Farshadfar, OmidAjaam, Ali HusseinHano, MunaO’Reilly, MatthewDarwin, David2016-01-292016-01-292014-08Farshadfar, O., Ajaam, A., Hano, M., O'Reilly, M., Darwin, D., "Bond Strength of Reinforcing Bars with Deformation Spacings that Exceed Maximum Specified in ASTM A615," SL Report 14-2, The University of Kansas Center for Research, Inc., Lawrence, KS, August 2014, 26 pp.https://hdl.handle.net/1808/19819The bond strength of two sets of No. 7 reinforcing bars was evaluated in accordance with ASTM A944. One set satisfied the criterion for maximum deformation spacing specified in ASTM A615, while the other had deformations that exceeded the maximum spacing. All bars exceeded the requirements for minimum deformation height. Research related to the effect of deformation properties on bond strength, including the research used to establish the requirements for deformations in ASTM A615, is also reviewed. The test results match earlier research and demonstrate that (1) the bond strength of the bars with deformation spacings that exceed those specified in ASTM A615 is similar to the bond strength of the bars that meet the specification, and (2) the differences in bond strength observed in the tests are not statistically significant. The bars tested in this study with deformation spacings that exceed those specified in ASTM A615 will provide satisfactory bond performance and can be used in all concrete construction.Bond (concrete to reinforcement)Deformed reinforcementRelative rib areaStructural engineeringTechnical Reporthttps://orcid.org/0000-0001-5039-3525openAccess