民国钢筋混凝土历史建筑的锈胀开裂寿命预测方法

Life prediction method for corrosion-induced crack of historical reinforced concrete buildings built in the Republic of China

为准确评估使用方形钢筋的民国钢筋混凝土历史建筑的耐久性,对其锈胀开裂寿命的预测方法进行研究.首先,对9个民国钢筋混凝土历史建筑的混凝土构件进行现场检测分析,获得混凝土的抗压强度、混凝土保护层厚度、混凝土的碳化深度等数据,并据此对原有的碳化系数计算公式进行修正.然后,对民国方形钢筋进行电化学加速锈蚀试验,测量其临界锈蚀深度.结果表明:计算民国时期钢筋混凝土的碳化系数时,需引入修正系数1.16;针对圆形钢筋的临界锈蚀深度计算方法不适用于方形钢筋.民国钢筋混凝土历史建筑的锈胀开裂寿命基本为55~80 a.

To accurately evaluate the durability of historical reinforced concrete(RC)buildings using square steel rebars in the Republic of China,the life prediction method for corrosion-induced crack was studied.First,the components of nine historical RC buildings in the Republic of China were tested and analyzed.The concrete compressive strength,the concrete cover thickness of square steel rebars and the carbonation depth of concrete were obtained,and the existed calculation formula of the carbonization coefficient were modified according to these data.Then,the accelerated electrochemical corrosion experiments were carried out for the real square steel rebars in the Republic of China,and the critical corrosion depth of rebars were measured.The results show that the modified coefficient of 1.16 should be used during the calculation of the carbonization coefficient of the RC structures in the Republic of China.The calculation method for the critical corrosion depth of circular steel bars is not suitable for square steel bars.The corrosion-induced cracking life of the historical RC buildings in the Republic of China era is 55 to 80 a.