考虑面力作用的HFR-LWC梁抗爆试验研究

实际工程中，面力作用会导致梁板构件的承载力提高以及破坏模式改变。为确切把握面力作用在爆炸加载全过程的变化规律及其对结构抗力的影响，该文进行了混杂纤维轻骨料混凝土（HFR-LWC）梁抗爆性能试验研究，得到爆炸荷载超压时程曲线及梁跨中位移、破坏模式等试验数据，结合端部约束刚度计算方法分析了面力作用对HFR-LWC梁抗力及破坏形态的影响规律。结果表明：试验装置可以合理模拟爆炸加载过程中梁构件的面力作用，是一套定量评估面力贡献的有效工具。面力作用能有效阻止纵向钢筋过早进入屈服状态，充分发挥混凝土的抗压性能，抑制裂缝的开展，有效减小梁的跨中位移，从而提高HFR-LWC梁的抗爆能力。

EXPERIMENTAL STUDY ON BLAST-RESISTANCES OF HFR-LWC BEAM WITH MEMBRANE EFFECT

In practice, the carrying-capacity of beam-slab members is usually enhanced by membrane effect, which results in the change of failure pattern. In order to reveal the influences of membrane effect on the loading process and the ultimate capacity of beam structures, blast-resistance tests of HFR-LWC beam(hybrid fiber reinforced-lightweight aggregate concrete) are performed. The overpressure history, mid-span displacement and failure mode of HFR-LWC beam are obtained. The carrying-capacity and failure pattern of HFR-LWC beams are discussed based on measured data and theoretical analysis. Results show that the membrane behavior on beams during blast loading is reasonably simulated in the test, which provides a reliable tool to quantitatively evaluate the contribution of in-plane force. The existing of membrane effect can effectively avoid the steel yielding, fully use the compressive strength of concrete, prevent the crack propagations, and reduce the mid-span displacement of HFR-LWC beams;thus, the blast-resistance of HFR-LWC beams is improved greatly by membrane effect.