Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Coal Waste Could Provide Eco-Friendly Option to Cement

Jeff Hanson, department of photography, U. of Alabama
Fly Ash material in a University of Alabama laboratory.
Jeff Hanson, department of photography, U. of Alabama

Fly Ash material in a University of Alabama laboratory.

Abstract:
Concrete is the most common construction material used globally, accounting for 70 percent of all construction materials. Though concrete has advantages such as easy application and high availability, it has major disadvantages when considering sustainability.

Coal Waste Could Provide Eco-Friendly Option to Cement

Tuscaloosa, AL | Posted on December 22nd, 2011

Dr. Jialai Wang, a University of Alabama associate professor of civil, construction and environmental engineering, is working on a solution to these environmental problems by finding an alternative to cement use in concrete.
Wang received a $450,000 collaborative grant from the National Science Foundation to develop an inexpensive and eco-friendly construction material with fly ash. While the material is like cement, it eliminates many of its environmental concerns, Wang said.
Fly ash is a fine powder derived from burning coal. Use of these coal waste products conserves space in landfills, in which they would otherwise be dumped. Fly ash can be used to create a stronger and more durable form of concrete, Wang said.
And, because it displaces the use of cement, it eliminates the main disadvantages of cement. First, it eliminates the issue of greenhouse gas emissions, Wang said.
The production of cement releases a large amount of greenhouse gases, which account for 7 percent of the nation's total carbon-dioxide emissions. The achieved emissions reduction is equivalent to eliminating 25 percent of the world's vehicle emissions, he said.
Secondly, fly ash use eliminates the deterioration issues of cement. Cement tends to be highly brittle and weak, Wang said, in comparison to fly-ash materials. Roads and structures built with fly ash last longer and require less maintenance. Additionally, unlike cement, the material is easy to recycle, he said.

As cement materials harden and disintegrate, they release radon, Wang said. A harmful emission that can pose serious health risks, radon has been linked with certain cancers. Fly ash materials release significantly less radon than cement, he said.

Wang's three-year study is focused on perfecting fly-ash materials and developing methods for large-scale production. Fly-ash materials tend to be strong with compression, but brittle with tension. To combat this issue, Wang is experimenting with adding carbon nanotubes to the fly ash.
Carbon nanotubes, or CNTs, are modified forms of carbon with a cylindrical structure. They are spun into long, thin fibers, like yarn, that are tougher and stronger than steel, Wang said.
Adding CNTs to the fly ash not only strengthens the material, but it also makes it multifunctional. In addition, CNTs are excellent electrical and thermal conductors, he said.
By adding CNTs, fly ash materials become electrically conductive. Electric conductivity can be used to enhance melting ice on structures, such as bridges and airport runways, eliminating possible winter hazards.
The conductivity also changes with applied force. As applied force changes, the electric resistance changes. A change in conductivity often indicates damage or increased load to a material.
Therefore, testing the electric resistance of the fly ash materials reinforced with CNTs is a simple way to determine if there is any damage to a structure, he said.
Wang said CNT's can "sense" structural damage, a function called "self-sensing."
"Civil structures are just like the human body," Wang said. "They can be ‘sick.' If no action is taken, there can be serious consequences. Materials with self-sensing abilities can let you know promptly where there is a problem in a structure and catastrophic failure, like the collapse of a bridge, can be avoided."
Wang has received a patent for the technology he developed to combine CNTs with fly ash. The nanotube technology, nicknamed "Pop Tube technology," uses microwave radiation to initiate nanotube formation. The microwaves cause nanotubes to pop out, like popcorn.
The PopTube technology has many advantages compared to existing methods, he said. It requires very simple equipment, can be easily scaled up for large-scale manufacture and is highly energy-efficient and cost-effective.
Wang has partnered with Dr. Shanlin Pan, UA assistant professor of chemistry, and Dr. Xingyu Zhang, an assistant professor of fiber and textile engineering at Auburn University.

The goal of this study is to garner information valuable for further studies in eco-friendly and durable materials. Such materials would, Wang said, have significant social, economic and environmental benefits for the construction industry.

####

For more information, please click here

Contacts:
Chris Bryant
UA media relations
205/348-8323


Source:
Dr. Jialia Wang
205/348-6786

Copyright © Newswise

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Tiny bubbles provide tremendous propulsion in new microparticles research-Ben-Gurion U. June 21st, 2017

Enhanced photocatalytic activity by Cu2O nanoparticles integrated H2Ti3O7 nanotubes June 21st, 2017

Researchers developed nanoparticle based contrast agent for dual modal imaging of cancer June 21st, 2017

Nanotubes/Buckyballs/Fullerenes/Nanorods

Tests show no nanotubes released during utilisation of nanoaugmented materials June 9th, 2017

Ag/ZnO-Nanorods Schottky diodes based UV-PDs are fabricated and tested May 26th, 2017

Fed grant backs nanofiber development: Rice University joins Department of Energy 'Next Generation Machines' initiative May 10th, 2017

Nanotubes that build themselves April 14th, 2017

Discoveries

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Tiny bubbles provide tremendous propulsion in new microparticles research-Ben-Gurion U. June 21st, 2017

Enhanced photocatalytic activity by Cu2O nanoparticles integrated H2Ti3O7 nanotubes June 21st, 2017

Researchers developed nanoparticle based contrast agent for dual modal imaging of cancer June 21st, 2017

Materials/Metamaterials

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Alloying materials of different structures offers new tool for controlling properties June 19th, 2017

Smart materials used in ultrasound behave similar to water, Penn chemists report June 16th, 2017

Development of low-dimensional nanomaterials could revolutionize future technologies June 15th, 2017

Announcements

Rice U. chemists create 3-D printed graphene foam June 22nd, 2017

Tiny bubbles provide tremendous propulsion in new microparticles research-Ben-Gurion U. June 21st, 2017

Enhanced photocatalytic activity by Cu2O nanoparticles integrated H2Ti3O7 nanotubes June 21st, 2017

Researchers developed nanoparticle based contrast agent for dual modal imaging of cancer June 21st, 2017

Environment

Enhanced photocatalytic activity by Cu2O nanoparticles integrated H2Ti3O7 nanotubes June 21st, 2017

Can crab shells provide a 'green' solution to malaria? Study shows how a mixture of chitin and silver nanoparticles inhibits growth of mosquito larvae May 12th, 2017

NanoMONITOR shares its latest developments concerning the NanoMONITOR Software and the Monitoring stations April 21st, 2017

Wood filter removes toxic dye from water April 21st, 2017

Construction

Russian scientists create new system of concrete building structures: Sientists of Peter the Great Saint-Petersburg Polytechnic University developed a new construction technology April 24th, 2017

Next-gen steel under the microscope March 18th, 2017

Graphene foam gets big and tough: Rice University's nanotube-reinforced material can be shaped, is highly conductive February 13th, 2017

New low-cost technique converts bulk alloys to oxide nanowires January 24th, 2017

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project