Experimental study on acoustic emission characteristic of fatigue crack growth of self-compacting concrete

Abstract

Summary In order to study the fatigue crack growth (FCG) of self‐compacting concrete, in this paper, the 100 mm × 100 mm × 400 mm specimens with a 30‐mm initial notch were used for three‐point bending test under three different stress levels (0.75, 0.8, and 0.85) and three different loading frequencies (0.5, 1, and 2 Hz), and the acoustic emission (AE) technique was used for monitoring the FCG. According to the results, the changes of the crack mouth opening displacement, the stiffness, and the effective crack length all present three obvious stages with the increase of fatigue cycles. According to Paris law, under the same stress level, the increase of loading frequency results in the increase of fatigue life and the decrease of FCG rate, but the curves of da/dN are approximately parallel under different loading frequencies. Furthermore, the research results of characteristic parameters of AE show that cumulative hits, counts and energy show three stages, which are similar to the change of stiffness, and there is a failure point in the curves of cumulative counts and cumulative energy. The cumulative laws of hits and counts can be used to well describe the FCG, and the b value can be used to analyze the three stages of fatigue fracture. Therefore, the AE technology can be used to monitor the FCG in concrete engineering.

Investigation of tensile fracture of rubberized self‐compacting concrete by acoustic emission and digital image correlation

“…Rubberized concrete produced by the self‐compacting technique was expected to inherit the benefits of SCC, such as high mechanical strength and low porosity, and the benefits of rubber addition, such as higher toughness. This expectation for a rubberized self‐compacting concrete (RSCC) was explored in a number of studies 11–22 . The majority of these used conventional experimental techniques, that is, standard stress and strain measurements, for determining the mechanical properties of RSCC 11–16 .…”

Smart monitoring of strengthened beams made of ultrahigh performance concrete using integrated and nonintegrated acoustic emission approach

“…There are several applications of AE in concrete structures such as damage identification, damage monitoring, damage classification, etc 16 . Some of the recent studies such as damage detection of concrete beams by integrating AE and Weibull damage function, 17 AE characterization of fatigue crack growth, 18 determination of yielding point, 19 damage characterization of crumb rubber concrete, 20 analysis of the bond behavior of corroded reinforcement, 21 and fracture monitoring in carbon nanotube‐crumb rubber mortar highlight successful implementation of AE testing for failure characterization in concrete structures. Application of machine learning‐based algorithms 22,23 such as support vector machine and Gaussian mixture modeling are also studied by various researchers to identify local fracture mechanism, crack classification, and damage identification in reinforced concrete structures.…”

Crack identification method for concrete structures considering angle of view using RGB-D camera-based sensor fusion

“…[5][6][7] Furthermore, an acoustic emission technology has been employed for measuring elastic waves in solids generated due to cracks formed inside concrete. 8,9 Ahn et al 10 summarized the principles and applications of other nondestructive techniques. The contact-type sensor is useful for crack evaluation; however, it is inefficient for monitoring cracks in full-scale civil engineering structures because the available sensing areas are limited to the proximity of the sensors.…”