The application of a reinforced plaster mortar for seismic strengthening of masonry structures

The effects of plaster mortar on the behaviour of 1/3 scaled, one storey, one bay masonry-infilled steel frames under horizontal in-plane static loading are experimentally investigated in this paper. Two types of steel frames are considered: one with high flexural rigidity of the beams and columns and another with low flexural rigidity of the beams and columns. Each frame was tested with three masonry variants: (i) bare masonry infill, (ii) masonry infill with pre-mixed plaster on both sides and (iii) masonry infill with pre-mixed plaster on both sides and reinforced with a polyvinyl chloride (PVC) net. All of the frames were loaded successively by a horizontal force in the beam direction until structural collapse. Afterward, the experimental results were compared to those from the presented numeric model for the nonlinear static analysis of planar structures made of concrete, steel and masonry. The model was upgraded by including the effect of plaster on the overall stiffness and strength of the masonry and verified using the experimental tests. This experimental investigation shows that plaster significantly contributes to the strength and load-bearing capacity of masonry and therefore to the strength and load-bearing capacity of masonry-infilled frames.