24 SPRING/SUMMER 2022 The smoothness of the ride felt by the traveling public, called the camber, is an important consideration when paving a roadway. The original contract did not have a camber specification, but Allan Myers added a requirement to the contract to improve the camber by a minimum of 20%. All the trestles were tested, pre-mill ride data was evaluated, and targets and goals were established for the paving crews. Kicking Off With Milling Once all crew members received safety training, the milling operation started on the C trestle southbound outside travel lane with multiple milling crews to remove all the asphalt material down to the concrete deck. This process was started by a support crew installing drain protection in each drain slot to prevent millings from falling into the cable trays and then into the Chesapeake Bay. Once the material was removed and decks were cleaned, any needed concrete repairs were made. Once both layers were completed, the bridge support crew cut out the asphalt and prepped each joint for the installation of elastomeric joint material every 300 feet fullwidth across the deck. Trestle C southbound after milling and cleanup, ready to be tacked and edges sealed. You can see the drain outlets that had to be sealed with foam backing to prevent material from leaving the deck. Myers then kicked off the 2020 paving season by starting the C and D trestles northbound. The CBBT District permitted Myers to close the full span from Island 4 to just before the northside toll plaza, which entailed moving traffic to a two-way configuration on the southbound lanes for more than seven miles. Three MOT setup trucks were used the night of the traffic switch to quickly remove the seven-plus miles of lane closure. With every barrel and cone being triple weighted, it was quite an undertaking. Trestle C northbound paving operations— traffic was put back into the original configuration with 2-way traffic on the southbound C trestle. This allowed for a safe work zone due to the northbound trestle having no shoulder. C and D trestles northbound were the first sections where the team encountered the angle iron end dams on each of the 75-foot A RIBBON OF BLACK: PAVING THE CBBT Trestle C northbound being paved. bridge decks. The milling on this section compared to the southbound section was slow and methodical. The mill had to pick up every 75 feet to prevent any damage to the metal dams. Each of the joints then had to be milled using skid steer milling attachments and any remaining material chipped out. Once the joints and deck were milled and cleaned, everything was inspected. Any needed repairs were made to concrete decks and joints were cut and new sections welded into place as needed. Once the section was approved for paving, the leveling course was installed. The method to install this course was planned out and carefully executed by the crew to reduce the camber feel and to level out the spans so the final course could be installed in a consistent and level 1 1/2-inch lift. Myers also wanted to be able to pave over all the joints in the section to ensure a smooth and consistent final layer. To ensure the CBBT District was completely satisfied with the results, a section was milled out and repaved to confirm the ride they were looking for on the final layer. Allan Myers repeated the process that was learned on northbound trestle C to ensure that trestle B and trestle A northbound exceeded the requirements and high standards that were set upon the completion of trestle C. Roughly 668 joints on the northbound trestle were milled, cleaned and paved over. Strict Moisture Control The southbound trestle offered a simpler approach for the milling and paving crews due to the method of construction of the new sections. Each southbound span was 300 feet in length and did not have metal angle joints. The method used for the separation between spans was an elastomeric joint compound. These joints allowed the milling crew to mill through them so once the deck was cleaned, the joint areas were covered with strips of plywood to prevent any asphalt material from dropping through during the installation of the leveling course and the final layer. When the paving operation was complete, the bridge support crew would lay out the area and saw-cut the material to be removed. Forms were then installed to allow the elastomeric compound to be placed to form the end joints. Each southbound joint required mixing and installation of roughly 300 gallons of material. The area had to be completely voided of moisture. Once the mixing △ continued from page 23 continues on page 27 △ Highway work is always dangerous, but working on a bridge deck with no place for traffic or crews to escape in the event of an incident brought a new focus to safety. When the time came for Maintenance of Traffic (MOT) setups and protection, nothing was left to chance.
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