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

Author(s):  
Xing Li ◽  
Xudong Chen ◽  
Andrey P. Jivkov ◽  
Jiang Hu
Author(s):  
Xudong Chen ◽  
Dandan Shi ◽  
Jinhua Zhang ◽  
Xiyuan Cheng

As no extra vibration is needed in the casting procedure of self-compacting concrete for its excellent workability under its own dead weight, the material can be applied to construction projects where vibrations are hard to perform. To better utilize self-compacting concrete in practical engineering, it is essential to conduct an in-depth study on its fracture performance. In this study, three-point bending tests on notched self-compacting concrete beams were performed considering different loading rates and notch-to-depth ratios as variables. Acoustic emission technique and digital image correlation method were utilized to collect acoustic emission signals generated in the loading procedure and monitor crack propagation in the fracture process zone, respectively. Results show that the b-value from acoustic emission analysis can be divided into three stages and the variation range increases as the notch-to-depth ratio increases. Based on clustering analysis, three cluster groups can be obtained, and it is found that the ratio of the first cluster group decreases while that of the third cluster group increases when notch-to-depth ratio increases. With the aid of digital image correlation technique, effective crack length and horizontal crack opening displacement can be recorded and it is observed that crack tip opening displacement decreases as the notch-to-depth ratio increases.


2019 ◽  
Vol 18 (5-6) ◽  
pp. 1686-1697 ◽  
Author(s):  
Wen-zheng Zhao ◽  
Wei Zhou

Understanding the damage and failure of carbon/glass epoxy hybrid woven composites under tensile loading based on acoustic emission signals is a challenging task in their practical uses. In this study, an approach based on fuzzy c-means algorithm is proposed to process the acoustic emission signals from tensile loading of composites monitored by combining acoustic emission technology and digital image correlation method. The results show that the acoustic emission signals from tensile loading can be divided into three clusters. The three clusters correspond to three kinds of damage modes including matrix cracking, fiber/matrix debonding, delamination, and fiber breakage. By comparing the acoustic characteristics of these classes, a correlation procedure between the clusters and the damage mechanisms observed is proposed. Meanwhile, it can be found that debonding and fiber break signals for glass fiber correspond to a lower frequency range than that for carbon fiber. Moreover, the method combining acoustic emission and digital image correlation can effectively monitor the damage process of the specimen both on the inside and outside, which can provide a reference for the health monitoring of composite structure.


Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5622 ◽  
Author(s):  
Fengqiao Zhang ◽  
Gabriela I. Zarate Garnica ◽  
Yuguang Yang ◽  
Eva Lantsoght ◽  
Henk Sliedrecht

In the Netherlands, many prestressed concrete bridge girders are found to have insufficient shear–tension capacity. We tested four girders taken from a demolished bridge and instrumented these with traditional displacement sensors and acoustic emission (AE) sensors, and used cameras for digital image correlation (DIC). The results show that AE can detect cracking before the traditional displacement sensors, and DIC can identify the cracks with detailed crack kinematics. Both AE and DIC methods provide additional information for the structural analysis, as compared to the conventional measurements: more accurate cracking load, the contribution of aggregate interlock, and the angle of the compression field. These results suggest that both AE and DIC are suitable options that warrant further research on their use in lab tests and field testing of prestressed bridges.


Sign in / Sign up

Export Citation Format

Share Document