Compatibility of superplasticizers with fly ash and limestone fillers ternary blended cements

Ternary blended cement is more and more used for technical, environmental and economical purposes. Depending on availability, blast furnace slags, fly ashes and limestone fillers are mixed in large proportions for cement production, allowing reduction of CO2 production and use of natural resources. As limestone fillers are largely produced in Wallonia because of quarries and aggregate delivery, this product has been incorporated in concrete up to 35% and properties of concrete containing also fly ashes have been evaluated. This paper presents the results of the study of the compatibility between ternary blended cements and superplasticizers. Tests are realized on mortars and concrete. They clearly show that concrete containing the highest limestone fillers rate, have a low initial setting and zero setting after 30 minutes when a superplasticizer is not used. Impure fillers seem to have a very negative impact on the loss of consistency after 30 min. Air content systematically increases with the use of superplasticizer type polycarboxilate; the naphthalene type seems to have a lower impact on air content. Finally, cement having higher clinker contents exhibit higher compressive strengths and many of ternary blended cements are fulfilling standard requirements.