DefinePK

Abstract

The continuous increase in road traffic couple with an insufficient degree of maintenance due to shortage of funds has caused an accelerated and continuous deterioration of the road network in Nigeria. To alleviate this process, several types of measures are reported to be effective, for instance, securing funds for maintenance, improved roadway design, use of better quality of materials and the use of more effective construction methods. Improving the quality of materials used in road construction had been shown to improve road service performance in the wake of the increase usage. Practical experiences over the last four decades have shown that the modification of the bituminous binder with polymer additives offers several benefits in asphalt concrete and has been tested in a number of countries around the World. The use of polythene materials for pure water sachet in the country has received a great boost due to its abundant supply and high resistance to insects, fungi, animals, as well as molds, mildew, rot and many chemicals. However the disposal of the waste polythene materials in large quantities has been a problem all over the country. This study was therefore designed to investigate the effect of polythene as contained in pure water sachet in the asphalt concrete properties. Polythene was added in grinded state as binder modifier. It was introduced to the mixture by melting it in the bitumen used in preparing the asphalt concrete mix. Marshall Mix design method was used, first to determine the optimum bitumen binder content and then further to test the modified mixture properties. In total, 17 samples were prepared (10 samples were used to determine the binder content and the remaining samples were used to investigate the effect of modifying the asphalt mixtures). The optimum asphalt content was 7.0%. Six proportions of polyethylene by weight of the optimum binder content were selected to be tested (2.5, 5.0, 7.5, 10, 12.5 and 15%). The properties tested include bulk density, stability and flow of the concrete mix. The obtained optimum proportion of the modifier is 12.5% by the weight of the optimum bitumen content. It is found to increase the stability, reduce the density and slightly reduce the flow of asphalt concrete specimen. Findings from this study suggest that polythene modifier offers better engineering properties and its usage as bitumen modifier could serve as a means of managing the waste menace.