摘要
为了解决在实际施工前精确预测混凝土内部的温度场从而采取适当的施工措施预防混凝土热裂的问题,基于水泥水化反应三阶段的特征,提出S型水化热模型,通过对有限元软件ABAQUS进行二次开发,建立构件的三维实体有限元模型,对早龄期混凝土的水化热温度场进行数值模拟.为验证数值模拟的准确性,对2个1.5 m×1.2 m×4.0 m大尺寸混凝土构件进行硬化期水化热温度场测试.同时,选取拆模时间在混凝土浇筑后72、96、120、144 h进行有限元分析.对比分析数值模拟结果和温度场测试数据,二者吻合较好,而拆模后最大降温速率随着拆模时间的加长而减小,表明本文建立的模型能较精确地预测大尺寸混凝土构件硬化期的水化热温度场,且适当延长拆模时间降低了大尺寸混凝土构件温度裂缝出现的风险.
To solve the problem of accurate temperature field prediction inside concrete before construction so as to take appropriate construction measures to prevent the thermal cracking of concrete,a sigmoidal hydration heat model was proposed based on the characteristics of cement hydration in this paper.By means of the secondary development of finite-element(FE)software ABAQUS,a 3D thermal model was developed to calculate the temperature field inside early-age concrete.To verify the accuracy of the numerical simulation,the temperature field test during the hardened period of two 1.5 m×1.2 m×4.0 m members were carried out.Meanwhile,FE simulations on the condition of demoulding time at 72 hours,96 hours,120 hours and 144 hours after casting were carried out.According to the comparative analysis of numerical simulation results and temperature field test data,the FE simulation of temperature field is in good agreement with the site-measured data,and the maximum cooling rate after demoulding decreases with the extension of the demoulding time,showing that the thermal model established in this paper can accurately predict the hydration temperature field of the large-size concrete member during the hardened period,and the appropriate extension of the demoulding time will lower the temperature cracking risk.
作者
薛素铎
康广博
李雄彦
耿岩
李金光
宋延杰
XUE Suduo;KANG Guangbo;LI Xiongyan;GEN Yan;LI Jinguang;SONG Yanjie(College of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100124,China;Department of Civil Engineering,China Huanqiu Contracting&Engineering Co.Ltd.,Beijing 100012,China)
出处
《北京工业大学学报》
CAS
CSCD
北大核心
2020年第2期147-153,共7页
Journal of Beijing University of Technology
基金
国家自然科学基金资助项目(51578019)
关键词
大尺寸混凝土构件
早龄期
水化热模型
温度场
数值模拟
拆模时间
large-size concrete member
early-age
hydration heat model
temperature field
numerical simulation
demoulding time
