Ali Rastegar - M.Sc., Faculty of Engineering, Behbahan Khatam Alanbia University of Technology, Behbahan, Iran
sasan motaghed - Assistant Professor, Faculty of Engineering, Behbahan Khatam Alanbia University of Technology, Behbahan, Iran
alireza dadpour - M.Sc., Special Concrete Center (SCC), Behbahan Khatam Alanbia University of Technology, Behbahan, Iran

Rice husk ash (RHA) produced under certain conditions from rice husk as an agricultural surplus material can be used in concrete as a pozzolanic material. Pozzolanic materials improve the durability properties of concrete mainly, but their effects on fresh properties and strength can be different depending on the constituent materials and type of concrete. In this paper, RHA produced from the rice farms of Khouzestan province, Iran has been evaluated for the optimal level of replacement in self-compacting concrete (SCC). To this end, the fresh properties and compressive strength of SCC have been investigated. The used RHA contains ۸۷% silica, mainly in the amorphous state, and has an average specific surface area of ۳۹۹ m۲/kg. The results obtained in this research show that increasing RHA up to ۱۵ % can improve the fresh properties by up to ۱۰%, but it reduces the compressive strength by about ۱۰%. So the ۱۰-۱۵% replacement of cerement with RHA is recommended.

pozzolanic materials, Compressive strength, slump flow, J-ring, V-funnel