Study the Effect of Mineral Filler on the Mechanical Properties of Hot Mix Asphalt

Abstract

The important component in the asphalt mixture is mineral filler materials as it plays an essential part in the stiffening and toughening of asphalt binder. In addition, the mechanical properties of asphalt binder are influenced by the mineral filler, and significantly affected with respect to stripping or moisture susceptibility. This paper is displayed the mechanical properties of asphalt mixtures that used asphalt binder grade (40-50), the gradation of aggregates selected with the mid-point according to the Iraqi specification and two types of mineral filler materials (High Reactivity Attapulgite (HRA) and Portland Cement (PC)) according to the empirical requirements. The mixtures are produced and compacted according to the Marshall Mix design method. In addition, this paper is displayed the positive influence of HRA and PC in the asphalt mixtures such as (Volumetric Properties, Marshall Properties, Marshall Stiffness, the Indirect Tensile Strength and Moisture Susceptibility). The results explained that the (5%) and (7%) HRA had an important influence on the properties of asphalt mixtures. With the increment in the percentages of HRA, the volumetric properties of asphalt mixtures enhanced. Laboratory investigation results support the advantage of adding HRA to the asphalt mixtures. HRA as an active mineral filler has good resistance to moisture sensitivity and mechanical properties, which contributes to extending the life cycle of the pavement layer.