低温养护条件下水泥改良风积沙无侧限抗压强度试验研究

Experimental study on unconfined compressive strength of cement-stabilized aeolian sand cured at low temperature

为了研究低温养护对水泥改良风积沙的影响,开展无侧限抗压强度试验研究。试验选用的水泥掺量为4%,5%和6%,压实系数0.90,0.93和0.95。研究了−20℃低温养护对水泥改良风积沙的应力应变曲线、无侧限抗压强度、峰值应变和刚度的影响。研究结果表明,低温养护条件下,压实系数0.95时,水泥掺量为4%,5%和6%时,对应的无侧限抗压强度分别为0.27,0.36和0.54 MPa,峰值应变分别为2.46%,2.69%和2.78%,E50分别为8.26,11.10和14.32 MPa。对比标准养护条件,水泥掺量4%,压实系数0.95时,低温养护的水泥改良风积沙的无侧限抗压强度、峰值应变和E50分别降低了32.5%,14.0%和18.3%。本文的研究成果对风积沙铁路路基基床的设计、施工有借鉴意义。

In order to study the effect of low temperature on cement-stabilized aeolian sand,a series of unconfined compressive strength tests were carried out.The three different cement content levels of the specimens were 4%,5%and 6%,and the degree of compaction levels were 0.90,0.93 and 0.95,respectively.The effect of−20℃low temperature on the stress-strain curve,unconfined compressive strength(UCS),peak strain and stiffness of cement-stabilized aeolian sand was studied.The results show that when the degree of compaction is 0.95 and the cement content is 4%,5%,and 6%,the UCS is 0.27,0.36,and 0.54 MPa,the peak strain is 2.46%,2.69%and 2.78%,and the E50 is 8.26,11.10 and 14.32 MPa,respectively.Compared with standard curing conditions(20℃and 95%HR),the UCS,peak strain and E50 of the cement-stabilized aeolian sand cured at low temperature are reduced by 32.5%,14.0%,and 18.3%,respectively,when the cement content is 4%and the degree of compaction is 0.95.The research results provide reference for the design and construction of railway subgrade layers using aeolian sand.