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

 

Download our free Wastewater Treatment Coating Systems eResource Book

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.

Fischer Technology Inc.
DUALSCOPE®FMP100 with DataCenter IP

Transfer customized inspection plans from PC to FMP100 using step-by-step guidance with prompts and pictures throughout the measurement procedure


KTA-Tator, Inc. - Corporate Office
KTA-TATOR LABORATORY SERVICES

• Coating failure analysis
• Independent
  comparative testing
• Accelerated
  weathering testing
• Toxic metals testing
• A2LA Accredited
Contact: Kevin Brown,
at 336-386-4000


HoldTight Solutions Inc.
NO FLASH RUST -
NO CONTAMINANTS

Our HoldTight®102 salt remover & flash rust preventer prevents flash rust by removing surface contaminants. It has no equal; only wannabees.
Contact us for your
nearest distributor.
(800) 319.8802 sales@holdtight.com


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.


DeFelsko Corporation
A Smart New Way to Measure

PosiTector SmartLink and free mobile app turns your cell phone or tablet into a virtual PosiTector gage.


Atlantic Design, Inc.
ENGINEERING SOLUTIONS, NOT EXCUSES

See our website for features of our best seller, the ADI 3500CFM 4-Pot Blast Vacuum Recycler. A smaller package with all the ADI power you need. 866.Call.ADI


SAFE Systems, Inc.
SAFE Systems'
Blast Lights &
Deadman Switches

Halogen or LED blast lights available with our NEW urethane bumper. Switches available in many colors for color coding your hoses.


NLB Corporation
MiniARM automates surface prep

NLB’s Mini ARM lets an operator control high-pressure water jets remotely, with fast tool changes for different jobs. It maximizes protection and productivity.


Avalotis Corporation
Choose experience. Choose quality. Choose safety.

Avalotis Corporation has been meeting and exceeding clients’ specifications and expectations for almost 50 years. The first name in painting and protective coatings: Avalotis.


Montipower, Inc.
The MBX Bristle Blaster

Get a 2.7 to 3.3 mil profile and a Near White Metal Clean. For info visit www.mbxit.com or call 877 629-8777

 
 
 
 
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 2000-2016, 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