Research On High Temperature Spalling Behavior Of Reactive Powder Concrete

Reactive Powder Concrete(RPC)has the characteristics of high strength,toughness,durability and good volume stability.These features make RPC widely popularized and applied in the engineering field.Recent studies have shown that RPC is superior to ordinary concrete in terms of mechanical properties and durability under normal temperature conditions.RPC is more susceptible to explosion spalling in high temperature environments because of its denser internal structure and lower porosity.In this paper,the explosion spalling of RPC,the influencing factors of high temperature explosion spalling,the mechanical properties of RPC before and after high temperature,and the mechanism of explosion spalling are studied.The main work of this study is as follows:(1)RPC explosion spalling test at high temperature.In this experiment,the effect of high temperature on RPC spalling was studied from the aspects of heating rate,moisture content,size of test pieces,adding fibers alone,and adding mixing and fibers.This paper introduces burstiness as a measure.Through the observation and statistics of experimental phenomena,the main factors affecting the high temperature explosion spalling of RPC are obtained.According to the conclusions of this experiment,the suppression of explosion spalling at high temperature under RPC is proposed.(2)RPC high temperature strength test.The quality and strength of RPC specimens before and after high temperature were measured respectively.Comparing the results under different conditions,the quality loss and strength loss of the RPC specimen after high temperature can be obtained.With the combination of mass loss and strength loss,we can get the best mix ratio to reduce the intensity loss of RPC.(3)Scanning electron microscope test.By comparing and analyzing the internal structure of RPC before and after high temperature,we can obtain the change rule of internal structure of RPC before and after high temperature.Combining the results of RPC high-temperature explosion spalling test and strength test,this section analyzes the mechanism of RPC explosion spalling.