活性粉末混凝土高温爆裂规律与抗火设计方法研究

活性粉末混凝土（RPC）抗压强度高达120~800MPa，微观结构致密，具有受火爆裂易发性，温度-荷载路径对RPC柱高温性能影响显著。针对上述问题，开展如下工作：（1）考察RPC强度、应力水平、渗透性等关键参数对爆裂临界温度的影响，建立RPC爆裂临界温度计算公式。（2）考察聚丙烯（PP）纤维和钢纤维掺量对不同尺寸、不同强度、不同应力水平RPC高温爆裂的影响，建立防爆裂用纤维掺量计算公式。（3）基于孔隙压力理论，考虑RPC渗透性、纤维种类及掺量的影响，将Darcy定律引入数值模型，分析高温下RPC的孔隙压力，提出预测RPC高温爆裂的数值方法。（4）考察应力水平、恒温时间等关键因素对可有效避免爆裂的RPC热徐变、瞬态热应变的影响，建立RPC瞬态热应变、热徐变的计算公式，提出RPC温度-应力耦合本构关系。（5）揭示温度-荷载路径对RPC柱高温性能的影响规律，提出抗火设计方法。

The compressive strength of reactive powder concrete (RPC) is up to 120 ~ 800MPa. RPC is believed to be more susceptible to spalling because of its high density in microstructure. Further, temperature-load paths have significant effect on fire resistance performance of RPC columns. To overcome some of the current limitations, the following studies should be conducted: (1) Investigate the influence of RPC strength, stress levels and permeability on the critical temperature of fire-induced spalling in RPC. The calculation formula of critical temperature of fire-induced spalling in RPC could be obtained. (2) Investigate the influence of the PP fiber and steel fiber contents on fire-induced spalling in RPC with different size, different strength and different stress levels. The calculation formula of fiber content to prevent explosive spalling can be obtained. (3) Based on the pore pressure theory, using Darcy's Law in the RPC hydrothermal model considering the influence of permeability and fiber contents, the numerical model to predict fire-induced spalling in RPC could be presented. (4) Investigate the influence of stress levels and constant temperature time on creep and transient thermal strain of RPC, the formula of creep and transient thermal strain of RPC could be proposed. Then, the temperature-stress constitutive relations of RPC could be obtained. (5) Research the influence of temperature-load paths to the fire resistance performance of RPC column, and its fire safety design method could be proposed.