The use of shredded polystyrene waste in concrete

Abstract

The focal point of this study was the production of lightweight aggregate concrete using expanded polystyrene as a filler material. The expanded polystyrene used was recovered from waste disposal plants, which material would otherwise be disposed of into landfills. The expanded polystyrene was then shredded in order to be used to produce the lightweight aggregate concrete. The experimentation that was carried out was divided into three phases, Phase A, B and C, each having different goals. The first phase served as a foundation to the subsequent two phases. In this phase, a shredder was developed in order to achieve the small expanded polystyrene particles which were used in all the mixes in the study. The mixes in Phase A were very important to find adequate mix designs to be used in Phases B and C. Phase B was characterized by the production of lightweight concrete using cement as a binder, and only shredded waste expanded polystyrene as a filler material. On the other hand, phase C was then characterized by the production of lightweight concrete using cement as a binder and sand and shredded waste expanded polystyrene as filler materials. The aim of this study was to find adequate mix designs for the production of super lightweight aggregate concrete yielding a density lower than 1000 kg/m3 and for the production of lightweight aggregate concrete yielding a density ranging between 1000 and 1500 kg/m3 , and in turn assess the compressive strength achieved by the concrete produced. This was done in view that this concrete could be used in the production of lightweight non load-bearing concrete blocks to be used in local construction. Lightweight concrete blocks decrease construction loads, dead loads on supporting members, decrease construction time, and also improve on the thermal and acoustic insulation achieved by normal aggregate concrete.