Re-Characterization of Strength Properties of Asphalt Concrete Mixtures Using Non Bituminous Modifier – Candle Wax

Abstract

Improving the performance of asphalt concrete mixtures synonymous with flexible pavement has been a major concern in highway engineering. However, design of flexible pavement begins with proper material characterization to ensure that designs are appropriate. It is also pertinent to say that sometimes if not most times the properties of the individual materials that make up the pavement structure falls short of desired expectations. This has led to exploring techniques that will help improve the properties of the pavement structure. The present research therefore focused on re-characterizing the strength properties and in particular stability and density of asphalt concrete mixtures that simulate flexible pavements by the inclusion of candle wax as a modifying agent. The research was carried out for three categories of traffic – light, medium and heavy respectively and modifications were made by adding 5-25% of the candle wax at optimum content. The results obtained revealed the following; percent increase in stability - 36% for light traffic, 44.4% for medium traffic and 17.3% for heavy traffic at a threshold candle wax content of 15%. Similarly, results for density increase were – 14.6% for light traffic, 15.5% for medium traffic and 15.7% for heavy traffic at a threshold candle wax content of 15%.