APPLICATION OF LOW-DENSITY POLYETHYLENE WASTE AS BINDER IN SUSTAINABLE PAVING BRICKS

Abstract

Plastic waste disposal is a serious environmental issue especially in developing countries like Nigeria. Low-density polyethylene (LDPE) in solid state has been a recurring pollution problem to waterways, rivers, aquatic lives and even the soil. This paper experiments the application of LDPE waste as binding medium in sustainable paving bricks. The laboratory tests involved the use of washed and dried samples of the waste material melted into a thin paste and mixed with quarry dust, which passed through sieve 4.75 mm size at different mix ratio of 1:3, 1:4 and 1:5. The paving bricks were subjected to compressive test after 48 hrs of natural air curing and 24hrs of water absorption test. Tests results on the samples indicated that the compressive strength increased progressively from 7.93 - 11.93 N/mm² with increase in quarry dust content at specified different ratios. The water absorption test in particular indicates that the samples have low water absorption property that varies from 0.50 - 0.59% for all the mixes. For the heat resistant test, the paving bricks deform with visible cracks at 130 ºC. In addition, at 100 - 120 ºC, the bricks show no visible cracks or deformation. It is our suggestion therefore, that, replacement of cement as a binder with LDPE in the production of pavement bricks will help reduce the associated hazards on the environment in particular.