Engineering properties of blended concrete with Colombian rice husk ash and metakaolin

The effects of partial replacements of Portland cement by Metakaolin (MK) and Rice Husk Ash (RHA) on the mechanical and durability properties of concrete mixtures were investigated. Two types of RHA -thermal (TRHA) and chemical treated (ChRHA)-and a sample of MK, at different percentages of replacement by weight, were studied. MK was produced by heat treatment (700 degrees C for 2 hours) of a Colombian kaolin. The properties of the investigated concrete include compressive strength and durability. The durability aspects tested were: water absorption, chloride ion penetration, carbonation and sulfate resistance. The results were compared with those of cementitious materials without the pozzolanic admixtures and with addition of Silica Fume (SF). It was noted, in general an enhanced performance on the mechanical and durability properties of the concretes, proving the feasibility of its rational utilization in engineering as supplementary cementing materials for environmental sustainability.