What is the collapse slump?

In a collapse slump the concrete collapses completely. In a shear slump the top portion of the concrete shears off and slips sideways. In a true slump the concrete simply subsides, keeping more or less to shape.

What is a good slump?

Slump is the measure of concrete consistency and fluidity. It shows the flow and overall workability of freshly mixed concrete. Simply put, the higher the slump, the wetter the mix. Four-inch (4”) slump is very common with normal weight concrete and is a good for pumping.

Which type of slump is good?

True slump: In a true slump concrete just subsides shortly and more or less maintain the mould shape. This type of slump is most desirable. Shear slump: If one-half of the cone slides down in an inclined plane, it is called a shear slump. Shear slump indicates lack of cohesion in the concrete mix.

What is slump explain?

slump, in geology, downward intermittent movement of rock debris, usually the consequence of removal of buttressing earth at the foot of a slope of unconsolidated material. It commonly involves a shear plane on which a back-tilting of the top of the slumped mass occurs.

What are the 4 types of slump?

There are three types of slump that may occur in a slumps test, namely, true slump, shear slump and collapse slump.

What is collapse slump in concrete testing?

Collapse Slump – Here the concrete completely collapses. This is an indication that the mix is too wet. Zero Slump – Here the concrete maintains the shape of the mold. This type of concrete is too stiff and has almost no workability. If shear slump, collapse slump or zero slump are found, the slump test should be repeated.

What is collapse slump and shear slump?

A collapse Slump generally means that the mixture is too moist or is a highly workable mixture, for which the Slump test is not appropriate. This means that the water-cement ratio is very high, that is, the concrete mixture is very wet or is a highly workable mixture, for which a Slump test is not appropriate. 3. Shear Slump:

What are the ASTM standards for slump testing?

The ASTM standards also state in the procedure that when the cone is removed, it should be lifted up vertically, without any rotational movement at all. The concrete slump test is known as “Standard Test Method for Slump of Hydraulic-Cement Concrete” and carries the code (ASTM C 143) or (AASHTO T 119).

What happens if you fail a slump test?

This type of concrete is too stiff and has almost no workability. If shear slump, collapse slump or zero slump are found, the slump test should be repeated. If the second test also results in a failed slump test, then that batch of concrete should be rejected according to the established safety standards.