| 摘要 |
A process for the production of cement-concrete by intimate mixing of aggregates, cement, optional filler, and water in a concrete mixer, wherein the fine fraction of the aggregates is only added into the mixer after the remaining components have been mixed, with the result that the coarse fraction of the aggregates is coated with a paste, consisting of cement, optional filler, and water in which the fine fraction is absorbed. The addition of the fine fraction is effected successively, controlled by the proportioning means for the fine fraction, preferably by controlled vibration technique. The fine fraction is advantageously added into a zone of the mixer in which the mass consisting of the paste-coated coarse fraction and free-flowing cement paste is moved in a material flow under the influence of an external pressure from the mixin means. In the plant for the realization of the process and comprising a mixing container with proportioning means for the components of the concrete, mixing and discharge means, the proportioning means for the fine fraction of the aggregates is equipped with devices for the control and regulation of the flow of the fine fraction, and is preferably a vibratory feeder. A homogeneous concrete having excellent strength properties is obtained with considerable cement savings. |
