Comparison of details for controlling end-region cracks in precast, pretensioned concrete I-girders

In this article, the authors compare four detailing schemes for controlling end-region web-splitting cracks, which typically form during or in the weeks following prestress transfer due to vertical tensile stress. The four schemes are: end reinforcement per AASHTO LRFD specifications; large-diameter end reinforcement; vertical-end-region posttensioning; and partial debonding of 45% of prestressing strands. The evaluation includes the monitoring of crack locations, lengths and widths in 63 inch deep Florida I-beams both during prestress transfer and in the months following. Load testing is performed on specimens to determine each scheme’s effect on capacity. The three modified details all show reduced web cracking in comparison with the standard detail.