Incorporation of high contents of textile, acrylic and glass waste fibres in cement-based mortars. Influence on mortars’ fresh, mechanical and deformability behaviour

Abstract Cracking is an anomaly that affects the durability of renders. It is well known that fibres improve the deformability of the mortars and promote the distribution of the stresses within their matrix, consequently reducing the susceptibility of mortars to cracking. The combination of the improvement of durability with the addition of waste fibres is a doubly sustainable solution, as not only the durability of the renders and of the walls they aim to protect is enhanced but also the landfill of waste fibres is reduced. In this research, textile, acrylic and glass fibres wastes recovered from textile and polymers industry are recycled and their influence when incorporated in mortars is analysed. These1.5 and 3.0 cm long fibres were added with to cement-based mortars at a volumetric ratio of 1:4 (binder: aggregates) and about 5% of the total mortar volume. The influence of the fibres’ addition was analysed based on the fresh properties and deformability and mechanical behaviour. Specific tests that are not usually analysed in the literature concerning the effect of fibres, as adherence strength and impact resistance tests, were performed and the results presented on this research. Improvements on deformability when the fibres were added were noticed, contributing to the reduction of mortars’ cracking susceptibility and extend renders’ durability and their ability to protect the walls. The impact resistance of the reinforced mortars was shown to increase, while slight reductions of other mechanical characteristics were in general not significant in the medium-long term. Within the fibres analysed, the textile ones presented the best behaviour when applied in cement-mortars.