Details

Autor(en) / Beteiligte

• Mostafa, Ahmed M.
• Diederich, Paco
• Yahia, Ammar

Titel

Effectiveness of rotational shear in dispersing concentrated cement suspensions

Ist Teil von

• Journal of sustainable cement based materials, 2015-10, Vol.4 (3-4), p.205-214

Ort / Verlag

Taylor & Francis

Erscheinungsjahr

2015

Quelle

Taylor & Francis

Beschreibungen/Notizen

• Buildup of cement suspensions has a great impact on their structural behavior. Cement suspensions differ considerably in their buildup kinetics because of the various mixture and testing parameters. Accurate assessment of buildup of cement suspensions relies on their dispersion state before measurements. The effectiveness of various rotational shear rates to disperse concentrated cement suspension proportioned with a water-to-cement ratio (w/c) of 0.35 is evaluated. The storage modulus and the shear stress were measured before and after applying disruptive shear rate using small-amplitude oscillatory shear. Test results indicated that the highest dispersed state can be attained using a rotational shear rate corresponding to the transition shear rate from shear thinning to shear thickening. Beyond this value, shear-thickening effects dominate and flocculation can take place, resulting in less dispersed state.