Simulation of Influence of End Anchorage Degradation of Stirrups Caused by Alkali Aggregate Reaction on Shear Performance of Reinforced Concrete Beams

Abstract

This paper conducted a three-point loading experiment and analytical investigations on the shear performance of reinforced concrete (RC) beams with anchor defect at the lower end of stirrups. In the experiment, artificial methods were used to simulate the anchor degradation of the lower end of the stirrup caused by the alkali-aggregate reaction (AAR). The results show that, compared with the sound beams, the anchorage degradation of stirrups reduces the shear capacity of RC beams, and the degree of reduction becomes more pronounced with the increase of the local bond degradation area. The decrease in shear capacity is thought to be attributed to the reduction of the shear contribution by the stirrups and the reduction of the shear resistance by interlock action of coarse aggregate between diagonal cracks. The quantitative evaluation of shear contribution based on the computed stirrup strains confirms that the anchorage defect at the lower end of the stirrup reduces both the shear contribution Vc by concrete and Vs by stirrups, and the reduction of Vs is more significant than Vc.

Keywords

• reinforced concrete beams
• alkali aggregate reaction (aar)
• end anchorage degradation of stirrups
• shear performance
• finite element method analysis