Investigation of the effects of polyurea application on shear behavior in masonry wall elements

Abstract

In masonry structures that have collapsed or suffered severe damage under the impact of an earthquake, it has been observed that the necessary survival spaces, known as 'life triangles,' generally do not form adequately. To contribute to improving this issue, experimental studies were conducted to determine the effects of applying polyurea material-characterized by high ductility-on wall surfaces, with a focus on both its impact on mechanical performance and fracture behavior. In this study, four different brick types were used: burnt clay brick, vertically perforated brick, pumice brick, and mud brick. These bricks were bonded using a 10 mm thick joint mortar with a volumetric ratio of lime, cement, and sand of 1:2:4. Each brick type was tested in four different combinations: uncoated, plastered without polyurea-coated, unplastered-polyurea coated, and plastered- polyurea coated. The coatings were applied with a thickness of approximately 1 mm for polyurea and 20 mm for plaster. A total of 44 specimens were subjected to three-point shear tests. The mechanical behavior of the specimens under shear force was examined, and the obtained data were analyzed. The results showed that the shear strength of polyurea-coated specimens increased by up to five times, with the highest performance improvement observed in burnt clay brick walls. Additionally, the fracture toughness of plastered-polyurea coated samples can increased by up to nine times. Despite fractures occurring in the polyurea-coated specimens, it was observed that the wall elements maintained their structural integrity as a whole.