Basics In Civil Engineering

Slump test can be employed either in laboratory or at site of work for measuring consistency of concrete. This test is used conveniently as a control test and gives an indication of the uniformity of concrete from batch to batch. Repeated batches of the same mix, brought to the same slump, will have the same water content and water cement ratio, provided the weights of aggregate, cement and admixtures are uniform and aggregate grading is within acceptable limits. Additional  information on workability and quality of concrete can be obtained by observing the manner in which concrete slumps. Figure: Typical Mould for Slump Test If concrete slumps evenly it is called  true slump . If one half of the cone slides down, it is called  shear slump . In case of shear slump, the slump value is measured as the difference in height between the height of the mould and the average value of the subsidence. Shear slump also indicates that the concrete is non cohesive and shows the charac...