Influence of Wood and Plastic Waste as Aggregates in Gypsum Plasters

Abstract

Large amounts of waste are generated each day in the world, being a major concern for the EU28, who establish waste management as a priority line of work within the Horizon 2020. Construction sector is one of the largest residues generators. In that sense, architects and civil engineers should give an answer to solve that environmental problem. One of the options is to reuse waste for the generation of new materials and products for construction. In this research, wood waste (sawdust) from demolition works and polycarbonate waste have been used as aggregates to generate new gypsum plasters. Different percentages of additions (5, 10, 20 and 40%) for each type of waste have been conducted to develop the gypsum composites. Physical (density and thermal conductivity) and mechanical (flexural and compressive strength) properties of the new plasters have been measured using the procedure regulated by standards, comparing them with the reference material values (commercial gypsum without aggregates). The results of the tests show that lighter composites have been obtained when the percentage of waste increased for both type of aggregate. This lightening is higher in composites with wood waste than in those with plastic at the same percentage of addition. Furthermore, an improvement in the thermal conductivity of the plasters have been achieved. On the other hand, a decrease on the mechanical properties of the composites, with higher percentages of additions, have been obtained. For all the cases, the minimum strength value required by standards have been achieved. As a conclusion, lighter gypsum composites with enhanced thermal properties have been obtained, achieving in all the cases an acceptable flexural and compressive strength.