Experimental study on the thermal and mechanical performance of graphite-cement based composites
As a new-type energy conservation technology, energy pile adopts the method of concrete pile exchanging thermal energy with underground constant temperature soil, which can achieve an effect of emission reduction and has gained rapid development these years. In the process of energy pile research, most of the scholars focus on optimizing energy pile’s pipe laying pattern, analyzing heat pump equipment’s best matching parameter, changing backfilling materials and other approaches to improve thermal conduction efficiency. Being the basic material of pile foundation, concrete’s thermal conduction nature will directly influence energy pile’s thermal conduction efficiency with surrounding soil. This essay investigates graphite-cement based composites’ mechanics and thermal conduction specialty’s change rule in circumstances of adding different amount of graphite admixture through adding graphite powder that possesses a property of high thermal conduction into the cement to prepare graphite-cement based composites material as well as deploying indoor physical mechanics experiment. The research demonstrates that with the increase of graphite’s amount of admixture, cement mortar’s demand for water increases, decreasing amplitude of pressure resistance intensity is quite large, decreasing amplitude of tensile resistance intensity is quite small, yet this can enhance thermal conduction efficiency of concrete materials. It can be concluded from the result of SEM, with the increase of graphite’s amount of admixture, strengthened exposure level between graphite particles and formation of obvious passages, graphite-cement based composites materials’ thermal conduction property is strengthened as well. In addition, when concrete’s amount of admixture attains 12% by replacing 42.5R-level ordinary silicate with natural scaly graphite, both compression and fracture resistance intensity of the composites material can meet the demand of 32.5R-level concrete.