Impact response of self-compacting concrete incorporating asphalt emulsion and fiber

Due to its excellent workability, self-compacting concrete (SCC) has been increasingly utilized in various concrete structures, including transportation infrastructures like highways, tunnels, slab tracks of high-speed rail, and bridges. However, the frequent and occasional impact loads significantly threaten the serviceability of concrete structures. This work evaluates the dynamic mechanical performance of SCC prepared with asphalt emulsion (AE), polypropylene fiber (PPF), and basalt fiber (BF) using the split Hopkinson pressure bar (SHPB) test. To further understand the combined impacts of AE and fiber on SCC, damping capacity was also experimentally evaluated. Results demonstrate that the dynamic increase factor (DIF) rises with the decimal logarithm of strain rate, demonstrating an excellent strain rate effect, and SCC with AE and fiber achieved a 20 – 60 % increase in DIF. The impact toughness index was greatly enhanced, with an enhancement of 10.8 % achieved by adding AE alone. When AE was combined with PPF and BF, the improvements were 10.2 % and 11.6 %, respectively, representing a significant increase in the impact resistance. Specimens containing AE and fibers also demonstrated an enhanced damping ratio and loss factor; AE alone increased the damping ratio by about 21 %, while the incorporation of AE together with PPF, BF, and the hybrid fiber enhanced the damping ratio by 8 %, 13 %, and 16 %, respectively; the loss factor increase within the range of 8 – 21 %, indicating an excellent improvement in energy absorption and vibration reduction performance of SCC. Besides, the SCC matrix was refined by the synergistic network structure created by AE, fibers, and cement hydrates, providing excellent bridging and toughening effects; consequently, the overall impact resistance, damping capacity, and vibration reduction performance of SCC were successfully optimized.