闭口型压型钢板-再生混凝土组合楼板抗火性能研究
Fire performance of recycled aggregate concrete composite slabs with closed profiled steel decking
赵晖 1王杰堂 1赵金泽 1刘发起 2王蕊1
作者信息
- 1. 太原理工大学 土木工程学院,山西太原 030024
- 2. 哈尔滨工业大学 结构工程灾变与控制教育部重点实验室,黑龙江哈尔滨 150090
- 折叠
摘要
闭口型再生混凝土组合楼板兼具组合结构的优点与固废利用的特点,但高温下再生混凝土热工和力学性能与普通混凝土有明显差别,进一步造成了相应结构构件火灾下抗火性能的差异.为此,对闭口型再生混凝土组合楼板基于承载能力的耐火极限进行了试验与有限元研究,主要参数为再生粗骨料取代率、板型与荷载水平,分析挠度与不同位置处的温度发展,并建立了适用于该类楼板耐火极限简化计算方法.结果表明:受火90 min后,压型钢板与混凝土未发生分离,组合楼板保持了较好整体性;压型钢板闭口位置温度明显低于受火面底钢板,相同位置处再生混凝土组合板温度低于普通混凝土板;耐火极限受取代率的影响较小,再生混凝土组合板相对普通混凝土板耐火极限提高幅度在1.2％～9.2％,且远超过一级耐火极限90 min的要求;考虑钢板闭口部分受弯承载力贡献提出了耐火极限简化计算式,其可较好地预测组合板耐火极限.
Abstract
Recycled aggregate concrete(RAC)composite slabs with closed-profiled steel decking offer the combined advantages of composite structures and utilization of solid waste.However,the thermal and mechanical properties of RAC at high temperature are significantly different from those of normal concrete,which further results in the difference of fire resistance between RAC and normal concrete structural members.Therefore,the fire resistance of RAC composite slabs with closed-profiled steel was experimentally and numerically studied based on the load-bearing failure criteria in this paper.The main investigated parameters included coarse recycled aggregate replacement rate,type of steel deck and load ratio.The developments of deflections and temperatures at different locations within the slabs were emphatically analyzed,and a simplified formula for predicting the fire resistance was developed.Results show that the steel deck remains bonded to the concrete and the integrity of the slabs is effectively maintained even after exposure to fire for 90 minutes.The temperatures recorded at the embedded decking rib are noticeably lower than those at the decking soffit.Additionally,the RAC slab exhibits lower temperatures at the same positions than the normal concrete slab.Furthermore,the fire resistance of the RAC slab is minimally affected by the replacement rate of coarse recycled aggregate.There is a modest improvement of 1.2％to 9.2％in fire resistance than the normal concrete slab.The capacity of all composite slabs far exceeds the minimum fire resistance requirement of 90 minutes.In conclusion,the proposed formula can yield a good prediction for the fire resistance of this type of composite slabs by considering the bending contribution of the embedded decking rib.
关键词
闭口型压型钢板/再生混凝土/受火试验/耐火极限/抗火性能Key words
closed profiled steel decking/recycled aggregate concrete/fire test/fire resistance/fire performance引用本文复制引用
基金项目
国家自然科学基金项目(52108162)
中国博士后科学基金项目(2020M670656)
出版年
2024
国家科技期刊平台
NSTL
维普
万方数据