Effect of specimen size and type on real-mode-I fracture toughness of hooked-end steel fiber-reinforced concrete
##plugins.themes.bootstrap3.article.sidebar##
##plugins.themes.bootstrap3.article.main##
https://orcid.org/0009-0008-6605-6994
Ahmed A. Elakhras
Materials Engineering Department, Zagazig University, Zagazig, Egypt
https://orcid.org/0000-0002-3821-1327
Hossam El-Din M. Sallam
Materials Engineering Department, Zagazig University, Zagazig, Egypt
https://orcid.org/0000-0001-9217-9957
Ashraf H. Elsafoury
Building and Construction Department, Zagazig Higher Technology Institute, Zagazig. Egypt
Abstract
This paper studied the effects of specimen size and type on the real-mode-I fracture toughness (KIC )of steel fiber-reinforced concrete (SFRC) specimens. Mode I KIC tests were performed using semicircular bend (SCB) and center-cracked circular disk (CCCD) specimens with different sizes and crack-to-depth ratios, (a/R). SCB Specimens were tested under three-point bending, and CCCD specimens were tested under indirect tension test conditions to achieve pure Mode I crack growth. Moreover, KIC was analyzed as a function of specimen type (SCB and CCCD), specimen size (R values of 50, 75, 100, and 125 mm), and a/R ratios of 0.2, 0.3, 0.4, and 0.5. The results clearly show that the KIC of SFRC exhibits a distinct size effect: it increases with specimen radius up to a critical range of 75-100 mm, after which it levels off. The a/R ratio is an important parameter affecting the toughness; higher values of a/R result in increased KIC values, with increases of 12.9% for CCCD specimens and 22.7% for SCB specimens when a/R is raised from 0.2 to 0.5 at R=75 mm. In addition, the failure mode shifts from ductile fiber pull-out at shallow a/R to brittle fiber rupture at highera/R. The results also emphasize the importance of using geometry-adjusted models, such as Bazant's size effect law (SEL), especially when dealing with SFRC, since fiber distribution and crack-bridging efficiency depend on both size and geometry.
##plugins.themes.bootstrap3.article.details##
How to Cite
This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright
Authors are allowed to retain both the copyright and the publishing rights of their articles without restrictions.
Open Access Statement
Fracture and Structural Integrity (F&SI) is an open-access journal which means that all content is freely available without charge to the user or his/her institution. Users are allowed to read, download, copy, distribute, print, search, or link to the full texts of the articles in this journal without asking prior permission from the publisher or the author. This is in accordance with the DOAI definition of open access.
F&SI operates under the Creative Commons Licence Attribution 4.0 International (CC-BY 4.0). This allows to copy and redistribute the material in any medium or format, to remix, transform and build upon the material for any purpose, even commercially, but giving appropriate credit, providing a link to the license, and indicating if changes were made.