A Comparative Analysis of the Magnetization Methods Used in the Magnetic Nondestructive Testing of Reinforced Concrete Structures

Abstract

This work presents how significantly the proper selection of the magnetization method can improve almost all parameters of the magnetic method and affect the effectiveness of the evaluation of reinforced concrete (RC) structures. Three magnetization methods are considered in this paper: opposite pole magnetization (typical solution), same pole magnetization, and (as a reference point) no magnetization. The experiments are carried out in a three-dimensional (XYZ) space. Measurements along each of the axes are discussed in a separate section. The results show that the appropriate selection of the magnetization method can affect noise reduction, signal strength, and the separation of measurements carried out on different samples. This paper also discusses the situations when the magnetization may change the shape, cause deformations of waveforms, affect the area testing, and be used to significantly increase the efficiency of simultaneous evaluation of three basic parameters of RC structure. Experiments and simulations have proven that properly applied magnetization may strongly affect the evaluation’s effectiveness, making the magnetic method one of the most promising techniques in testing RC constructions.

Multisensory Spatial Analysis and NDT Active Magnetic Method for Quick Area Testing of Reinforced Concrete Structures

“…Passive methods are more economical and straightforward. Methods of this kind can be used to evaluate RC structures but are less effective than active ones [16]. One of the methods of this kind is the Magnetic Memory Method (MMM).…”

“…The magnetic method has a sufficiently large range and resolution, and its simplicity makes the construction of an area transducer straightforward and cheap. However, depending on the sensors used, the magnetic transducer for area testing can possess different properties [13][14][15][16]. Due to the rapid development of sensors, the method seems to have excellent development potential [50][51][52][53].…”

“…Unfortunately, even NDT methods in the vast majority can only be used for spot testing. A very small number of techniques can be used for quick testing of large areas in their entirety [13][14][15][16]. The need to develop area testing methods results from the specificity of reinforced concrete structures.…”

“…These methods are usually also cheaper and faster than other techniques. Many different parameters of RC structures can be tested, including pressure exerted on formwork by concrete [3], porosity of the concrete [4][5][6], durability of the concrete [7], strength of the concrete [8], microcracking (caused by overloading, deficient design, and fatigue) [9,10], defects (such as voids, honeycombs and tendon ducts) [11,12], carbonation level of the concrete [13], concrete cover thickness [14][15][16], diameter of the reinforced bar (rebar) [14][15][16], alloy of the rebar [14][15][16], etc. This work focuses on the evaluation of reinforcement parameters using NDT.…”

“…This work focuses on the evaluation of reinforcement parameters using NDT. This problem was discussed many times, e.g., in [13][14][15][16][17][18][19][20][21]. Therefore, a detailed description is skipped in this work.…”