多年冻土区水泥稳定砂砾基层抗冻性能研究

A study of anti-freezing properties of cement-stabilized gravels in permafrost regions

多年冻土地区路面使用过程中的许多病害与基层状况直接相关.水泥稳定砂砾作为我国传统的半刚性基层材料,在多年冻土地区公路路面结构中得到了普遍运用.为研究水泥稳定砂砾不同水泥掺量、不同养生龄期下的抗冻性能,通过提出合理的抗冻试验方法分别进行了水泥稳定砂砾冻融温度、冻融时间、冻融次数、试件的养生龄期及抗冻指标方面的试验研究.结果表明:水泥剂量越高,水泥稳定砂砾冻前、冻后的抗压强度值越高,说明其抗冻性能越好;水泥稳定砂砾从28 d开始抗压强度、冻融后抗压强度及冻融后劈裂强度都明显增加,证明水泥稳定砂砾从28 d开始已具有一定的抗冻性.提出的抗冻试验方法和指标要求适合多年冻土地区半刚性基层材料,有一定的实用价值.

The damages of pavement in permafrost regions are related to the basis. As a traditional semi-rigid base material, the cement-stabilized gravels were used in the pavement structure of highway in permafrost re- gions. In order to study the anti-freezing properties of cement-stabilized gravels with different cement contents and different curing periods, in this paper, a reasonable experiment method is suggested to conduct, aiming at many important factors, such as freeing temperature, freezing time, freezing-thawing cycles and specimen curing period. It is found that with increasing of cement content from 4% to 6%, the compressive strength of cement- stabilized gravel will gradually increase before and after freezing. The compressive strength and cleavage strength of the cement-stabilized gravel will increase significantly since the 28th day. Although there is no uniform testing method to evaluate the anti-freezing roperties of the cement-stabilized grave, the results in this paper show that this anti-freezing experiment method and specific indexes have certain practical value in permafrost regions.