Caracterização mecânica e física de concreto leve com pérolas de poliestireno expandido modificado com látex estireno-butadieno e estireno-butadieno carboxilado

Abstract

Mechanical and physical characterization of lightweight concrete with expanded polystyrene beads modified with styrene-butadiene and carboxylated styrene- butadiene ABSTRACT The main purpose of this study was characterize mechanical and physical properties of lightweight composites with expanded polystyrene beads (EPS), modified with styrene-butadiene (SB) and styrene-butadiene carboxylate (XSB), designated its future application in pre-cast for buildings. The production of concrete with EPS pearls aims to reduce their apparent specific mass and increase the performance of their thermal properties, while the modification with latex is intended to improve properties in the fresh state and hardened state, such as: workability, flexural strength, impermeability and the adhesion between EPS beads and the cementitious matrix. In order to reach the proposed objectives, a compatibility study was carried out between latex SB, XSB and other components of EPS concrete by means of a mini-slump rheological test. Afterwards, latex modified EPS concrete specimens were submitted to mechanical and physical characterization tests under different curing systems (wet and dry), in order to evaluate the influence of the curing type on the material performance. The results show that the lightweight concrete produced had a specific mass 34% lower than conventional concretes, average compressive strengths of 19,3 MPa and an average efficiency factor of 12.8 MPa.dm³ / kg. The modification with SB and XSB latex further the development of the characteristics of the material even in a dry curing system, promoting the maintenance of the hydration of the cementitious matrix, considerably increasing tensile strength and material impermeability. These characteristics made it possible to qualify XSB latex-modified lightweight concretes and SB for structural applications and, both in the fresh state and in the hardened state, it was found that these composites exhibited physical and mechanical performances suitable for use in precast systems.