Elastomeric Pad Expansion Joint Replacement Without Bridge Closure

Replacing elastomeric pad expansion joints can be accomplished with minimal traffic disruption using rapid-setting concrete and efficient work methods. A well-planned replacement can be completed in a single overnight closure of 6-8 hours. Pre-planning is essential for rapid replacement. The replacement pad must be procured and delivered to site before the work begins. The concrete mix design must be verified to achieve the required strength within the available curing time. All tools and equipment must be on site and in working order before traffic is stopped. Removal of the old pad begins with saw cutting the perimeter of the pad to prevent damage to the adjacent concrete. The pad is then removed by prying or chiseling, and the substrate is cleaned of all adhesive residue. Any deteriorated concrete is removed and the substrate is prepared to the required standard. Installation of the new pad follows the same procedure as for a new installation. The gap is set for the current temperature, the adhesive is applied, and the pad is positioned and restrained. Rapid-setting concrete is cast around the pad edges to provide additional restraint and to restore the road surface level. Curing of the rapid-setting concrete is the critical path item. The concrete must achieve the minimum specified strength before traffic is permitted. For most rapid-setting systems, this requires 4-6 hours at 20 degrees C. In cold weather, the curing time increases significantly, and heated enclosures may be required. Traffic reopening requires verification that the concrete has achieved the minimum strength, the pad is correctly positioned, and the road surface is smooth and level. A final inspection should be performed before traffic is released to ensure that the installation is safe.