多年冻土地区水泥稳定砂砾抗冻融耐久性模拟试验

A Simulation Test of the Frost Resistance of Cement-Stabilized Gravel in Permafrost Regions

通过控制试件湿度,模拟基层实际使用中的最不利湿度状况下的冻融循环试验,分析了冻融循环次数和试件湿度状况对混合料耐冻系数的影响.结果表明,耐冻系数随冻融循环次数的增加而不断减小,湿度对抗冻融耐久性评价结果有明显影响.多年冻土地区水泥稳定砂砾的抗冻融耐久性评价不宜直接采用水泥混凝土的饱水冻融试验方法,采用模拟基层的最不利湿度状况的冻融试验,以10次冻融循环时弯拉强度损失表示的耐冻系数作为指标,评价结果稳定,更符合实际使用情况.

There is still not having a uniform testing method to evaluate the frost resistance of the cement-stabilized gravel. Frost-thaw cycle test was done by controlling the sample moisture to simulate the worst humidity condition of the base in the real in permafrost regions. Influence of the frostthaw cycle times and the sample humidity on the frost resistance index of the base mixture was analyzed. It is found that the frost resistance index of the cement-stabilized gravel gradually decreases with the cycle times, and the humidity has an evident effect on the evaluating result. The results indicated that the full-water frost-thaw test on cement concrete is not feasible to directly evaluate the frost resistance of cement-stabilized gravel in permafrost regions. Controlling the sample moisture to simulate the worst humidity of the base mixture in the real and taking the frost resistance index of the tenth cycle as the evaluating index can well evaluate the frost resistance. The evaluating result is steady and more accordant with the true.