Experimental Research Of Fly Ash Cement Slurry Grouting In The Sand

With the rapid development of economic and engineering, the large scale construction of railways, roads, mines and other projects in our country have made the problem of subsoil layer and sand soil foundation more and more prominent. Therefore the strata-reinforcement technology, water-stopping engineering and anti-seepage treatment become more and more important, which put forward higher requirements for grouting engineering. As an indispensable part of grouting technique, grouting materials play a very important role in grouting quality. Cements and chemical material are now the widely-used grouting materials, thus they are not suitable for micro-fine hiatus strata. So there comes the claim to develop more appropriate materials, used to improve the performance of existing grouting materials.Superfine fly ash is a brand-new kind of building material, equipped with the advantages of high fineness and extensive source, which is mainly utilized in building reinforced concrete projects other than as grouting material.In this paper, we take superfine fly ash as the main grouting material and introduce a method of improving the grout characters by mixture with sodium silicate and appropriate cement. By way of orthogonal design and indoor simulation test, we explore the feasibility of using superfine fly ash as the grouting material. The following are the main work of this paper.According to the disadvantage of superfine fly ash grout in coagulability and poor strength at the beginning, in addition to the analysis of many relevant literatures, we choose sodium silicate and cement as the agent to stimulate the performance of superfine fly ash. First we investigative the physical and mechanical property by single factor experiments respectively and provide parameters for the following orthogonal experimental design.Then we formulate the factor, levels and target of orthogonal experiment and design experimental program by use of orthogonal table. There are totally nine groups of recipes, which is tested group by group concerning on the physical and mechanical property. At last the optimum mix ratio of the grout of superfine fly ash and cement is advanced after theoretical analysis.By taking advantage of the results of the optimum mix ratio from orthogonal experiment, we carry out the grouting model test using fine sand as the casting body, which concludes that superfine fly ash and cement grout possess excellent groutability.In the paper we introduce a set of grouting experimental study in sandy stratum using superfine fly ash as the grouting material, which is just a preliminary exploratory experiment. The research achievement has not been applied to engineering practice, while the practical applications still need further study.