Recycled polyamide mortars modified with non-ionic surfactant: physical and mechanical strength after durability tests

This paper presents an investigation into the incorporation of polyamide powder waste in mortars with a polymeric organic soluble non-ionic surfactant. Several samples were prepared by replacing the aggregate with amounts of 0, 25, 50, 75 and 100 % polyamide powder, to obtain lightweight materials. It was found that the presence of powder waste modifies the characteristics of fresh and hardened mortar while maintaining suitable properties such as workable life, water retention, vapour permeability and bonding in mixtures with up to 50 % of sand replaced by polyamide. The surfactant modifies the matrix microstructure and contributes to the hydration of the various cement phases. The assessed mechanical strength after performing the accelerating ageing tests remains sufficient with moderate amounts of waste, meaning that these mortars possess good overall durability. The experimental results showed that the addition of polyamide waste makes it possible to obtain lightweight materials more environmentally sustainable for use as masonry mortars.