Newsletter – WY Technology Transfer Center (TPD1112023)

Additional training sessions for paved roads will be developed and presented in the near future.

In the infrastructural area, the center has begun working with the counties in the southeastern corner of the state to develop strategies for mitigating the impact of oil and gas drilling activities. The report of the first phase of this study has been completed and it will be shared with the Wyoming legislature in their 2012 session.

The Local Project Administration (LPA) Certification has been implemented in cooperation with local governments, WYDOT and FHWA. Four certification sessions have already been presented and over 100 individuals have been ce1tified. Each local agency requesting federal funding must have a ce1tified individual before signing an MOU with WYDOT. There will be another ce11ification session in conjunction with our safety congress early in April. Our web site contains valuable info1mation on this certification and the names of all certified individuals.

Late in 2011, we presented training on the new County Road Funds Manual. That training helped in highlighting the changes and the updates in the new manual. La.st year was full of challenges and accomplishments and we are looking forward to working with all of you for years to come. Please feel free to call if you have any questions about any of our ongoing or new programs.

2nd Road Dust Best Management Practices Conference

by Josh Jones

The road dust institute conducted their second conference on road dust best management practices on November 7-9, 2011. The conference brought together local, state and county road practitioners, as well as researchers and federal agencies to discuss current practices and lessons  learned  to  assist  practitioners. The themes of the 2011 conference were environmental compatibility and sustain ability, general and international best practices, and unique and extreme conditions. On their website, roaddustinstitute.org, all of the presentations and papers from the 2008 conference and the 2011 conference are located in the archives.

The Wyoming T2/LTAP Center presented the findings of a recently completed study that examined the use of reclaimed and recycled asphalt pavement (RAP) millings on unpaved roads assessing both dust emissions and overall performance. Gravel  loss in the form  of  dust is a problem on many of Wyoming’s unpaved roads. As asphalt is milled from Wyoming’s state highways, yielding RAP, its use as a roadway material on Wyoming Department of Transportation (WYDOT) projects is usually in plant mix pavement (PMP) or as a road base. T2 studied the performance of RAPin unpaved roads, emphasizing dust loss and surface performance, along with an economic comparison between its use on unpaved roads and its use in PMP or in road base.

The conference began with opening remarks from David James- University of Nevada welcoming all the attendees to the 2nd road dust conference. The keynote speeches included presentations from Steve Albert,Western Transportation Institute; Roger Surdahl, FHWA Central Federal Lands Highway; and Dave Jones, University of California Pavement Research Center. Dave Jones presented the highlights from the gravel roads tour and survey. They received 287 surveys back; 73% of the respondents use  chemical  dust control mainly for public safety, health, complaints, to reduce road maintenance and preserve the gravel. The most commonly used additives included chlorides, lignosulfonate and ligno blends, asphalt emulsions , and synthetic polymer emulsions. Some the of  the  reasons for limited use or not using dust control include funding, cost-effectiveness , environmental issues, equipment limitations, and insufficient information to make informed decisions.

Twelve vendors gave presentations on their different dust abatement chemicals and techniques. All of  the  different  vendors  a:nd  products  a.re shown in the archives. Another session concentrated on the evaluation of the performance of materials and addressed different dust control methods and materials currently available. The performance of polymer-based products was compared to traditional hygroscopic products in Canada and infused applications. Next came a presentation by the US Army Engineer Research and Development Center about the results of an ongoing research project that has allowed them to compile a set of best practices, in terms of  the method of application, application rate, and laboratory testing of dust palliatives for military dust abatement. Their dust abatement handbook provides guidance for selecting dust palliatives and application methods. A PDF of the handbook can be downloaded at http://w ww.soilworks.com/ docs/soilworks-usmc-dust -abatement-handbook. pdf.

Bethany Williams from the USGS Columbia Environmental Research Center presented ongoing research about potential impacts of different products on the environment surrounding gravel roads. They tested five different types of products: electrochemical, organic, hydrocarbon, polymer, and chloride. Of the five products tested, only electrochemical products tested at slightly toxic to moderately toxic. Polymer and chloride products tested the best at practically nontoxic.

Steve Monlux from LVR Consultants LLC presented a chloride optimization study for the USDA Forest Se1vice. They considered two different techniques for chloride treatments: annual dust treatments and heavy “mixed in­ place” treatment. They found that for annual dust treatment more chloride at the road surface was good for light traffic but had a  greater  long te1m cost associated with it. Stabilization with light treatment eve1y three to five years had less dusting, raveling, and wash boarding, required less blading and rock replacement and had greater public satisfaction. The cons were a higher initial cost and only suitable for good gravel gradations. When different percentages of clay were added to the road surface, it was concluded that 1.5% calcium chloride and 3.5% bentonite produced the best compaction.

Another interesting presentation was on an unpaved road management system for mining operations in Chile. Before they started using magnesium chloride as dust abatement the mines, they were  using  2000 m3    of water each  day for dust suppressant. Currently, over 80% of the mines are using magnesium chloride and have reduced the amount of water needed by 90%. The two pictures below show a mining vehicle on an untreated road and on a treated road. It definitely passes the eye test when looking at the results. Some general conclusions were: add water while rota1y mixing, do not exceed optimum moisture, use <2% pure salt, shape to 4% crown to reduce pothole formation, and compact to reduce permeability and improve chloride retention.

The conference proved to be very informative about techniques practitioner are using around the world. The main conclusion was that there is no “silver bullet” for all roads and each product will pet-form differently depending on the material type, climate and type of maintenance. It was recommended that practitioners try out different test segments on their road networks to see what works best. Road dust abatement is still a relatively new field and much more work/studies need to be done to find the best solutions.

Before treatment with magnesium chloride

After treatment with magnesium chloride