花岗岩石粉掺量对机制砂混凝土力学性能和耐久性的影响

Effect of Granite Powder Content on Mechanical Properties and Durability of Machine-Sand Concrete

本文主要研究了花岗岩机制砂石粉含量(10%、20%、30%)对机制砂混凝土力学性能和耐久性关键参数的影响。试验结果表明:石粉对混凝土早期强度发展不利,但是提高了混凝土后期强度和弹性模量。和纯水泥混凝土相比,加入石粉的混凝土56 d龄期抗氯离子渗透性提高显著。随着石粉含量的增加,混凝土的电通量随之增加但都保持在较低的渗透性水平。当石粉掺量在20%以内时,经过350个冻融循环周期后,机制砂混凝土的相对动弹模只有稍微下降,但当石粉掺量达到30%时,混凝土相对动弹模显著降低。和纯水泥混凝土相比,掺加石粉的混凝土干缩在14 d内有所抑制。整体来看,石粉掺量在20%,机制砂混凝土各项性质最佳。

This paper mainly studied the effects of gravel powder content（10%, 20%, 30%） on the key parameters of mechanical properties and durability of the machined sand concrete. The test results show that： stone powder is unfavorable for the early strength development of concrete, but it improves the later strength and elastic modulus of the concrete. Compared with pure cement concrete, the addition of powdered concrete has a significant increase in chloride ion permeability at 56 days. As the content of stone powder increases,the electrical flux of the concrete increases with it but maintains a low level of permeability. When the content of stone powder is less than20%, the relative dynamic modulus of the machine-made sand concrete only slightly decreases after 350 cycles of freeze-thaw cycles, but when the amount of stone powder reaches 30%, the relative dynamic modulus of the concrete decreases significantly. Compared with pure cement concrete, dry concrete shriveled with stone powder was suppressed within 14 days. As a whole, the content of stone powder is 20%,and the properties of machine-made sand concrete are the best.