摘要
为了探明固化期间缓黏结预应力混凝土梁的力学性能,制作了4根缓黏结预应力混凝土梁,每根梁直线布置3根缓黏结预应力钢筋,进行试验梁的抗弯承载力测试。通过邵氏硬度计测得试验梁缓黏结剂的硬度,用以反映缓凝材料在加载试验时的固化性质;然后把试验梁分4批进行三分点两点同步单调静力加载试验;最后通过监测梁挠度、关键截面混凝土的应变变化、预应力钢筋张拉端和锚固端的压力变化、裂缝分布等指标,明确缓黏结预应力钢筋与混凝土之间的传力机理以及混凝土梁的抗弯承载能力。结果表明:缓黏结剂的固化度对预应力混凝土梁的开裂荷载影响较小,对最大承载力影响较大,利用现有的预应力混凝土计算理论计算得到的开裂荷载与试验结果吻合较好,但最大承载力的理论计算结果相对保守;随着缓黏结剂逐渐固化,预应力混凝土梁的极限承载力随之增加,当缓黏结剂的邵氏硬度(D型)达到80时,缓黏结预应力钢筋与混凝土具有良好的共同工作状态,梁纯弯段部分的裂缝开展均匀,数量较多,其承载力及延性也最大。
To investigate the mechanical behavior of retard-bonded pre-stressed concrete（RBPC）beam during curing period,four RBPC beams which had arranged three straight retard-bonded pre-stressed tendons in each beam were made and bending resistance capacity tests of these RBPC beams were carried out.The hardness of retard-bonded adhesive in each beam was measured by the Shore durometer to reflect the curing property of the retard-bonded material in loading experiment.These RBPC beams were divided into four groups for monotonic static loading experiment at the one third point and the two thirds point at the same time.Finally,to explore clearly the force transfer mechanism between retard-bonded pre-stressed tendons and concrete and bearing capacity of these RBPC beams,the force-deflection curve,the concrete strain change of key-sections,the pressure change at the tensile end and the anchoring end of pre-stressed tendon,the cracks distribution and other parameters were measured.The result shows that the curing degree of retard-bonded adhesive has little impact on the cracking load of pre-stressed concrete beam,however,it has great impact on the maximum bearing capacity;based on the existedcalculating theory of the PC structure,the calculated cracking load has good agreement with experimental result,but the theoretically calculated maximum bearing capacity is conservative comparatively;with the increase of curing degree,the maximum bearing capacity of RBPC beam also increases.When the Shore hardness（D type）of retard-bonded adhesive reaches 80,the retard-bonded pre-stressed tendons and concrete work synergistically well.Large amount of cracks in the bending segment are distributed uniformly,where its bearing capacity and ductility are also the largest.
作者
王占飞
胡正伟
曹少朋
王强
徐岩
WANG Zhan-fei HU Zheng-wei CAO Shao-peng WANG Qiang XU Yan(School of Traffic Engineering, Shenyang Jianzhu University, Shenyang 110168, Liaoning, China School of Civil Engineering, Shenyang Jianzhu University, Shenyang 110168, Liaoning, China)
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2017年第1期56-62,共7页
China Journal of Highway and Transport
基金
辽宁省高等学校杰出青年学者成长计划项目(LJQ2014060)
关键词
桥梁工程
预应力混凝土梁
抗弯性能试验
缓黏结剂
硬度
bridge engineering
PC beam
bending resistance capacity test
retard-bonded adhesive
hardness
