Improving the vibration damping capacity of cement

Cement pastes containing latex (20-30% by weight of cement), methylcellulos e (0.4-0.8% by weight of cement) and silica fume (15% by weight of cement, either as received or acid treated) were compared in terms of the dynamic f lexural mechanical properties, as expressed by the loss tangent (damping ca pacity), storage modulus and loss modulus at 0.2-2 Hz (loading frequency) a nd 30-150 degrees C. Treated silica fume and latex are by far the most effe ctive admixtures for enhancing the loss tangent (up to 0.18, an increase of up to 390%). Silica fume (whether as received or treated) is the most effe ctive admixture for enhancing the storage modulus (up to 15 GPa). Latex ten ds to give a high loss modulus (up to 0.18 GPa) at 2 Hz; silica fume tends to give a high loss modulus (up to 2.2 GPa, an increase of up to 2200%) at 0.2 Hz. (C) 1998 Kluwer Academic Publishers.