Bridge Slab Behavior at Expansion Joints

The primary objective of this research study was to evaluate the behavior and capacity of the IBTS and alternate 8 in. UTSE (Uniform Thickness Slab End) details at expansion joints, especially on skewed ends of bridge slabs. The two full-scale CIP (cast-in-place) specimens, 0o and 45o skews, were constructed to test the effect of skew on the IBTS and UTSE details. Test results showed that at design load levels, skew had no significant effect on the behavior of the two details. All test areas failed in shear, predominantly punching shear. The UTSE details failed at slightly lower load levels than the IBTS detail due to a 2 in. difference in section depth. However, both details had ultimate capacities at loads well above the design load levels.

Another objective of the research study was to develop alternate details and investigate construction issues of those alternate details. Since the UTSE details performed satisfactorily at design and ultimate load levels, an alternate detail using the stayin- place PC (precast) panels in the end regions was developed and tested. The PCPE (Precast Panel End) details would eliminate special formwork construction and reduce safety concerns associated with such formwork construction at heights. The full-scale PCPE specimen, 0o skew, was built since panels cannot be easily incorporated in bridge decks with a skewed end. In addition to the behavior and capacity of PCPE details, the effects of armor joints (AJ) and sealed expansion joints (SEJ) on slab ends at design and ultimate loads were investigated. Test results showed that the PCPE details performed similar to the IBTS and UTSE details at design and failure load levels. The PC panel details failed at loads lower than the IBTS details, and the AJ and SEJ increased ultimate capacity by 20 to 25% when compared to PCPE without AJ or SEJ.