ANALYSIS OF FLY ASHES PRODUCED IN TEXAS

Abstract

Five fly ashes produced in Texas from sub-bituminous coals and lignites were analyzed in terms of variability and their effect on fresh properties of mortars. As these fly ashes contain significant quantities of CaO, a rapid and reliable method of determining the total CaO content was developed. Using the CaO Heat Evolution Test, the CaO content can be determined in a field laboratory in less than 10 minutes. The Texas fly ashes, although somewhat variable, exhibit excellent properties for use as a partial lime replacement in soil stabilization and as a partial portland cement replacement in concrete. Extremely strong correlations were found between many of the physical characteristics and chemical properties of the five fly ashes. (FHWA)