A novel holistic approach for the seismic-energy performance assessment of masonry infill walls

Abstract

The masonry infill walls are often used in the envelopes of reinforced concrete buildings for different purposes, but a large part of them was built before the enforcement of modern seismic and/or energy codes. Due to that, the envelope of the reinforced concrete buildings is responsible for the energy consumption needed for indoor heating and cooling. At the same time, recent earthquakes proved that the infill walls located at the envelope are quite vulnerable under OOP seismic loadings resulting in extensive damage or collapse. The existing standards only provide slight provisions for designing new infill walls and do not combine their energy and seismic performance. Based on that, this research work aims to present a novel holistic performance assessment approach for masonry infill walls. This novel approach aims to classify each wall according to its seismic plus energy performance, allowing to identify which type of retrofitting is needed. A global overview of the international standards concerning the seismic design and assessment of masonry infill walls is performed. Also, the maximum and recommended U-values for external walls indicated by the national code of each European Union country are compared. After that, the new performance assessment methodology is presented and discussed. Finally, a pilot application is performed by carrying out the performance assessment of the infill walls of three buildings (with different numbers of storeys) located in different seismic-climate zones in Portugal. Several types of walls are studied according to their retrofitting type, i.e. non-retrofitted or with independent energy or seismic retrofitting or with combined seismic plus energy retrofitting. It was found that this performance assessment methodology provides important information to support future wall retrofitting. Combined seismic plus energy retrofitting is often needed in the different seismic-climate zones of the Portuguese territory.