IS: 455 is associated with Portland slag cement.

According to Indian standards

In sampling, catch sample collected from sampling spot at any instant. It is also known as grabbing sample. It is influenced by nature of tests are to be conducted.

The framework of truss should be built in a way that, it does not change its shape when loaded. The triangular shape of frame offers great rigidity and hence it is generally adopted.

High Alumina cement is used for marine structures.

The stress corresponding to 0.2% of strain in stress-strain curve of mild steel is known as proof stress and this also taken as yield stress. The maximum stress is generally taken as yield stress.

The stress developed in a material without any permanent stress is called elastic limit and breaking stress is always less than ultimate stress.

Purlin is a roof beam supported by roof truss. The purlin is designed as a beam subjected to bending moment about to axes. The various loads used in design of purlins are:
i. Dead load
ii. Imposed load
iii. Wind load.

Aeration is a method by which water is brought in close contact air so as to absorb oxygen for reduction of taste, odour etc. by virtue of oxidation.

The turbidity of potable water should be within 10 PPM or with in 10 units on silica scale. High turbidity of water can be determined by Jackson turbidity metre and low turbidity of water can be determined by baylis turbidity metre.