Innovative systems for earthquake-resistant masonry infill walls: characterization of materials and masonry assemblages

Abstract

Masonry infill walls are the standard solution to build envelopes and partitions walls in reinforced concrete buildings in southern Europe. In Portugal, masonry infill walls appeared in the sixties, with the massive use of reinforced concrete frames for residential and commercial buildings. Since then and until our days the masonry infills walls (cavity walls) have not experienced significant changes, apart from some variations in thickness and introduction of thermal isolation between the masonry layers. The construction system remains based on cavity walls without any connection between layers and constructed with horizontal perforated bricks and poor mortars. Their vulnerability under seismic actions is recognized by the scientific community and proven whenever an earthquake occurs. Nevertheless, they continue to be used, because until now there was not much innovation in the development of attractive solutions to be implemented in new constructions, and particularly there are no clear design and detailing construction guidelines that can contribute to higher quality masonry infill walls with reduced seismic vulnerability.This paper aims to contribute for the advance on the innovation in brick masonry infills by presenting two proposals of new masonry infill walls systems to be enclosed by RC frames. An extensive experimental campaign is presented and results are discussed on mechanical properties of materials and masonry assemblages associated to the two innovative masonry infill wall systems. The data provided in this paper is important to understand further in-plane and out-of-plane experimental tests to be carried out on the masonry infill walls as well as further numerical simulations and analytical analysis of the masonry infill systems.