Abstract
The quantificational exploration of the propagation law of fracture process zone (FPZ) is of great importance to the research on concrete fracture. This paper performed fracture experiments on pre-cracked concrete beams under various loading rates. Digital image correlation (DIC) method was applied to obtain the whole field displacement of concrete in the fracture test. The crack opening displacement (COD) and the evolution of FPZ were determined based on the whole field displacement. The results show that the length of FPZ first increases and then decreases with the development of the effective crack length and the maximum length of FPZ is about 60 mm. It can be found that the length of FPZ corresponding to the peak load decreases with the increase of loading rates. Based on the fictitious crack model, a bilinear softening model was established. According to the proposed model, the mechanical behavior and the propagation law of FPZ were analyzed. The bilinear softening model can reflect the microcrack development and the aggregate interlocking in the FPZ.
Highlights
Most concrete structures in service are subjected to static loads as well as are frequently disturbed by dynamic loads such as earthquakes, shocks and explosions
Rosa et al (2012) conducted three-point bending tests on pre-cracked concrete beams under five loading rates ranging from 1.74 × 10–5 to 17.4 mm/s and found that both the peak load and the fracture energy of concrete increase with the increasing of loading rates
It was found that the peak load of concrete specimen increases with the increasing of loading rates and the increase amplitude is influenced by the initial crack-depth ratios
Summary
Most concrete structures in service are subjected to static loads as well as are frequently disturbed by dynamic loads such as earthquakes, shocks and explosions. Bazant and Gettu (1992) studied the variation of concrete fracture mechanical parameters under different loading rates with size effect model and their results indicated that the fracture toughness, FPZ length and the critical crack opening
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Concrete Structures and Materials
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
