不同应力作用下粉煤灰混凝土徐变后力学性能研究  

Mechanical Properties of Fly Ash Concrete After Creep and Being Subjected to Different Stresses

作　　者：仲志武[1] ZHONG Zhiwu(China Railway Eighteenth Bureau Group Co.,Ltd.,Tianjin 300222,China)

机构地区：[1]中铁十八局集团有限公司,天津300222

出　　处：《工业建筑》2022年第4期152-157,132,共7页Industrial Construction

摘　　要：为研究持续荷载作用对粉煤灰混凝土静力性能的影响,以天津地铁6号线渌水道站为工程背景,进行了不同持荷时间、不同持荷应力条件下混凝土轴压徐变和徐变后静力性能的测试,同时进行了同环境条件下无持荷混凝土收缩和收缩后的静力性能测试。试验结果表明:在15%和30%应力级别下,随着持荷时间延长,混凝土弹性模量会逐渐增加,其增长速率随着持荷时间的增加而减小;相同环境条件下,无持荷收缩试件的弹性模量也有一定增长,数值较30%应力级别持荷试件低5%左右。随着持荷时间的延长,混凝土徐变后的应力-应变曲线弹性阶段的斜率增大,峰值应力也增大;相同环境条件下,无持荷收缩试件的应力-应变曲线弹性阶段的斜率也会增大,峰值应力低于徐变试件,峰值应力增长不明显,增长幅度为徐变试件增长幅度的65%左右。In order to research the influence of sustained loads on the mechanical properties of concrete,taking the Tianjin Metro Line 6 Lushuidao station as the engineering background,the creep development of concrete under different sustained times and sustained stresses was tested,as well as the static performance of concrete after creep.At the same time,the static loading test for shrinkage specimens with the same environmental conditions of creep specimens was also carried out.The results showed that under 15%and 30%stress level,the elastic modulus of concrete after creep increased gradually with the sustained time,but its increase rate reduced.The elastic modulus of shrinkage specimens under the same environmental conditions also had a certain growth,and the value was about 5%lower than that of holding specimens at 0.3 stress level.With the increase of sustained time,the slope of the stress-strain curve of concrete after creep increased in the elastic stage,and the peak stress also increased.Under the same environmental conditions,the slope of the stress-strain curve of the shrinkage specimen without sustained loads also increased in the elastic stage,the peak stress was lower than that of the creep specimen,which was about 65%of that of the creep specimen.

关 键 词：混凝土 力学性能 收缩 徐变 本构 

分 类 号：U231[交通运输工程—道路与铁道工程]