Shear stop criteria for reinforced concrete slab strips

Abstract

Proof load testing for assessment can involve a large risk due to the high loads. Stop criteria can reduce this risk. Stop criteria are necessary for shear, which is a brittle failure mode. This paper describes the development of shear stop criteria for slab strips. The shear stop criteria are developed by combining theoretical concepts related to cracking, as well the relationship between bending- and shear-critical regions, along with insights from the Critical Shear Crack Theory and the Critical Shear Displacement Theory. The shear stop criteria are validated with fourteen beam tests. The result is a set of shear stop criteria in a “traffic light system” with a green light level related to serviceability, and yellow and red light related to the ultimate limit state for shear. These stop criteria serve as the basis for a global approach for proof load testing of reinforced concrete bridges.