Graduate Thesis Or Dissertation

 

Developing a Standard to Assess Water Repellency and Dimensional Stability of Preservative Treated Railroad Ties or Other Large Timbers Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/x059cd088

Descriptions

Attribute NameValues
Creator
Abstract
  • Untreated wood is inherently hygroscopic and moisture content variations can have substantial effects on dimensional stability leading to the development of deep surface checks that further enhance moisture uptake and ultimately encourage deterioration. The horizontal exposure of wood crossties makes water repellency and dimensional stability particularly important in railroad applications. Ties are typically preservative treated to prolong service life. Preservatives primarily protect against insect and fungal attack, but many also alter hygroscopicity and enhance dimensional stability. Currently, there is no standard method for assessing the water repellency and its interaction with dimensional stability in large wooden members such as railroad ties.Potential methods for assessing moisture behavior were investigated on four wood species. Untreated or materials treated with creosote, pentachlorophenol or ammoniacalcopper zinc arsenate were assessed. Samples were subjected to eight accelerated wetting and drying cycles. Dimensional stability and water repellency were evaluated after each cycle using digital image analysis techniques to quantify checking and observing water droplet contact angle over time, respectively. Water repellency varied widely with cycles, but creosote and pentachlorophenol treated samples provided the best resistance to moisture uptake. Dimensional stability was more variable and more dependent on treatment in terms of check development. The results of this work will be used to develop a rapid, reproducible and cost-effective method for assessing the water repellency and dimensional stability of preservative treated wood used in railroad and other applications.
  • Keywords: Pentachlorophenol, Wood, Preservative, Water Repellency, Creosote, Contact Angle, ACZA, Dimensional Stability, Image Analysis, Checking
License
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Committee Member
Academic Affiliation
Non-Academic Affiliation
Rights Statement
Publisher
Peer Reviewed
Language
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items