A novel approach to estimate the evolution of fracture energy and tensile softening curve of concrete from very early age

Concrete fracture properties and their evolution over time are critical inputs for numerous engineering aspects. Despite substantial efforts invested, there exists a crucial need to establish a comprehensive model for reliable estimation of such evolution. In this paper, combining reliable experimental data and in-depth analysis, a novel approach for proper estimation of the evolution of fracture energy and tensile softening curve of concrete from early age is proposed. Fundamentally, the approach relies on three key criteria related to (i) tensile strength, (ii) tensile strength-fracture energy correlation and especially, (iii) centroid coordinates of the area under the stress-crack opening curve. The capability and reliability of the proposed approach are clearly demonstrated through a detailed assessment of these criteria and examples of practical applications.