混凝土高温爆裂临界温度和防爆裂纤维掺量研究综述与分析

发布时间：2018-01-06 11:26

本文关键词：混凝土高温爆裂临界温度和防爆裂纤维掺量研究综述与分析　出处：《建筑结构学报》2017年01期 　论文类型：期刊论文

【摘要】：确定无纤维或低纤维掺量的不同强度等级混凝土的爆裂临界温度,以及防止火灾时不同强度混凝土爆裂所需聚丙烯(PP)纤维或钢纤维最小掺量,对混凝土结构抗火设计具有重要意义。为此,对国内外大量高温爆裂试验研究结果进行分析,获得了爆裂临界温度与混凝土抗压强度(23~238 MPa)的关系曲线,发现混凝土抗压强度越高,爆裂临界温度越低。通过大量试验数据拟合得到了防爆裂PP纤维掺量、钢纤维掺量与混凝土抗压强度的关系曲线,发现随着混凝土抗压强度的提高,所需防爆裂PP纤维掺量呈线性增长,而所需防爆裂钢纤维掺量呈指数增长。按EN 1992-1-2:2004《欧洲混凝土抗火设计规范》建议值,PP纤维掺量为0.22%的防爆裂混凝土,火灾下仍可能发生爆裂;按所提出计算式计算的掺量,则可有效降低火灾下混凝土爆裂的风险。
[Abstract]:No fiber or low fibre content of different strength grade concrete crack critical temperature, and prevent the fire of different strength concrete burst for polypropylene (PP) fiber or steel fiber concrete structure of minimum volume, fire resistance design has important significance. Therefore, for a large number of domestic and foreign high temperature burst test results analysis the burst of critical temperature and compressive strength of concrete (23~238 MPa) curve, found that the compressive strength of concrete is higher, the lower the burst critical temperature. Through a large number of experimental data obtained by fitting PP anti crack fiber content, the curve of compressive strength of steel fiber and concrete, with the increase of concrete compressive strength. The anti burst PP fiber content increases linearly, while the required anti cracking of steel fiber content increases exponentially. According to the EN 1992-1-2:2004< Europe concrete fire resistance design specification It is suggested that explosion cracking concrete with PP fiber content of 0.22% is still likely to burst under fire. According to the calculated amount of the proposed formula, the risk of concrete burst under fire can be effectively reduced.

【作者单位】：哈尔滨工业大学结构工程灾变与控制教育部重点实验室;华南理工大学亚热带建筑科学国家重点实验室;
【基金】：国家自然科学基金项目(51208146,51578184) 教育部博士点基金项目(20122302120084) 长江学者特聘教授奖励计划(2009-37)
【分类号】：TU528.572
【正文快照】： 0引言火灾时不爆裂、不坍塌,火灾后可修复,是混凝土结构抗火设计所应遵循的原则。国内外学者对普通混凝土(NSC)、高强混凝土(HSC)和预应力混凝土(PC)耐火性能的研究表明,这三类混凝土结构均存在高温爆裂风险[1-6]。爆裂是指火灾下混凝土内部蒸汽压力不断增大,导致混凝土瞬间裂

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