PaintSquare.com
      | Connect Follow us on Twitter Like us on Facebook
About | Subscribe | Advertise
  

 

Download our free e-book! Protecting and maintaining transmission pipeline

Protecting Concrete on the Beijing-Shanghai Railway Bridge

From JPCL, December 2011

More items for Quality Control

by Huang Weibo, Liu Xudong, Lu Ping, and Ma Xueqiang, Research Institute of Functional Materials, Qingdao Technological University, China.

The authors give a brief history of polyurea use in China, describe the Beijing-Shanghai High-Speed Railway and the polyurea specification for it, explain the project's major coating challenges, and describe the tests that led to a solution. The authors are with the Research Institute of Functional Materials, Qingdao Technological University, China. ...
(Login to read the full article)

   

Tagged categories: Bridges; Concrete; Durability; Polyurea; Rail

Comment from Jerry Trevino, (2/7/2012, 6:02 AM)

It seems that the failures of the polyurea (if I understand this correctly) are attributed to the concrete conditions, temp, humidity, bug holes, etc. Also the incompatibility of the epoxy primers to the Polyurea. Maybe the early failures should be blamed on the characteristics of the Polyurea not the primers or the concrete. The concrete is what it is. If you shot blast or abrasive blast, you will get more profile and more bug holes, that is what you want to remove weak layers of concrete. Maybe the solution is to apply the epoxy at normal curing temps, then spray a thin coat of a aliphatic polyurethane. Polyurea is intriguing, however, it likes to bond to itself more than it likes to bond to concrete. Any moisture on the concrete surface will tend to react with the isocyanates in the curing agents of the polyurea, releasing Co2 and making foam. Polyureas have great potential, I do not think applying them to concrete, especially where there is moisture transmission through the concrete. Most existing structures do not have the luxury of a vapor barrier before they were installed. Just my biased opinion.


Comment from Jerry Trevino, (2/8/2012, 8:25 AM)

I apologize to my overreaction to my first scan reading of this article. Properly due respect should be given to this case study. Obviously, an impressive feat. A lot of questions first came to mind, one is why was a polyurea selected in the first place? What was the decision making process on that, secondly, based on the extreme temperature conditions, how was the concrete placed and cured in those conditions? If not then why is the coating expected to be applied under those conditions, or did the placement happen at better temperature and humidity environments ? Also what was the concrete composition, design, mechanical properties, post tension conditions etc. Could have the original concrete surface be abrasive blasted then coated with a high pozzolanic reactive cement coating, then be coated with a primer and then the polyurea application? Microsilica and other pozzolan cements will reduce permeability of water and thus chlorides and sulfates in the ground into the main concrete structure by at least 10 times. This also allows primers and maybe polyureas to bond better to protect the overall structure. Could have an elastomeric polyurethane, an amine cured epoxy, or polyester resin perform just as well as the polyurea? Just Asking ! Great Article by the way. Congratulations to the publisher.


Comment Join the Conversation:

Sign in to our community to add your comments.

KTA-Tator, Inc. - Corporate Office
KTA-Tator EH&S Services

• Ambient & Worker Exposure Air Monitoring
• Safety & Health Program Development
• Lead Paint Assessments
& Specifications
• Health Hazard & Jobsite Safety Assessments
Call 1-800-245-6379


Elcometer, Inc.
New Elcometer 456 Coating Thickness Gauge

Best In Class Just Got Better. Technologically Intelligent And Robust. Marvelous Design And Durability. An Earth-Shattering Revolution In Coating Inspection.


SSPC: The Society for Protective Coatings
http://www.sspc.org/

Join SSPC and Enhance
Your Career !


U.S. Zinc
Service. Better With U.S.

From custom-blend zinc dust products to technical support, logistics and environmental compliance, we are there for you.


Absolute Equipment/Grand Rental Station
Portable Power from Absolute Equipment

•Compressors
•Lighting Systems
•Generators
•Light Compaction
Sales • Rental • Service
Call 1-866-931-6655
Over a century of
providing excellence.


Abrasives Inc.
One Call Orders it All!

Life is good when it’s simple. We distribute Clemco blast equipment, nozzles & parts alongside our proven blast media. Make your call: Abrasives Inc. 800-584-7524


Fischer Technology Inc.
MP0R with rotating display screen

Automatic rotating display screen just like your smart phone. Click for Video
Call 800-243-8417


Minerals Research & Recovery

HIGH PERFORMANCE ABRASIVES


“Made in the USA!”

Why recycle waste from other countries? Go FASTER, CLEANER, at 1/3 THE COST with MR&R “All-American” Sharpshot®HP!!

WATCH THE VIDEO


BASF
New resins from BASF will have metals loving water:

Excellent corrosion resistance, low VOC, high gloss, thin films basf.us/industrialcoatings
polyorders@basf.com
800-231-7868


Safway Services
One Source. Every Solution.

The Safway Group is your source for multiservices. Painting, coating, insulation and more – all from the most trusted name in the industry.

 
 
 
 
Technology Publishing

The Technology Publishing Network

The Journal of Protective Coatings & Linings (JPCL) PaintSquare
Durability + Design Paint BidTracker

 
EXPLORE:      JPCL   |   PaintSquare News   |   Interact   |   Buying Guides   |   Webinars   |   Resources   |   Classifieds
REGISTER AND SUBSCRIBE:      Free PaintSquare Registration   |   Subscribe to JPCL   |   Subscribe to PaintSquare News
MORE:      About PaintSquare.com   |   Privacy policy   |   Terms & conditions   |   Site Map   |   Search   |   Contact Us
 

© Copyright 2000-2015, Technology Publishing / PaintSquare, All rights reserved
2100 Wharton Street, Suite 310, Pittsburgh PA 15203-1951; Tel 1-412-431-8300; Fax 1-412-431-5428; E-mail webmaster@paintsquare.com