摘要
为研究单箱三室混凝土箱梁水化热温度场及应变场分布规律,在广西来宾浇筑混凝土箱梁缩尺(1∶2)模型,埋置148个温度传感器和20个应变传感器,并布置气象传感器,通过现场实测数据分析,得到C60高强混凝土箱梁水化热温度场分布规律。单箱三室箱梁水化热共分为3个阶段:温升阶段(0~24 h)、快速温降阶段(24~96 h)和平稳温降阶段(96~240 h)。箱梁截面平均温度需179 h才低于入模温度,说明箱梁水化产生的热量至少需要7 d才能完全消散。全截面温度峰值为浇筑后24 h,最高区域为梗腋位置处,最高温度达90.2℃,此时顶板最大横向温差达32.2℃。受分层浇筑影响,浇筑后12 h,边腹板最大竖向温差达40.1℃,现场可观察到施工冷缝。梗腋处温度场分布复杂,梗腋最大横向温差为22.5℃,最大竖向温差为29.9℃,梗腋表面横向收缩应变小于竖向。梗腋外表面温度较低且受模板约束,应变小于梗腋内部,有6个梗腋存在竖向开裂风险,最大收缩拉应力为抗拉强度的1.51倍。
In order to study the distribution law of concrete hydration heat temperature field and strain field in concrete single box and three chamber girder,a concrete box girder scaled-down(1∶2) model was cast in Laibin,148 temperature sensors and 20 strain sensors were embedded in the concrete.Meteorological sensors were arranged,and the distribution law of hydration heat field of C60 high-strength concrete box girder was obtained through the analysis of field actual measurement data.The research results showed that the hydration heat of single-box three-compartment box girder was divided into three stages:temperature rise stage(0-24 h),rapid temperature drop stage(24-96 h) and smooth temperature drop stage(96-240 h).The average temperature of the box girder cross-section needed 179 h before it was lower than the entering temperature,the heat generated by the hydration of the box girder needed at least 7 d to be completely dissipated;the peak temperature of the whole cross-section was 24 h after pouring,and the highest area was at the pedicle axillary position,with the highest temperature reaching 90.2 ℃,and the maximum horizontal temperature difference of the top plate reached 32.2 ℃ at this time.Influenced by the layered pouring,the maximum vertical temperature difference of the side web reached 12 h after pouring 40.1 ℃,and the construction cold joints could be observed on the site.The temperature field distribution at the stalk axle was complicated,and the maximum transverse temperature difference at the stalk axle was 22.5 ℃ and the maximum vertical temperature difference was 29.9 ℃,and the transverse shrinkage strain at the surface of the stalk axil is smaller than the vertical one.The strain on the outer surface of the stalk axil is lower and constrained by the template,so the strain is smaller than that inside the stalk axil.it was calculated that there was a risk of vertical cracking in six pedicle axils,and the maximum shrinkage tensile stress was 1.51 times of the tensile strength.
作者
王鹏
黄成
赵国浩
张峰
WANG Peng;HUANG Cheng;ZHAO Guohao;ZHANG Feng(China Merchants Chongqing Communications Technology Research and Design Institute Co.Ltd.,Chongqing 400067,China;Guangxi Road Construction Engineering Group Co.Ltd.,Nanning 530001,Guangxi,China;Geotechnical and Structural Engineering Research Center,Shandong University,Jinan 250061,Shandong,China)
出处
《山东大学学报（工学版）》
CAS
CSCD
北大核心
2024年第1期109-122,130,共15页
Journal of Shandong University（Engineering Science）
关键词
水化热
试验模型
温度场
应变场
混凝土箱梁
heat of hydration
test model
temperature field
strain field
concrete box girder
作者简介
第一作者:王鹏(1973-),男,山东邹平人,高级工程师,博士,主要研究方向为桥梁结构可靠性与安全性评估。E-mail:wangpeng@cmhk.com;通信作者:张峰(1978-),男,江苏泰州人,教授,博士生导师,博士,主要研究方向为桥梁加固。E-mail:zhangfeng2008@mail.sdu.edu.cn。
