Effect of Natural Bitumen on the Performance of Hot Asphalt Mixture‏

Abstract

Globally, for more than a century, large quantities of asphalt binder have been consumed in the production of asphalt mixtures. There are two types of natural asphalt (NA) deposits in the Heet region: rock asphalt and sulphur spring asphalt. NA from sulphur springs was used in this study to assess NA performance and determine the suitability of using NA in local asphalt mixtures. The NA was treated by heating it to 163 °C for several hours. NA was subjected to laboratory testing after industrial treatments, and it was found that the physical properties of NA can conform to Iraqi specifications by heating it for 20 hours. The results showed that treated NA is better suited to hot climates because it is less temperature sensitive than traditional petroleum asphalt. NA was discovered to be highly effective in improving mechanical properties. In addition, the NA mixture had the highest indirect tensile strength values and a tensile strength ratio of 81.2%, which was 0.37% higher than the TSR of the conventional mix. NA will play an important role in the production of flexible pavements and provide a significant economic benefit without compromising the overall performance of the mixture because it is less expensive than conventional asphalt and is available in large quantities in Iraq.