Properties of green concrete using sawdust and PET as fine aggregates

Abstract

The use of sawdust and waste polyethylene terephthalate (PET) flakes is investigated in this research as a partial replacement of fine aggregate in production of composite green concrete units. To achieve the property of sawing and nailing ability of the resulting concrete, sawdust and PET were used in different ratios to replace fine aggregates from 40% to 80% by weight. Concrete cube specimens measuring 50ϰ50ϰ50 mm, cylinder specimens with a diameter of 100mm and height of 200mm and 100ϰ100ϰ500 mm prisms were cast to test the compressive strength, splitting tensile strength and flexural strength of the concrete respectively. Density and water absorption ratio were also tested for the same specimens used for compressive strength determination and tested at the age of 28 days. The addition of sawdust and PET in the concrete reduced the compressive strength, splitting tensile strength, flexural strength and density values and increased water absorption ratio. Lightweight concrete units produced by a replacement ratio of 40% of sand with equal parts of PET and sawdust showed good mechanical properties as well as good nailing and sawing ability, which can be used as a low cost alternative to wooden and plastic elements in many structural uses.