Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Materials science: The secret of nanoparticle packing in cement

Abstract:
Cement production is responsible for 5% of carbon dioxide emissions. If we are to invent a "green" cement, we need to understand in more detail the legendary qualities of traditional Portland cement. A research group partly financed by the Swiss National Science Foundation (SNSF) is tackling this task.

Materials science: The secret of nanoparticle packing in cement

Switzerland | Posted on December 20th, 2012

Discovering the perfect composition of Portland cement, the most common type of cement, was the result of years of experience as well as repeated trials and errors. Emanuela Del Gado, SNSF professor at the Institute for Building Materials of the ETH Zurich, explains that its success is the result of two key factors: its legendary hardness and the availability of its constituent elements.

5% of carbon dioxide emissions
The flipside of the coin: its production requires burning calcium carbonate. This process is responsible for approximately 5% of all carbon dioxide emissions or the equivalent of the entire 2007 emissions of India. But a more sustainable recipe for cement has to meet high standards both in terms of material hardness and accessibility to raw materials.

Because of the massive ecological impact of cement production, various research groups worldwide are trying to understand why the mixture of this powder and water sets to such hardness.

Different densities at the nano level
Researchers of the Massachussetts Institute of Technology (MIT) have concentrated on studying the behaviour of concrete at the nano level. In their experiments, they used an instrument capable of applying mechanical stress at the sub-micro level. As a result, they were able to show that densities vary strongly from one measuring point to the other at this scale. But they were not able to explain why.

This is where physicist Emanuela Del Gado enters the scene. She takes a special interest in amorphous materials whose constituents combine in a disorderly manner. Her studies of such materials focus on the nano level. "It is at this level and not at the atomic level that certain material properties are revealed. This also applies to hydrated calcium silicate, a major component of cement which plays an important role in the setting process," she explains.

Packing particles of different sizes
The researchers first developed a packing model of hydrated calcium silicate nanoparticles. They then devised a method for observing their precipitation based on numerical simulations. This approach has proven successful (*). "We were able to show that the different densities on the nano scale can be explained by the packing of nanoparticles of varying sizes. At this crucial level, the result is greater material hardness than if the particles were of the same size and it corresponds to the established knowledge that, at macroscopic level, aggregates of different sizes form a harder concrete."

Until today, all attempts to reduce or partially replace burnt calcium carbonate in the production of cement have resulted in less material hardness. By gaining a better understanding of the mechanisms at the nano level, it is possible to identify physical and chemical parameters and to improve the carbon footprint of concrete without reducing its hardness.

Full bibliographic information

E. Masoero, E. Del Gado, R. J.-M. Pellenq, F.-J. Ulm, and S. Yip (2012). Nanostructure and Nanomechanics of Cement: Polydisperse Colloidal Packing. Physical Review Letters. DOI: 10.1103/PhysRevLett.109.155503

####

For more information, please click here

Contacts:
Martina Stofer


Prof. Dr. Emanuela Del Gado
Institut für Baustoffe
ETH Zürich
CH-8093 Zürich
Tel.: +41 44 633 37 44

Copyright © AlphaGalileo

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

International research partnership tricks the light fantastic March 2nd, 2015

UC research partnership explores how to best harness solar power March 2nd, 2015

Researchers turn unzipped nanotubes into possible alternative for platinum: Aerogel catalyst shows promise for fuel cells March 2nd, 2015

Important step towards quantum computing: Metals at atomic scale March 2nd, 2015

Govt.-Legislation/Regulation/Funding/Policy

New nanodevice defeats drug resistance: Tiny particles embedded in gel can turn off drug-resistance genes, then release cancer drugs March 2nd, 2015

Forbidden quantum leaps possible with high-res spectroscopy March 2nd, 2015

Researchers turn unzipped nanotubes into possible alternative for platinum: Aerogel catalyst shows promise for fuel cells March 2nd, 2015

First detailed microscopy evidence of bacteria at the lower size limit of life: Berkeley Lab research provides comprehensive description of ultra-small bacteria February 28th, 2015

Discoveries

Colon + septic tank = unique, at times stinky, study: Researchers use lab-scale human colon and septic tank to study impact of copper nanoparticles on the environment March 2nd, 2015

New nanodevice defeats drug resistance: Tiny particles embedded in gel can turn off drug-resistance genes, then release cancer drugs March 2nd, 2015

Breakthrough in OLED technology March 2nd, 2015

Important step towards quantum computing: Metals at atomic scale March 2nd, 2015

Announcements

International research partnership tricks the light fantastic March 2nd, 2015

UC research partnership explores how to best harness solar power March 2nd, 2015

Researchers turn unzipped nanotubes into possible alternative for platinum: Aerogel catalyst shows promise for fuel cells March 2nd, 2015

Important step towards quantum computing: Metals at atomic scale March 2nd, 2015

Research partnerships

Breakthrough in OLED technology March 2nd, 2015

UC research partnership explores how to best harness solar power March 2nd, 2015

Researchers turn unzipped nanotubes into possible alternative for platinum: Aerogel catalyst shows promise for fuel cells March 2nd, 2015

Imec Demonstrates Compact Wavelength-Division Multiplexing CMOS Silicon Photonics Transceiver March 1st, 2015

Construction

Nanoparticles Increase Durability of Concrete Decorations in Cold Areas January 26th, 2015

Transparent artificial nacre: A brick wall at the nanoscale January 22nd, 2015

Atomic placement of elements counts for strong concrete: Rice University researchers model particulate systems to determine their qualities January 14th, 2015

Iranian Researchers Prolong Life of Steel Armatures in Concrete Structures January 9th, 2015

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







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE