Slump Test of Fresh Concrete

Welcome to this video. In today’s session, we’re going to discuss the concrete slump test. The test will be done following the code ASTM C143. So, without further ado, let’s get started. Basically, the slump test is used to measure the consistency and workability of fresh concrete." 1. Consistency: meaning how wet/soft or stiff/hard the mix is. 2. Workability: How easily the concrete can be mixed, transported, placed, and compacted without segregation or bleeding. What Happens if the Slump is Not Properly Maintained? • Segregation and bleeding: The aggregate will separate from the paste, creating a weak, uneven mix. • Shrinkage Cracking: due to the evaporation of Excess water. • Placement Issues & Honeycomb: it happens when the slump is very low. which creates • Reduced Strength of concrete: Slump Test Apparatus 1. Slump cone/Mold: The test specimen is made of metal, Thickness not less than 1.5 mm, base Diameter 200mm, Top diameter 100, and the Height is 300mm. The handles exist 100 mm down from the top. 2. Temping Rod: Round Temping rod, Diameter 16mm ±2mm. temping rod length should be greater than Mould height and a maximum 600mm. 3. Measuring Device: A scale or a measuring tape not less than 300mm. 4. Scoop: Sufficient large to pour the concrete. Test Procedure: First, moisten all the apparatus. Then place the base plate on a rigid, flat, and non-vibrating surface. Position the mold on the base plate, and to prevent any movement place the feet on the foot pieces. From the concrete sample, fill the mold in three equal layers by volume: 1st Layer • Fill up to one-third of the total volume (Asper code approx. 70 mm height). • While placing the concrete, move the scoop around the perimeter of the mold opening to ensure even distribution and minimize segregation. • Rod the layer using the tamping rod with 25 blows, distributed throughout the depth. • Ensure that about half of the strokes are near the perimeter, then continue with vertical strokes spiraling