Concrete containing high-calcium fly ash is vulnerable to sulfate attack, but in some regions this type of fly ash is abundantly available and represents a valuable resource to the construction industry.

This research is aimed at improving the sulfate resistance of concrete containing high-calcium fly ash and elucidating the mechanisms control the performance of fly ash concrete exposed to sulfates.

The project includes the following studies:

• Monitoring performance of concrete in cyclic (wet/dry) and static sulfate exposure tests
• Chemical and mineralogical study of a wise range of fly ashes
• Mechanistic studies using scanning electron microscopy and x-ray diffraction to determine the quantity and nature of reaction products

This project is being funded by Texas DOT (through collaboration with the University of Texas at Austin).