Use of Wastewater Treatment Sludge (WTS) As Filler in Hot-Mixed Asphalt Concrete

This research deals with the use of sludge from the Water Treatment Plant of Ponta do Ismael, in the city of Manaus, state of Amazonas, Brazil, as a filler fraction in hot-mixed asphalt concrete, replacing the mineral filler traditionally used in this region (Portland cement). Five asphalt mixtures were analysed, one as reference (100% Portland cement) and four others, using sludge in the proportions of 25%, 50%, 75% and 100%, by mass, reaching a maximum of 5%, in relation to the total mass of the mixture. Specimens of the five asphalt mixtures were moulded and the results according to Marshall stability, flow value, static indirect tensile strength, resilient modulus and repeated-load indirect fatigue (fatigue life) were analysed. All the physical and mechanical properties of the five mixtures met the specifications of Brazilian standards, having mixtures with sludge showing better performances than the reference mixture.