高温后高强矿渣砂浆裂缝发展与力学性能

Crack development and mechanical property of high-strength slag mortar after elevated temperatures

通过对高温后高强矿渣砂浆(HSM)进行裂缝发展观测及抗折和抗压试验,研究了温度和矿渣取代率对HSM细观结构及残余抗折和抗压强度的影响规律。结果表明:20~200℃后,HSM表面未出现裂缝,而400~800℃后,裂缝逐渐发展为网状,HSM变得疏松;20℃时,矿渣取代率越高,HSM的抗折和抗压强度越低;200℃后,HSM的残余抗折强度增大而抗压强度降低;400~800℃后,HSM的残余抗折和抗压强度均随温度升高而降低,其中矿渣取代率为18%的HSM具有最高的残余抗折和抗压强度;根据试验结果,建立了高温后HSM残余抗折和抗压强度的计算式。

The observation of crack development,flexural and compressive tests of high-strength slag mortar(HSM)after elevated temperatures were carried out to study the effects of the temperature and the slag replacement ratio on the meso-structure,the residual flexural and compressive strengths of HSM.The results show that after 20~200℃,there is no crack on the HSM surface,yet after 400~800℃,the crack develops into the net-like structure,and HSM become loose.At 20℃,the higher the slag replacement ratio is,the lower the flexural and compressive strengths of HSM are.After 200℃,the residual flexural strength of HSM increases and the residual compressive strength reduces.After 400~800℃,the residual flexural and compressive strengths of HSM reduce with the increasing temperature,and HSM with slag replacement ratio of 18%has the highest residual flexural and compressive strengths.According to the test results,the equations for calculating the residual flexural and compressive strengths of HSM after elevated temperature are established.