一般大气环境下混凝土经时抗压强度的变化规律  

Change law of time-dependent concrete compressive strength in the atmospheric environment

作　　者：高向玲[1] 颜迎迎[1] 李杰[1] 

机构地区：[1]同济大学,上海200092

出　　处：《土木工程学报》2015年第1期19-26,共8页China Civil Engineering Journal

基　　金：国家"十二五"科技支撑计划(2011BAJ09B03-02);国家自然基金委员会高铁联合基金(U1134209)

摘　　要：随着服役年限的增加,既有建筑中混凝土材料的力学性能会发生变化。文中共收集分析上海地区服役年限从1到60年的民用建筑中混凝土回弹法检测数据1923组,钻芯法检测数据172组,并进行归一化处理。基于实测数据,采用假设检验及参数估计方法确定混凝土经时强度的概率分布函数,并与通过概率密度演化得到的混凝土强度概率分布进行比对,证明既有建筑中混凝土抗压强度服从正态分布,并采用随机变量的概率模型描述。建立上海地区民用建筑混凝土强度正态分布样本的均值和标准差与龄期的变化关系,分别确立回弹法和钻芯法测得的混凝土强度经时变化模型,并将回弹法和钻芯法的强度模型进行比对,建立两者之间的联系,为预测既有建筑混凝土经时强度奠定基础。The compressive strength of concrete in existing buildings changes with service age. In this paper,1923 groups of concrete compressive strength tested by rebound method in 33 existing civil buildings and 172 groups of concrete strength tested by core-drilling method in 25 existing civil buildings are analyzed. The service ages of the tested buildings are between 1 to 60 years in Shanghai area. Because the concrete grade of the tested buildings are different,tested concrete strength is normalized to their average strength of 28-day based on the code for design of concrete structure of China correspondingly. Hypothesis test and parameter estimation method were adopted to determine the probability distribution function of the normalized concrete strength. Meanwhile the probability density evolution distributions of the concrete strength with the same service age were calculated and compared with the normal distribution with the same mean value and standard deviation. It demonstrates that time-dependent concrete compressive strength obeys normal distribution. Therefore,probability model of random variable is adopted to express the relationships between service age and mean value or standard deviation of the normalized strength. Finally,the time-dependent concrete strength models tested by rebound method and core-drilling method in Shanghai area are established,respectively. The conversion coefficient of the concrete strength tested by these two detection methods is proposed.

关 键 词：混凝土强度 经时变化模型 回弹法 钻芯法 概率分布 

分 类 号：TU528[建筑科学—建筑技术科学]