Evaluation of stone mastic asphalt using palm oil fuel ash as filler material

Abstract

This paper presents a study of laboratory evaluation on the performance of Stone Mastic Asphalt (SMA) using Palm Oil Fuel Ash (POFA) as filler material. POFA produced by burning palm fibre and shell which is generally used as boiler fuel to produce steam for electricity generation in the mill. POFA is one of the materials identified to have a potential of becoming an alternative filler material in SMA mixes. In this project, a small portion of POFA (passing 75µm) was used to modify asphalt mixtures. POFA was incorporated into asphalt mixes by using dry process method which refers to technologies that mix POFA with the aggregate prior to mixing it with asphalt binder. The aggregate gradations use in this study is gap graded (stone mastic asphalt with 14mm nominal maximum aggregate size-SMA14). The percentage of POFA added was varied from 0 to 7 % (2% hydrated lime) by weight of the total aggregate which is 0 to 100% by weight of the filler content. Samples was prepared and compacted using Marshall Method. Several performance indicators of mixes was evaluated using laboratory work were moisture induced damage/stripping resistant and Marshall volumetric properties. The performance results of modified asphalt mixes were compared to conventional asphalt mixes (unmodified samples). Based on the results, the performance of HMA mixes such as stability, flow and stiffness was significantly affected with the addition of POFA. The results suggest that 50% POFA by weight of filler content is the optimum value.