SUPERPLASTICIZER AND AIR-ENTRAINING AGENT DEMAND IN OPC MORTARS CONTAINING SILICA FUME . ADMIXTURES FOR CONCRETE: IMPROVEMENT OF PROPERTIES. PROCEEDINGS OF THE INTERNATIONAL SYMPOSIUM HELD BY RILEM (THE INTERNATIONAL UNION OF TESTING AND RESEARCH LABORATORIES FOR MATERIALS AND STRUCTURES), BARCELONA, MAY 14-17, 1990

Blends of ordinary portland cement with different parts of silica fume have been used for mixing of mortars in which the superplasticizer and air-entraining agent (AEA), requirement was investigated. Mortars were prepared with a water-binder ratio of 0.6. The fresh mix consistancy (measured by flow table test), the components blends proportions, micro-sieve analysis and the particle size distribution (measured by sensing zone method) of anhydrous cement blends as well as the added water reducing agents and AEA-agent quantity were considered. The results have shown that increasing the fine particles content of anhydrous blends, also increases the quantity of superplasticizer and air entraining agent needed to produce a given mortar consistency. (TRRL)