Synergistic effects of asphalt emulsion and fiber reinforcement on fracture properties and energy absorption of self-compacting concrete

The stability and durability of concrete structures are determined by various factors, including fracture properties. In this study, self-compacting concrete (SCC) was prepared by incorporating asphalt emulsion (AE) and fiber to improve its fracture properties and energy absorption capacity. Basalt fiber (BF) and polypropylene fiber (PPF) were used at 0.2% volume fraction, and the content of AE was 10%. Fracture parameters, including fracture energy, ductility index, and fracture toughness were evaluated by analyzing the load-crack mouth opening displacement (P-CMOD) curves obtained through a three-point bending test. In addition, quasi-static compression and gas permeability tests were conducted to evaluate the compressive energy absorption and durability, respectively. Results show that fracture energy, ductility index and fracture toughness were significantly improved after adding AE and fiber, and the specimens with PPF generally exhibited higher fracture parameters. Although the compressive strength was slightly decreased, the compressive toughness ratio was greatly improved. The stress–strain curves of specimens with AE and fiber show an obvious plastic behavior and exhibited a more gentle descending section, indicating a ductile failure mode. Moreover, gas permeability was reduced due to the filling effect of asphalt and the bridging action of fiber. Overall, incorporating AE and fiber into SCC could improve the matrix structure by creating a network with excellent toughening and bridging effects. This, in turn, optimizes crack resistance, energy absorption capacity, and durability of SCC. © 2023 Elsevier Ltd