Title:
Longitudinal Bar Spacing and Intermediate Ties
Author(s):
Ben DeGagné, Ece Erdogmus, and John Savage
Publication:
Concrete International
Volume:
38
Issue:
5
Appears on pages(s):
43-46
Keywords:
lateral support, concrete, strain, strength
DOI:
10.14359/51688951
Date:
5/1/2016
Abstract:
The column design provisions in ACI 318-14 require that alternate longitudinal bars have lateral support provided by crossties or a corner of a tie, and they allow no unsupported longitudinal column bar to be farther than 6 in. (152 mm) clear on each side along the tie from a laterally supported bar. These requirements originated with the publication of the 1963 Code. However, the clear spacing limit was apparently based on the engineering experience of the ACI committee members writing the original provision. Based on a review of the existing literature, the authors believe that research is needed to determine if the spacing limit can be increased.
Related References:
1. ACI Committee 318, “Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14),” American Concrete Institute, Farmington Hills, MI, 2014, 519 pp.
2. ACI Committee 318, “Building Code Requirements for Structural Concrete (ACI 318-11) and Commentary,” American Concrete Institute, Farmington Hills, MI, 2011, 503 pp.
3. ACI Committee 318, “Building Code Requirements for Reinforced Concrete (ACI 318-63),” American Concrete Institute, Farmington Hills, MI, 1963, 144 pp.
4. ACI Committee 318, “Building Code Requirements for Reinforced Concrete (ACI 318-56),” ACI Journal Proceedings, V. 52, No. 9, May 1956, pp. 913-986.
5. Pfister, J.F., “Influence of Ties on the Behavior of Reinforced Concrete Columns,” ACI Journal Proceedings, V. 61, No. 5, May 1964, pp. 521-537.
6. Burdette, E.G., and Hilsdorf, H.K., “Behavior of Laterally Reinforced Concrete Columns,” Journal of the Structural Division, V. 97, No. 2, Feb. 1971, pp. 587-602.
7. Bunni, N.G., “Rectangular Ties in Reinforced Concrete Columns. Reinforced Concrete Columns,” Reinforced Concrete Columns, SP-50, M.W. Huggins, ed., American Concrete Institute, Farmington Hills, MI, 1975, pp. 193-210.