University of New Mexico
Civil Engineering Department
Civil Engineering Materials Laboratory, CE 305L
SLUMP OF HYDRAULIC CEMENT CONCRETE
ASTM C143
Apparatus
Slump mold w/base plate (see photo)
Tamping Rod (5/8” diameter)
Scale (tape measure)
Shovel, hand scoop
Materials
0.3 ft3 of mixed plastic concrete
Procedure
The test procedure for the air content by pressure method test is part of ASTM 192.
Download the procedures for Slump Test here
1) Start the test within 5 min. after obtaining the final portion of the mixed concrete sample.
2) Dampen the mold (inside) and place on the dampened base plate.
3) Hold the mold firmly in place during the filling and rodding operation (by the operator standing on the two foot pieces).
4) Fill the mold in three layers, each approximately one-third the volume of the mold.
5) Rod each layer with 25 strokes of the tamping rod. During filling and rodding the top layer, heap the concrete above the mold before rodding is started.
6) Strike off the surface by a screeding and a rolling motion of the tamping rod.
7) Remove the mold immediately by raising it in a vertical direction. (steps 2 through 7 should be completed in less than 2.5 minutes).
8) Place the empty mold (inverted) adjacent to the concrete sample and measure the vertical difference between the top of the mold and the displaced original center of the sample. This is the slump.
Reading the slump
Report
1) Record the slump in inches to the nearest ¼ in.