A novel low-cost hybrid retrofitting scheme utilizing PP bands and coconut fibre-reinforced mortar for unreinforced brick masonry

Unreinforced brick masonry (URM) is the most commonly constructed type of building worldwide. However, because of their extremely poor seismic performance, they are not considered the most feasible solution for seismically active regions. The current study proposed a low-cost hybrid retrofitting scheme utilizing Polypropylene (PP) bands obtained from recycled plastic bottles and coconut fibre-reinforced mortar (CFRM) to enhance the seismic capacity of URM buildings. The reduced-scale URM model was initially tested without retrofitting under frequency-based seismic excitations with the PGA ranging from 0.40 g to 0.62 g. Afterward, the model was retrofitted with PP band mesh and CFRM and subjected to the same seismic excitation, and the corresponding acceleration and displacement responses were recorded. It was observed that utilizing CFRM with PP band mesh significantly enhances the seismic performance, with a reduction of up to 33% and 40% in the acceleration and displacement response, respectively. Moreover, the retrofitting cost was only 15.23% in comparison to the cost of a new model. The low cost and high seismic efficiency of the proposed hybrid retrofitting scheme for URM buildings make it more robust for active seismic regions.