Title:
Concrete Q&A: Coefficient of Friction for Not Intentionally Roughened Contact Surface and Verifying Compliance Requirements for Intentional Roughening per Table 22.9.4.2 in ACI CODE-318
Author(s):
Publication:
Concrete International
Volume:
47
Issue:
6
Appears on pages(s):
64
Keywords:
concrete, section, roughness, contact
DOI:
10.14359/51747838
Date:
6/1/2025
Abstract:
This month’s Q&A discusses changes in ACI CODE-318-25 for coefficient of friction for concrete placed against hardened concrete that is clean, free of laitance, and not intentionally roughened, as well as new provisions for determining if an intentionally roughened surface meets the 1/4 in. roughness specified in Table 22.9.4.2.
Related References:
1. ACI Committee 318, “Building Code Requirements for Structural Concrete (ACI 318-19) and Commentary (ACI 318R-19) (Reapproved 2022),” American Concrete Institute, Farmington Hills, MI, 2019, 624 pp.
2. ACI Committee 318, “Building Code for Structural Concrete—Code Requirements and Commentary (ACI CODE-318-25),” American Concrete Institute, Farmington Hills, MI, 2025, 702 pp.
3. Krc, K.; Wermager, S.; Sneed, L.; and Meinheit, D., “Examination of the Effective Coefficient of Friction for Shear Friction Design,” PCI Journal, V. 61, No. 6, Nov.-Dec. 2016, pp. 44-67.
4. ICRI, “ICRI Guideline No. 310.2R-2013—Selecting and Specifying Concrete Surface Preparation for Sealers, Coatings, Polymer Overlays, and Concrete Repair,” International Concrete Repair Institute, Minneapolis, MN, 2013, 54 pp.