摘要
为了研究大直径钢绞线在先张法超高性能混凝土(UHPC)梁中的合理间距,利用ABAQUS软件建立单根及双根大直径钢绞线的非线性有限元模型,研究大直径钢绞线与UHPC的界面黏结特征、钢绞线及其周围混凝土的应力分布规律。结果表明:部分黏结模型能够有效模拟大直径钢绞线与UHPC的界面黏结特征。在先张法UHPC梁中,以钢绞线中心为圆心,以1.4倍钢绞线公称直径为半径的范围内,约85%的预应力能传递给周围混凝土;在1.4倍钢绞线公称直径范围以外混凝土受钢绞线影响较小;随着混凝土强度的提高,预应力筋的传递长度逐渐减小,且接近线性变化。布置净距为1.8倍钢绞线公称直径时,两根钢绞线之间中心点处的混凝土应力远小于混凝土抗压强度,不会引起开裂。考虑适用性,建议先张法预应力UHPC结构中大直径钢绞线之间的净距不应小于1.8倍公称直径。
In order to study the reasonable clearance of large diameter strands in pre-tensioned UHPC(Ultra-High Performance Concrete)girder,two nonlinear finite element models of a single large-diameter strand and two large-diameter strands were established by using ABAQUS software to study the bonding characteristics of the interface between the large-diameter strand and UHPC,and the stress distribution laws of strand and its surrounding concrete.The results show that the partial bond model can effectively simulate the interface bond characteristics between large diameter strands and UHPC.In the pre-tensioned UHPC girder,with the center of the strand as the center and 1.4 times the nominal diameter of strand as the radius,about 85%of the prestress can be transferred to the surrounding concrete.More than 1.4 times the nominal diameter of strand,the influence of strand on concrete is significantly reduced.With the increase of concrete strength,the transmission length of prestressed reinforcement decreases gradually,and is close to the linear proportion.When the clearance is 1.8 times the nominal diameter of strand,the concrete stress at the center point between the two strands is far less than the compressive strength of the concrete and will not cause cracking.Considering the applicability,it is recommended that the clearance between large-diameter steel strands in pretensioned prestressed UHPC structure should not be less than 1.8 times the nominal diameter.
作者
占玉林
王振洋
程学友
张程
乔瑜
卢思吉
刘矗东
ZHAN Yulin;WANG Zhenyang;CHENG Xueyou;ZHANG Cheng;QIAO Yu;LU Siji;LIU Chudong(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;Institute of Civil Engineering Materials,Southwest Jiaotong University,Chengdu 610031,China;Qingdao Metro Line 8 Co.Ltd.,Qingdao Shandong 266000,China)
出处
《铁道建筑》
北大核心
2021年第12期8-12,22,共6页
Railway Engineering
基金
国家自然科学基金(51878564)
四川省科技计划项目(2021JDTD0012)
四川省留学回国人员科技活动项目(〔2021〕29号)。
作者简介
第一作者:占玉林(1978-),男,博士,教授。E-mail:yulinzhan@home.swjtu.edu.cn。
