集中荷载作用下超高强混凝土无腹筋梁抗剪强度的试验研究

Testing Study on the Shearing Strength of Beams of Super-strong Steel-concrete under Concentrated Loads

通过对18根超高强混凝土无腹筋梁(包括9根简支梁和9根约束)在集中荷载下抗剪强度的试验,观察了试件从裂缝出现到完全破坏失去承载能力全过程的试验现象,获得了试件的各阶段荷载值和各项应变值以及挠度值等试验数据,得出约束情况、剪跨比和混凝土强度3个因素对构件抗剪强度影响 同时将试验实测值与国内外多个抗剪强度公式的混凝土项计算进行验算比较,对其用于计算超高强混凝土构件时的适用性、安全性进行了评价。

With the tests for the shearing strength of 18 super-strong steel-concrete sample beams (9 free beams and 9 restrained beams) under concentrated loads, the whole process from the appearance of cracks to breakage of the sample beams is observed, the data on loads, variables, and deflection are obtained, and the effects of the three factors of restraining conditions, shear span ratio and intensity of concrete on the shearing strength of beams are confirmed. This paper carries out comparison and checking calculation between the resulted testing data and that of many foreign shearing strength tests with their testing formulas, evaluates the applicability and safety when they are used in super-strong steel concrete beams, and finally, based on the regression analysis on the testing data, produces the regression formula for the shearing strength of super-strong steel concrete beams under concentrated loads.