Bond of Flax Textile-Reinforced Mortars to Masonry

Abstract

This paper investigates the structural performance of Flax Textile-Reinforced Mortars (FTRM) systems bonded to a masonry substrate. Single-lap shear bond tests were carried out to assess the influence of bond length, the number of TRM layers and bonded width on the behaviour of two flax textiles of different architecture embedded in lime-‍based mortar. Conventional and non-contact measuring methods (Digital Image Correlation - DIC) were employed to gain additional insights into the development of stress transfer mechanisms and load-slip behaviour at the global and local scale. It was found that textile architecture significantly affects overall bond performance, with a smaller diameter and twisted yarns arranged in a denser mesh utilising the fibre strength to a higher degree. The effective bond length for the tested single-layer systems is between 150 and 210 mm, and failure is dominated by fibre rupture. A high variation in stress distribution was seen in multi-layer specimens with a wider bonded width, and this can lead to premature delamination. Finally, recommendations for testing in line with the existing RILEM experimental methodology are given to account for the high variability and unique failure modes observed in natural fibre TRM. This work aims to provide design guidelines for sustainable and effective structural strengthening solutions, which are particularly suitable for less developed countries.