b'RUNWAYSBNA 49To ensure that the airfield was ready for such settlement,At BNA, tests performed by the Garver team determined that the project team combined multiple stabilization techniques tothe existing concrete on Runway 2R-20L was durable enough mitigate consolidation in the new runway. The key strategy was thefor reuse and would achieve required FAA gradations. Antigo elimination of as much top-down water entering the fill as possible. subsequently broke up the concrete and hauled it to an onsite The reconstruction process in and of itself created a lot of finesplant for rubblizing. Crews operated three to four guillotine at the top of the subgrade to fill voids and choke off the ability tobreakers for 17 days to remove the old concrete, and then used drain water. Then we added an edge drain system to collect andan MHB breaker for three days to rubblize it. Processing the convey that water away from the pavements, Sisemore explains.material took almost a full month and involved two stages of The contractor sealed that off well before placing new concrete.crushingfirst with jaw crushers, then with impact crushers to Then, we strengthened the concrete with additional reinforcingremove contaminants and screening.and both longitudinal and transverse dowel bars for addedAggregating the concrete provided enough base course and support.stabilized base for the entire runway reconstruction project, plus material to spare. The airport plans to use the remaining fill for a Reclamation for Replacement ramp expansion that is slated to begin next year. Using reclaimed asphalt pavement for new construction has been a popular practice in the roadway industry for years. However, theNoise and EfficiencyFAA has moved more slowly to approve the process for runwaysWhen rebuilding its busy main runway, BNA temporarily shifted all and other key airfield pavements. The No. 1 goal is always safety,traffic to the airfields other three runways. This, however, resulted so adopting new construction practices takes time, Sisemorein more flights over nearby residential neighborhoods. And being a explains. Over the last decade, airports have increasingly usedgood neighbor is important to the airport, Holton notes. reclaimed asphalt as aggregate for new pavements. We still mustGarver brought in HMMH to model noise levels, then submitted use virgin aggregates in the top layer concrete, but below that weits findings to the FAA. The airport responded by shifting heavy can use recycled aggregate. Improve winterproductivity with the best products and services in the industryLiquid Potassium Acetate Product Liquid Potassium Formate ProductSAE AMS1435D SAE AMS1435DTHE Solid Sodium Formate Product Unique Patented Liquid TechnologyS C I E N C E SAE AMS1431E SAE AMS1435DVisit us at www.nasi-tm.comOF 800.622.4877, Ext. 310nasi_cs@nasindustrial.comDE-ICING 2021Nachurs Alpine Solutions.All rights reserved.AirportImprovement.comMay | June 2022'