Strength Development of Concrete with Proto-Machine-Made Sand
The proto-machine-made sand is a new artificial material for environmental protection with grain size smaller than 5 mm made of water cleaned crushed stones or gravels broken and separated by machines, in which the stone powder maintains as prototype and certain content by improving the production technology. The paper introduces a series of test results of grade C50 concrete mixed by proto-machine-made sand with stone powder in mass content of 3 %, 7 % and 13 %. Based on the cubic compressive strength of concrete at different ages of 3 d, 4 d, 7 d, 14 d, 28 d, 56 d, 90 d, 120 d, 150 d and 180 d, the developing regularities of strength affected by the content of stone powder are analyzed, the formula for predicting the cubic compressive strength of concrete at any ages is proposed. It is proved that the effect of stone-powder in proto-machine-made sand on concrete strength is virtually different from that of the stone powder mixed with powdered mud in ordinary machine-made sand, and the limit value of stone powder content lower than 5 % is not suitable to proto-machine-made sand for mixing concrete with grade of C50.
Zhengyi Jiang, Jingtao Han and Xianghua Liu
F. L. Li and Q. Zhu, "Strength Development of Concrete with Proto-Machine-Made Sand", Advanced Materials Research, Vols. 152-153, pp. 1479-1482, 2011