Using Short Ultra-High Performance Concrete Link Slab as an Alternative to Steel Dowel Bars in Rigid Pavements

Abstract

To prevent problems from occurring at the joint region in bridge construction, link slab was introduced to hide the apparent expansion joint and retain its function. This research describes experimental tests that investigate the use of an ultra-high performance concrete (UHPC), for its high sustainability properties, as a short link slab instead of apparent expansion joints and their respective steel dowels in joint plain concrete pavement (JPCP) while maintaining the expansion joint’s proper function. Similar to dowelled joints, the proposed joint distributes load between adjoining slabs while allowing for contraction and expansion of the pavement due to temperature and moisture variations. Modified cantilever tests were conducted on JPCP slab segments with regular dowelled joints and UHPC link slab joints to investigate the load-deflection response and load transfer of both joints and make comparison. The experimental results showed that UHPC link slab specimens exhibited less deflection at the face of the joint and less relative deflection between the adjoining slabs than steel dowel bar specimens. The test outcomes also showed that joint width did not have a noticeable influence on the load-deflection behavior of the UHPC link slab specimens, but it obviously affected the dowelled joints. Also, UHPC link slab specimens showed an improvement in ultimate load capacity by 23.33% and 11% compared with dowelled joints. Furthermore, the UHPC link slab joints exhibited a better load transfer between slab segments than the dowelled joints. It was concluded that even a short link slab can be superior to standard dowelled joints