Title: Shear Tests on Beams Cut from ASR-Affected Bridge Decks

Author(s): J. A. den Uijl and N. Kaptijn

Publication: Symposium Paper

Volume: 211

Issue:

Appears on pages(s): 115-134

Keywords: anisotropic material behavior; ASR; shear capacity; slab bridge; tensile strength

DOI: 10.14359/12587

Date: 2/1/2003

Abstract:
During the last decade dozens of concrete bridges were raced in The Netherlands that had suffered from alkali-silica reaction (ASR). Since the bridge decks were not provided with vertical reinforcement, their shear capacity fully depends on the concrete tensile strength. To study the effect of ASR on the shear capacity, six beams sawn from two viaducts were loaded in bending till failure. Failure occurred at about 75% of the theorectical shear capacity of undamaged concrete. Contrary to what normally would be expected, failure was not attended with the development of inclined bending cracks, but with diagonal cracks that originated at mid-depth. Hence, the tensile strength reduction due to ASR resulted in a change of the failure mechanism from flexural shear into diagonal shear. To explain the observed crack development and shear strength, the influences of a longitudinal compressive stress due to the restraint of ASR-induced expansion and an orientation dependent tensile strength were taken into consideration.