Fatigue durability test of mortars incorporating polyurethane foam wastes

The fatigue behavior of lightweight polyurethane foam waste cement mortars was analyzed, in which the sand is replaced by polyurethane waste in volumetric proportions of 50%, 60% and 75%. For this purpose, having calculated the static modulus of elasticity of the mortars, successive loading and unloading cycles under compression are performed. These tests confirm the fatigue capacity and structural properties of the mortars, aspects that are indicative of their long-term durability and suitability for use in masonry works. Two test phases were performed with increasing and variable loads of 20% and 90% of the breaking strain, reaching 300,000 cycles in the first phase and 525,000 in the second one. Both phases showed that the cement mortars with substitutions of up to 60% of sand by polyurethane foam waste were capable of withstanding loading and unloading cycles similar to the conditions of typical masonry mortars in construction works. The results underlined the long-term durability of these lightweight recycled materials. Their good fatigue behavior could be corroborated through the images taken by computerized axial tomography. No significant fractures were observed when comparing the sections before and after the loading cycles, which indicates that no structural collapse took place. (C) 2018 Elsevier Ltd. All rights reserved.