Seismic retrofitting of hollow brick partitions using low-cost self-expanding foam

The study was aimed at assessing the effectiveness of a rapid and low-cost solution for seismic retrofitting of hollow brick partitions, in the context of both existing and new buildings. The retrofitting solution, consisting in a detailing variant, was implemented by providing lateral and superior thin slots between partition panels and surroundings, injected by self-expanding polyurethane foam. Shake table tests were carried out according to the international shake table protocol AC156. Both dynamic identification and seismic performance tests were carried out up to peak table accelerations representative of high seismic hazard conditions. Dynamic properties, hysteretic behavior, and capacity measures were associated with physical damage conditions and conventional damage states. A safety assessment was carried out by comparing experimental capacities and code demand measures, considering low to high seismicity sites (in Italy) and both importance class II and IV buildings. The retrofitted partition response and performance was compared to the one associated with non-retrofitted conditions, and it was confirmed that the developed retrofitting solution potentially reduces the seismic vulnerability of hollow brick partition panels. A simplified initial cost and seismic loss/repair analysis referred to a realistic building/apartment scenario finally proved the potential effectiveness of the retrofitting intervention.