Reuse of drill cuttings in hot mix asphalt mixture: A study on the environmental and structure performance

Abstract

The pollution caused by oil and gas drilling waste is among the major problems affecting the oil industry. In this study, drill cuttings are used as an additive in the asphalt mixture for constructing road pavements. The materials used for manufacturing asphalt samples were neat bitumen with penetration grade 60/70 (PG 64-16), granite aggregates, and drill cuttings in both unwashed and washed states. After determining the optimum bitumen percentage based on Marshall Design, five mixes were considered for combining aggregates, bitumen, and drill cuttings. Marshall Stability, resilient modulus (Mr), indirect tensile strength (ITS), and dynamic creep tests were carried out on all asphalt mixture samples. The test results were applied to evaluate the efficiency and moisture damage susceptibility of drill-cuttings-modified asphalt mixture. The results indicated that the addition of washed drill cuttings in the asphalt mixture increases Marshall Stability, as well as decreasing Flow and thus Marshall Quotient (MQ). Also, the asphalt mixture containing washed drill cuttings has a higher resilient modulus and indirect tensile strength than the control and unwashed mixtures. Also, these results indicated a reduction in the thickness of the asphalt layer (increasing in the layer life with the same thickness) and moisture damage. According to the results of the one-way ANOVA analysis, using unwashed drill cuttings in the asphalt mixture has a reverse effect on the above parameters and the outcome. Besides, the dynamic creep results showed that unwashed and control mixtures have the same resistance against the permanent deformation while using washed drill cutting increased the rutting resistance of asphalt mixture. Therefore, it is recommended using washed drill cuttings in the asphalt mixture to make a suitable pavement. The results suggest that the feasibility of the application of washed drill cuttings in road construction not only could enhance the physical and mechanical properties of asphalt mixture but could also relieve the environmental concerns regarding landfilling of such waste.