This research builds on a previous investigation, which found that corrosion-inhibitor-added deicing salts caused degradation of concrete by both anions and cations. The latest research phase looked at methods to detect the chemical reactions between concrete and corrosion-inhibitor-added deicing salts, and to determine the chemical
compositions of the precipitates formed by chemical reactions between concrete and the corrosion-inhibitor-added deicing salts.
The research led to the following conclusions:
* a simple method was developed for the detection of chemical reactions between deicing chemicals and concrete;
* the results provided clear evidence of the chemical reactions between concrete and the corrosion-inhibitor added deicing salts;
* the different amounts of precipitates (chemical reaction products) found in the test cells were dependent on the type and concentration of corrosion-inhibitor-added deicing salts;
* precipitates formed by chemical reactions between deicing chemicals and concrete were identified by using chemical analysis, scanning electron microscopy, and X-ray diffraction analysis;
* and precipitates were calcium and/or magnesium phosphates as a major component, and gypsum as a minor component.
The testing of various deicing chemicals (salt and salt substitutes) and their effect on metal corrosion is a phenomenon that has not been studied very extensively. This study was conducted under laboratory conditions to evaluate the various chemicals and their effect on rebar corrosion under various conditions (room temperature, high temperature, wet-dry, excess oxygen (bubbled and stirred).
The results show that the various chemicals react to different tests with varying results. No one chemical deicer was successful in all tests.
Many chemical additives designed to inhibit the corrosive effect of salt on rebars are being marketed. Their effort on Portland Cement Concrete is neither known or understood. This study is an attempt to determine if there is an effect and to understand the nature and results of the effects
