Assessment of the Physical Properties of Bricks Made from Sand, Moorum and Quarry Dust with Molten Plastic as a Binding Agent

Plastics are multipurpose manmade materials used for various purposes. They are widely used because of their light weight, cost and ease of manufacturing. Despite their wide use, plastics are not biodegradable and cannot easily decompose when they are disposed as a waste. An alternative is to recycle these materials instead of disposing them to the environment. In this research work, we tried to assess the use of different fractions of molten plastic water bottles as a binding agent in the production of bricks. The materials used with the molten plastics were sand, moorum and quarry dust. The physical properties of the bricks were tested according to the ASTM specifications. The test results showed maximum compressive strengths with plastic fractions of 35% in all the three materials. The strengths increased up to 35% and showed reduction thereafter. At 35% plastic fraction, bricks from quarry dust exhibited the highest strength of 7.7 MPa while moorum bricks showed 7.15MPa. Brick weights decreased with increasing molten plastic fraction; the highest ranged from 2.85 – 3.0 kg while the minimum ranged from 2.1 – 2.5 kg. Moorum bricks had the least weight and quarry dust bricks had the highest. All of the bricks exhibited water absorption of less than 5.5% at 35% plastic fraction. Moorum had the highest absorption while sand bricks had the least water absorption. Qualitatively, the bricks from all the three materials fulfilled the ASTM specifications. Two tests that were not conducted in this research work and need more testing are the heat tolerance level of the bricks and the amount of volatile gases liberated to the atmosphere during the melting process of the shredded plastics.