Title:
Effect of Concrete Roughness and Displacement Rate on Steel-Concrete Friction (Prepublished)
Author(s):
Siham Al Shanti, Daniel Heras Murcia, Elena Kalinina, and Mahmoud M. Reda Taha
Publication:
Materials Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
shear displacement rates; static coefficient of friction; steel-concrete interface; surface roughness
DOI:
10.14359/51749501
Date:
1/21/2026
Abstract:
The determination of the static coefficient of friction between steel and concrete is essential for the design and safety of structures, particularly in systems operating under low axial stresses, such as foundation slabs supporting waste storage casks. In such applications, sliding resistance and shear transfer at the steel–concrete interface play a critical role in ensuring stability and overall structural performance. Inadequate friction at this interface can lead to sliding, reducing the structure’s capacity to resist lateral forces and potentially resulting in serviceability or safety concerns. This study presents an innovative approach to evaluate the static coefficient of friction between steel, prepared to a specific steel surface roughness level (SSPC-SP 6), and concrete with varying surface roughness profiles, including light sandblast, light-to-medium sandblast, medium bush hammer, and heavy sandblast finishes. Tests were performed under low normal stresses (18, 33, and 50 kPa) and shear displacement rates (3, 5, 7, and 9 mm/s). A custom test setup was developed to apply controlled displacement to a concrete block while measuring the horizontal force required to initiate sliding against the steel plate. The results indicate that the static coefficient of friction across all concrete surface roughness levels ranges from 0.68 to 0.75, with a mean value of 0.72. Statistical analysis at a 95% confidence level reveals that variations in concrete surface roughness, shear displacement rates, and applied normal stresses do not produce significant differences in the static coefficient of friction. Consequently, utilizing concrete with light sandblast surface preparation in the field is sufficient to achieve a static coefficient of friction comparable to aggressive surface roughness profiles. These findings simplify construction practices while ensuring reliable shear transfer and sliding resistance at steel-concrete interfaces in low axial stress applications.