水泥粉煤灰改良南方红黏土的试验研究

Experimental Study on Cement and Fly Ash Improving the Southern Red Soils

以南方红黏土为研究对象,研究水泥粉煤灰固化土的物理力学特性。为找出水泥粉煤灰改良红黏土的混合比,选择普通硅酸盐水泥P·O42.5(PC)、粉煤灰(阳西电厂F类Ⅱ级)为胶凝材料、CTD溶液为RSM固化剂,通过单掺与复掺的方式,分析了不同混合比下固化土的塑性指数、最大干密度及抗剪强度。结果表明,复掺10%混合料(4%PC+6%FA),1∶200 CTD溶液改良的固化土强度是同比例下单掺PC、FA固化土强度的1.2倍,且比原土强度高84.4 k Pa;土的抗剪强度增加最为明显,能有效改善水泥粉煤灰固化土强度。

An experimental investigation was conducted to evaluate the physical and mechanical properties of southern red soils. The primary objective of the study was to use cement and fly ash to rein- force the southern red soil. Three major groups of mixes were used for the study; Portland cement P · O42.5 （PC） , fly ash （ level 11 of grade F of Yangxi Power P/ant） and CTD solution. The first group was stabilized with 0% , 0.5% , 0.67% , 1% and 2% of CTD, the second group contained 2 -8% （i. e. 2% , 4% , 6% and 8% ） of PC and FA respectively. The properties of solidified soil including plasticity index, maximum dry unit weight and shear strength were analyzed. The results show that the shear strength of soil solidified by 10% mixture （4% PC ＋6% FA） and 2% CTD solution is 1.2 times the soil solidified by the same content of PC and FA, and 84.4 kPa higher than the original soil. The shear strength of soil increases obviously, which can effectively improve the strength of cement-fly ash solidified soil.