Q. Define Shear slump and collapse slump in slump test?

There are three kinds of slump which can take place in a slumps test, namely, true slump, shear slump and collapse slump. True slump denotes to general drop of concrete mass evenly all around without disintegration. 

Shear slump denotes the concrete lacks cohesion. It can undergo segregation and bleeding and so it is undesirable for durability of concrete. 

Collapse slump denotes that concrete mix is too wet and mix is regarded as lean andharsh.

Fig: Type of concrete slump