基于涡流热成像的锈蚀钢筋混凝土表面温度变化试验研究

Experimental research on surface temperature changes of corrosive reinforced concrete based on eddy current thermal imaging

电涡流红外热成像检测技术是一种新兴的无损检测技术,其利用混凝土内部钢筋锈蚀程度不一样导致钢筋的发热效率不一样,使传导至混凝土表面的温度变化速率不一样的原理来判定混凝土内部钢筋锈蚀程度。通过试验研究了锈蚀钢筋混凝土在不同锈蚀时间、钢筋直径、混凝土强度及保护层厚度等影响因素下的表面温度变化规律。结果表明,不同钢筋直径,不同保护层厚度,不同混凝土强度的钢筋混凝土试件的表面温度增长速率都随锈蚀时间的增加而增大,即钢筋混凝土表面温度增长速率与钢筋锈蚀时间正相关;锈蚀时间越长、钢筋直径越大,混凝土表面温度增长速率越快,相反,混凝土强度越低、保护层越小,混凝土表面温度增长越快,即锈蚀时间和钢筋直径与混凝土表面温度增长速率成正比,混凝土强度和保护层厚度与混凝土表面温度增长成反比。

Eddy current infrared thermal imaging detection technology is a new non-destructive testing technology.It uses the principle that different corrosion degree of steel bars in concrete leads to different heating efficiency and different temperature change rate in concrete surface to determine the corrosion degree of steel bars in concrete.The surface temperature variation of corroded reinforced concrete under different corrosion time,diameter of steel bar,strength of concrete and thickness of protective layer was studied by experiments.The results show that the surface temperature growth rate of reinforced concrete specimens with different diameter of steel bars,different thickness of protective layer and different strength of concrete increases with the increase of corrosion time,that is,the surface temperature growth rate of reinforced concrete is positively correlated with the corrosion time of reinforcement.The longer the corrosion time and the bigger the diameter of steel bar,the faster the growth rate of concrete surface temperature,on the contrary,the lower the strength of concrete and the smaller the protective layer,the faster the surface temperature of concrete increases.That is to say,the corrosion time and the diameter of reinforcing bar are directly proportional to the growth rate of concrete surface temperature,and the strength of concrete and the thickness of protective layer are inversely proportional to the growth rate of concrete surface temperature.