The researcher’s attention is being drawn to the examination and analysis of fracture parameters. Every concrete structure experiences crack formation, initiation, and propagation; studying fracture mechanics is crucial for particular structures like dams and power projects in order to gage the crack’s severity. A common ingredient in environmentally friendly, sustainable concrete is supplementary cementitious material (SCM). In current work, fracture characteristics of concrete were examined using ground granulated blast furnace slag (GGBS) as SCM. With a water-to-cement (w/c) ratio of 0.42, the GGBS was used at 10, 20, 30, and 40%. Size effect method was used to conduct three-point bend test. A 50 kN universal testing equipment with a 0.003 mm/min crack mouth opening displacement (CMOD) was employed. The test was conducted in compliance with RILEM’s criteria. According to the findings, using GGBS has resulted in a modest 4.08% improvement in fracture energy and a considerable 35.64% improvement in fracture toughness. However, there was an improvement of 18.69, 17.34, and 24.74% in compressive, tensile, flexural strength, respectively.