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The main objectives of this study are to conduct principle analysis of mix design and evaluate the performance of the Buton rock asphalt (BRA) modified Superpave mixture through wheel tracking test, freeze–thaw indirect tensile strength ratio test, bending beam test, dynamic modulus test, and flow number (FN) test. The results prove that the voids in mineral aggregate (VMA) and the initial asphalt content calculated using the new equations proposed by this study based on theoretical analysis are more accurate than those of the traditional Superpave’s empirical equations. The high temperature performance and the moisture damage resistance of the Superpave mixture modified with BRA were improved, but the low temperature performance was slightly declined comparing with the control mixture. The values of E∗/sinφ from dynamic modulus test of the BRA modified Superpave mixture were larger than those of the control mixture at various test temperatures and loading frequencies. In conclusion, the Superpave mixture modified by BRA has excellent high temperature performance.

Bayer red mud (RM) was produced from aluminum ore according to Bayer process. In order to study the feasibility of stabilized Bayer RM for use in road construction, strength properties of RM stabilized by lime-fly ash using orthogonal experimental method were evaluated. In test design, the normalized orthogonal table of L9 (34) was adopted. The influence of ratio of lime-ash, the dosage of lime and fly ash, and the type of Bayer RM (Two kinds of Bayer RM from different producers) on the unconfined compressive strengths (UCS) of 7-day and 28-day curing age were studied. The experimental results showed that these factors significantly influenced the UCS. The principal factors influencing 7-day UCS was ratio of lime-ash, followed by chemical compositions of Bayer RM and the dosage of lime and fly ash in last. The principal influencing factor of 28-day UCS was chemical compositions of RM, followed by ratio of lime-ash and the dosage of lime and fly ash in last. Then the optimum proportion for the UCS was determined through the orthogonal analysis. The X-ray fluorescence (XRF) showed that chemical compositions and contents of two types of RM were significantly different in iron, silicon and calcium. The microscopic analysis of the raw material and stabilized material employed X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS) showed that C3A(Ca3Al2O6), C2S, and calcium carbonate increased under the optimal conditions of lime-fly ash stabilization, and hydrated silica aluminate and CSH were gradually generated. The stabilization mechanism of Bayer RM by lime-fly ash is related to hydration like aluminate cement. There is no essential difference in reaction mechanism for two kinds of Bayer RM and the difference in the strength properties is essentially originates from the active material content.