摘要
由于红粘土中存在蒙脱土等粘土矿物，红粘土的强度随含水量的增加而显著降低。采用钢渣(SS)粉、粉煤灰(FA)粉和磨细高炉渣(GGBS)三种不同工业固体废弃物粉提高红粘土的强度。同时，选择普通硅酸盐水泥(OPC)作为上述工业固体废弃物粉改性红粘土强度改善效果的对比。对红粘土和工业固体废弃物粉体的性能进行了全面的综述。对经OPC、SS、FA和GGBS改性的红粘土和红粘土在25℃下分别固化3、7和21天的试件进行了(UCS)无侧限抗压强度试验。结果表明，三种工业固体废弃物粉体均能显著提高红粘土的强度。试验结果表明，7%SS、5%FA和5%GGBS改性红粘土的UCS分别比未改性红粘土提高252%、131%和140%。然而，SS、FA和GGBS对红粘土的改性效果一般低于OPC。通过对改性粘土微观结构的观察，分析了工业固体废弃物粉和水泥提高红粘土强度的机理。研究结果可为公路工程中采用改良土方法提高路基强度提供参考。
Abstract
Because of the existence of clay minerals such as montmorillonite in red clay, the strength of red clay decreases significantly as water content increases. This study aims to improve the strength of red clay by using three different kinds of industrial solid waste powder, i.e., steel slag (SS) powder, fly ash (FA), and ground-granulated blast furnace slag (GGBS). At the same time, the ordinary Portland cement (OPC) was selected as a comparison of the improvement effect on the strength of red clay modified by the aforementioned industrial solid waste powder. The properties of the red clay and the industrial solid waste powder were documented comprehensively. The unconfined compressive strength (UCS) tests were conducted on the specimens of the red clay and the red clay modified by the OPC, SS, FA, and GGBS, which had been cured for 3, 7, and 21 days at a temperature of 25°C, respectively. The results showed that the strength of red clay can be significantly improved by the three kinds of industrial solid waste powder. After a 21-day curing period, the experimental results showed that the UCS of the red clay modified by 7% SS, 5% FA, and 5% GGBS increased by 252%, 131%, and 140% compared to that of the red clay without modification. However, the modification effects of the SS, FA, and GGBS on the red clay were generally inferior to that of the OPC. By observing the microstructures of the modified clay, the mechanism of industrial solid waste powder and cement improving the strength of the red clay was analyzed. The findings in this study can provide a reference for improving subgrade strength by a soil-modification method in road constructions.
NETL
NSTL
Wiley