Self-compacting microconcretes containing ornamental stone waste and expanded polystyrene residue: influence of the ratios filler/cement and lightweight /conventional aggregates

Microconcretos autoadensáveis contendo resíduo de rocha ornamental e resíduo de poliestireno expandido: influência das relações filler/cimento e agregados leves/convencionais

Abstract

Eco-efficient self-compacting micro concretes with partial replacement of Portland cement by ornamental stone waste (OSW) and replacement of conventional aggregates by expanded polystyrene waste were addressed in this study. A base mixture was obtained using a particle packing method, and replacement fractions followed a second-order composite experimental design. The mixtures’ rheological, physical, mechanical and eco-efficiency parameters were evaluated and discussed. As expected, the incorporation of residues reduced the mechanical strength, and mixtures with high incorporation of lightweight aggregates tended to segregate. However, OSW has been shown to increase workability and decrease viscosity, contributing to control segregation due to the reduced amount of water required without impairing the fluidity of the mix. At the same time, the lightweight aggregate decreased both the density of the mixtures and the viscosity. The interaction of the residue with the lightweight aggregate proved promising in obtaining more eco-efficient lightweight microconcretes.

Keywords:
lightweight concrete; self-compacting concrete; microconcrete; ornamental stone waste; expanded polystyrene waste; lightweight aggregate