中文摘要：

为了研究硝酸腐蚀条件下T型混凝土梁抗弯性能的变化规律,采用p H值为4.5的硝酸溶液对4根相同的T型混凝土梁分别浸泡20,40,60,80 d,然后对标准试验梁和腐蚀试验梁进行受弯试验。研究在不同硝酸腐蚀时间下的试验现象、开裂荷载和极限荷载、抗弯刚度和钢筋应变。结果表明：经过不同时间硝酸溶液腐蚀后的T型混凝土梁的受弯破坏仍为适筋梁弯曲破坏;随着硝酸腐蚀时间的增长,T型混凝土梁的开裂荷载减小,极限荷载明显下降,但达到一定程度后不再出现大变化;在弹性阶段,跨中位移增长缓慢且曲线大致呈线性关系,在屈服阶段,腐蚀时间越长,试验梁的位移突变的荷载越小,试验梁破坏时的最大挠度越大,即抗弯刚度越小。采用最小二乘法拟合出硝酸腐蚀下T型混凝土梁承载力衰减模型,其衰减函数大致符合指数函数的变化规律。

英文摘要：

To study the variation of flexural performance of T-shaped concrete beams under nitrate solution,4 beams soaked in nitrate solution which p H is 4. 5 for 20,40,60,80 d,and flexural contrast tests were carried out for the standard test beam and the corroded. The experimental phenomena,cracking load,ultimate load,bending stiffness,and reinforcement strain were researched under different nitrate corrosion time. The result showed that T-shaped concrete beams remained bending damage of under-reinforced beam; the longer soaked in nitrate solution was time,the lower cracking load and an obvious decrease in ultimate load,but reaching a certain level there were no big change in them. The increase in midspan displacement was slow with curves being roughly linear relationships in elastic stage; the longer time soaked in nitrate solution was,the smaller the load making test beam displacement mutation and the bending stiffness in yield phase would occured. The decay model for the bearing capacity of the corroded T-shaped concrete beams was fit by using the least square method,its attenuation function was basically in accordance with the changing rule of the exponential function.