Experimental evaluation of the effects of partial replacement of coarse aggregate with Graded Palm Kernel Shell in Asphaltic Wearing Course

This research looked at the evaluation of the effect of partial replacement of coarse aggregate (4-8mm crushed stone) with graded palm kernel shell in asphaltic wearing course. The volumetric and physical properties of the asphalt mixtures were evaluated in order to determine the performance characteristics of PKS in the mass production of wearing course asphalt concrete for medium traffic road. Percentages of PKS used were 0%, 30%, 50%, 70% and 100%. Specifically, 15 samples for control mix and 60 samples for the PKS proportions of compacted asphalt mixtures were prepared by using Marshall mixing procedure. The samples were prepared by varying bitumen contents from 5.0% to 7.0% in an increment of 0.5% and tested using the Marshall method. In summary, at 30% replacement of coarse aggregate (4-8mm crushed stone) with the graded palm kernel shell at 5.8% bitumen content, the Marshall stability was 12.800KN, Flow was 2.920mm, Va was 3.0%, VFB was 83.100%. The results indicated that the mixture at 30% PKS meets the criteria provided in the Asphalt Institute Standard Specification. It was observed that for medium trafficked roads, graded palm kernel shells between 10%-30% by weight of coarse aggregate (4-8mm crushed stone) can be used for the replacement while even 100% replacement is possible for lightly trafficked rural roads.