Tensile and shear bond tests on Flax-TRM systems

Abstract

This paper presents the preliminary results of an experimental programme investigating the bond behaviour between natural fibre Textile Reinforced Mortar (TRM) composites and masonry substrates. The TRM system used in the study consisted of one and two layers of flax textile reinforcement embedded within a lime-based mortar matrix, selected due to its compatibility with historic and traditional masonry materials. The mechanical performance of the textile–matrix composite, as well as its interaction with the masonry substrate were evaluated through a series of laboratory tests. These included direct tension tests to determine the tensile capacity and behaviour of the composite, and single-lap shear bond tests to assess the bond strength and stress transfer at the TRM–masonry interface. The results obtained from both test programmes are analysed and discussed in detail, highlighting the main parameters influencing bond performance, such as textile layers, mortar properties, and interface characteristics. Particular attention is given to the stress-transfer mechanism between fibres, mortar matrix, and the parent masonry material. Based on the experimental findings, the feasibility and effectiveness of flax-based TRM systems as a sustainable and compatible strengthening technique for masonry structures are also evaluated.