预制混凝土叠合板钢筋黏结性能的研究
侯和涛,陈 磊,程佑东,朱文灿
(山东大学土建与水利学院,济南250061)
摘要:通过钢筋的拉拔试验研究了预制混凝土叠合板内钢筋的黏结性能。设计30个预制板与后浇混凝土的
叠舍板试件,主要研究混凝土强度、钢筋锚固长度、钢筋位置、钢筋直径四个因素对黏结性能的影响。并设计12个混
凝土现浇试件作为对比,以研究两种试件钢筋与混凝土黏结强度的差异。试验结果表明:叠合试件发生剥离破坏和
劈裂一剥离破坏,现浇试件均发生劈裂破坏;叠舍试件内钢筋的黏结强度随钢筋直径和锚固长度的减小、混凝土强度
和钢筋至预制板距离的增大而增大.并且明显小于现浇试件中钢筋的黏结强度。根据试验结果,统计回归出预制混
凝土叠合板钢筋的极限黏结强度计算公式,并由此推出钢筋锚固长度的计算公式以指导工程应用。
关键词:预制混凝土叠合板;黏结性能;拉拔试验;锚固长度
Abstract:This paper investigates the bond behavior of steel bars in precast concrete composite slabs through pull-out
tests.A total of 30 specimens representing steel rebars embedded in precast concrete composite slabs were prepared for evaluating
the influences of concrete strength,anchorage length,embedded location and rebar diameter on bonding strength
of the rehars.For comparison purpose,another 12 specimens of the steel rebars embedded in cast-in—place concrete were
also tested.Test results show that the rebars embedded in precast concrete composite slabs either exhibit debonding fail—
ures or cause splitting failures in the surrounding concrete while the rebars embedded in cast-in:place concrete consistent—
ly failed due to splitting failures of the concrete.Additionally,it is found that bonding strength of the rebars embedded in
precast concrete composite slabs increases when the rebar diameter and anchorage length reduce.Moreover,bonding
strength of the rebars embedded in precast concrete composite slabs tends to be higher when concrete strength is higher
and the distance between steel rebars and precast panels becomes larger.Further,test results reveal that bonding strength
of the rebars embedded in precast concrete composite slabs is remarkably lower than that of the rebars embedded in cast——
in—place concrete.Based upon regression analysis of the test data,an analytical model was proposed for calculating bond—
ing strength of the rebars embedded in preeast concrete composite slabs. I e model can be used to determine the required
anchorage length of the rebars embedded in cast-in-l~lace concrete in design.
Key words:Precast concrete composite slab;Bond properties;Pull-out experiment;Anchoring length
中图分类号:TU522 文献标识码:A 文章编号:1000—4637(2016)02—63—06
O 前言
预制带肋混凝土叠合板由实心平板与设有预
留孔洞的板肋组成,可在板上铺设横向穿孔钢筋、
拼缝防裂钢筋以及配置在叠合层上部的受力钢筋
等,再浇筑混凝土形成混凝土叠合板,见图1。预制
带肋混凝土叠合板既可以满足施工期间的荷载要
求,也可以作为现浇混凝土的模板,具有整体性好、
施工方便、工期短、成本低的优势【 ]。
图1 混凝土叠合板示意图
预制混凝土叠合板通过两端预留150mIn的“胡
子筋”与梁或墙进行锚固连接,在实际应用中,“胡
子筋”对预制混凝土叠合板的制作、运输、安装等造
成了不便;JGJ/]r 258—2011《预制带肋底板混凝土
叠合楼板技术规程》规定,可在预制混凝土叠合板
一端上方设置端部连接钢筋替代胡子筋圆。端部连
接钢筋位于预制叠合板和后浇}昆凝土之间的叠合
面处。不同于现浇混凝土。为研究叠合面处钢筋与
混凝土的黏结性能,本文通过拉拔试验,探讨混凝
土强度、钢筋锚固长度、钢筋位置、钢筋直径对叠合
板内钢筋与混凝土黏结性能的影响。
1 试验方案
1.1 试件设计
拉拔试验共设计A F六组42个试件,具体参
数见表1。A~E组试件是混凝土叠合板试件,由预制
板与后浇混凝土叠合而成:F组试件为现浇混凝土
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