Biotite influence on the binding properties of bituminous materials.

Abstract

The effect of biotite on rheological properties of bitumen was investigated using biotite extracted from gneiss rocks. The research methodology involves two phases. The first phase involves the separation of biotite from gneiss rock. The second phase involved tests carried out on bitumen- biotite blend to determine the effect of biotite on the rheological properties of bitumen. The biotite was ground to 75µm size and blended with bitumen AC-10 prepared in various proportions and the rheological properties determined in the laboratory. The results of this study shows that biotite improves the binding properties of bitumen. At low temperatures, the presence of biotite in bituminous mixtures in the proportion of 2 to 3.5% by weight of bitumen improves the binding properties. Conversely, at higher temperatures of about 135oC, the biotite bitumen mix showed best result at 2%. An increase of up to 3.5% by weight of biotite resulted in a drop in the kinematic viscosity values even though there was an improvement in the binding properties over the pure AC-10 bitumen results.