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原文传递 Effects of Cyclic Temperature on the Time-Dependent Behavior of Posttensioned Concrete Bridges

题名：	Effects of Cyclic Temperature on the Time-Dependent Behavior of Posttensioned Concrete Bridges
其他题名：	ABAQUS version 6.10[Computer software].Dassault Systèmes,Providence,RI.
正文语种：	英文
作者：	Brock D. Hedegaard
关键词：	Concrete creep and shrinkage;Posttensioned bridges;Temperature effects;Thermal gradients;Temperature cycles;Concrete and masonry structures
摘要：	Typically, measurement and analysis of concrete time-dependent behaviors such as creep and shrinkage are performed under the assumption of constant temperature conditions. However, many structures in the field are subject to variable seasonal and daily temperatures. This paper explores how changes in temperature affect the time-dependent behavior of concrete structures, with a particular focus on posttensioned concrete bridges. Temperature-dependent creep, shrinkage, aging, and relaxation models were incorporated into structural finiteelement analyses examining a posttensioned concrete beam under variable thermal loading. The impacts of uniform temperature changes on the time-dependent deflections, strains, and stresses were accounted for using an Arrhenius-adjusted age based on the structure temperature. However, nonuniform temperature changes, such as thermal gradients through the depth of the cross-section, caused time-dependent behavior that could not be accounted for using the Arrhenius-adjusted age based on the average structure temperature. Time-dependent vertical deflections and especially longitudinal stresses throughout the structure were altered by the repeated application of thermal gradients. The different creep and shrinkage strain rates through the depth of the section, driven by the temperature and stress differences from the applied thermal gradients, induced residual stresses. The presence of these residual stresses implies that time-dependent stress changes from a creep and shrinkage analysis at a constant temperature cannot be linearly superimposed with the stresses caused by thermal gradients computed using an independent elastic analysis.
出版年：	2016
论文唯一标识：	P-26Y2016V142N10005
英文栏目名称：	TECHNICAL PAPERS
doi：	10.1061/(ASCE)ST.1943-541X.0001538
期刊名称：	Journal of Structural Engineering
拼音刊名(出版物代码)：	P-26
卷：	142
期：	10
页码：	42-55