混凝土叠合梁凹口构造对抗剪性能影响研究

Study on the influence of concave openings on shearing capability of composite beam in assembly concrete structure

广东省《装配式混凝土建筑结构技术规程》(DBJ 15—107—2016)及行标《装配式混凝土结构技术规程》(JGJ 1—2014)针对叠合层小于150 mm的混凝土叠合梁,规定其必须采用带凹口构造的预制截面方案。但在工程实践中可发现,凹口构造叠合梁的制造既费工费时、质量也不易保证,且在成品运输及吊装过程中易发生凹口开裂现象。文章针对规范推荐的凹口构造叠合梁,对其进行静载抗剪承载力试验研究,对比其与非凹口构造叠合梁及整体浇筑梁在抗剪性能上的差异。结果表明,凹口构造叠合梁与非凹口构造试件的静载抗剪承载性能基本一致,且皆可等同现浇,因此在抗剪设计时非凹口构造叠合梁在一定条件下替代凹口构造叠合梁是可行的。

Guangdong provincial standard(DBJ 15—107—2016)and industrial standard(JGJ 1—2014)of assembly concrete structures recommend prefabricated part to be manufactured with concave openings for composite beam of which the overlapping layer is less than 150mm.However,it can be found in engineering practice that manufacturing of concave openings is timeconsuming and hard to ensure quality,also can crack of concave openings be found in the process of product transportation and lifting.In this paper,static load shearing tests of composite beams with standard recommended concave openings are carried out with contrast to the ones without concave openings and integral casting beams on their shearing capabilities.The results show that the static shearing behavior of the composite beam with concave openings is consistent with that of the ones without concave openings,both of them have property of cast-in-place equivalence.Therefore,it is feasible under certain conditions that using composite beams without concave openings instead of the ones with standard recommended concave openings in anti-shearing design.