Pavement Preservation Journal - Spring 2012 - (Page 35)

Maryland Identifies Right Fix for Right Road, Right Time by Geoff Hall, P.E. I f the mantra of pavement preservation is the Right Fix, for the Right Road, at the Right Time, the question for pavement managers is “How does an agency identify the right fix, or treatment, or the right road, or the right time?” More specifically, how does an agency identify when a pavement preservation treatment is appropriate? The Maryland State Highway Administration (SHA) has identified an approach to help pavement engineers better manage surface distresses and appropriately integrate pavement preservation from a pavement management perspective. It is well known among pavement engineers that preservation treatments are intended for structurally sound pavements: roads with distresses primarily limited to the surface. So, how do we identify and manage which of the thousands (if not millions) of pavement sections are structurally sound, especially in the era of automated collection? Agencies may collect ride quality, rutting and cracking data. A challenge those agencies have is to dissect this data to determine whether a pavement preservation treatment is appropriate, as readings showing poor pavement condition could be a result of either structural or surface (functional) distresses. Another challenge facing some agencies is how their pavement management systems operate. Their optimization programs typically focus on roads that are in need of rehabilitation (perhaps based on ride quality), rather than preservation. In order for preservation treatments to become viable, suggested solutions, there must be a way to calculate and assign benefit to those treatments. Otherwise, roads that could benefit from cost-effective pavement preservation treatments will be skipped over in favor of roads needing more costly rehabilitation. STRUCTURAL VS. SURFACE CRACKS To properly assign benefit, it is critical to be able to separate out structural distresses from surface distresses, since different treatments provide different benefits. Depending on the situation, placing micro surfacing on a cracked pavement provides some benefit, as does placing an HMA overlay. However, if those cracks are structural, the micro surfacing benefit is negligible, and the HMA overlay benefit is significant. On the other hand, if those cracks are superficial, the micro surfacing benefit is significant relative to the HMA overlay benefit. To distinguish the variable benefits, one approach the Maryland SHA has recently taken for asphalt-surfaced pavements is to identify and separate out surface and structural cracks, declaring that longitudinal cracks in the wheel paths are structural, and all other cracks are surficial. With this methodology, we are able to identify roads that are still performing well structurally, yet could benefit from a preservation treatment. In turn, preservation treatments are assigned a higher benefit for surficially distressed roads than for structurally distressed roads. Roads that are identified as being in good structural condition but perhaps not as good condition functionally can then be classified by the pavement management optimization program to be a good candidate for pavement preservation. These roads can thus go to the top of the list of the right road to fix with a preservation treatment, at the right time to do it. NEPPP NEWS The Northeast Pavement Preservation Partnership (NEPPP) held its most recent meeting in early November in Boston. During the meeting, Geoff Hall was named the new chair, Scott Nazar of PennDOT new vice-chair (agency), and Mike Fowler of the Vermont Agency of Transportation new secretary/treasurer. Rod Birdsall of All States Asphalt continued as vice-chair (industry). Similar to the other regional partnerships, the NEPPP has five task forces. The Project Database Task Force will work to collect preservation project information (three or four projects/ agency). The Preservation Specifications Task Force will collect a list of preservation-related specifications from the member DOTs, as well as a contact person from each to ensure that the latest specifications are used. The Promotion, Marketing, and Public Relations Task Force will solicit and develop article ideas for promotional brochures, and will develop a plan to get involved with LTAP centers. The Treatment Performance and Cost Effectiveness Task Force will identify one or two preservation treatments on which to focus, and for those treatments, try to figure out what information to collect to determine cost effectiveness. Finally, the Education / Certification and Work Force Development Task Force will review NHI training courses and the TSP•2 Research Roadmap to compile suggestions for needed additional training and to choose one or two high priority research items for the NEPPP. The NEPPP will next meet in August in Nashville during the National Pavement Preservation Conference, and then intends to hold the 2013 annual meeting in Maryland. Geoff Hall, P.E., is the pavement engineering chief for the Maryland SHA, and is the 2012 chair of the Northeast Pavement Preservation Partnership. Spring 2012 pavement preservation journal 35 PARTNERSHIPS

Table of Contents for the Digital Edition of Pavement Preservation Journal - Spring 2012

President’s Message
National Preservation Conference: Make Plans Now
Pavement Preservation is ‘Sustainable’ Choice
Deck Micro Surfacing Cuts Accidents, Wins Award
Enhanced Fog Seals Boost Chip Retention
Sophisticated ‘Seal Coats’ Enhance Texas DOT Pavement Preservation
Rejuvenating Treatment Preserves Runway, Grooving
Fine-Mill Pavements for Smooth Thin Overlays
Puerto Rico, Southeast States Focus on Preservation
Maryland Identifies Right Fix for Right Road, Right Time
‘Thin is In’ for New Texas Center Courses
Why to Cut Back on Cutback Asphalt
Test Sections Constructed at Virginia Smart Road
Ground Penetrating Radar Fills Gaps in PMS

Pavement Preservation Journal - Spring 2012