FLOW PROPERTIES OF CEMENT PASTES - INFLUENCE OF MIXING METHOD, WATER REDUCER AND WATER TO CEMENT RATIO

摘要

This study estimate the effect of mixing method - i.e. two mixers and different loading sequence - on the rheology of cement pastes without and with different water reducers. The water to cement ratio is adapted to obtain a large domain of consistencies. Rheological properties of cement paste are studied by rheometry with vane geometry and also by two simple consistency tests: flow time measured with Marsh cone and spreading. The two simple consistency tests seem appropriate to describe the effect of different mix-design and mixing method evolutions on cement paste rheology. At same solid content and admixture, cement pastes are more fluid when they are produced with the mortar mixer rather than with the blender. This effect practically vanishes when more effective water reducers are used. The loading sequence of the mixer also can change in a significant way the consistency of the cement paste.