Experimentation on lime mortars reinforced with jute fibres: Mixture workability and mechanical strengths

Given the high number of masonry buildings on the Italian territory, which was scenario of numerous devastating earthquakes, it is clear the importance of restoration programs. Thanks to a renewed technique sensitivity towards sustainable interventions, it is evident that the recovery techniques to protect the historical heritage should be carried out with innovative green compound materials, such as mortars reinforced with natural fibres. In the current paper laboratory tests on lime mortars strengthened with raw jute fibres have been performed. Workability of the fibre-reinforced mixture has been assessed through shaking table tests and the mechanical resistances of standard specimens has been evaluated by bending and compression tests. Given the hygroscopic nature of jute, it has been identified the optimal water/lime ratio and the maximum water percentage absorbed by jute fibres. From analysis results it has been evaluated how the spreading of the mixture, which is indicative of the mortar consistency, changes with the water/lime ratio. From bending tests, it has been noticed an effective behaviour of fibres, which provide a cracks seam effect able to make more ductile the behaviour of investigated fibre-reinforced lime mortars. Finally, the results of compression tests have shown that the examined fibre-reinforced mortars can be effectively used as building products according to the actual Italian technical code NTC 2018.