Structural Behavior of Masonry Beams with Alternative Shear Reinforcement
Publication: Journal of Structural Engineering
Volume 147, Issue 3
Abstract
Shear reinforcement, or stirrups, for reinforced masonry beams made of concrete blocks are placed inside the cells of the units. Since it is a requirement by masonry standards for shear stirrups to hook around the longitudinal reinforcement, the placement of conventional steel rebar as shear reinforcement in 200 mm (8 in.) or narrower masonry beams becomes challenging. Even the smallest size steel rebar available in Canada [10M or 11.3 mm (0.44 in.) actual diameter rebar], a standard hook detail is difficult for a mason to accommodate within field construction conditions. Hence, the current study investigated two different alternative shear stirrup configurations, namely, the use of 8-mm () diameter smooth steel bars and the use of commercially available repurposed bed joint wire reinforcement. The current study showed that the masonry beams with the alternative stirrup details exhibited similar ductility as the masonry beam built with conventional steel rebar. The beam containing the bed joint wire as shear stirrups enhanced the capacity of the beam slightly more than the beams with conventional rebar and with the 8 mm () smooth bar. Most importantly, the use of bed joint wire as shear reinforcement reduced crack width in a similar manner as the conventional rebar. In addition, the study found that the Canadian and American standards overestimated the shear strength of narrow masonry beams. The present study also found that the directionally based strength reduction factor (Chi factor, ) recommended in the Canadian design standard is overly conservative.
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Data Availability Statement
All data, models, and code generated or used during the study appear in the published article.
Acknowledgments
The current work was completed with the financial assistance from the Mitacs, Canada Masonry Design Centre (CMDC), and Canadian Concrete Masonry Producers Association (CCMPA). The authors sincerely thank Con-Tact Masonry Ltd. located in Oldcastle, Ontario for their support and help. Special thanks many graduate students and Matthew St. Louis for their help in the lab work.
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© 2021 American Society of Civil Engineers.
History
Received: Oct 21, 2019
Accepted: Oct 9, 2020
Published online: Jan 4, 2021
Published in print: Mar 1, 2021
Discussion open until: Jun 4, 2021
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