Experimental Research Of Mass Concrete By Porous Phase Change Steel Slag Aggregate

In mass concrete structure, temperature crack caused by temperature difference between inside and outside has always been a serious problem in the quality of civil engineering. The temperature cracks were universally penetrating the cracks, and seriously had an impact on the safety of the structures. At present,the study on preventing the cracks of the mass concrete temperature was primarily based on the internal and external reasons, the text was taking the internal reasons into consideration, putting the phase change material into the mass volume concrete to decrease the center temperature and delay the arrival of the summit of center temperature.Phase change material had the characteristic of the large energy storage density as well as approximate isothermal of phase change process. So we can consider lowering the center temperature of the mass concrete from internal factors. This paper used paraffin as phase change materials and porous steel slag as carrier adsorbing phase change material, ultimately using the method of vacuum adsorption to prepare porous steel slag aggregate of phase change. Subsequently, we engaged in analyzing and testing the heat performance of porous steel slag aggregate of phase change. Then porous steel slag aggregate of phase change concrete was prepared by porous steel slag aggregate of phase change, then we tested the mechanical properties as well as heat performances of porous steel slag aggregate of phase change concrete and porous steel slag aggregate of concrete and analyzed the two kinds of concrete of The micro-analysis of the aggregate-cement's surface through scanning electron microscope(SEM).Finally, based on geometric model of basis of building in practical engineering finite element model was established, temperature field and center temperature of porous steel slag aggregate of phase change concrete and porous steel slag aggregate of concrete were simulated and analyzed by using the finite element analysis software MIDAS Civil. The practical engineering decreases the internal temperature of the mass concrete on using the mixed mineral substance. We end up this with comparing The measured data and the finite element simulation results of the porous steel slag aggregate of phase change mass concrete.The results show that the adsorption rate of the porous steel slag to phase change material was 7.75%, and the absorption amount will increase with the decrease of the particle size. Heat performance tests and analysis show that porous phase change of steel slag are good at storing its energy, compared with the ordinary steel slag concrete temperature. the porous phase change temperature at the center of the steel slag concrete decreased by 4.9 ?in temperature-rise experiment, and the summit of temperature extends nearly 60 min. The compressive strength of the porous phase change of steel slag concrete was under the porous steel slag of concrete. The micro-analysis of the aggregate-cement's surface show that the surface of the porous phase change of steel slag concrete was not enough compact, and has tiny cracks. The numerical simulation results show that the temperature control technology of mixed phase change materials and the temperature control technology of mixed mineral admixture are similar effect in decreasing the temperature of mass concrete.