Crack Propagation and Control in Concentric Posttensioned Anchorage Zones

Abstract

In past decades, significant progress has been made in prediction of the behavior of posttensioned anchorage zones. An aspect that has not been sufficiently cleared up yet, however, is the service behavior of posttensioned anchorage zones designed at the ultimate limit state, especially with regard to crack formation. To address this problem, a numerical method based on the cohesive crack model is proposed to investigate crack propagation in posttensioned anchorage zones and predict structural behavior in the service state. These numerical analyses of the tested anchorage zone specimens show that the proposed procedure can describe crack-propagation behavior accurately, including first cracking load, crack length, crack width, crack trace, and ultimate load. To control crack width in the service state, parameter analysis, based on the proposed method, is performed. The results show that for concentric anchorage zones, proper bar diameters and bar spacing can lead to significant decreases in crack width, whereas the stirrup contributes little to cracking control.