Rheology of Mortar and Concrete Containing Mineral Admixtures

WOS:000325240000002 International audience The demand of the concrete of high durability was increased in Algeria due to seismic destructions, which took place in 2003. After this disaster the construction works increased significantly. Also the importance of mineral addition application, as partial replacement of Portland cement rose considerably, but under conditions of maintaining high properties of the mix and hardened concrete. In order to choose such mineral additions in this work the rheological properties of the mixture and concrete were tested, in which 10% of Portland cement were replaced by metakaolin, natural pozzolana and grand chamotte bricks. The rheological tests have shown that this additions caused the increase of concrete mix densification and increase significantly the stress yield value. It is linked with the increase of mix thixotropy in the case of pozzolana and metakaolin addition. It means that at given w/c ratio and superplasticizer content the concrete has high flocculation degree. In order to enhance fluidity it is necessary to increase of water content or superplasticizer addition. However, the addition of ground chamotte bricks increase only the content of fine aggregate, but it needs also water increase in order to workability improvement.