Mechanical behaviour of masonry panels strengthened by flax TRM systems

Among the existing techniques to retrofit and reinforce masonry elements, the use of Textile Reinforced Mortar (TRM) composite systems represents these days an efficient and compatible solution. Aiming to improve the sustainability of these composite systems, the efficiency of plant fibres as reinforcement fabric of TRMs is analysed in the present study. Specifically, relying on previous works concerning the mechanical characterisation of the system on a local scale, it proposes an experimental analysis on a greater scale of investigation. Clay bricks masonry panels (1 x 1 x 0,12 m3) strengthened by a Flax-TRM system (hydraulic lime-based matrix) were subjected to diagonal compression tests. Two strengthening configurations characterized by one and two layers of flax fabric were tested. The reinforcement was applied all over the surface of both the panel sides. The response of the externally strengthened walls is examined and compared herein with that of unstrengthened walls. The results show that the reinforcing system strongly influences the performance of the walls by conferring them a post-peak behaviour totally absent in the brittle response typical of unstrengthened walls. In terms of peak load, an increase of the 118% and 136% is observed respectively in panels externally strengthened with one and two layers of textile, with respect to the unstrengthened walls. The experimental study confirms a considerable potential in the use of plants fibres as reinforcement of TRM composite systems for the strengthening of masonry elements and paves the way for further investigation aimed to improve their mechanical behaviour.