湿热环境下CFRP-水泥砂浆的抗弯性能

Flexural properties of CFRP-cement mortar under moisture and heat environment

利用三点弯曲试验研究了水泥砂浆外贴碳纤维片材后在不同湿热条件下的抗弯性能 ,考察了CFRP 水泥砂浆的破坏模式 ,探讨了湿热对CFRP 水泥砂浆抗弯性能的影响机理。结果表明 :在 2 5℃下分别水浴 1、3和 5d时 ,其对应的抗弯断裂载荷随时间的增加基本不变 ;当其在 6 0℃下分别水浴 1、3和 5d时 ,其对应的抗弯断裂载荷随时间的增加而逐渐上升 ;当其在 90℃下分别水浴 1、3和 5d时 ,其对应的抗弯断裂载荷随时间的增加先增大后减小。当CFRP 水泥砂浆在 2 5℃和 6 0℃下分别水浴 1、3和 5d时 ,其破坏表现为具有一定的延性。在 90℃下分别水浴 1和 3d时 ,其破坏模式保持不变 ,但继续水浴到 5d时 ,其破坏模式则转变为脆性破坏。

The flexural properties of cement mortar externally bonded carbon fiber sheets under different moisture and heat environment were studied by means of three\|point bending test.The fracture modes of CFRP\|cement mortar system were examined.The experimental results show that when the specimens were immersed in 25 ℃ water for 1 to 5 days,their strength did not change with the time.When the specimens were immersed in 60 ℃ water for 1 to 5 days,their strength increased with the time.When the specimens were immersed in 90 ℃ water for 1 to 5 days,their strength increased for 1 to 3 days,but decreased for more than 3 days.The fracture modes of CFRP\|cement mortar specimen were accumulation with certain ductility,when they were immersed in 25 ℃ and 60 ℃ water for 1 to 5 days,as well as 1 to 3 days at 90 ℃.But when they were immersed in 90 ℃ water for 5 days,the brittle collapse took place.