Physical Properties of Composites Manufactured with Two Wastes from Food-Processing Industry

The sheer amount of waste being produced nowadays by the food processing industry makes it imperative to identify alternative procedures to recycle them. This paper describes an innovative use of protein waste with consumed plastic bottles within composite materials for building applications. The aim of this study was to investigate this two wastes association on the lightening of the composites. The effect of the protein waste introduction on the physical properties of the concrete manufactured with PET aggregates in the hardened state is studied: total and surface porosity, mechanical strengths, dynamic elasticity modulus and thermal conductivity. The optimal formulation of the basic composite, with PET aggregates, is: S/C = 2.8, W/C = 0.45 and a volume percentage of PET aggregates equal to 35%. The hemoglobin powder was introduced after water in the optimal PET composite. Various H/C mass ratios were used: 0.5, 1 and 2%. The influence of the mixing time after hemoglobin addition was also studied. Relative changes in composites properties due to protein introduction are experimentally investigated. For example a decrease in mechanical strengths and in thermal conductivity was observed. The results obtained allowed the elaborated composites to be functionally classified. So they show that the simultaneous valorization of two kinds of waste of the food process industry may be technically feasible and very interesting for the environment.