PaintSquare.com
Follow us on Twitter Follow us on LinkedIn Like us on Facebook Follow us on Instagram
Search the site

 

Download our FREE eResource: Specifier's Choice Guide. Get it now.

Coatings Industry News

Main News Page


Concrete Reuse Gets Bolt from the Blue

Thursday, March 7, 2013

More items for Coating Materials

Comment | More

A flash of inspiration has led researchers to a remarkable new lightning-laced advance in recycling concrete.

With the aid of lightning bolts, researchers at the Fraunhofer Institute for Building Physics' Concrete Technology Group in Holzkirchen, Germany, have developed a method to zap concrete into its components—cement and aggregate.

lightning strike

l∞senut / Flickr

Fraunhofer Institute’s Concrete Technology Group has developed a new concrete recycling method with help from lightning and some research from the 1940s.

This jolting method of recycling is much better than crushing it, according to the scientists' research announcement.

Reducing CO2

Concrete manufacturing accounts for eight to 15 percent of global carbon dioxide production, according to the researchers. One ton of burned cement clinker of limestone and clay releases 650 to 700 kilograms of CO2.

“And when it comes to recycling waste concrete, there is no ideal solution for closing the materials loop,” the team said. Germany alone generated 130 million tons of construction waste in 2010, the scientists note.

Although various groups are pursuing concrete recycling, the current processes produce huge amounts of dust; at best, the stone fragments end up as sub-base for roads, not building material, the German team said.

concrete recycling
© Fraunhofer IBP

The new method can break down concrete into its constituent parts.

“This is downcycling,” explains Volker Thome, a researcher from the institute.

To curb some of the harmful carbon emissions and efficiently reduce concrete into workable ingredients for new construction, the team revived a method that Russian scientists developed in the 1940s and “put it on ice,” they said.

Pulsed Lightning

The new process involves using “electrodynamic fragmentation”—very short pulses of induced lightning—to separate concrete into aggregate and cement materials.  

“Normally, lightning prefers to travel through air or water, not through solids,” said Thome. To ensure that the bolt strikes and penetrates the concrete, the experts used the Russian scientists’ expertise.

water

Malene Thyssen / Wikimedia Commons

Lightning prefers to travel through water rather than a solid.

More than 70 years ago, they discovered that dieletric strength (the resistance of every fluid or solid to an electrical impulse) is not a physical constant, but changes with the duration of the lightning, the scientists said.

“With an extremely short flash of lightning—less than 500 nanoseconds—water suddenly attains a greater dielectric strength than most solids,” explains Thome.

'A Small Explosion'

Fraunhofer researchers learned that when concrete immersed in water is hit with a 150-nanosecond bolt of lightning, the discharge runs through the concrete and weakens it.

“In the concrete, the lightning then runs along the path of least resistance, which is the boundaries between the components, i.e. between the gravel and the cement stone,” the researchers said.

Explained Thome: “The pre-discharge which reaches the counter-electrode in our fragmentation plant at first, then causes an electrical breakdown.

“At this instant, a plasma channel is formed in the concrete, which grows within a thousandth of a second, like a pressure wave from the inside outwards. The force of this pressure wave is comparable with a small explosion.”

Currently, the laboratory fragmentation plant can process one ton of concrete waste per hour. Thome said the researchers have a goal of at least 20 tons per hour, which could be market-ready in less than two years.

   

Tagged categories: Concrete; Construction; Recycled building materials; Research

Comment Join the Conversation:

Sign in to our community to add your comments.

Advertisements
 
BASF
 
New resins from BASF will have metals loving water!
 
Excellent corrosion resistance, low VOC, high gloss, thin films www.basf.us/industrialcoatings dpsolutions@basf.com 800-231-7868
 

 
PPG Protective and Marine Coatings Group
 
We Protect and Beautify the World
 
PPG is widely recognized as a world leader in protective and marine coatings, developing innovative, cutting-edge products and services.
 

 
Mitsubishi Gas Chemical America
 
Performance Amine 1,3-BAC
 
A highly reactive cycloaliphatic diamine offering superior performance. Reasonable cost and curing efficacy makes it suitable for all types of epoxy resin applications.
 

 
Hempel (USA) Inc.
 
Trusted worldwide for advanced protective coatings
 
Trusted worldwide
for advanced
protective, coatings
–Full range of 
  advanced coatings
–Optimised application
–Fast, reliable service  worldwide. Contact us at oilandgas@hempel.com
 

 
Jotun Paints Inc.
 
Jotachar JF750 - The Time Saving Solution
 
The only mesh free solution for jet fire scenarios. Jotachar saves installation time and material costs - the next generation of epoxy passive fire protection.
 

 
Carboline Company
 
Carboline is pouring with opportunities
 
We are proud of our exceptional products and services, and believe that people are our greatest asset. Come grow with us!
 

 
Corrosion Probe, Inc.
 
From Detection to Correction
 
Corrosion Probe, Inc. has the Most Concrete Coatings Experience and Expertise. Contact us today at
860-767-4402, www.cpiengineering.com
 

 
Sherwin-Williams
 
Sherwin-Williams General Polymers Resinous Flooring App
 
Our coatings and linings expertise available 24/7, allowing you to explore the Sherwin-Williams systems best suited for your flooring needs. Android Users Click here to Download the app today!
 

 
Detail Masters
 
Overspray Removal
 
We offer professional, turnkey service and unparalleled quality!
Our process can save hundreds— even thousands of dollars. It's fast, environmentally safe and 100% guaranteed.
 

 
PreTox Products - NexTec, Inc.
 
GOT LEAD? Specify Pretox System products
 
The ONLY Lead Stabilizer Compatible with All Paint Removal Methods. Works with all Blast Media: Grits | Recyclable Abrasives | CO2 | Water | Power Tools | Etc. Call Dave Steffen at 800.338.8296.
 

 
 
 

Technology Publishing Co., 2100 Wharton Street, Suite 310, Pittsburgh PA 15203-1951

TEL 1-412-431-8300  • FAX  1-412-431-5428  •  EMAIL webmaster@paintsquare.com


The Technology Publishing Network

Durability + Design PaintSquare the Journal of Protective Coatings & Linings 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