The acoustic emission technique is used in this study to understand the fracture behavior of concrete beams reinforced with high-strength steel rebars under three-point bending configuration. Standard notched beams of two reinforcement ratios of high-strength steel rebars are tested monotonically with the crack mouth opening displacement (CMOD) control mode. The reinforcement ratios are chosen in order to understand the failure mode and AE activity in both an under-reinforced and an over-reinforced concrete specimen. The acoustic emission technique was used to determine crack movement and source classification. The AE parameters such as AE events, hits, counts, rise time, absolute energy, and amplitude are analyzed to study the evolution of damage and the location of cracks. To comprehend the various kinds of fracture response, the classification between the nature of the crack source was demonstrated at various salient points in the Load versus CMOD plot. The mode I (flexure) and mode II (shear) fracture responses have been observed in both specimens. It has been also found that AE activity decreases in an over-reinforced concrete specimen, indicating a lesser number of micro-cracks being formed.