&lt;strong&gt;Full-scale testing of a masonry building monitored with smart brick sensors&lt;/strong&gt;

Antonella D'Alessandro,Andrea Meoni,Nicola Cavalagli,Massimiliano Gioffrè,Filippo Ubertini,Enrique García-Macías

doi:10.3390/ecsa-5-05764

Abstract

The seismic monitoring of masonry structures is especially challenging due to their brittle resistance behavior. A tailored sensing system could, in principle, help to detect and locate cracks and anticipate the risks of local and global collapses, allowing prompt interventions and ensuring users’ safety. Unfortunately, off-the-shelf sensors do not meet the criteria that are needed for this purpose, due to their durability issues, costs and extensive maintenance requirements. As a possible solution for earthquake-induced damage detection and localization in masonry structures, the authors have recently introduced the novel sensing technology of “smart bricks”, that are clay bricks with self-sensing capabilities, whose electromechanical properties have been already characterized in previous work. The bricks are fabricated by doping traditional clay with conductive stainless steel microfibers, enhancing the electrical sensitivity of the material to strain. If placed at key locations within the structure, this technology permits to detect and locate permanent changes in deformation under dead loading conditions, associated to a change in structural conditions following an earthquake. In this way, a quick post-earthquake assessment of the monitored structure can be achieved, at lower costs and with lower maintenance requirements in comparison to traditional sensors. In this paper, the authors further investigate the electro-mechanical behavior of smart bricks, with a specific attention to the fabrication of the electrodes, and exemplify their application for damage detection and localization in a full-scale shaking table test on a masonry building specimen. Experimental results show that smart bricks’ outputs can effectively allow the detection of local permanent changes in deformation following a progressive damage, as also confirmed by a 3D finite element simulation carried out for validation purposes. Related video presentation available here.

Highlights

The majority of historical buildings worldwide are made of stone or brick masonry and their cultural value makes their maintenance and preservation of pivotal importance for the community
The authors further investigate the electro-mechanical behavior of smart bricks with respect to previous work, with a specific attention to the fabrication of the electrodes, and exemplify their application for damage detection and localization in a full-scale shaking table test on a masonry building specimen
Three different types of tests were carried out to compare the electrical behavior of the smart bricks with different types of electrodes and to investigate their sensing capabilities: electrical tests for investigating conductivity properties, electromechanical tests for the analysis of strain sensitivity and a full-scale test on a masonry small building to demonstrate the potential of the technology for in situ monitoring purposes

Summary

Introduction

The majority of historical buildings worldwide are made of stone or brick masonry and their cultural value makes their maintenance and preservation of pivotal importance for the community. Proceedings 2018, 2, x; doi: FOR PEER REVIEW www.mdpi.com/journal/proceedings. Proceedings 2018, 2, x FOR PEER REVIEW. Structural Health Monitoring (SHM) can be useful to recognize such occurrence and increase occupants’ safety [3]. To this purposes, several researchers are working at developing low-invasive and effective techniques for evaluating mechanical properties, as well as dynamic signatures, of masonry structures [4]. The authors further investigate the electro-mechanical behavior of smart bricks with respect to previous work, with a specific attention to the fabrication of the electrodes, and exemplify their application for damage detection and localization in a full-scale shaking table test on a masonry building specimen. Experimental results show that smart bricks’ outputs can effectively allow the detection of local permanent changes in deformation following a progressive damage, as confirmed by a 3D finite element simulation carried out for validation purposes

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Results

Conclusion