Fracture behavior of flax fibers reinforced earth concrete

•Effect of the percentage and length of flax fibers on the fracture behavior of earth concrete.•Monitoring of damage evolution and discrimination of different damage mechanisms with the acoustic emission technique.•Monitoring of the fracture process with the digital image correlation technique.•Importance of adding fibers to increase earth concrete ductility.•Correlation between the fracture energy and the acoustic emission energy. The mechanical behavior of earth concrete for sustainable construction has been studied in this paper. The effect of flax fibers on the fracture behavior has been monitored using digital image correlation (DIC) and acoustic emission (AE) techniques to better understand the fracture process and damage mechanism. Three-point bending tests have been conducted on prismatic specimens with different percentages (0%, 0.3% and 0.6%) and lengths (12 mm, 24 mm, 50 mm) of flax fibers. The AE activity and fracture energy increased with the percentage and length of fibers. Moreover, the AE signal parameters varied with the loading rate and different damage mechanisms have been distinguished. Crack opening resistance also increased due to the bridging effect of fibers along developed cracks. Those results show the benefits of adding flax fibers to enhance the ductility of earth concrete.