Carbonation, oxygen diffusion and water absorption in non-ground natural rice husk ash structural concrete

ISAIA, G.C.; GASTALDINI, A.L.G.; HOPPE, A. E.; CERVO, T.C.; ZERBINO, R.; RODRIGUEZ DE SENSALE, G.

San Juan, Argentina

Congreso; XXIV Jornadas Sudamericanas de Ingeniería estructural; 2010

Asociación Sudamericana de Ingeniería Estructural

In order to amplify the using of rice husk ash near the places where is produced, this work presents the viability of its employment in natural state, without grinding, for conventional concrete constructions. The placement sequence and materials mixture time in the mixer where studied, for obtainment the better performance of the self-grinding in the drum. Concrete reference mixtures with 100% of Portland cement, and with substitution of 15% and 25%, by mass, by natural and grinding RHA where tested. Axial compressive strength, accelerated carbonation, oxygen diffusion and water absorption tests were performed. The results indicate that there is technical viability of RHA using in natural state, without grinding, for employment in structural concrete, for substitution contents of 15%. This limit is determined by the mechanical performance of the RHA natural mixtures. This new employment of this RHA decrease the generate pollution by deposition of this residue in inadequate places and increase the construction sustainability