The particle size distributions of ground bagasse ashes are shown in Fig. 2, with some 2.8% of the particles of ground bagasse ash L20 retained on a 45-lm sieve compared with 47.1% of the OBA. The OBA had large particles with a mean particle size (d50) of 23 lm. Following grinding, the mean particle size was reduced to near 10 lm. For Portland cement, the mean particle size was 14.6 lm.