Effect of Metakaolin’s finesses and content in self-consolidating concrete

Self-consolidating concrete is characterized by its high deformability or its capability of filling all the spaces without external forces, maintaining the stability, without segregation or blocking. SCC needs high content of fines, which could be mineral admixtures, superplasticizer and low content of aggregates with limited maximum dimensions. Present work intends to verify the effect of the finesses and content of Metakaolin in SCC properties with different paste volumes, at fresh and hardened states. Metakaolin was used at three different finesses and at 5% and 35% of substitution to cement mass. It was found that the superplasticizer consumption increased with higher finesses and content of Metakaolin. Increasing the paste volume, less superplasticizer was necessary. Better mixtures were obtained with the paste contents of 0.45 and 0.50, by total volume, which presented good cohesion and a reduced admixture consumption. However, for the compressive strength, a reduction occurred at high paste volumes.