Strip Seal Expansion Joint for Bridges with Concrete Barriers

Strip seal expansion joints at the transition between the bridge deck and concrete traffic barriers require special design to maintain the continuity of the barrier while accommodating the movement of the bridge deck. The barrier joint must meet the structural requirements for vehicle containment. Barrier continuity at the expansion joint is required to prevent vehicles from being deflected into the gap between the barrier sections. The barrier must be continuous across the joint, with a sliding connection that allows the deck to move while maintaining the barrier alignment. The sliding connection must be strong enough to resist the vehicle impact forces. Sliding connection design for barrier joints uses a steel plate that slides within a channel in the adjacent barrier section. The plate transfers the vehicle impact force from one barrier section to the other without transferring the thermal movement forces. The plate must be designed for the vehicle impact force specified in the applicable standard. Waterproofing at the barrier joint must prevent water from infiltrating the joint and running down the face of the barrier. A flexible sealant is applied to the joint face to provide waterproofing. The sealant must be compatible with the concrete barrier and must be flexible enough to accommodate the movement of the joint. Aesthetic requirements for barrier joints on urban bridges may require a smooth, uniform appearance. The sliding connection must be designed to be as inconspicuous as possible, with a flush surface that does not create a visual discontinuity in the barrier. Paint or coating systems that match the barrier color can be used to improve the appearance. Maintenance of barrier joints requires annual inspection of the sliding connection and the sealant. The sliding connection must be inspected for wear and corrosion. The sealant must be inspected for cracking and debonding. Any damage must be repaired promptly to maintain the structural integrity of the barrier.