Initial study of Eucalyptus Wood Ash (EWA) as a mineral admixture in concrete

Abstract

This study evaluated the possibility of using in natura Eucalyptus Wood Ash (EWA) from aviary furnaces as a mineral admixture in concrete. The ash was 100 mesh-sieved and added to the mix in 5, 10, 15 and 20% of the cement bulk. Physical analysis unveiled that EWA has a specific gravity higher than other organic originated residues, whereas its BET specific surface area is not enough to enhance its filler and/or pozzolanic effects. Chemically, the residue presented a low organic matter rate and a SAI below the minimum required by the Brazilian standards. EWA interfered in the times of cement set, increasing them, while FTIR unveiled mainly the presence of calcium carbonate bonds. The admixture compromised the concretes mechanical performance, leading to the conclusion that the sieving procedure of EWA alone is not enough do admit its usage as a mineral admixture.