Diagonal shear behaviour of limestone masonry walls strengthened with jute-TRM composite systems

Abstract

Ancient masonry buildings constitute a valuable historical and architectural heritage. Nevertheless, the vulnerability of masonry to structural and environmental actions necessitates the assessment of innovative solutions for strengthening and retrofitting, aimed at their conservation. The building materials industry is progressively intrigued by innovative and sustainable solutions, due to a rising environmental consciousness. Composite systems such as Textile Reinforced Mortar (TRM) incorporating natural fibers as reinforcement into an inorganic matrix, represent a possible innovative alternative to traditional composites made with industrial/synthetic fibers, to minimize the environmental impact and carbon footprint in civil engineering. Nevertheless, several unresolved matters regarding the accurate mechanical behaviour of these innovative systems remain. Multiple studies have been carried out to evaluate the bond properties between the fibers and mortar, as well as the tensile behaviour of TRMs that use natural textiles such as jute. However, there is still a lacking knowledge involving experimental tests concerning the effectiveness of TRM materials when applied to structural elements such as masonry walls. This paper provides the results of an experimental study on the diagonal compression shear capacity of limestone walls strengthened with jute TRMs, by varying the amounts of the textile reinforcement. The use of Digital Image Correlation (DIC) had permitted to deeply analyse the failure mechanisms related to each test. The outcomes revealed a good increase in terms of load carrying capacity of the walls, while the strain capacity remained very low, confirming a brittle failure mode in all cases. The results provided in this study are assumed to be strongly helpful in understanding the mechanical behaviour of such systems and calibrating future research.