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

 

Download our free ebook on Advances in Corrosion Control Coating Technology

Paint and 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.

Wasser High-Tech Coatings Inc.
Wasser Coatings Protect

Wasser Coatings offer a complete range of Moisture Cure Urethane (NEPCOAT approved) systems in addition to Polyurea membranes and linings(NSF).
www.wassercoatings.com


Hempel (USA) Inc.
Wider range of Hempel Protective Coatings now approved by Norsok.

Proven high performance products that protect your assets. Contact us today at protective@hempel.com to find out more.


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.


Sherwin-Williams
Sherwin-Williams Protective & Marine Coatings

With 4,000 distribution points and 3,700+ years of experience, Sherwin-Williams delivers the products, support and expertise you need, right where you need it.


Seymour Midwest
Coating Application Tools & Supplies

Visit our “Where to Buy” site to find a local paint or tool supplier near you. Click here for a chance to win $500 of Tools & Supplies. 1(844)739-6687 Sales@SeymourMidwest.com


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


Carboline Company
Fireproofing Solutions

Pyroclad® X1 Thermo-Lag® Pyrocrete® – protecting against hydrocarbon and jet fires, explosions, and cryogenic spills.


PPG Protective and Marine Coatings Group
Bringing innovation to the surface.™

PPG Protective & Marine Coatings is widely recognized as a world leader in protective and marine coatings, developing innovative, cutting-edge products and services.


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.


CS Unitec
Work Cleaner and Safer

CS Unitec’s new ATEX Vibro-Lo Kits feature low-vibration scalers for use in hazardous environments. Kit includes dust shroud, CuBe needles, fall arrestor and lanyard.

 
 
 
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