| Abstract: | In order to facilitate self-compacting concrete to be better used in tunnel linings that can resist fires,a SiO_2 aerogel-cement mortar coating was prepared.Based on the HC curve,a self compacting concrete cube specimens coated and uncoated with SiO_2 aerogel-cement mortar (SiO_2-ACM) were heated to simulate tunnel fire for 0.5,1,1.5,2,2.5,3 and 4 h,respectively.The residual compressive strength was tested after the specimens were cooled to room temperature by natural cooling and water cooling.The results show that,the damages of specimens become more serious as fire time goes on,but the residual strength of specimens coated with SiO_2-ACM is always higher than that of uncoated with SiO_2-ACM.In addition,the residual strength of specimens cooled by water cooling is lower than that of natural cooling.However,for the specimens coated with SiO_2-ACM,the adverse effects of water cooling are lessened.With the increase of fire time,the protective effect of SiO_2-ACM is still gradually improved.Finally,a formula was established to predict the residual 150 mm cube compressive strength of specimens protected by SiO_2-ACM after a simulated tunnel fire. |
