Nebraska LTAP
Date of this Version
6-22-2017
Document Type
Article
Citation
Rosenbaugh, S.K., Schmidt, J.D., Faller, R.K., and Holloway, J.C. "Evaluation of Adjustable Continuity of Join Variations for Use in the Restore Barrier" (2017) Nebraska Department of Transportation Research Report
Abstract
During MASH TL-4 full-scale crash testing of the RESTORE barrier, concrete cracking and spalling was observed on the barrier beams that would likely require repairs or replacement. This study sought to evaluate joint design alternatives for use in the RESTORE barrier in order to limit the amount of system damage. Three variations of the Adjustable Continuity Joint (ACJ) were identified as potential modifications: 1) incorporating rubber bearing pads within the ACJ, 2) utilizing normal weight concrete instead of lightweight concrete, and 3) incorporating a steel end cap into the ends of the beam segments.
Four dynamic component tests were conducted to evaluate the performance of these three joint variations against the performance of the original, as-tested, RESTORE ACJ. All three modified designs showed improved durability over the original ACJ. The normal weight concrete beams delayed the onset of cracking and fracture, but ultimately had similar damage to that of the baseline test. The rubber pad reduced cracking and prevented fractures, but it increased the flexibility of the joint. Finally, the steel end caps allowed only small hairline cracks to form while also stiffening the joint.
Although these component tests showed promise for the ACJ design variations, further evaluation and analysis is recommended prior to utilizing any of these joints in real-world barrier installations.