Evaluation of Link Slab Performance on Texas Highway Bridges

Multispan bridges with simply-supported girders are straightforward to construct and economical but have historically utilized expansion joints between the spans. The negative long-term impacts of expansion joints are well-documented in the literature: eventual leaking causes damage to the girder ends and substructures. To avoid this deterioration associated with the use of expansion joints, link slabs may be used instead. This paper presents the results of a study examining the performance of existing link slabs on Texas bridges. Although these link slab details have been used for over four decades in Texas, their performance had not been widely studied. To understand the performance of these details, the design characteristics and damage conditions of 468 Texas bridges were recorded using as-built drawings and inspection reports. A damage rating was developed to evaluate the performance of the link slabs on each bridge. Using this information, an analysis was conducted to determine how different bridge design characteristics correlate with the performance of link slabs. The results showed that attributes such as continuous deck length and mean span length correlated with link slab performance. Certain loading characteristics such as average daily traffic, average daily truck traffic, link slab rotational demand, and the ratio of link slab moment capacity to -demand were found to have an age-dependent correlation with link slab performance. The performance of different deck detail types and skewed decks was also investigated.