Experiment And Analysis On Synthesis And Properties Of Butyl Stearate/Perlite Phase Change Silica Concrete

Firstly,the concrete specimens with silica fume content of 0%,5%,10%,15%,and phase change aggregate content of 0%,5%,10%,15%and 20%were produced.Then the thermal insulation,storage and heat release properties of concrete and the crack resistance of phase change silica fume concrete were studied.Thermal insulation tests show that when the silica content is certain,the general law is that the thermal conductivity decreases with phase aggregate content increasing,presenting that insulation properties of phase change concrete increase.When the phase change aggregate content is 20%,the rate of decrease of thermal conductivity is high,when the silicon powder is 15%,the thermal conductivity of phase change concrete reduce the rate generally higher.When the phase change materials doped with a certain amount of time,the silica fume content is less than 10%,the thermal conductivity of phase change of the basic concrete increases with the increasing of silica fume content,but the content of silica after 10%,the thermal conductivity of phase change of concrete in addition to a group of not adding the aggregate transformation continues to increase,the rest showed a decreasing trend.Heat storage and release experiments show that the addition of phase change material improves the heat storage capacity of the concrete,the heat generated delay,temperature measuring surface temperature fluctuations small,greatly reduces the heat transmission through the concrete slab.Therefore,the use of the energy storage concrete in building envelope can decrease the content of heat transferation of the wall and the energy consuming of the building.Cracking test show that the amount of silica can improve the crack resistance of concrete.However,the test moved on in winter,while the best environment is temperature(20±2)?,relative humidity(60 + 5)%of the constant temperature and humidity chamber.This is a direct result of the slow solidification of concrete.There is no phase change process and the phase change material has been solid,so there is no temperature cracks.But according to the relevant data show that the shrinkage increase with the silica content of silica fume concrete increasing.The dry shrinkage cracks was not found,this may be because of the amount of silica is relatively small,and the temperature of actual experiment at room is low,reducing the cracks.This conclusion is that the very fine particles of silica can fill gap between cement particles,and increase the density of concrete,so as to enhance the crack resistance of the phase change concrete.Further experiments are need to be done in order to verify this conclusion.