Superplasticized Portland cement: Production and compressive strength of mortars and concrete

This paper deals with the effect of intergrinding different percentages of a naphthalene-based superplasticizer with Portland cement clinker and gypsu m on the fineness of the product, and on the water requirement and the comp ressive strength of the mortars made with the superplasticized cement. The properties of the fresh and hardened concrete made with the superplasticize d cements were also investigated. The results showed that the intergrinding of a given amount of a naphthalene-based superplasticizer with Portland cl inker and gypsum reduced the grinding time required for obtaining the same Blaine fineness as that of the control Portland cement without the superpla sticizer. The water requirement of the mortars made with the superplasticiz ed cements was similar to that of the mortars made with the control Portlan d cements when the same amount of the superplasticizer was added at the mor tar mixer; for a given grinding time and a Blaine fineness of similar to 45 00 cm(2)/g, the mortars made with the superplasticized cement had higher co mpressive strength than those made with the control Portland cement. For a given grinding time or Blaine fineness of cement greater than or equal to 5 000 cm(2)/g, the slump loss, air content stability, bleeding, autogenous te mperature rise, setting times, and compressive strength of the concrete mad e with the superplasticized cements were generally comparable to those of t he concrete made with the control Portland cements when the superplasticize r was added at the concrete mixer. Crown Copyright (C) 1998 Published by El sevier Science Ltd.