Estudo sobre a utilização do resíduo com origem no processamento do caulim como filler em misturas asfálticas.

Abstract

Kaolin is largely used by several industries, especially the paper industry that absorbs 47% of world production of this mineral in the coating (33%) and filling (14%) phases of paper production. Kaolin processing industry sector has been considered responsible of environment contamination and pollution because it generates a great amount of silica-rich residue. Kaolin industry agents are considering mitigating this problem by finding a practical and environmental friendly use for this residue, such as filler in asphalt mixtures. This may reduce the environmental problem caused by kaolin residue and pavement costs. Thus, this residue was characterized by chemical, thermogravimetric and thermic differential analyses, as well as by X-ray and laser diffraction, and sedimentation granulometry. Penetration and Saybolt-Furol viscosity tests were also performed to evaluate the use of this residue as filler in asphalt mixtures. Lottmam portic and Marshall frame trials were run to determine the effect of kaolin residue and lime on the resistance of the asphalt mixture to the presence of water. The presence of these fillers in the asphalt mixture increased its water resistance. However, kaolin residue resulted in a more flexible mixture that probably will prevent premature cracks during pavement lifetime