活性粉末混凝土灌注的碳纤维预应力索粘结型锚固系统抗火性能研究

The bond-type anchorage system for CFRP (Carbon Fiber Reinforced Polymer) prestressed cable grouted by RPC (Reactive Powder Concrete), with excellent anchorage performance and anti-fatigue resistance, has promising application prospect in civil engineering. At present, the application of this bond-type anchorage system is seriously restricted due to the lack of systematic research on its fire resistance. Therefore, the fire resistance of the bond-type anchorage system for CFRP prestressed cable grouted by RPC is to be systematically investigated in this project, including anchorage performance of the bond-type anchorage system for CFRP cable without pretension under high temperature, anchorage performance of the bond-type anchorage system for CFRP prestressed cable under thermo-mechanical coupling effect, and calculation method of the fire resistance limit of the bond-type anchorage system for CFRP prestressed cable. With the combination of experimental study, theoretical analysis and numerical simulation, the degradation mechanism of bearing capacity of the bond-type anchorage system for CFRP prestressed cable can be uncovered, the bond-slip constitutive model of CFRP cable-RPC interface under high temperature can be developed, the failure criterion based on interface slip and its rate can be established, and the practical formula of fire resistance limit of the bond-type anchorage system for CFRP prestressed cable can be provided. The aforementioned results can provide theoretical basis for preparation of fire resistance design specification for CFRP prestressed cable structure and its application.

活性粉末混凝土(RPC)灌注的碳纤维增强复合材料(CFRP)预应力索粘结型锚固系统以其优良的锚固性能与抗疲劳性能而在土木工程中具有良好的应用前景。然而，目前对该类锚固体系的抗火性能仍缺乏系统性的研究，严重制约了其推广应用。为此，本项目将系统研究RPC灌注的CFRP预应力索粘结型锚固系统抗火性能，包括：高温下无初张力CFRP索粘结型锚具锚固性能、热力耦合作用下CFRP预应力索粘结型锚具锚固性能、CFRP预应力索粘结型锚固系统耐火极限计算方法。采用试验研究、理论分析与数值模拟相结合的方法，揭示热力耦合作用下CFRP预应力索粘结型锚具承载能力退化机理；建立高温下CFRP索-RPC界面粘结-滑移本构模型；建立基于界面滑移及滑移速率的破坏判定准则；提出CFRP预应力索粘结型锚固系统耐火极限实用计算公式，为CFRP预应力索结构抗火设计规范的编制及其工程应用提供理论依据。

本项目对CFRP单筋拉索及其以RPC (或UHPC)为粘结介质的粘结型锚固系统的抗火性能进行了研究，提出了相应的耐火极限计算方法，为CFRP拉索结构抗火设计规范的编制提供理论依据。项目研究共完成论文14篇，其中硕士学位论文3篇，期刊论文11篇；授权发明专利1项；荣获江苏省工程师学会科学技术二等奖1项；主要成果如下：.(1) 建立了适于表征正常使用状态下绞线式CFRP拉索偏轴应变法修正系数、承载能力极限状态下绞线式CFRP拉索承载能力折减系数的实用计算公式。.(2) 建立了适于无初张力压纹式、绞线式CFRP拉索的高温轴拉本构模型。.(3) 建立了以处理温度、钢纤维体积掺量等为参数的RPC高温轴拉本构模型。.(4) 构建了适于高温下无初张力CFRP单筋拉索粘结型锚固系统中CFRP拉索-RPC界面粘结-滑移本构模型、粘结强度及CFRP拉索临界锚固长度的实用计算公式。.(5) 建立了适于热力耦合下CFRP单筋拉索粘结型锚固系统锚固承载能力的退化模型，明确了温度-荷载路径对高温下CFRP单筋拉索粘结型锚固系统锚固性能的影响规律。.(6) 建立了适于CFRP单筋拉索高温蠕变与高温松弛模型，揭示了温度-荷载路径对拉索高温蠕变及松弛性能的影响规律。.(7) 建立了适于CFRP单筋拉索粘结型锚固系统高温蠕变模型与高温松弛模型，明晰了温度-荷载路径对拉索粘结型锚固系统高温蠕变及松弛性能的影响规律。.(8) 提出了适于分析CFRP单筋拉索耐火极限的理论方法；建立了适于CFRP单筋拉索耐火极限的实用计算方法；揭示了热力耦合下绞线式CFRP拉索非均匀受力特性对其耐火性能的影响规律。.(9) 构建了基于CFRP拉索-RPC界面滑移与滑移速率的破坏准则，提出了适于CFRP单筋拉索粘结型锚固系统耐火极限的实用计算方法。.(10) 建立了适于高温后CFRP单筋拉索及其粘结型锚固系统承载能力的恢复模型。