Pub. 2 2019-2020 Issue 2

23 T he St GeorgeRegional Airport RunwayReconstructionProjectwas unique inmany ways and caught a lot of media attention because of the failure of the previous runway after only eight years.The project consisted of reconstructing 5,400 feet of the9,300-foot runway after apremature failureof theexisting runway. During theproject, the following was provided and placed: • 27,600 tons of P-401a (bituminous surface course) • 41,400 cubic yards of P-926 (unstabilized permeable surface course) • 44,000 tons of P-209 (Crushed Aggregate Base) The large-project dollar amount of the subcontract was $5,836,627.73. Crewsworked24hours a day, 7days aweek during a 4-month runway closure to remove blue clay 17’below the runway and 215’wide, replacing the material with a much more suitablematerial froma borrow source located on the airport. On top of all the dirt was a geomembrane liner, typically utilized for dams toprevent water fromdraining 17’ below the runway section to the virginblue clay.This project also added an underdrain, a drain- age layer and a new road base to help provide a pavement section that would not only hold up to planes but would also keepmoisture frompenetrating to the clay below. The airport build schedule was designed to impact the community as little as possible, which necessitated firm dates on finishing each phase. The asphalt paving was put into a two-weekwindowat the end of August. To facilitate the operation,Western Rock dedi- catedtwopavingcrewsandtwosetsof equipment forechelonpaving.Theproject required two hot plants to keep upwith the tonnage passing through eachmachine. The asphalt coming fromboth plants had to have the same gradations, oil content, etc. Asphalt was constantly tested at both plants to make sure the mixes were consistent and mirroring theother plant’s results. Crewcoordinationwas accomplished through theuseofTrimble 3Dpaving software and hardware installed on both asphalt laydownmachines. Training the paving foreman tomanage the 3Dmodel in conjunctionwith another crewwas per- formed before starting the asphalt paving on the airport. The echelon paving reduced the number of cold joints and seams on the project. The final QA testing, along with our internal QC testing, assured the final product was per specifications. The smoothness of the runway asphaltwas remarkable. Eachpaving lanewas testedwith bothaprofilographanda12-foot straight edge toensure that themat rode smoothly and helda constant grade toallowpositivedraining.Thegrade is very importantwithechelon pavingbecause it is possible tohave aminor bump at the seambetween the twopavers. Wewereveryawareof thesmoothnessexpectationsonthisproject andwouldconsistently check behind the pavers and rollers to ensure each paver was placing a smooth, consist- entmat.Wealsoelected to topography thebasebeforepaving tohelpfill in theholes and remove any bumps left in the base. The results of the extra effort put forth showed in the final productwhen theprofilographwas completed.Theoverall profilograph showedan WESTERN ROCK PROJECT LOCATION: St George PROJECT START: May 2019 PROJECT COMPLETION: September 2019 ST GEORGE REGIONAL AIRPORT AIP PROJECT averagedeviationof 0.69 inches per 1/10mile. Theaveragedeviationisconsideredexceptional byFAAstandards. Even the transitions fromthe new surface to the old surface provide a ride that didnot showupon thefinal profilograph . Construction crews worked more than 6,560 hours, trucking provided and additional 3,200 hours and crushing expended 3,025 hours for thisproject.Therewerenorecordable incidents, andno lost timeaccidents for each lineof busi- ness. Safety performance can be attributed to utilizing internal tools (i.e., T.R.A.C.K., G.O.A.L., andSee, Stop,Do) andbyempoweringall levels of project employees. 3 UAPA QUALITY IN CONSTRUCTION WINNER: