洪雷++马腾龙++王苏岩

摘要：通过试验研究了湿度为98%，温度分别为20 ℃，40 ℃，60 ℃的湿热环境下预应力碳纤维增强复合塑料（CFRP）加固高强混凝土的破坏形态和承载性能，分析了预应力等级、温度、环境作用时间等因素对加固试件耐久性的影响。结果表明：经过湿热环境作用后，施加预应力等级为CFRP极限抗拉强度30%的预应力加固试件的开裂荷载和极限荷载均有不同程度的下降；随着环境温度的提高，加固试件的破坏形态逐渐由弯剪破坏转变为弯曲破坏；湿热环境作用对预应力CFRP加固试件的整体不利影响大于非预应力试件，并且随着预应力增加，不利影响会进一步加剧。

关键词：CFRP；高强混凝土；耐久性；湿热环境；预应力；开裂荷载；极限荷载

中图分类号：TU528文献标志码：A

Durability of High Strength Concrete Strengthened with Prestressed

CFRP Under Wetthermal EnvironmentsHONG Lei， MA Tenglong， WANG Suyan

（State Key Laboratory of Coastal and Offshore Engineering， Dalian University of

Technology， Dalian 116024， Liaoning， China）Abstract： The failure patterns and bearing performances of high strength concrete specimens strengthened with prestressed carbon fiber reinforced polymer（CFRP）were studied by experiments under wetthermal environment where the humidity was 98% and the temperatures were 20 ℃， 40 ℃， 60 ℃. The influences of different factors including prestressed degree， temperature and environment action time on durability of strengthened specimens were analyzed. The results show that the cracking loads and ultimate loads of specimens strengthened with prestress being 30% of tensile strength for prestressed CFRP decline in varying degrees after being subjected to wetthermal environments. With rising of the environment temperature， the failure patterns change from bending shear failure to flexural failure. In addition， the overall adverse effects of wetthermal environments on specimens strengthened with prestressed CFRP are greater than those on specimens strengthened without prestressed CFRP， and the adverse effect will be aggravated when prestress rises.

Key words： CFRP； high strength concrete； durability； wetthermal environment； prestress； cracking load； ultimate load

0引言

碳纤维增强复合塑料（Carbon Fiber Reinforced Polymer，CFRP）在土木工程混凝土结构加固修复技术领域已经应用得十分广泛[1]。应用于土木工程领域的CFRP通常强度都达到3 000 MPa以上，而其弹性模量相对强度来说却低得多。要发挥较大的强度，CFRP需要相当大的变形[2]。因此，可以对CFRP施加预应力来克服其材性上的缺陷，从而有效地避免CFRP布出现应力滞后的现象[38]。

研究表明，CFRP材料本身拥有良好的稳定性和耐久性。国内外学者对CFRP加固混凝土结构的耐久性進行了大量研究[914]。任慧韬等[15]研究了湿热环境对FRP加固混凝土结构耐久性能的影响。郭春红[16]对纤维增强复合材料加固混凝土结构的力学性能和耐久性评价技术进行了研究。目前对预应力CFRP加固高强混凝土结构在湿热环境下的研究还较少。……