In-depth analysis of notched 3-p-b concrete fracture

Comprehensive fracture tests of notched three-point-bending (3-p-b) concrete specimens have recently been reported by Çağlar and Şener (2016), which covers specimen size W from 40 to 500 mm, notch/W ratio = 0, 0.02 to 0.3. The authors discussed size effect models from Bazant (1991 and 2013), Carpinteri (1995), Karihaloo (1999 and 2003) and Hu and Duan (2003 and 2006), and made a specific comparison between Bazant and Hu and Duan models. This study presents in-depth systematic analyses of the results from Çağlar and Şener (2016) under different sample grouping conditions. We would like to show that reliable tensile strength and fracture toughness can be obtained conveniently from notched 3-p-b results, although they have not been determined in the publication by Çağlar and Şener (2016). This is significant as neither direct tensile tests nor fracture toughness tests can be easily performed for concrete. Size effect models compared in the publication by Çağlar and Şener (2016) are also discussed for a better understanding of concrete fracture.