Comparative aspects regarding a novel lightweight concrete of structural grade containing brick aggregate as coarse particles and expanded polystyrene beads

Abstract

Recycled brick aggregate (RBA) and expanded polystyrene (EPS) are both considered lightweight aggregate. These aggregates are considered eco-friendly because they assure preservation of the non-renewable natural resources and environment protection. Recycled brick aggregate (RBA) may came from building demolition, ceramic industry waste, building construction waste. Expanded polystyrene may be as recycled waste and as beads available in the building materials market. Expanded polystyrene is a widespread material in many engineering branches because it has some distinguished properties like very-low density, high-impact absorption capacity, low-thermal coefficient, insignificant water absorption capacity, etc.For concrete, both the recycled bricks and polystyrene beads may be embedded into concrete as lightweight aggregate, replacing entirely or partially the natural aggregate. For structural applications, lightweight concrete with natural coarse aggregate (NCA) which contains polystyrene beads in diverse percentages of natural aggregate replacement, has some limitations regarding obtaining a structural grade strength for a density lower than 1700 kg/m3. Obtaining such concrete having a compressive strength 20 to 30 MPa and a density lower than 1700 kg/m3 is a difficult target.The study develops lightweight concrete of structural grade embedding both recycled brick aggregate and polystyrene beads as coarse aggregate and investigates their influence on density and compressive strength considering the expanded polystyrene beads in diverse percentages of brick aggregate replacement. For comparative aspects regarding the properties, within the experimental investigation, a polystyrene aggregate concrete (PAC) containing normal weight aggregate and EPS beads in the same percentages of aggregate replacement it was developed based on the same mix parameters.For the each replacement percentage of natural aggregate by EPS beads, it has been found that when recycled brick particles replace the NCA, the resulted concrete is lighter with 200 kg/m3 and has a strength very close to concrete made entirely with natural aggregate.