Dynamic Modulus and Phase Angle of Asphalt Concrete Mixtures Containing Municipal Solid Waste Incinerated Fly Ash as Mineral Filler Substitution

Abstract

Waste and recyled materials have been introduced in asphalt concrete mixtures as substitute for raw aggregates along with the efforts towards constructing sustainable pavements. Municipal solid waste incinerated (MSWI) fly ash is among the alternative materials that can be be used as substitute for the natural mineral filler. However, the effect of using (MSWI) fly ash on the mechanical properties of bituminous mixtures is fragmented and not thoroughly evluated. Additionally, various studies assessed the performance of asphalt mixtures with (MSWI) fly ash as filler replacement in terms of indirect tensile strength, moisture susceptibility, frost resistance and Marshall stability. Therefore, there is a need for the evaluation and realistic prediction of the performance of asphalt concrete mixtures with (MSWI) fly ash used as filler substitution. The objective of this research study is characterising asphalt concrete mixtures with (MSWI) fly ash used as subtitute for the limestone filler, notably 0%, 25%, 50%, 75% and 100% by weight of aggregates and evaluating their performance in comparison with the control mix. This is conducted mechanistically through linear viscoelastic characterisation. Linear viscoelastic characterisation comprises measurement of the stiffness of the mixture expressed in terms of dynamic modulus and the extent of elastic and viscous response expressed in terms of phase angle. The findings revealed that the use of (MSWI) fly ash in asphalt concrete mixtures as filler substitution increased the rutting resistance up to 50% of incorporation and the resistance to low temperature cracking when incorporated in percentages higher than 25%. © 2022, The Author(s), under exclusive licence to Chinese Society of Pavement Engineering.