基于温度影响下早期变形特征的混凝土凝结时间的确定  

Determination of Concrete Setting Time Based on Early Deformation Characteristics Caused by Temperature

作　　者：赵智辉 杨双锁[1] 马耀荣 罗百胜 牛少卿[1] ZHAO Zhi-hui;YANG Shuang-suo;MA Yao-rong;LUO Bai-sheng;NIU Shao-qing(College of Mining Engineering,Taiyuan University of Technology,Taiyuan 030024,China;China Railway No.3 Engineering Group Co.,Ltd,Taiyuan 030001,China)

机构地区：[1]太原理工大学矿业工程学院,太原030024 [2]中铁三局集团有限公司,太原030001

出　　处：《科学技术与工程》2018年第22期266-272,共7页Science Technology and Engineering

基　　金：国家自然科学基金(51274145)资助

摘　　要：通过模板侧压力实验和温度实验,监测新浇混凝土24 h模板侧压力和24 h混凝土内部温度变化过程,研究由混凝土水化时释放的热量引起温度的变化而造成混凝土初凝前后的变化特征。将工程实验测得的初凝时间与贯入阻力法测得的初凝时间进行对比,结合混凝土早期变形特征,提出了确定混凝土凝结时间的新方法。实验结果显示:随着浇筑高度的增大混凝土模板侧压力也增大,当混凝土浇筑完成到混凝土初凝这段时间模板侧压力出现减小趋势,混凝土初凝后因温度升高发生膨胀,模板侧压力也随之增大;将混凝土模板侧压力再次增大的时间点定为混凝土初凝时间与贯入阻力法测试得到的初凝时间有良好的相关性。Through side pressure experiments on templates and temperature experiments,monitor the changing processes of the side pressure on templates and of the temperature inside the concrete within 24 h after the concrete has been poured,and research on change features before and after the prehardening of the concrete incurred by the temperature change caused by the heat released by the hydration heat of the concrete.Comparing the prehardening time got from the engineering experiment and that got from the penetration-obstruction method and combining deformation characteristics in the early stage of the concrete,propose a new method to determine the hardening time of the concrete.Results of the experiment show that as the height of pouring increases,the side pressure on templates also increases.During the period from finishing the pouring to the prehardening,the side pressure decreases.As the temperature increases,the concrete expands,and the side pressure on templates also increases.The time when the side pressure rises again is set as the prehardening time of the concrete.It has a good correlation with the prehardening time got from the penetration-obstruction method.

关 键 词：温度应变 凝结时间 膨胀 收缩 模板侧压力 

分 类 号：TU528[建筑科学—建筑技术科学]