纵向接缝密度的实践状态

Longitudinal Joint Density State of PracticeDave Johnson, P.E.Alaska Asphalt Pavement SummitAnchorage AlaskaNovember 6, 2023•Background Information•Case Studies•Best Practices•QuestionsOutlineBackgroundWhat we “know”Asphalt Institute study (2012) showed that longitudinal joint construction is an area where consensus is nearly unachievable, but that with attention to detail, we can produce good joints with differing techniques.•Longitudinal Joints are most pavement’s weakest point•Typically, joint density is ~2% less than mat density•Unsupported edge will usually have the lowest density•Joint density specifications typically 89-92% of TMD•For each 1% loss in density = about 10% loss of lifeAreas of General AgreementCase Studies•August 2021•26-Mile Project•State Highway #8•3” CIR•Two 1.5” 12.5 mm Superpave Lifts•58S-28 (MSCR) •Mix Temperatures 250-280°F at Paver•90.5 Joint Density RequiredNorth DakotaND Highway 8•Notched Wedge Configuration•Willow Design Devise•PaveScan RMD 2.0Unique Fea