Enhancement of road pavement material using conventional and nano-crude oil fly ash

This paper presents the use of crude oil ash in asphalt flexible pavement and concrete rigid pavement. Conventional micro-size fly ash produced from burning crude oil in Jizan electrical power plant in Saudi Arabia was used in this study. The size of conventional crude oil ash waste reduced from micro-scale to nano-scale using ball-milling techniques. The first series of testing investigate the development of flexible pavement using asphalt bituminous AC60/70 incorporated conventional and nano-crude oil fly ash waste. The percentage of conventional and nano-ash used in asphalt mixes was varied from 0 to 15% of asphalt binder. The use of nano-fly ash increases the rutting factor by 0%, 33%, 61% and 38% at 0%, 5%, 10% and 15% nano-fly ash content, respectively. The nano-fly ash improves the rutting factors and bearing load capacity of flexible pavement mixes more than the control mix and mixes containing conventional micro-fly ash. The second series of testing investigates the use of nano-fly ash in rigid pavement asphalt concrete. Conventional and nano-fly ash replaced cement content in concrete material at 0%, 5%, 10%, and 15%. Concrete material incorporated nano-fly ash shows higher compressive strength and lower absorption compared to concrete control sample and concrete containing conventional micro-fly ash. The strength of concrete incorporated nano-fly ash increases by 14.8%, while absorption of concrete improves by 20.1% at 10% nano-fly ash content. The optimum nano-fly ash content was 10% to achieve the highest performance of both pavement materials. The use of nano-crude oil fly ash improves the performance of both pavement materials and helps in reducing the cost of repair in road and highway construction. Moreover, the use of nano-fly ash in paving materials can help in the recycling of this toxic waste to produce sustainable and environmentally friendly road construction materials.