Why Is a Slump Test Necessary to Understand The Nature Of Concrete?

The slump test is the empirical evaluation to determine the quality of fresh concrete. The test lets you check and measure the consistency of concrete from a specific batch relative to the original mix design, and it is necessary to make sure that you are using concrete that is workable and suitable for certain applications. This method of testing fresh concrete is popular because it is easy, with simple equipment and an easy-to-follow procedure. However, the simplicity of the test may result in a wide variability in the ways a test is performed. Using the right equipment should help ensure a more accurate and repeatable way to measure and understand the nature of concrete.

With a slump test, you can be sure that different batches of concrete have a uniform quality under field conditions. It can be used to determine the effects of certain plasticisers in the concrete, too. The slump test typically uses a metal mould, which is shaped like a cone's frustum, but open at both ends. The top diameter is usually 102mm (four inches), and the bottom diameter is about 203 mm or eight inches. The cone is typically 305mm tall or a foot long. A 620mm or two-foot long bullet-nosed metal rod is used for a slump test, and it must be 16mm in diameter.

Some manufacturers make specialty slump test sets with paint-coated or galvanised equipment to prevent corrosion. A set may come with a funnel, a base plate, a rubber mallet, steel ruler, and a tamping rod. When performing a slump test, make sure that you are using equipment that conforms to AS 1012.3.1 standards in Australia.

To do a slump test, you need to fill the slump cone in layers and compact every layer with the rod. Then, you need to take away the slump cone and measure the vertical drop of the concrete when it is not confined into the cone any more.