Study On Vertical Bearing Capacity Of The Concret Core With Recycled Aggregate & Cement-Soil Composite Pile

This article is achieved by studying on the basic strength features of recycled concrete aggregate experiment, experimental study on cement-soil unconfined compressive strength, and the study on static load tests of 12 combined model piles. The main results are as follows:(1) Prepare the recycled aggregate concrete whose replacement of material is 50% and the cube compressive strength is 28.1Mpa. It should meet the strength requirements of concrete C20. And the mix proportion of cement, water, girt, natural aggregate, recycled aggregate is 355.6:88.9:213:697.3:422.9:416.2(2) Keep the content of gelatinization 20%. Adding appropriate fly ash into cement can greatly improve late strength of cement through the study on the development law in compressive strength of the cement with the mixture of fly ash, fly ash and silica fume. The incorporation of silica fume also improves the strength of cement-soil, not only in the early one but also in the late one. When the replacement ratio of fly ash is 40% instead of only cement, the strength of the test block is increased by 17.6%. Due to the lower price of fly ash than that of cement in the practical engineering application, proper fly ash can take the place of cement. It can reduce cost in the case of meeting the bearing capacity. When the replacement of fly ash is 40%, silicone 10%, the strength of cement-soil is raised by 25.3% than the common one.(3) Through the static charge test of model pile, it can be concluded that adding proper fly ash into the model pile can improve the ultimate bearing capacity of composite pile with the appropriate replacement rate,40%. The ultimate capacity of concrete core with rapid aggregate & cement-soil composite pile, whose replacement of fly ash is 40%, silicone fume 40%, is raised by 11.8%.(4) According to the analysis from the ANSYS finite element analysis software, simulating the laboratory test piles, the maximum pressure cloud appears at the bottom of the column, which is consistent with the actual results.