands for “Thermo Mechanically Treated”. Generally we use TMT bars and sheet for construction purposes for the reason that they have high strength and high corrosion resistance compared to normal steels.
Que- What is difference between working stress method and limit state method?
Working stress method is an elastic design method in which structure is designed to bear the load upto elastic limit. Whereas, limit state method is a plastic design method in which structure is designed to bear the load beyond plastic limit.
Que- What field tests are required for quality check of cement?
Quality of cement can be checked with color, physical properties, etc. Cement should have grey color with light greenish shade. It should feel smooth when rubbed between fingers. If hand is inserted in a heap of cement or its bags, it should feel cool. When pinch of cement is thrown in Water then cement should float for some time before it sink. Also, it should be lump free.
Que- What are the types of foundation used in construction?
There are basically two types of foundation: Shallow & Deep foundation. Again shallow foundation can be classified as spread footing, combined footing, strap or cantilever footing and finally mat or raft footing. Deep foundations can be classified as pile footing, pier footing, caissons footing and well foundation.
Que- What are the types of cement?
There are various types of cement which are: Ordinary Portland Cement (OPC), White Portland Cement (WPC), Portland Pozzolana Cement (PPC), Low Heat Portland Cement, Coloured Portland Cement, Hydrophobic cement, Rapid Hardening Cement, Portland Slag Cement, Sulphate resisting Portland Cement, etc.
Que- What is guniting?
It is a process in which mixture of cement & sand in proportion of 1:3 is shooted on concrete surface with the help of cement gun under pressure of 2 to 3 kg/cm2. It is a highly effective process for repairing concrete walls or damaged surfaces.