Scientists in Ontario are studying a new, stronger type of concrete made with shale sand that will be used on improvements to the $75 million Seaway International Bridge near Cornwall, Ont., in 2011.
Daniel Cusson, leader of the National Research Council team, said the key is that shale sand evenly retains water, making it less permeable. Today's conventional concrete is more prone to erosion.
"The salt and moisture can diffuse and reach into the pores of the concrete and reach the re-enforcements," Cusson said.
"But our concrete has a low permeability … it's very dense."