Lamellae of waste beverage packaging (Tetra Pak) and gamma radiation as tools for improvement of concrete

Abstract

One of the most important problem when adding recycle or waste materials to cement concrete is the poor adhesion between these materials and the cement matrix. For this reason, in this work, the effects of lamellae from beverage packaging (waste Tetra Pak), as well as of gamma rays on the mechanical properties of cement concrete were evaluated. The concrete specimens were produced with cement, water, gravel and sand; this last was partial substituted by lamellae of waste Tetra Pak (up to 30 wt. %) with sizes ranging 1.5 mm and 3.0 mm. Then, the concrete was irradiated with gamma rays at doses of 200 kGy and 300 kGy. The results show improvements up to 39 % and 30 % for compressive strength and the elasticity modulus, respectively, for concrete produced with 10 % of waste lamellae and irradiated at 300 kGy, respect to the values obtained for control concrete (without lamellae and non-irradiated). Such improvements are produced by both gamma rays and the lamella concentrations. Mechanical features were related with the lamellae before and after irradiation, based on the morphological and thermal changes (analyzed by SEM and TGA-DSC analyses, respectively), as well as with the chemical stability of their components (polyethylene and cellulose), analyzed by FT-IR spectroscopy.

Keywords

• Lamellae
• Waste
• Packaging tetra Pak
• Concrete
• Gamma radiation
• Mechanical properties