基于磁感应的混凝土构件中钢筋有效直径检测方法研究

Research on detection method of rebar effective diameter in RC structure based on magnetic induction

钢筋混凝土结构被广泛应用于承重受力设施中,但当锈蚀等因素造成混凝土内部钢筋有效直径减小时,其力学性能将会受到严重影响。针对目前无法准确确定混凝土构件内部钢筋有效直径的问题,提出了一种基于磁感应原理的钢筋有效直径检测方法。利用混凝土构件内部钢筋直径减小处的磁通密度值突变确定直径减小区间,并将该区间的数据点进行最小二乘拟合得到磁通密度函数,定义该函数积分为直径判据值并用于钢筋有效直径判断。而后通过建立仿真模型得到不同直径对应的判据值并拟合为直径判据曲线,最后通过试验验证了该直径判据曲线能够有效地对混凝土构件内部钢筋直径进行判断。

Reinforced concrete(RC)structures are widely used in load-bearing facilities,but when the effective diameter of rebars in RC structures is reduced due to corrosion or other factors,the mechanical properties of RC structures will be seriously affected.Aiming at the problem that the effective diameter of rebars in RC structures can not be determined at present,it proposes a method to detect the effective diameter of rebars based on the magnetic induction.According to the magnetic flux density will change at the point of smaller diameter,the diameter reduction interval can be determined.Moreover,perform the least square fitting of the data points in this interval to obtain the magnetic flux density function.And the function will be used to define the diameter criterion value and judge the rebar effective diameter.Then,by establishing a simulation model,the criterion values corresponding to different diameters are obtained to fit the diameter criterion curve.Finally,the experiment verified that the diameter criterion curve can effectively judge the diameter of the rebar in RC structures.