类砂岩相似材料配合比方案试验研究

以白垩系中粒砂岩为模拟对象,采用细砂、高强水泥、细石膏、铁粉、蒸馏水为基础原料配制类砂岩相似材料。根据正交设计试验方法,确定以水灰比、骨料与水泥质量比、铁粉掺入量为控制因素的3因素3水平正交设计方案,利用极差敏感分析法分析以上因素对饱和密度、声波波速、导热系数、单轴抗压强度的影响。试验结果表明:骨料与水泥质量比对饱和密度、声波波速和单轴抗压强度起主导作用,且随着骨料与水泥质量比的增大,饱和密度及声波波速均显著降低;铁粉掺入量对导热系数起主导作用,掺入量增大,导热系数增加明显。通过多元线性回归分析,推算得到类砂岩材料的最优质量配合比方案,即水灰比0.53,骨料与水泥质量比0.45,掺入物质量分数4.2%,根据该配合比制作的类砂岩材料与白垩系砂岩各项参数值非常接近。

Experimental study on ratio of quasi-sandstone similar material

Taking the middle grained sandstone in the Cretaceous as simulation object, fine sand, high strength cement, fine gypsum, iron powder and distilled water were used as raw materials to configure the quasi-sandstone similar samples. According to the orthogonal experiment method, the design scheme was determined with the water-cement ratio, the ratio of aggregate to cement and the iron powder content being controlling factors, and the influence of these factors on saturation density, acoustic wave velocity, heat conduction coefficient and uniaxial compressive strength was analyzed with the range sensitive analysis method. Experiment results show that the ratio of aggregate to cement plays a leading role in saturation density, acoustic wave velocity and uniaxial compressive strength. The saturation density and acoustic wave velocity obviously decrease with the increase of the ratio of aggregate to cement. Meanwhile, the iron powder content has a governing effect on the thermal conduction coefficient, and the thermal conductivity obviously increases with the increase of the iron powder content. Through multiple linear regression analysis, the optimal mass ratio scheme of the sandstone material was deduced, which meant the water-cement ratio was 0. 53, the ratio of aggregate to cement was 0.45 and the iron powder content was 4.2%. The physics and mechanics parameters of the quasi-sandstone using this similar material ratio are very close to that of sandstone in the Cretaceous.