Engineered cementitious composite

Engineered Cementitious Composite, (ECC) is an easily molded and shaped mortar based composite reinforced with short random fibers,cite web
title = A brief introduction to ECC and ECC technology network
url = http://www.engineeredcomposites.com/html/introduction.html
accessdate = 2007-11-03
work =Engineeredcomposites.com ] usually polymer fibers.

ECC, unlike common fiber reinforced concrete, is a micromechanically designed material. This means that the mechanical interactions between ECC's fiber, and matrix are taken into account by a micromechanical model which calculates these elemental properties into a strong and flexible composite material. As a result, guidelines for the selection of fiber, matrix and interface characteristics advantageous to creating ECC, such as the use of polymer fibers instead of pumice, steel or clay become available.

ECC's tensile strain hardening behavior has a capacity in the range of 3-7%, which means that unlike common concrete, which is brittle and breaks under that amount of strain, ECC will bend under the same stress, like a piece of sheet metal. The high ductility is achieved by optimizing the microstructure of the composite employing micromechanical models. ECC looks exactly like regular concrete, but under excessive strain, the ECC concrete bends because the distinctively coated matrix of fibers in the cement is allowed to slide within the cement.cite web
title = U-M researchers make bendable concrete
url = http://www.umich.edu/news/?Releases/2005/May05/r050405
accessdate = 2007-11-03
work =Umich.edu ] ECC is made using the same ingredients of regular concrete but without the use of coarse aggregate. The University of Michigan has a research team whose ECC technology has been used on projects in Japan, Korea, Switzerland, Australia and the U.S.It has had a relatively slow adoption in the U.S. according to Professor Victor C. Li, who is the leader of U-M’s research team that is developing its own ECC. Traditional concrete's many problems: lack of durability, failure under severe strain, and the resulting expenses of repair, have been a pushing factor in the devolpment of ECC.

Comparison to other composite materials

Note: FRC=Fiber-Reinforced Cement. HPFRCC=High-Performance Fiber Reinforced Cementitious Composites

See also

*High performance fiber reinforced cementitious composites

References

External links

* [http://nisee.berkeley.edu/usjhcs/livc.html US - Japan Composite and Hybrid Systems Research Program]
* [http://www.j-act.org/4-3.html Surveys on the research and development of Engineered Cementitious Composites]