Study on properties of rice husk ash and its use as cement replacement material

• Published in: Materials research (São Carlos, São Paulo, Brazil) Vol. 13; no. 2; pp. 185 - 190
• Main Authors: Habeeb, G A, Mahmud, H B
• Format: Journal Article
• Language: English; Portuguese
• Published: ABM, ABC, ABPol 01.06.2010; Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
• Subjects: Ashes; Cements; compressive strength; Concretes; Density; ENGINEERING, CHEMICAL; fineness; MATERIALS SCIENCE, MULTIDISCIPLINARY; METALLURGY & METALLURGICAL ENGINEERING; Particle size; pozzolan; Rice; Strength; Surface area; XRD; compressive strength; pozzolan; XRD; fineness
• ISSN: 1516-1439; 1980-5373; 1516-1439
• DOI: 10.1590/S1516-14392010000200011

The properties of rice husk ash (RHA) produced by using a ferro-cement furnace were investigated. The effect of grinding on the particle size and the surface area was studied, then XRD analysis was conducted to verify the presence of amorphous silica in the ash. The effect of RHA average particle size and percentage on concrete workability, fresh density, superplasticiser content and compressive strength was also investigated. Although grinding RHA would reduce its average particle size, it was not the main factor controlling the surface area and it resulted from RHA's multilayered, angular and microporous surface. Incorporation of RHA in concrete increased water demand. RHA concrete gave excellent improvement in strength for 10% replacement (30.8% increment compared to the control mix), and up to 20% of cement could be valuably replaced with RHA without adversely affecting the strength. Increasing RHA fineness enhanced the strength of blended concrete compared to coarser RHA and control OPC mixtures.