绿色高性能纤维增强水泥基复合材料新型框架节点抗火性能试验研究

发布时间：2018-03-21 20:38

本文选题：绿色高性能纤维增强水泥基复合材料　切入点：框架梁柱节点　出处：《山东建筑大学》2017年硕士论文　论文类型：学位论文

【摘要】：绿色高性能纤维增强水泥基复合材料(Green High Performance Fiber Reinforced Cementitious Composites,GHPFRCC)是以水泥、水、高掺量粉煤灰、石英砂、聚乙烯醇纤维(Polyvinyl Alcohol Fiber,PVA纤维)及高效减水剂等原料制备而成。常温下GHPFRCC具有出色的多缝开裂性能和应变硬化的能力,GHPFRCC新型框架梁柱节点具有优异的抗震性能和耗能能力。但是在高温下,由于PVA纤维的熔化导致GHPFRCC力学性能出现劣化,因此GHPFRCC框架节点的抗火性能亟待研究探明。本文以GHPFRCC框架节点为研究对象,通过耐火试验研究了节点浇筑形式及配箍率等因素对GHPFRCC框架节点抗火性能的影响,主要内容包括以下两部分:第一部分主要是介绍GHPFRCC框架节点耐火试验。按照“强柱弱梁,强剪弱弯”的基本原则使用最佳配合比的GHPFRCC和C30混凝土两种材料制作5个相同尺寸的框架节点,进行高温-恒载耦合作用下的耐火试验准备工作;主要研究不同浇筑材料、浇筑形式、核心区有无配箍等因素对节点耐火性能的影响。第二部分主要是分析讨论了GHPFRCC框架节点抗火性能的影响因素及规律。对高温下及高温后各框架节点的耐火极限、爆裂现象、梁柱端位移及梁端破坏现象等进行了分析讨论。试验结果表明,(1)虽然高温下GHPFRCC的热稳定性不佳,且GHPFRCC浇筑的框架节点爆裂现象比混凝土框架节点严重,但GHPFRCC框架节点的耐火极限大于混凝土框架节点;(2)使用GHPFRCC及C30混凝土混合浇筑的框架梁柱节点在高温作用下耐火极限最长、试件破坏最小,表现出优异的耐火性能;(3)已有研究表明常温下仅在节点核心区浇筑GHPFRCC可以减少甚至替代核心区箍筋的配置,但本文研究结果表明在高温下核心区配置箍筋的必要性,核心区未配置箍筋的GHPFRCC框架节点在高温作用下框架梁发生明显的剪切破坏,节点核心区GHPFRCC发生隆起,框架节点耐火极限最短,破坏最突然。
[Abstract]:Green High Performance Fiber Reinforced Cementitious compositions (GHPFRCCC) is made of cement, water, fly ash and quartz sand. Poly vinyl Alcohol fiber and high performance water reducer were prepared from polyvinyl alcohol fiber. At room temperature, GHPFRCC has excellent multi-joint cracking and strain hardening ability. GHPFRCC new type frame Liang Zhu joint has excellent seismic performance and energy dissipation. But at high temperatures, Because the melting of PVA fiber leads to the deterioration of GHPFRCC mechanical properties, it is urgent to study the fire resistance of GHPFRCC frame joints. In this paper, the GHPFRCC frame joints are taken as the research object. The effect of joint pouring and hoop ratio on the fire resistance of GHPFRCC frame joints is studied by means of fire resistance test. The main contents include the following two parts: the first part mainly introduces the fire resistance test of GHPFRCC frame joints. The basic principle of "strong shear and weak bending" is to make five frame joints of the same size from GHPFRCC and C30 concrete with the best mix ratio, and to prepare for the fire resistance test under the coupling action of high temperature and dead load. In the second part, the influence factors and rules of the fire resistance of GHPFRCC frame joints are analyzed, and the fire resistance limits of each frame joint at high temperature and after high temperature are discussed. The phenomena of burst, displacement of Liang Zhu end and failure of beam end are analyzed and discussed. The experimental results show that although the thermal stability of GHPFRCC is not good at high temperature, and the crack phenomenon of GHPFRCC cast frame joints is more serious than that of concrete frame joints, However, the fire resistance limit of GHPFRCC frame joints is greater than that of concrete frame joints. It has been shown that GHPFRCC can reduce or even replace the stirrups in the core area of the node at room temperature, but the research results show that it is necessary to deploy stirrups in the core area at high temperature. The GHPFRCC frame joints with no stirrups in the core region have obvious shear failure under the high temperature, the GHPFRCC in the core region of the joints is raised, the fire resistance limit of the frame joints is the shortest, and the damage is the most sudden.
【学位授予单位】：山东建筑大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB332

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