Augusthus Nelson, L ORCID: https://orcid.org/0000-0003-3092-7635, Lees, J and Weekes, L
ORCID: https://orcid.org/0000-0002-3711-8198
2022,
'Size effects in unreinforced and lightly reinforced concrete beams failing in flexure'
, Engineering Fracture Mechanics, 259
, p. 107987.
|
PDF
- Accepted Version
Available under License Creative Commons Attribution Non-commercial No Derivatives 4.0. Download (20MB) | Preview |
|
|
PDF (Appendix A)
- Supplemental Material
Available under License Creative Commons Attribution Non-commercial No Derivatives 4.0. Download (127kB) | Preview |
|
|
PDF (Appendix B)
- Supplemental Material
Available under License Creative Commons Attribution Non-commercial No Derivatives 4.0. Download (120kB) | Preview |
Abstract
Fracture-based models commonly use a characteristic length as the basis for determining size effects in concrete beams. The characteristic length is related to the concrete fracture process zone and defined in terms of the concrete fracture properties. Semi-empirical constants are then developed to accommodate any unidentified (geometric or crack bridging) parameters. However, a reliance on semi-empirical factors can limit the applicability to different systems, concretes and reinforcing materials. The aim of the current work is to formulate an analytical size effect model based solely on fundamental material and geometric properties. The particular focus is unreinforced and lightly reinforced concrete beams that fail in flexure due to unstable crack propagation. The proposed ’generalised’ characteristic length approach is based on the mode-I fracture behaviour of concrete and includes crack bridging forces due to the presence of longitudinal reinforcement. The theoretical expressions suggest that the geometric shape of a beam, the fracture properties of the concrete and the crack bridging forces (where present) significantly influence the characteristic length. Experimental investigations on geometrically similar unreinforced and lightly reinforced concrete beams in 2-D are undertaken as a means for initial validation. The validation is then extended to a wider dataset of existing experimental results in the literature. The generalised characteristic length approach is able to capture both the influence of the concrete strength and the size effect mitigation due to the inclusion of longitudinal reinforcement. This confirms that the generalised approach holds promise and could be expanded to other quasi-brittle materials and non-conventional reinforcing materials.
Item Type: | Article |
---|---|
Schools: | Schools > School of Computing, Science and Engineering > Salford Innovation Research Centre |
Journal or Publication Title: | Engineering Fracture Mechanics |
Publisher: | Elsevier |
ISSN: | 0013-7944 |
Related URLs: | |
Funders: | Overseas Research Studentship, Cambridge Commonwealth Trust |
Depositing User: | L Augusthus Nelson |
Date Deposited: | 02 Sep 2021 07:13 |
Last Modified: | 23 Sep 2022 02:30 |
URI: | https://usir.salford.ac.uk/id/eprint/61716 |
Actions (login required)
![]() |
Edit record (repository staff only) |