How do you perform a field slump test?

• A. Fill the slump cone in three layers, rodding each layer, lift cone vertically, and measure the subsidence of the concrete after removal
• B. Fill the slump cone in two layers
• C. Drop the cone from height
• D. Use a flow table test

Answer: (A)

The field slump test measures the workability of fresh concrete by how much it subsists after the cone is removed. To do it correctly, you fill the slump cone in three layers, rodding each layer to compact and consolidate the concrete and to expel air voids. After the final layer is rodded, you strike off the top level with the rim, lift the cone straight up, and immediately measure the vertical subsidence of the concrete—the difference between the original cone height and the height of the concrete after the cone is removed. This direct, vertical measurement is the slump value.

Filling in only two layers isn’t in line with the standard, and dropping the cone from height or using a flow table test describes different procedures or tests, not the slump test.