New Life Expectancy. Self-curing Concrete from Canada and Long-lived Bridge Decks

This article describes a more durable concrete that will increase the average lifespan of bridge decks by more than 20 years compared to typical high-strength concrete, and by more than 40 years compared to normal-strength concrete. This high-performance concrete has been specially formulated to minimize shrinkage, which is typical of high-strength concrete, while maintaining its excellent mechanical properties. It also greatly reduces cracking, which diminishes the penetration of aggressive agents into the concrete, such as chlorides from the de-icing salts used on roads. As a result, it takes considerably more time for the chlorides to reach the steel reinforcement, initiate corrosion and induce further damage to the structure. The key difference is in the sand: lightweight, porous, shale-fine aggregate, which replaces about a quarter of the normal sand used to make concrete. This porous sand can hold up to 20 percent of its own weight of water, which serves to cure the concrete uniformly from the inside, thus preventing self-desiccation. With a unit cost only 5 percent higher than that of a standard high-strength concrete, Cusson expects concrete bridge decks made with this new concrete to last longer, saving taxpayers money in annual bridge maintenance, recurring repairs and associated traffic disruption, and replacement.

Language

  • English

Media Info

  • Media Type: Print
  • Features: Figures;
  • Pagination: p 5
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 01349453
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 6 2011 7:26PM