Book Description

The effectiveness of two concrete mixers in mixing concrete for use in the casting of mattresses was evaluated. One of the mixers was of the turbine type mixing 3-1/2 cu yd, and the other was of the stationary-drum type mixing 61.6 cu ft. A concrete mixture of medium consistency (approximately 3-in. slump) with nominal 1-1/2-in. maximum size natural aggregate, which was being used to cast articulated concrete mattresses, was used in the evaluation. The following tests were made on samples representing three portions of the mixture and the results were compared with Corps of Engineers test criteria: coarse aggregate content, unit weight of air-free mortar, and moisture and cement content of the mortar fraction.