Seminar : Crack-based assessment and retrofit of concrete members

Abstract

The main indicator of damage in concrete structures are existing cracks. In this regard, modern wireless sensing networks can be used to provide continuous measurements of crack displacements, strains, corrosion indicators, temperature and other quantities. In addition, drones equipped with high-resolution cameras and coupled with artificial intelligence (AI) algorithms can provide accurate maps of the cracks and damage in the structure. However, despite the advances in modern technology, a key question remains: how to transform the monitoring data from existing cracks into useful knowledge about the safety of the structure?

To address this question, a kinematic modelling approach has been developed at the University of Liege for various concrete members and regions. This approach is based on an explicit kinematic modelling of the critical cracks (crack widths and slip), and also includes equilibrium conditions and constitutive relationships for the load-bearing mechanisms of the member. The seminar will discuss how this approach can use crack data as an input to predict the complete behaviour and residual load-bearing capacity of cracked members. Furthermore, for members with inadequate residual capacity, a retrofit solution using ultra-high performance fiber reinforced concretes (UHPFRC) will be discussed. It will be shown that the crack-based modelling approach is also well suited for evaluation of the effect of UHPFRC strengthening.

Short bio

Boyan Mihaylov is an Associate Professor in Structural Engineering and the Head of the research group in Concrete Structures at the University of Liege in Belgium since 2013. He completed his bachelor and master studies in Civil Engineering in Bulgaria in 2002, where he also worked as a structural engineer on projects in the nuclear and mining industry. In 2009 he completed his doctoral studies in Seismic Engineering at ROSE School, University of Pavia in Italy. Part of his doctoral studies and his post-doctoral research were performed at the University of Toronto in Canada in the lab of Michael Collins and Evan Bentz. Dr. Mihaylov has also been a visiting scholar at the École polytechnique fédérale de Lausanne and has taught courses at the graduate level in universities in Canada, Spain, Romania and Italy. His research interests include the development of rational kinematics-based approaches for the assessment of existing concrete structures, monitoring of existing structures by using advanced technologies, retrofit of existing structures by using ultra-high performance cementitious materials, the displacement capacity and resilience of concrete structures in seismic zones, as well as large-scale testing of structures.