Slump test

about slump test
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1. SLUMP TEST TALAVIYA MALAY

2. Slump test is the most commonly used test of measuring workability of concrete. It can be employed either in laboratory or at site of work . It is used conveniently as a control test and gives an indication of the uniformity of concrete from batch to batch.

3. The apparatus for slump test consists of a metallic mould in the form of a frustum of a cone with internal dimension as follow Bottom diameter = 20 cm Top diameter = 10 cm Height = 30 cm Apparatus

4. The internal surface of the mould is thoroughly cleaned and freed from superfluous moisture and adherence of any old set concrete before commencing the test . The mould is placed on a smooth, horizontal and non-absorbent surface. The mould is filled with concrete in 4 equal layers. Each layer is tamped with 25 strokes of tamping rod. Procedure

5. After the top layer has been tamped, the concrete is struck off level with a trowel and tamping rod. Then, the mould is removed by lifting it slowly and carefully in a vertical direction. This allows the concrete to subside. This subsidence is referred as slump of concrete.

6. True slump shear slump collapse slump slump patterns

7. True slump : If concrete subsides evenly it is called true slump. Shear slump : If one half of the concrete cone slides down, it is called shear slump. The shear slump is measured as a difference in height between the height of the mould and the average value of subsidence. Collapse slump : The collapse indicates a leaner mix.

8. NO Types of construction Recommended slumps in mm Minimum Maximum 1 pavements 25 50 2 Mass concrete structures 25 50 3 Unreinforced footing 25 75 4 Cassions and bridge deck 25 75 5 Reinforced foundation, f ooting and walls 50 100 6 Reinforced slabs and beams 30 125 7 columns 75 125

9. THANK YOU Malay Talaviya