Compósitos acústicos verdes à base de resíduos de chapas de gesso acartonado e espuma rígida de poliuretano (PUR) reciclados

Abstract

Adding value to waste through recycling and attenuating sound through acoustic absorption support the contribution of studies to be developed in urban and environmental sustainability. He main objective of the present is to use the core elimination of recycled plasterboard and polyurethane from civil construction to develop “green” compounds with acoustic absorption performance similar to or superior to acoustic materials applied to conventional commercially available materials. Six compositions were developed with different proportions of waste united by binders through crushing, granulating, trace preparation and drying processes. Applied and descriptive research of an exploratory nature was used with quantitative data sources compared to current technical standards divided into two stages: preliminary results and definitive results. Firstly, the preliminary results of the acoustic tests validated the six new compositions for acoustic absorption at different frequencies and minimum values of compression resistance (400 N) and flexion (160 N) according to NBR 16831:2002 for plasterboard sheets differentiated for drywall. The following compositions and frequencies stood out acoustically superior in relation to the commercial lucero lining; a) composition1: 200 Hz, 250 Hz, 315 Hz, 400 Hz, 500 Hz, 630 Hz, 800 Hz, 2000 Hz and 2500 Hz); b) composition 4 (acoustic absorption properties at frequencies; 200 Hz; 250 Hz; 315 Hz; 1600 Hz; 2000 Hz; 2500 Hz). These compositions are made up of 100% urban waste united by a polyurethane foam binder, bringing lightness and porosity for use in cardboard sheet cores or in sandwich panels in walls for acoustic applicability. Subsequently, composition 1 was chosen to further the analysis due to its greater acoustic potential at different frequencies and recycling of two wastes. The tests revealed that it is minerologically composed of gypsum, quartz and calcite with acoustically efficient results in its porous morphology of 43.12% and because it includes 61.27% of open pores with low water absorption of 12.5%. The carton offers five times the mechanical strength of the core. New tests can be carried out by cartoning the green material with layers of paper, plasticization or fiberglass in different perforation techniques and formats. The mechanical resistance of the 9.5 mm thick sheets was similar to Lucero Sirius Mineral Commercial Acoustic Ceiling and the acoustic resistance was superior at frequencies of 200, 250, 315, 400, 500, 630, 800, 2000 and 2500 Hz. Lower in 1000, 1250 and 1600 Hz. Plates with a thickness of 30.0 mm are 51.04% higher in mechanical resistance. New acoustic tests can be carried out at this thickness. It was concluded that green acoustic material can replace part of the commercial material in specific applications as it is a raw material made from waste and through recycling it brings a solution to the problem of waste management, promoting the circular economy in the construction sector.