Effects of carbon black on the thermal, mechanical and electrical properties of pitch-matrix composites

The softening temperature of asphalt (pitch-matrix composite containing sand) was increased from 44 to 81°C upon addition of 7.0 vol.% carbon black. Accompanying effects are increase of the storage modulus, decrease of the damping capacity and decrease of the electrical resistivity. All these effects increase with increasing carbon black content. Carbon black and sand together are much more effective than carbon black alone or sand alone for raising the softening temperature. Carbon black is more effective than silica fume for raising the softening temperature, but is less effective for increasing the storage modulus.