Re-use of incinerated agro-industrial waste as pozzolanic addition. Comparison with spanish silica fume

Abstract

This study attempted to determine the viability of using incinerated agro-industrial waste, ashes C1 and C2, as possible artificial pozzolanic additions in traditional and highperformance concretes and mortars, mainly, and for this reason, a comparative study was likewise conducted with Spanish silica fume (HS). The conclusion drawn from the findings was that the two ashes used could be regarded to be centainly, silicic artificial pozzolanic additions but only C2, which had a higher SiO2 content, could be regarded to be a “microsilica”, however, because its loss on ignition, L.O.I., fell within the acceptable range of variability. In contrast, C1 could not be so regarded because its L.O.I. was too high, despite its higher reactive silica SiO2r- content. For this reason, ash C1 had to be ruled out for any of the proposed uses, even though in terms of chemical and sulfatic characterization it was closer to HS than C2. By contrast, the mechanical strength values of C2 and HS were comparable, making the former initially acceptable for any of such uses. Finally, it has also been justified that, adoption of any method of trial to determine potential resistance to the sulfates of the Portland cements with calcareous filler lacks of sense.

Keywords

• agro-industrial ashes
• pozzolanic additions
• microsilica
• portland cement
• sulfate attack