Investigation of the design and performance of a fluid mastic asphalt mixture

Gussasphalt (GA) mixture, commonly used in bridge deck pavement for its superior fatigue resistance, crack resistance and waterproofing, suffers from limited rutting resistance. To leverage and preserve the advantages of GA while improving the anti-rutting performance of the mixture, this study proposed the theory and design method of the Fluid Mastic Asphalt (FMA) mixture. The influence of mix proportions and preparation process on the anti-rutting performance of FMA was studied. The test results verified the feasibility of the design method. The results showed that the fluid mastic can fill the void of the skeleton structure and form a novel skeleton-ultra-dense structure. This significantly enhances the anti-rutting performance of FMA, with rutting dynamic stability exceeding 3000 cycles/mm. At the same time, the fatigue resistance and crack resistance of FMA are significantly better than those of GA, stone-mastic asphalt (SMA) and asphalt concrete (AC) mixtures. It is recommended to eliminate fine aggregates below 4.75 mm to improve the rutting resistance. The vibration moulding process can compact the skeleton further, improving the anti-rutting performance. To ensure the mastic's fluidity meets the moulding requirements, its rotational viscosity should be below 0.5 Pa·s. FMA exhibits outstanding pavement performance, thus significantly enhancing the durability of pavement structures.