关键词: 可控低强度材料;粉煤灰;外加剂;配合比优化;正交试验

Abstract: Using fly ash as the main raw material with a certain amount of cement, polycarboxylate super plasticizer and the admixture such as slump retaining agent and thickening agent, a type of controlled low-strength materials (CLSM) is developed that can be used to fill the discarded oil pipeline.For optimization of the mix proportioning of the filling material, the orthogonal experiment was adopted, and the range analysis, variance analysis and comprehensive statistical analysis of acquired results were performed.Mathematical statistical variation coefficient method was used to entrust with the weight to the flow of the filling material performance, bleeding rate and the intensity of three parameters, adopting efficacy function method to uniform the parameters for the dimensionless indicators, to evaluate the performance of materials according to the calculated indexes.When mix proportions were optimized, optimal comprehensive strength at 28 d was nearly 2.60 MPa, while 4 h fluidity and 4 h bleeding rate were 250 mm and 4.2%, which sufficiently meets the performance requirements of pipeline-filling material.The results show that comprehensive statistical analysis can be used to evaluate the comprehensive performance of the filling material accurately and intuitively as a new route to the design and choice of CLSM mix proportions.

Key words: controlled low-strength material;fly ash;admixture;mix optimization;orthogonal experiment