PCCP管内环向预应力加固验证试验研究

Experiment study on reinforcement of PCCP inside with circumferential pre-stressed carbon fiber plate

为快速有效修复难以开挖区域破损的预应力钢筒混凝土管(PCCP),减少甚至避免PCCP爆裂事故的发生,研究提出PCCP管内环向预应力加固技术。该技术对管内碳纤维板材施加环向预应力,再利用高性能结构胶粘贴至PCCP管道内壁,达到加固目的。通过设计混凝土内环、外环相结合的试验,验证该加固方法的可行性,并调整优化施工工艺。试验结果表明,碳纤维板经预张拉后成功粘贴至外环混凝土,混凝土表层经过凿毛、基底处理后形成的混凝土-结构胶-预应力碳纤维板体系是可靠的,可提供不低于0.8 MPa的黏结力。基础试验方案(即内环、外环设计)及加固方案可行,依此提出PCCP加固二期试验方案,即首尾搭接的碳纤维板管内环向预应力加固试验。

In order to repair the damaged prestressed concrete cylinder pipe(PCCP)which is hard to be excavated timely and effectively,so as to reduce or even avoid PCCP burst,the reinforcement technology of circumferential prestressed carbon fiber plate in PCCP was proposed.This technology pre-stresses the carbon fiber plate inside the pipe,and sticks it to the inner wall of PCCP with high-performance structural adhesive.PCCP is strengthened with a higher bearing capacity.A test of concrete inner ring combined with outer ring was designed to verify the feasibility of the reinforcement method and optimize the construction technology.The test showed that the pre-tensioned CFRP was successfully bonded to the outer concrete ring.After roughening and base treatment of the surface of concrete,the system formed by concrete,adhesive and pre-stressed carbon fiber plate was reliable,and could provide a bond strength of no less than 0.8 MPa.The test result indicates the foundation test scheme and reinforcement scheme are feasible.A further test scheme to strengthen PCCP is put forward with end-to-end carbon fiber plate.