Assessing the Use of Marble Dust as a Mineral Filler in Asphalt Concrete to Reduce Rutting

Abstract

Flexible road pavements are primarily built using materials such as aggregates, bitumen, and fillers. This study explores the potential of using marble dust, a byproduct generated during the extraction, cutting, polishing, and shaping of marble blocks, as a mineral filler in asphalt concrete for flexible pavements. Approximately 30% of raw marble is converted into waste in the form of dust or slurry during these processes. In this research, marble dust collected from the cutting and polishing stages is utilized as a filler material in the bituminous layers of asphalt pavements for experimental evaluation. The first objective of the study is to assess the engineering properties of marble dust, bitumen, and aggregates. The second objective focuses on identifying the optimum bitumen content for asphalt mixes containing marble dust. To achieve this, various aggregate sizes such as 20mm, 14mm, 10mm, 6mm, stone dust, and marble dust were used, and the bitumen content was varied incrementally by 0.5% from 3.5% to 5.5%. The optimum bitumen content was determined using the Marshall Stability test, analysing parameters such as Marshall Stability, Flow Value, Bulk Density, Voids Filled with Bitumen (VFB), Voids in Mineral Aggregates (VMA), and Air Voids in relation to bitumen content. Additionally, the study evaluated tensile strength characteristics through the Indirect Tensile Strength (ITS) test. Results indicated that incorporating marble dust improved Marshall Stability and VMA values while reducing air voids. The third objective of the study centered on the indirect tensile strength performance of the asphalt mix. The key finding is that waste marble dust serves as an effective mineral filler in hot mix asphalt. An optimal mix was achieved with a 5% volume of marble dust and 4.8% bitumen content, making it suitable for road pavement applications.