As of 2007, the world had approximately 79,000,000 miles of unpaved roads.
An abundance of evidence posted on the internet suggest that the number of unpaved road miles is growing, not decreasing. Rationale: cost of petroleum and world financial conditions prohibit construction and limit the maintenance of asphalt/concrete roads. Further evidence identifies communities and states, by name, that are abandoning paved roads in favor of dirt and gravel driving surfaces.
The Wall Street Journal covered the issue of costly asphalt maintenance in an article named "Road to Ruin" where they reported the following on July 17, 2010:
"Paved roads, historical emblems of American achievement are being torn up across rural America and replaced with gravel or other rough surfaces as counties struggle with tight budgets and dwindling state and federal revenue."
Lack of information in the 'alternatives" leads many municipal and state authorities to believe that replacing asphalt is a compromise of sorts. However, research in chemical and materials science and the amount of experience and testing in the paving industry make some solutions better than others.
At first sight everyone in the soil stabilization industry will sell you an enzyme or a polymer and claim stellar results. Your first priority is to decide which direction to take when nobody volunteers solid information to allow intelligent conclusions.
After all, the industry is in its' infancy and there are no enforcement bodies to hold the alternative pavement players to any normative standards. A good way to start would be to hold these products to the same standards as the Asphalt industry by subjecting their work to the same testing requirements as developed by American Association of State Highway and Transportation Officials (AASHTO) or American Society for Testing and Materials (ASTM).
When you ask an experienced paver what is the key element to success is, she will say "all of them" so let's review what you are looking for in an alternative method as a beneficiary.
- Do not settle for vinyls and copolymers, read the MSDS carefully. A range instead of a number for percentage of solids is inconsistent, and so will be your pavement. You are dealing with a reseller who buys the cheapest, which is not of the same standards with each shipment.
- The biggest single problem with the vast majority of polymers is high water absorption and/or lack of wet bonding strength. The polymer soil stabilization industry must get film strength testing wet and dry as well as bond strength testing wet and dry to be written into the specifications. The industry also needs to make the end consumer and the spec writers understand the importance of the polymer hydrophobicity standards and polymer wet strength.
All water-based latex polymers have some inherent limitations but some have more limitations than others. As a consumer or client you must incorporate proper testing into your requirements, forcing out all but the vendors of product which makes the cut! The fact is that nearly all of the polymer soil stabilization companies will accept, market, sell and use any and every water-based polymer that they can obtain at low cost regardless of the quality or consistency of the polymer.
An easy way to determine polymer quality and type is by reviewing the respective product's MSDS. An MSDS that shows a wide range of pH will be inconsistent, will likely be a vinyl copolymer blend, and if the pH is below 7 it will likely be all vinyl. An MSDS that has a range for percent solids will be inconsistent, and so will be your road.
When long-term stabilization is the goal, it is important to check the MSDSs of each potential product to ensure that one is using a product that can stand up to the required task for the time frame necessary with the least possibility of requiring reapplication.
Additional details are available from projects@polymerpaving.com, a serious provider of alternative solutions that stresses importance of polymer formula, base and subgrade quality assurance, eliminating cappilaries (hydrophobicity), proper aggregate, proper percentage of fines, proper curing and compaction, and all the other success factors.
Author Resource:
http://online.wsj.com/article/SB10001424052748704913304575370950363737746.html
Implication of Aggregates in the Design, Construction, and Performance of Flexible Pavements
http://hubpages.com/hub/Are-green-roads-possible Cady, P D , Blankenhorn, P R, and Khne, D E , "Upgrading of Low Quahty Aggregates for PCC and Bituminous Pavements," National Cooperative Highway Research Program Report 207, 1977
"Synthesis on Low Quality Aggregates Improvement Techniques," Subtask A-2, Final Report, Resource International, Inc, Weskrvllle, Oct 1986
![[Valid RSS feed]](http://www.look4articles.com/images/icon_Rss.png "XML Feed For RSS"){kind=icon}
Category Rss Feed
Print This Article
Add To Favorites
![[Valid RSS feed]](http://www.look4articles.com/images/rss.jpg "XML Feed For RSS")