Reactive Silicate Coatings for Protecting and Bonding Reinforcing Steel in Cement-Based Composites

This is a paper describing the laboratory testing results from using reactive silica to coat steel reinforcing bar imbeded in concrete.  The ASTM pullout strength was exaluated and found to be more than double the strength based on mechanical interlock alone.  Corrosion testing was performed on the coated bars, and a shift in the corrosion potential was observed at the locations where the coating was deliberately damaged.  The technology is of particular interest to coastal infrastructure where high atmospheric chlorides makes spalling of concrete a serious issue.  Currently this technology is being installed at Corpus Christi Army Depot, and the results to date will be presented.