Wood tie failure solution railroad tie protector asphalt coating for wood rail tie

  

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Extending the service life of wood ties is a critical goal for railroads facing high replacement costs and operational challenges. One logical approach is to shield ties from the elements—essentially putting a “roof” on them to reduce weathering. This report examines the performance of Tietan™, an asphalt-based coating engineered to protect wood ties and mitigate deterioration caused by moisture and ultraviolet exposure. 

A team from Heritage Research Group conducted an experiment, starting with new, identically matched, incised red oak wood ties. To encourage rapid weathering, the seasoned ties were not preserved with a typical chemical treatment such as Creosote or CuNap, but borate-treated and dry-stacked. Half were coated with Tietan™, an engineered asphalt coating, and the others were not. The ties were left side-by-side on an outdoor pallet. After 20 months of exposure to precipitation and ultraviolet (UV) rays, the uncoated ties warped, with an increase in surface opening size as well as check and split presence. In contrast, the Tietan-coated ties maintained a straight form with minimal weathering. Any pending cracks on the top surface were sealed by the asphalt.  No further checks or splits were visible. 

For more information, we’re here to talk:

Erin Meehan – Business Development Manager  emeehan@tietan.com

Buddy Clark – Vice President  buclark@tietan.com

engineered asphalt coating to extend the life of wood railroad ties

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And the Protective Capabilities of an Asphalt Coating

Ft. Outdoor Weathering Experiment, Moisture Content Fluctuation Study

Railway Innovative Solutions, LLC

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Table of Contents

  1. Executive Summary
  2. Introduction
  3. Understanding How Moisture Affects Wood Ties
  4. Impact of UV Radiation on Degradation of Wood Surfaces
  5. Current Wood Treatment Methods and The Need for Supplementary Protection
  6. Introducing Tietan: a Formulated Asphalt Coating as Supplementary Tie Protecting Solution
  7. Performance Attributes of Tietan
  8. Outdoor Weathering Studies
  9. Summary of Benefits and Conclusions
  10. References

Executive Summary

Railroad professionals are well aware that wood rail ties inevitably deteriorate and require costly replacements. While chemical preservatives are the go-to option to extend rail tie operational lifetime, maintenance-of-way professionals have noticed alarming rates of tie deterioration, notwithstanding the type of treatment these ties have undergone. Consequently, engineers have recently sought additional solutions to the issue of expensive wood tie turnover, but have yet to find a definitive answer to improve this situation. 

Wood Rail Ties Coated with Tietan Asphalt Costing to protect them from early failure

To address this issue, Railway Innovative Solutions, LLC has formulated an asphalt-based coating under the commercial name Tietan. Tietan eliminates the threat of UV and minimizes water damage from the top surface of the tie. It is applied hot and seeps into existing openings in the wood prior to cooling, forming a durable and flexible membrane that will bond with solvent-based treatments like creosote, copper naphthenate, and DCOI. The hot asphalt is immediately covered with aggregate for slip resistance. Over time, the engineered asphalt flexes with the natural expansion and contraction of wood, ensuring a complementary protective layer to extend the service life of wood ties. 

This coating has recently demonstrated major reductions in the impact of weathering on wood, whether applied to untreated or preservative-treated nondurable hardwoods such as red oak, sweetgum, and southern yellow pine, to name a few. Outdoor weathering shows that untreated ties can deteriorate rapidly. Water and UV radiation are a threat to wood’s mechanical integrity, where their combined effect with temperature fluctuations accelerates both dimensional changes and accumulation of internal stresses. Tietan can reduce levels of water uptake by 34% on average, offering the tie a more stable environment where moisture content, stress and strain on the wood fibers can be minimized, thus reducing the development of cracks, splits, and checks. 

 

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