The purpose of this work is to study the influence of Rice Husk Ash (RHA)
on the mechanical strength of mortars. For this purpose, ash was produced by
calcining rice husk at 680˚C for 5 hours to produce reactive pozzolan. The
chemical and mineralogical composition studied by Inductively Coupled
Plasma-Atomic Emission Spectrometry (ICP-AES) and X-Ray Diffraction
(XRD) showed that this ash is rich in amorphous silica. The ash presents a
good pozzolanic activity with a lime fixation rate of 100% after only 7 days of
treatment. The addition of RHA to cement contributes to the formation of
calcium silicate hydrate (CSH) and calcium aluminate hydrate of C3ASH6
type. The presence of RHA in the mortars improves their mechanical
strength. This improvement is due to the filler effect of RHA and to formation of the CSH resulting from the pozzolanic reactivity between the
amorphous silica of the RHA and the portlandite released by hydration of the
cement.

Mortar, Rice Husk Ash, Mechanical Strength, Filler Effect