Improved Life for Longitudinal Joints in Asphalt Pavement - WisDOT ...

Maine“Longitudinal Joint Study,” Federal Experimental Report 96-2, September 2001.http://mainegov-images.informe.org/mdot/transportation-research/pdf/report9602f.pdfThis five-year study of longitudinal joints constructed in 1996 evaluated various methods of longitudinal jointconstruction during rolling of HMA pavement. Joint-making equipment, rolling patterns, edge trimming and othertechniques were evaluated in various combinations. The best performance was in the section in which rolling wasconducted from the cold mat with a 6-inch overlap into the hot mat; this method is the reverse of the recommendedmethod by NCAT and other studies.New Hampshire“Field Trial of Infrared Joint Heater to Improve Longitudinal Joint Performance in New Hampshire,” Jo Sias Daniel,University of New Hampshire, and William Real, NHDOT; Transportation Research Record No. 1946, 2006: 157-162. (See attached file.)This field study evaluated the use of infrared joint heaters to improve longitudinal joint performance. The heateressentially affects only the top layer of the full-depth asphalt structure, suggesting potential for using this methodwith overlays.Ontario“Longitudinal Joint Compaction: Improving Paved Lanes,” Road Talk, Vol. 10 (2), May 2004.http://www.mto.gov.on.ca/english/transtek/roadtalk/rt10-2/index.html#jointThe Ontario Ministry of Transportation evaluated the use of incentives and testing of density at joints to ensure thatjoints were constructed as specified. Investigators evaluated the long-term performance of four trial sections pavedin 1997 in which compaction was tested at the longitudinal joints to ensure contractor compliance, not a requirementat the time. Trials included both standard and unconventional methods and equipment. Highlights include:• Four methods were evaluated, including standard paving and compaction, use of a joint heater, use of ajoint-building system with a compactor and kicker-plates as well as an electronic monitoring device, anduse of both a heater and the jointing and monitoring system.• No method proved superior to the others, but all achieved compaction rates of 95 percent or greater.• After four years and after six years, joints were in excellent condition.• Contractor performance has been encouraged through bonuses for meeting standards on 95 percent or moreof examined edges, and penalties for meeting standards at 90 percent or less of examined edge points.PennsylvaniaEvaluation of Eight Longitudinal Joint Construction Techniques for Asphalt Pavements in Pennsylvania, PrithviKandhal, Timothy Ramirez and Paul Ingram, NCAT Report No. 2002-03, February 2002.http://www.eng.auburn.edu/center/ncat/reports/rep02-03.pdfFollowing up on some of the sites included in the 1997 NCAT study, researchers evaluated the six-year performanceof the eight techniques used in Pennsylvania in 1995. Findings included:• Joints using rubberized joint material had performed best.• The joint constructed using a cutting wheel was a close second.• Sections on which rolling from the hot side away from the joint was used performed reasonably well.• The New Jersey wedge joint performed reasonably well.TexasDensity Evaluation of the Longitudinal Construction Joint of Hot-Mix Asphalt Pavements, Cindy Estakhri, ThomasFreeman and Clifford Spiegelman, Texas Transportation Institute: April 2001.http://tti.tamu.edu/documents/1757-1.pdfThis Texas study of density in longitudinal joints in HMA evaluated joints at 35 sites, considered airfield andpavement regulations, and conducted laboratory tests. One of the study’s goals was to identify the viability of adensity specification for longitudinal joints in asphalt pavement, and investigators developed and proposed aspecification. Findings include:• Some states and the Federal Aviation Administration maintain a density specification for longitudinal jointsin asphalt, and contractors have little trouble meeting the requirement.• Density was always lower at the unconfined edge of the pavement than at the middle of the lane. Thedifference averaged about 4 to 5 percent, about 6 to 7 pounds per cubic foot.• The proposed specification would require the difference to be kept to 5 pounds per cubic foot.4