Title:
Compression Bond Lengths: Study of Test Data and Design Equations (Prepublished)
Author(s):
Guido Valentini, Rémy D. Lequesne, Andrés Lepage, and David Darwin
Publication:
Structural Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
bond; database; design equations; development length; lap splice
DOI:
10.14359/51746821
Date:
5/15/2025
Abstract:
Compression development and lap splice length provisions in ACI 318-19 §25.4.9 and §25.5.5 are reexamined after an example is used to show that existing provisions can produce unexpected results in some design conditions, such as compression lap splices longer than tension lap splices. A historical review of ACI Building Codes shows existing compression bond length provisions are largely based on provisions adopted before test data were available. The provisions in ACI 318-19 are compared with a database of 89 test results, and are shown to poorly fit the data. Several compression and tension bond equations are also examined that fit the data better. It is shown that compression development and lap splice lengths can be based on a number of expressions available in the literature for tension development length, with minor modification, including the ACI 318-19 equation for tension development length. Using this approach would simplify design by eliminating the use of different expressions to calculate tension and compression development lengths, prevent calculated lengths from being longer in compression than in tension, and provide a better fit to available data.