Pozzolanic activity of feedlot biomass (cattle manure) ash

► The pozzolanic activity of cattle manure ash and fly ash has been determined. ► Cattle manure ash is a suitable replacement for cement in the preparation of concrete. ► Management of the cattle manure ash can assist the cattle raising industry to drastically reduce waste disposal problems. The pozzolanic activity of cattle manure ash (CMA) was determined and compared with fly ash (FA) in this study. X-ray diffraction (XRD) and energy-dispersive analysis (EDA) were used to determine the chemical composition of the CMA and FA. Scanning electron microscope (SEM) images indicated that the microstructure of the CMA is mainly in the shape of floccules. Mortar prism and concrete cube specimens were tested to determine the reactivity of CMA; the compressive strength of CMA mortar was found to be greater than that of FA mortar. The same result was obtained for concrete cube compressive strengths at 7, 28 and 56 days. Tests of electric flux to assess chloride anion penetration resistance of the concrete gave the CMA concrete the highest results for the four materials after 28 days, and least after 180 days. These results indicate that the pozzolanic activity index of CMA exceeds that of FA, indicating that CMA is a suitable replacement for cement in the preparation of concrete. Such a result can assist the cattle raising industry to drastically reduce waste disposal problems.