| 摘要: |
| 基于蒸汽压力爆裂理论,采用多相多孔介质一维模型对自密实混凝土（SCC）和纤维自密实混凝土（FRSCC）内部蒸汽压力进行了预测,并对由蒸汽压力引起的混凝土爆裂行为进行了分析.为了验证模型的有效性,开展了SCC和FRSCC火灾作用下内部蒸汽压力的测试试验,分析了钢纤维、细聚丙烯（PP）纤维、粗PP纤维以及混杂纤维对SCC内部蒸汽压力时间温度关系的影响规律.结果表明：纤维的掺入降低了SCC内部的蒸汽压力，延长了峰值蒸汽压力出现的时间，降低了峰值蒸汽压力对应的温度;细PP纤维对SCC内部蒸汽压力的降低效果优于粗PP纤维,相比于PP纤维掺量,PP纤维的根数对SCC内部蒸汽压力的影响更为显著;与单掺纤维相比,混杂纤维的掺入进一步降低了SCC内部的蒸汽压力;通过与试验结果的对比发现,多相多孔介质一维模型可以较好地预测SCC和FRSCC火灾作用下内部蒸汽压力发展过程和高温爆裂行为. |
| 关键词: 自密实混凝土 纤维 火灾 爆裂 预测模型 |
| DOI：103969/j.issn.1007 9629202102005 |
| 分类号: |
| 基金项目:国家自然科学基金青年基金资助项目（51908247）；江苏省自然科学基金青年基金资助项目（BK20170192）；绿色建筑材料国家重点实验室开放基金资助项目（YA 616）；中央高校基本科研业务项目（JUSRP11712）；中国矿业大学江苏省土木工程环境灾变与结构可靠性重点实验室开放基金项目（KFJJ202007） |
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| Spalling Behaviour Prediction for Fiber Reinforced Self consolidating Concrete under Fire |
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ZHANG Cong, XIA Chaofan, YUAN Zhen, LI Zhihua
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School of Environment and Civil Engineering, Jiangnan University, Wuxi 214000, China
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| Abstract: |
| Based on vapor pressure spalling theory, the vapor pressure in self consolidating concrete(SCC) and fiber reinforced self consolidating concrete(FRSCC) was predicted using the one dimensional model of multi phase porous media. Vapor pressure induced spalling behavior of SCC and FRSCC was analyzed. In order to verify the validity of the proposed model, vapor pressure tests for SCC and FRSCC under fire were performed. Effects of steel fiber, micro polypropylene(PP) fiber, macro PP fiber and hybrid fiber on the relationship of vapor pressure time temperature were discussed. The results indicated that the addition of fibers can decrease the vapor pressure in SCC, delay the occurrence time of the peak value of pore pressure and can decrease the corresponding temperature at peak pressure. The pore pressure can be reduced by using micro PP fibers more effectively than by macro PP fibers. The significant factor for reduction of vapor pressure depends mainly on the number of PP fibers as well as on the fiber content. Compared to mono fiber, the use of hybrid fibers can further reduce the vapor pressure in SCC. Through comparison with the test results, it is found that the simulation model presented can well predict the build up of vapor pressure and fire spalling behavior of SCC and FRSCC. |
| Key words: self consolidating concrete fiber fire spalling prediction model |
