Early Crack Detection of Reinforced Concrete Structure Using Embedded Sensors

Abstract

The damage in reinforced concrete (RC) structures can be induced either by the dynamic or static load. The inspection technologies available today have difficulty in detecting slowly progressive, locally limited damage, especially in hard-to-reach areas in the superstructure. The four-point bending test on the benchmark RC structure was used as a test of the quality and sensitivity of the embedded sensors. It allowed assessment of whether any cracking and propagation that occurs with the embedded sensors can be detected. Various methods are used for the analysis of the ultrasonic signals. By determining the feature from the ultrasonic signals, the changes in the whole structure are evaluated. The structural degradation of the RC benchmark structure was tested using various non-destructive testing methods to obtain a comprehensive decision about structural condition. It is shown that the ultrasonic sensors can detect a crack with a probability of detection of 100%, also before it is visible by the naked eye and other techniques, even if the damage is not in the direct path of the ultrasonic wave. The obtained results confirmed that early crack detection is possible using the developed methodology based on embedded and external sensors and advanced signal processing.

Detection of Multiple Cracks in Four-Point Bending Tests Using the Coda Wave Interferometry Method

“…The FOS technique was not implemented for the test at NEOSTRAIN; nonetheless, the approximate CODs of all the cracks were measured by the DIC technique, which covered the whole front surface. The DIC technique detected the COD by analysing the deformation of the surface of the beam which is caused by strain change [9]. Hence, different crack opening phases can also be determined by the stress-displacement curve Figure 13b.…”

“…The Non-Destructive Testing (NDT) technique is the highest quality assurance tool which allows the assessment of quality and condition of structure with out damaging the original structure. A wide variety of NDT methods have been developed and used for decades in the manufacturing industry and in the civil engineering domain, for example, ground penetrating radar [2][3][4], laser testing method [5,6], DIC [7][8][9] and FOS [10,11], etc. Among these methods, many of them can be used for long-term SHM.…”

Addressing the detection capability for scalable energy consumption using primary data acquisition system of embedded ultrasonic sensors in SHM

“…The sensors are intending for failures or impairment during practical field tests. Consequently, Bundesanstalt fur Materialforschung und -prüfung (BAM) and Acoustic Control Systems ® in Moscow designed a new ultrasonic transducer, which can be permanently placed inside the reinforced concrete beam (component of the civil structure) [10] [11]. The main benefit of this sensor is its durability, high sensitivity on monitored certain areas of a structure with a minimum number of transducers.…”

Concrete Preliminary Damage Inspection by Classification of Terrestrial Laser Scanner Point Clouds through Systematic Threshold Definition

“…Consequently, correct diagnosis of their health conditions is provided, and potential vulnerabilities are identified in order to prevent the risk of damage and to design adequate solutions in advance [6]. The inspection technologies available today have difficulty in detecting slowly progressive and locally limited damage, especially in hard-to-reach areas in the structure [7].…”