Tensile performance of lime-based natural-fibre composites as strengthening systems for masonry
Past earthquakes have highlighted the vulnerability of unreinforced masonry structures, especially in developing countries where non-engineered, masonry buildings make up the majority of the existing building stock. The use of natural fibres, which are readily available and abundant in these countries, has recently emerged as a cost-effective and sustainable strengthening solution. Although the performance of short dispersed natural fibres in inorganic binders has been examined in the literature, the behaviour of natural textile-reinforced mortars (NTRM) as externally bonded strengthening systems is still unknown.
This paper presents some preliminary results of a larger experimental programme on the mechanical performance of natural fibre grids embedded in lime-based mortars. Bare flax and jute yarns and textiles were tested in direct tension to characterise their mechanical properties. NTRM specimens reinforced with the same textiles were also tested to examine their tensile behaviour and assess the contribution of the fibres and mortar to their overall performance. Digital image correlation was used to obtain full-field displacement measurements on the NTRM composites to assist with the development of constitutive models.
The effect of different textile architectures and fibre type is discussed in detail and the potential use of NTRM to strengthen deficient masonry structures is assessed and commented upon.