Influência de aditivo incorporador de ar em argamassas mistas com agregado reciclado de PET

Abstract

The present work aims to evaluate the influence of air incorporating additive (EIA) on the behavior of mixed mortars with recycled PET aggregate. Based on the studies of Duó (2017), three distinct mixture of mortars with partial replacement were selected: recycled PET aggregate, this substitution occurred percentages 0% (reference), 5% and 15%. The additive was introduced into the mixtures in proportions of 0% (reference), 0.05%, 0.10% and 0.15%, relative to the cement mass. For this paper, the characterization of mortars was performed based on fresh rheological properties (consistency index, incorporated air content and water retention), physical properties (mass density), durability (capillarity water absorption and pipe water absorption) and mechanical properties (tensile stress, compressive stress and potential tensile bond strength). The control of properties in the hardened state was obtained at the age of twenty-eight days. The effect of EIA was positive, with regard to the physical and rheological properties of mortars, as its use resulted in an increase in the incorporated air content and consequently a reduction in the mass density of the mixtures in both fresh and hardened characteristics cause the reduction of mechanical properties. The results of tensile adhesion testing showed little variability between the analyzed features, however all samples obtained mean strength within the regulatory standards. The durability, the water absorption was reduced to traces without the addition of PET in contrast to the increase of the application of the additive, however, the additive introduction occurs in percentages of 0.05% for mixtures with 5% substitution PET and 0.10% and 0.15% for mixtures with 15% substitution. Therefore, the application of EIA in mortars is feasible as long as it occurs in the appropriate percentages for the satisfactory performance of its functions, and the additive must be compatible with the other components of the mixture.