USE OF SEWAGE-SLUDGE ASH(SSA)-CEMENT ADMIXTURES IN MORTARS

The chemical composition of sewage sludge ash (SSA) and their sized fr actions are studied, some differences in chemical composition are obse rved. SEM studies show irregular shape of SSA particles and sized frac tions, this shape has a decisive influence on workability of mortars. The effect of replacing 15% of portland cement by SSA and their sized fractions: coarse (SSAC) and medium (SSAM) obtained by sieving on comp ressive (R(c)) and flexural (R(f)) strength of mortars was investigate d. The study reveals an enhancement of strength when ashes are used, d ue to probably, pozzolanic properties of SSA.