为探索砂土掺量对水泥黄土性质的影响,以水泥掺量、粉煤灰掺量和砂土掺量为因素,设计L16(45)正交试验方案,试验研究掺砂水泥黄土的力学特性和抗冻性;分析其作用规律;建立水泥土强度、变形模量与各因素间的关系模型以及变形模量与强度间的相关关系.结果表明:掺砂对水泥黄土28d的力学性质和抗冻性不利;随砂土掺量的增加,水泥黄土28d的强度和变形模量减小,抗冻性降低;砂土掺量对水泥黄土的强度影响较显著,对变形模量的影响不显著;随冻融循环次数的增加,水泥黄土试件的完整性降低,经10次冻融循环破坏严重,强度损失大.掺砂水泥黄土的抗冻性较低,不宜用于冻结深度范围内的黄土地基处理.
In order to explore the effect of sand doping amount on the properties of cement loess, the doping amount of cement, fly ash, and sand were taken as the factors to design the orthogonal test scheme, conduct the experimental investigation of the mechanical properties and frost resistance of the cement loess doped with sand, analyze its functional rule, and set up the model of relationship of the strength and deformation modulus Of the cement loess to those factors and the correlation of the deformation modulus with the strength. The result shows that sand doping will be unfavorable to improvement of the mechani- cal property and frost resistance of the 28 d-cured cement loess. The strength, deformation modulus, and frost resistance of the cement loess will decrease with the increase of sand doping amount. Its effect on the strength of the cement loess will be more remarkable than on deformation modulus. The integrity of the cement loess specimen will decrease with the increase of the freezing-thawing cycles and after 10 cycles, the damage will be severe and the strength loss -- large. The frost resistance of the cement loess with sand doping will be low and it will not be suitable for treatment of loess foundation within freezing depth range.