中国矿山工程

In order to study the influence of replacing natural sand with manufactured sand (M-sand) from basalt on the performance of high-strength concrete, six replacement rates (0%, 20%, 40%, 60%, 80% and 100%) are pre-set to test the concrete compressive strength, ultrasonic sound velocity and compression strain at each of these rates and study the influence of different replacement rates on the performance of high-strength concrete. The variation of shrinkage strain over age of the mixed-sand concrete is studied through polynomial fitting analysis on the variation data of JZ40 shrinkage strain over age. The test results show that the M-sand replacing natural sand as fine aggregate can lead to a slight reduction in the 7d, 28d and 56d compressive strength of the concrete, and when ultrasonic sound velocity is used as an indicator of the compaction of the mixed-sand concrete, more influence factors should be considered. When the replacement rate is less than 40%, the use of M-sand is beneficial to reducing shrinkage of concrete, and quartic function fitting can better reflect the variation of shrinkage strain over age of concrete.