Several experimental studies have been done long time ago to calculate the fracture energy of concrete [2, 6]. Most of these studies neglected the loss of energy due to the frictional process in the mechanism of experimental set up. All these studies have used the indirect tensile testing method, as a suitable approach for determining the fracture energy of concrete of mature age [3, 7]. However all these experimental studies have not investigated the crack or the localization process of young age concrete yet.
So, a view to evaluate the fracture energy of concrete and to study the fracture and localization process, it is described herein this study an experimental investigation. Fracture energy for the early ages of concrete is estimated experimentally considering the weather of Kingdome of Saudi Arabia. Several experiment specimens of different ages, sizes, lengths and end head specimens are prepared and assessed. The specimens in early age are tested out to calculate the fracture energy of concrete using a direct tension test, taking into consideration the loss of energy due to the frictional process in the mechanism of experimental set up. Also the crack localization is considered during the experiment, as dealing with the localized fracture. In this experiment work, the measurements reach to the post peak softening branch of concrete using the direct tension.
Moreover, the fracture process of early age concrete is identified through an analytical study, using the Modified Lattice Model suggested earlier by the author [1, 19]. In the analytical study plastic modeling was done based on the Modified Lattice Model approach. A softening function to describe the fracture process of early age concrete which is proposed is used [11]. It is shown that the softening rule can be applied to simulate the fracture process of early age concrete using the Modified lattice Model. The results show that there is a fairly good agreement between the experimental data and the numerical results using the Modified Lattice Model. However, the change of different concrete ages results is quite the agreement with the numerical results but only using one case of gage length.