USE OF SILT OF DAMS AS A SUPPLEMENTARY CEMENTITIOUS MATERIAL IN SELF-COMPACTING MORTARS: EFFECT ON PHYSICAL AND MECHANICAL PROPERTIES

This paper deals with the valorization of silt recovered from dams as a supplementary cementitious material in self-compacting mortars (SCMs). Heat treatment (calcinations) of silt transforms the kaolin content into metakaolin thus making it more active. Portland cement (PC), calcined silt (CS), and ground granulated blast-furnace slag (GGBS) are used to make ternary blends. PC was replaced with 10, 20 30 and 40 % CS (by weight) while GGBS is fixed at 30% of total binder (cementitious materials). Five SCMs mixtures are manufactured with a constant water/binder (w/b) ratio of 0.45. SCMs properties are evaluated by compression and bending tests, water absorption, total drying shrinkage and weight loss measurements at different curing ages. The results obtained show that the introduction of 10% CS induces very little change in the performances of SCM and that a CS replacement level going up to 30% could be considered.