水泥和石膏胶结相似材料配比的确定方法

对以水泥和石膏为胶结材料、石英砂和重晶石粉为骨料的相似材料，规范了其制作原料与工艺，以砂胶比（骨料与胶结材料质量比）、水膏比（水泥与石膏质量之比）和重晶石含量（重晶石质量占骨料百分比）为控制因素，设计了一个正交试验，开展了称重、单轴压缩试验，获得了不同配比相似材料的密度、单轴抗压强度和弹性模量等物理力学性质指标。采用极差分析法分析了各因素的敏感性，研究了各因素对相似材料参数的影响规律。研究表明：重晶石含量对相似材料密度有明显的控制作用，而砂胶比和水膏比对密度也有明显的影响；砂胶比对相似材料单轴抗压强度和弹性模量影响最大，水膏比和重晶石含量的影响次之。相似材料密度随砂胶比的增大而降低，随水膏比和重晶石含量的增大而增大；抗压强度随砂胶比的增大而显著降低，但随着水膏比和重晶石含量的增大而缓慢增大；弹性模量随砂胶比的增大而显著降低，随重晶石含量增大而增大，随水膏比增大而缓慢升高。采用MATLAB程序对试验数据进行多元线性回归分析，得到确定相似材料配比的经验方程。工程应用证明，采用经验方程计算得到相似材料配比，并按规范的制作工艺，可以得到满足试验要求的相似材料。

A method for determining the ratio of similar materials with cement and plaster as bonding agents

In this study, a production method is proposed for making the similar material of sand and barite powder using cement and plaster as bonding agents. Three controlling factors including sand-blinder ratio, cement-plaster ratio and barite content are chosen to perform the orthogonal tests. The ratio schemes are obtained. A series of tests is carried out to determine the density, uniaxial compression strength and elasticity modulus of different similar materials. The extremum difference analysis is adopted to analyze the sensibilities of three factors to parameters of the similar material. It is found that the density is primarily controlled by the barite content, secondly by sand-blinder ratio, cement-plaster ratio; the uniaxial compression strength and the elasticity modulus are significantly affected by the sand-blinder ratio, next by the cement-plaster ratio and barite content. The density decreases as sand-blinder ratio increases, and increases with the cement-plaster ratio and barite content; the uniaxial compression strength and the elasticity modulus significantly decreases as the sand-blinder ratio increases, but gradually increases as cement-plaster ratio and barite content increase. Empirical equations for determining the similar material ratio are developed based on the multiple linear regressions of the test data using the program of MATLAB. The proposed method is validated through a practical case.