Initial cracking strength and initial fracture toughness from three-point bending and wedge splitting concrete specimens

摘要

In this study, a concept of initial cracking strength of concrete was elaborated. A fracture model and associated methods for determining independent initial cracking strength and initial fracture toughness by the three-point bending (3-p-b) and wedge splitting (WS) concrete specimens are presented. The initial cracking strength and initial fracture toughness can be simultaneously determined using a curve fitting method from the proposed fracture model. All of the initial fracture curves were obtained by the determined concrete materials. The initial loads of the 3-p-b and WS specimens were predicted on the basis of the curves with ±15% ranges. Furthermore, the initial cracking strength and the initial fracture toughness of concretes were directly determined by analytical functions. The determined values within ±15% ranges cover most of the initial loads of the 3-p-b and WS specimens.