Abstract: The thermal effect of paraffin/expanded graphite composite phase change materials ( CPCM ) was proposed to control the hydration heat of magnesium phosphate cement ( MPC) .By testing the setting time, fluidity, hydration temperature, compressive strength and thermal conductivity of CPCM , the effect of CPCM on the hydration properties of MPC was explored .The results showed that the hydration heat of MPC was controlled by the phase change .The hydration system temperature was reduced , and the hydration reaction rate was slowed down and the goal of reducing the hydration heat was accomplished .At the same time , the degree of crystallinity of MgKPO 4 · 6 H2 O was decreased lightly , and it made the compressive strength of MPC change small .CPCM did not participate in the hydration reaction of MPC , but combined by the physical effect with MPC , maintained their excellent performance , and ensured the stability and performance of the MPC system .

Key words: composite phase change material;magnesium phosphate cement;hydration;performance