Lab Experiments: MAKING TEST CUBES FROM FRESH CONCRETE ...
MAKING TEST CUBES FROM FRESH CONCRETE: Compaction: Filling the Cube Moulds and Compacting the Concrete. After the sample has been remixed, immediately fill the cube moulds and compact the concrete, either by hand or by vibration. Any air trapped in the concrete will reduce the strength of the cube. Hence, the cubes must be fully compacted.