Characterisation of asphalt concrete mixes with municipal solid waste incineration fly ash used as fine aggregates substitution

Abstract

ABSTRACT Characteristics of dynamic modulus (|E*|) and phase angle are necessary to determine the response of bituminous mixtures. Limited regressions are available in the literature for phase angle prediction. This research focuses on the effect of using municipal solid waste incineration (MSWI) fly ash as fine aggregates substitution on the performance of HMA mixes. Therefore, (MSWI) fly ash was incorporated in bituminous mixtures in five substitution percentages (0%, 5%, 10%, 25% and 50%). Mix design was conducted according to Superpave mix design method to find the optimum binder content of the various mixes. Two predictive models were used to better fit the phase angle mastercurvesand reduce the deviation at higher and lower limits of the frequency loading. The results indicated that the absorption of binder increased with higher substitution percentages. Similarly, higher voids in mineral aggregates and voids filled with asphalt values were observed with higher replacement percentages. The incorporation of (MSWI) fly ash affected the mixture's stiffness. Lower (|E*|) values were observed for all mixes as compared to the control mix. Mixes with MSWI fly ash developed lower and higher phase angle values as compared to the conventional mix depending on the percentage of replacement and the frequency range.