Strengthening Historic Masonry Walls Using Sprayed Glass-Fibre-Reinforced Gypsum (GFRG) Against Settlement-Induced Damage

In this study, large-scale settlement tests were carried out on two test building samples consisting of masonry load-bearing walls, which are known to be sensitive to differential settlements. Test buildings were constructed in ½ scale to represent the characteristics of historical row buildings built in Istanbul in the 19th century. Test buildings consisted of two masonry walls connected to each other with reinforced concrete slabs, where additional loads were placed to explore the influence of different dead load arrangements. The walls of one of the buildings were strenghtened by spraying specially produced glass-fiber-reinforced gypsum material. The unreinforced and strengthened building models were tested under the same loads and were subjected to settlements at wall base level. The structural response of the walls (displacements and deformations) was monitored during the tests using both conventional devices (LVDTs) and optical cameras. While significant damage occurred for the unreinforced building, no damage was observed on the walls of the strengthened building. The results show that the use of glass-fiber-reinforced gypsum strengthening can provide effective protection against settlement-induced damage. It can be a good alternative strengthening material for masonry structures where the use of cement-based materials may be unsuitable.