爆炸和火灾下活性粉末混凝土板受力性能与破坏模式

Reactive Powder Concrete (RPC) has broad application prospects in anti-explosion and prevention of terrorism for its high performances on deformation and crack arresting. The safety of RPC structures is reduced seriously in case of explosion and fire. RPC under fire spalls more easily or more seriously for its high strengeth and compactness. Temperature-load paths have significant effects on RPC constitutive relations. In response to these questions, firstly, expansion strain, creep and transient thermal strain can be obtained respectively by the results of constant temperature and variational stress tests and constant stress and variational temperature tests. Based on the method of the deformation components and temperature-stress paths decomposition of RPC200 under fire, the temperature-stress constitutive relations of RPC under different temperature-stress paths could be obtained. Secondly, the spalling rule of RPC at elevated temperature can be revealed by tests results considering the influence of permeability, water content and axial load ratio of specimens.The details to prevent RPC spalling will be proposed.Thirdly, the dynamic compression strength and dynamic increase factor of RPC under different strain rates and RPC dynamic stress -strain relations can be obtained by Split Hopkinson Pressure Bar tests. Finally, the numerical simulation of mechanical process of reinforced-RPC slabs subjected to explosion and fire considering the effects of members damage by explosion can be completed by using the algorithm of Lagrange and related numerical model. An extensive parametric study will be carried out to investigate the effects of form and location of explosion load, longitudinal reinforcement ratio, cross section dimension, load ratio. The load capacity, deformation, section stress and failure mechanism of RPC slabs under explosion and fire can be obtained. These research results can be applied to improve the safety of RPC slabs under explosion and fire.

活性粉末混凝土（RPC）变形、阻裂能力强，在抗爆、防恐等领域有较好应用前景。爆炸和火灾下RPC结构安全性急剧降低；RPC强度、致密性高，火灾下易爆裂，温度-荷载路径对RPC的本构关系有显著影响。针对上述问题，通过RPC200恒温加载和恒载升温试验，获得自由膨胀、瞬态热应变和高温徐变，将火灾下变形、温度-荷载路径分解，建立RPC温度-应力本构关系，揭示渗透性、含水量、应力水平等对火灾下RPC爆裂的影响规律，提出防爆裂措施。通过分离式霍普金森压杆试验，获得RPC的动态压缩强度和动态增长因子，建立RPC动态应力-应变关系。引入Lagrange型算法与相应数值模型，考虑爆炸对板的损伤作用，实现爆炸和火灾下钢筋RPC板灾变行为的数值模拟，研究爆炸荷载形式与位置、配筋率、板厚度、荷载水平、跨高比对板承载力、变形、截面应力的影响规律，研究板的破坏模式，为提高火灾和爆炸下RPC板的安全性提供参考。

活性粉末混凝土（RPC）具有超高强度和韧性，应用前景广阔。高应变率下其动态拉压性能尚不清晰；火灾或爆炸下RPC板力学性能尚未见报道，为此， 开展以下工作。.（1）完成了152个RPC动态压、拉SHPB冲击试验，结果表明：应变率为100~260s-1时，素RPC受压动力增长系数（DIF）在1.00~2.38之间；复掺、单掺2%钢纤维RPC受压DIF在1.15~2.39之间；掺5%钢纤维RPC受压DIF在1.07~1.73之间。建立了RPC动态抗压应力-应变关系计算模型；提出了复掺纤维RPC动态抗拉、抗压DIF-应变率计算公式。.（2）实现了RPC板动态响应的数值模拟，验证了数值模拟的正确性。结果表明：考虑应变率效应时，RPC板跨中位移显著减小。随爆炸作用折合距离增大、板厚增加、RPC强度提高、板纵筋配筋率增加，活性粉末混凝土板底中心点峰值位移减小。增加板厚，提高支座约束能力是提高板抗爆性能的有效方法。.（3）提出了将RPC填充于钢抗爆门空腔，以增强其抗爆能力的方法。实现了钢板-RPC抗爆门动态响应有限元分析。结果表明：钢板-RPC抗爆门抗爆能力优于钢抗爆门和钢板-混凝土抗爆门；增加钢板内肋数量、增大门扇钢板厚度能够显著减小抗爆门门扇中心位移；钢板内肋厚度、RPC强度对抗爆门的动态响应影响相对较小。.（4）火灾时不爆裂、火灾下不坍塌、火灾后可修复，是混凝土结构抗火设计所应遵循的原则。获得了爆裂临界温度与混凝土标准立方体抗压强度（23MPa~238MPa）的关系曲线，发现混凝土抗压强度越高，爆裂临界温度越低。提出了防爆裂PP纤维掺量、钢纤维掺量与混凝土抗压强度的关系曲线。.（5）完成了钢筋RPC简支梁抗火性能的数值分析，建立了耐火极限计算公式。结果表明：高宽比、配筋率、保护层厚度、荷载水平对钢筋RPC简支梁的耐火极限影响显著，跨高比对钢筋RPC简支梁的耐火极限的影响较小。.（6）实现了爆炸和火灾下RPC板受力性能数值模拟。结果表明，与不考虑火灾影响相比，爆炸和火灾下RPC板的固有频率降低，动态位移显著增加。.（7）4名硕士生结合本项目开展学位论文工作（已毕业3人）。撰写论文13篇，其中SCI收录3篇，EI源3篇，ISTP收录1篇，获国家发明专利1项，合作获2014年国家科技进步二等奖和2013年黑龙江省科技进步一等奖。

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