DHT土凝岩稳定风积沙底基层路用性能研究

Research on Road Performance of Aeolian Sand Subbase Stabilized by DHT Soil Condensate

以二秦高速公路为工程背景,进行了DHT土凝岩固化剂稳定风积沙底基层的试验研究。通过无侧限抗压强度试验、击实试验、红外光谱试验、温缩试验,比较了DHT土凝岩和水泥两种固化剂对风积沙的固化效果,以及温度对固化效果的影响,探究了DHT土凝岩稳定风积沙的工作机理,并就用于公路底基层的可行性进行了分析。结果表明:在两种固化剂稳定风积沙混合料含水率低于最佳含水率的情况下,土凝岩混合料试样干密度的灵敏度明显高于水泥混合料试样,便于实际施工;土凝岩固化剂掺量大于9%时,土凝岩稳定风积沙混合料7d无侧限抗压强度符合公路路基底基层的强度规范要求;土凝岩稳定风积沙混合料受温度的影响小于水泥稳定风积沙混合料,在高温区间存在较大的温度应力应变,但在平均年气温较低的寒冷地区应用是可行的;红外光谱证明,土凝岩中氨基、巯基等基团通过水化反应将风积沙胶结在一起形成空间网状结构,使土凝岩混合料获得强度。

In this paper,based on the engineering background of Erenhot-Qinhuangdao Expressway,the experimental study on stabilization of aeolian sand subbase with DHT soil cement is carried out.Through unconfined compressive strength,compaction test,infrared spectrum and temperature shrinkage test,the solidification effects of DHT and cement on aeolian sand are compared and the influence of temperature on the curing effect are compared.The working mechanism of stabilizing aeolian sand by DHT soil condensate is explored,and the feasibility of using it in highway subbase is analyzed.The results show that:when the moisture content of the two kinds of curing agent stabilized aeolian sand mixture is lower than the optimal moisture content,the sensitivity of dry density of the DHT soil condensate mixture sample is obviously higher than that of the cement mixture sample,which is convenient for the actual construction.When the content of the DHT is more than 9%,the 7 dunconfined compressive strength of the mixture meets the strength specification requirements of the highway subgrade.The influence of temperature on DHT stabilized aeolian sand mixture is less than that of cement stabilized aeolian sand mixture.There is a large temperature stress and strain in high temperature range,but it is feasible to apply it in cold area with low average annual temperature.Infrared spectrum shows that the amino group,sulfhydryl group and other groups in the soil cement rock can bond aeolian sand together through hydration reaction to form a spatial network structure,so that the strength of DHT stabilized aeolian sand mixture is obtained.