机制砂对中高等强度混凝土的影响试验研究

摘要:

以河砂为基准组研究了机制砂对混凝土拌合物工作、硬化后的力学性能和早期收缩性能。试验结果表明：在相同配比下机制砂混凝土拌合物的工作性能较河砂混凝土差,易出现离析和泌水现象；硬化后机制砂混凝土的抗压强度和劈裂抗拉强度大于河砂混凝土；机制砂混凝土的早期收缩大于河砂混凝土,并随水胶比的减小而收缩增大。复掺粉煤灰和矿粉能明显改善机制砂混凝土的早期收缩,但不利于混凝土早期抗压强度的发展。

Abstract:

Using river sand as the benchmark group, the work of machine-made sand on concrete mixtures, the mechanical properties and early shrinkage properties after hardening were studied. The test results show that the performance of the machine-made sand concrete mixture is worse than that of the river sand concrete at the same ratio, and segregation and bleeding are prone to occur; the compressive strength and splitting tensile strength of the machine-made sand concrete after hardening are greater than those of the river sand Concrete: The early shrinkage of machine-made sand concrete is greater than that of river sand concrete, and the shrinkage increases with the decrease of water-binder ratio. The compounding of fly ash and mineral powder can obviously improve the early shrinkage of machine-made sand concrete, but it is not conducive to the development of early compressive strength of concrete.