水泥改良黄土EDTA滴定法改进

Improvement of EDTA titration method for cement modified loess

为精准测定水泥改良黄土路基填料中的水泥剂量,研究了取样方法、环境温度、检测延迟时间和含水率对EDTA滴定结果的影响,提出EDTA滴定改进方法并进行验证.结果表明:拌和后未过筛水泥改良黄土的水泥剂量检测结果平均误差为13.8%,过10、5、2 mm筛水泥改良黄土的水泥剂量检测结果平均误差分别为5.0%、10.0%和12.5%;环境温度每上升10℃、检测延迟时间每多10 min、检测样本含水率每相差1%,水泥剂量检测结果平均误差分别增大6.7%、2.2%和2.6%;对3条城际铁路沿线共8种土样进行EDTA滴定试验,改进法平均误差比规范法降低10%,变异系数平均减小6%,具有较好的稳定性和真实性.

In order to accurately determine the dosage of cement in cement modified loess subgrade fill,the effects of sampling method,ambient temperature,detection delay time and moisture content on EDTA titration results are studied,and an improved EDTA titration method is proposed and verified.The results show that the average error of the cement dosage test results of unscreened cement modified loess after mixing is 13.8%,and the average errors of the cement dosage test results of cement modified loess screened with 10,5,2 mm sieves are 5.0%,10.0%and 12.5%,respectively.For every 10℃rise in ambient temperature,every 10 min increase in detection delay time,and every 1%difference in moisture content of the test samples,the average errors of the cement dosage test results increase by 6.7%,2.2%and 2.6%,respectively.EDTA titration test is carried out on a total of 8 soil samples along the 3 intercity railroads,and the average error of the improved method is reduced by 10%compared with the standardized method,and the coefficient of variation is reduced by 6%on average,which indicate that the improved method has better stability and authenticity.