Title:
Effect of Alkali-Silica Reaction on the Performance of Reinforced Concrete Corbels (Prepublished)
Author(s):
Reza Abbaspour and Hossein Yousefpour
Publication:
Materials Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
alkali-silica reaction (ASR); corbel; disturbed region; shear strength; strut-and-tie method
DOI:
10.14359/51750600
Date:
3/19/2026
Abstract:
Alkali-silica reaction (ASR) is a destructive phenomenon that may occur due to the use of certain types of siliceous aggregates in concrete with high alkali content. This study examines the performance of ASR-affected reinforced concrete (RC) corbels, which are short cantilevers that transfer concentrated forces to columns. Eighteen full-scale RC double corbels were designed according to ACI CODE-318-19 provisions and fabricated using concrete that contained reactive fine aggregates as well as sodium hydroxide to boost the alkali content up to 1.75%. Variables among the specimens included design methodology, shear spans-to-effective depth ratio, and reinforcement layout. The specimens were tested until failure either in control conditions before noticeable ASR expansions, or after 110, 220, or 300 days of accelerated curing in a relative humidity of 100% and a temperature of 45°C to achieve uniaxial expansion levels of 0.1, 0.15, and 0.2%, which are denoted as E1, E2, and E3 expansion levels. Results showed that ASR caused irregular and relatively small changes in compressive and splitting tensile strength of concrete cylinders, but up to a 58% reduction in their modulus of elasticity. Nevertheless, ASR-affected corbels containing distributed reinforcement exhibited increased stiffness compared to control specimens, likely due to restrained expansions. The ultimate strength of ASR-affected corbels compared to that of the control specimens was greater by up to 44% in the E1 expansion level and 32% in E2 and E3 expansion levels. Both the empirical design method and the strut and tie method (STM) provided conservative estimates of the ultimate capacity of corbels in control or ASR-affected conditions.