Monitoring of Epoxy-Grouted Bonding Strength Development between an Anchored Steel Bar and Concrete, Using PZT-Enabled Active Sensing.

Jian Jiang,Chuang Hei,Qian Feng,Jinwei Jiang

doi:10.3390/s19092096

Jian Jiang, Chuang Hei + Show 2 more

Open Access

https://doi.org/10.3390/s19092096

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Abstract

Anchored steel bars have been widely used in retrofitting of existing concrete structures. The bonding strength between the anchored steel bar and the concrete is critical to the integrity of the strengthened concrete structure. This paper presents a method to monitor epoxy-grouted bonding strength development by using a piezoceramic-enabled active sensing technique. One concrete beam with an anchored steel bar was involved in the monitoring test, and two concrete beams with six anchored steel bars were used in the pull-out test. To enable the active sensing, a Lead Zirconate Titanate (PZT) patch was bonded to the surface of the exposed end, and piezoceramic smart aggregates were embedded in each concrete specimen. During the monitoring experiment, signals from PZT sensors and smart aggregates were acquired at intervals of 0, 20, 40, 60, 80, and 100 min. In addition, a pull-out test was performed on each of the remaining six anchored steel bars in the two concrete beams, while the signal was recorded in the test. Furthermore, a wavelet packet analysis was applied to analyze the received signal energies to investigate the bonding strength development between the concrete and the anchored steel bar during the epoxy solidification process. The test results demonstrate the effectiveness of the proposed method in monitoring the bonding strength development between the anchored steel bar and the concrete, using the PZT-enabled active sensing.

Highlights

The retrofit, reinforcement, and strengthening of existing structures have been widely practiced and researched [1,2], and various guidelines and standards have been developed [3,4,5,6]
To verify the proposed methods, experiments were carried out on specimens monitor strength development an anchored steel bar and concrete concreteepoxy-grouted in real time
Tobonding verify the proposed methods,between experiments were carried out onthe specimens with anchored steel bars

Summary

Introduction

The retrofit, reinforcement, and strengthening of existing structures have been widely practiced and researched [1,2], and various guidelines and standards have been developed [3,4,5,6]. Anchored steel bar technology has been widely used in retrofits and new construction since the 1970s [7]. The technology, as a post-installed connection method, plants a steel bar into a concrete base with structural adhesives [8]. Anchored steel bars in concrete are required when an additional structural member is to be linked to the existing concrete structure [9]. Integrated with the original structural members, the anchored steel bars make the entire structural system more reliable, increasing the bearing capacity of the structure [10]. Due to its wide application, the anchored steel bar technology has received much attention in the literature. In the 1990s, Cook [11] and Cook et al [12,13] carried out a series of experimental

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Conclusion