The interfacial transition zone (ITZ) is the region between the aggregate and the cement paste in concrete, where the two materials come into contact and interact. It is a critical region in concrete as it represents the gradual transition in composition, microstructure, and properties from those of the aggregate to those of the cement paste. The properties of the ITZ are influenced by various factors, including the properties of the aggregate, curing conditions, and water-cement ratio. The interfacial transition zone plays a crucial role in the behavior of concrete structures due to its unique composition and properties. This study focuses on investigating the cracking mechanisms in concrete with different water-cement ratios using the acoustic emission technique and to evaluate the influence of ITZ volume fraction on cracking in concrete. Notched plain concrete beam specimens of dimensions 700 mm x 150 mm x 80 mm were cast with water-cement ratios varying between 0.3-0.5. Aggregates with a nominal maximum size of 12.5 mm have been used for this study. Experiments have been performed in a closed-loop servo-controlled Controls testing machine with a load cell of 10 kN capacity under centre point monotonic loading. The beams are tested under crack mouth opening displacement (CMOD) control at a rate of 0.5 µm/s. Acoustic emission technique was used to identify and monitor the development of cracks in the specimens, and the ITZ volume fraction was determined using the mathematical model proposed by authors. Correlations between acoustic emission parameters and ITZ volume fraction were analyzed to describe the effect of ITZ volume fraction on concrete damage. Based on the present study, it has been observed that the volume fraction of ITZ has a significant influence on concrete fracture. This study provides insights into the behavior of the interfacial transition zone and its effect on concrete damage and cracking process. Damage in concrete, due to the cracking has been studied with the help of statistical analysis of critical AE parameters such as rise time, average frequency, reverberation frequency etc. The acoustic emission parameters, including counts, absolute energy, and amplitude, were found to be positively correlated. The effect of ITZ volume fraction on the damage and fracture has been studied through b-value analysis using the generalised logistic equation. Inter-event time distribution analysis has been performed to evaluate the 1