纤维混凝土受压本构试验及其抗震应用

The compression constitutive test of fiber concrete and its seismic application

纤维混凝土是未来结构抗震的发展方向之一,其设计与应用的关键问题是确定其本构特性,但目前相关研究较少,其受压本构特性仍较模糊.为此,本文完成了3个纤维混凝土圆柱体受压本构试验,分析了纤维混凝土各特征点的应力、应变、割线模量和单位体积应变能(应变能密度).结果表明,纤维混凝土与普通混凝土("混规"本构)相比,存在一个"类塑性"阶段——达到或接近峰值后的一定应变范围内应力几乎不下降,且极限压应变值为后者的2~3倍,其应变能密度明显提高.综合已有剪力墙试验结果,发现纤维混凝土可抑制裂缝的开展,形成较理想的梁铰机制,改善剪力墙的抗震性能.

The fiber concrete is one of the development directions of structural seismic restriction in the future.The key issue of its design and application is to determine its constitutive characteristics.However,at present,there are few related studies,and its compression constitutive characteristics are still vague.Therefore,this study completes tests on the compression constitutive curve of three fiber concrete cylinders,to investigate the stress-strain relationship,secant modulus,unit strain energy(strain energy density),et al.The results show that compared with ordinary concrete,there is a plastic-like stage in which the stress hardly decreases in a certain strain range after reaching or approaching the peak exists in the stress-strain curve of each fiber concrete specimen.And the ultimate compressive strain is 2~3 times that of the latter,and the strain energy density increases obviously.Based on the existing test results of shear wall,it is found that fiber reinforced concrete can restrain the development of cracks,form an ideal beam hinge mechanism and improve the seismic performance of shear wall.