| The metakaolin base geopolymer is blended into the cement soil to partially replace the cement soil.The metakaolin base geopolymer is environmentally friendly inorganic material because of its excellent durability,low energy consumption and C02 emissions during synthesisIt overcomes the defects of Portland cement which has insufficient durability and poor environmental coordination,and has a good application prospect.In this paper,the geopolymer is used to partially replace the cement,and the static compressive strength test,dynamic compressive test and scanning electron microscopy are carried out on cement soils with 0%,1%,3%,5%and 7%.The mixing method of the geopolymer cement soil and the optimum geopolymer blending amount were tested.(1)Static compressive strength test and scanning electron microscopy were carried out on five different mixing methods.The morphology of the soil particles after mixing and the proportion of coarse particles were investigated.The morphology of the sample after failure was observed and analyzed.(2)The static compressive strength test and microscopic scanning electron microscopy were carried out on cement soil with metakaolin base geopolymer of content is 0,1%,3%,5%and 7%.The failure modes of the samples were observed and analyzed.The effect of the amount of geopolymer on the stress-strain relationship,strength and failure strain of cement soil under static load was determined to be 1%.(3)The dynamic compressive test was carried out on four kinds of cement soil samples with different geopolymer content by SHPB test system.The effects of geopolymer content at different strain rates on dynamic stress-strain curve and dynamic strength of cement soil were discussed.The destruction process of cement-soil samples was analyzed.The results show that the absorption energy increases first and then decreases with the increase of the amount of geopolymer,the maximum absorption energy was observed when the geopolymer content is 1%;the failure mode of the sample was observed and analyzed.The test determined that the proper content of geopolymer under dynamic loading was 1%.(4)In the impact compression test under different confining pressures,the impact compression test of cement soil samples under four different confining pressures was carried out,and the stress-strain curves of the geopolymer cement soil under different strain rates were discussed.With the influence of dynamic strength,the test results show that the geopolymer cement soil first increases and then decreases with the increase of confining pressure ratio at the same strain rate,and the maximum is obtained when the confining pressure ratio is 60%.Value;for the study of the absorption energy of cement soil,the maximum value is also obtained when the confining pressure ratio is 60%.Figure 33 table 5 references 74... |
