Research On The Performances Of Cement-based Grouting Material By Applied The Principle Of DSP

Grouting material as a building material was widely used for a long time. In some projects such as anchoring of bolt of heavy machinery, electric power, metallurgy, installation of chemical equipment, reinforcement and reconstruction need higher strength. However, common cement-based grouting material often can not reach the requirement of practical projects because of its high water-cement ratio, poor slurry stability and serious bleeding. It is crucial to develop the high strength and high-performance cement-based grouting material.To improve the performance of grouting material, the gradation of particles in system was rationalized and the size of particles was combined reasonably by applied the principle of DSP (Densified Systems Containing homogeneously arranged ultrafine Particles) first proposed by engineer Bache Han of denmark, which results in a low porosity of the material. Some measures were taken such as adding silica fume, quartz powder, expansive agent, and nano-SiO2 into the mixture, porosity between particles of cement was filled by silica fume whose particles was one or two order smaller than cement, and much smaller particles of nano-SiO2 was dispersed into porosity between cement and silica fume. In the effects of superplasticizer, a high-performance cement-based grouting material with an early strength, high strength, high fluidity, no bleeding, slight expansion was successfully developed at a low water-cement ratio and various components'influence on various performance of DSP grouting material was analyzed. The contents of the thesis are as follows:(1) The influence of the mass ratio of silica fume to cement on strength and fluidity was researched.The best mass ratio of silica fume to cement was obtained by test, when the strength and the fluidity achieved the best state at the same time. In condition of the best mass ratio of silica fume to cement, the packing density of silica fume and cement reached the maximum.(2) The influence of the content and particle size of quartz powder on strength and fluidity was researched and the best content of quartz powder was obtained,that was the best mass ratio of quartz powder to cement.(3) The influence of water-binder ratio and the content of superplasticizer on strength and fluidity was researched and appropriate water-binder ratio and the content of superplasticizer was obtained. (4) Through a large number of experiments,it was concluded that nano-SiO2 has enhancement in DSP grouting material and it can improve the strength especially the early strength of grouting material greatly.The grouting material with appropriate content of nano-SiO2 can effectively prevent bleeding, reduce settlement and segregation.(5) The influence of content of expansion agent on the expansion rate, strength, fluidity and fluidity loss was studied and the influence of water-binder ratio on expansion rate under the same expansion agent content was analyzed.(6) The study of electrical resistivity of DSP grouting material and performances of typical DSP grouting material was carried out.