Preparation and Mechanism Research of Hydrationheat-inhibiting Materials with Microcapsule Sustained-releasing Technology

Hydration-heat-inhibiting materials(HIM)with polysaccharide as core material was prepared using microcapsule sustained-releasing technology,through a centrifugal spray granulation process after melting together.The preparation process parameters of HIM were selected by the semi-adiabatic temperature rise test of cement paste.TAM air microcalorimeter was used to investigate the regulation performance of HIM on the hydration of cement.The influence of HIM on the microstructure of cement was investigated by XRD,SEM,and TG-DSC.The results showed that the most suitable wall material for HIM was polyethylene wax,the optimum polyethylene wax/polysaccharide mass ratio was 1,and the most effective particle size was 0.16-0.30 mm.Polysaccharide coated by polyethylene wax released slowly,and the peak heat release rate of cement could be reduced by 55.2%after continuous regulaion.The regulation period continued to 120 h.HIM mainly decreased the C3S reaction rate,which resulted in a 39.2%peak value reduction of hydration heat release rate.However,HIM had little regulation on C3A.The hydration heat release process of cement-based materials can be designed by adjusting the dosage of HIM.