In mid-2005, University of Michigan professor Victor Li unveiled a fiber-reinforced bendable concrete. The concrete is made of what Li’s group calls Engineered Cement Composites. The concrete certainly looks like regular concrete, and Li says it is 500 times more resistant to cracking and 40 percent lighter in weight.
In an interview given at that time, Li told the University of Michigan Daily that ECC-built roads might be able to last for 10 years. That kind of life span would be desirable given that Li estimated that ECC concrete might be triple that of traditional concrete.
The secret to ECC is the use of stretchable fibers that are embedded in the concrete. Traditional concrete has tremendous compressive strength but doesn’t do well under tension. In the past, builders have tried to get around this problem using rebar and mesh.
The use of fibers within concrete goes back at least 30 years. Li’s breakthrough is because of the type of polymers his group used.
Later today I will be posting another video and update on this story featuring Li’s latest improvement: Self-healing concrete.