Senior Engineering Manager
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Client Officer - Water Resources Engineer
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Erosion and Sediment Control Inspector
News Bits and Pieces -
May 23, 2006
Winter may be over, but its effects can still be seen in the cracked and deteriorating sidewalks across the Northern hemisphere. After over half a century of research by the concrete community, a new study published in the Journal of the American Ceramic Society identifies the mechanism responsible for this type of damage and suggests innovations that could help reduce the billions of dollars spent on repair annually.
Salt scaling is a physical mechanism whereby the smooth surface layer of new concrete is stripped away, leaving sidewalks and other concrete structures vulnerable to increasingly rapid deterioration caused by frost and salt. These cracks run a short distance into the surface of the concrete, eroding it in flakes. Over time, this process exposes the stone in the concrete and opens many small cracks, leading to an accelerated rate of damage and therefore causing states to spend more tax dollars on repair.
In the past, researchers focused on identifying a chemical explanation for this phenomenon, but this study demonstrates that the cause is actually physical and could be reduced by new procedures or additives that increase concrete’s surface strength. These findings suggest that more attention should be paid to how concrete is placed and initially cured.
Further research on solid or chemical additives that raise concrete’s surface strength could lead to stronger concrete that is able to withstand many more winters without the expense of being repaired or replaced.
The Virginia Engineer © IIr Associates 2005