EVALUATING THE EFFECT OF HYDRATED LIME ON THE WORKABILITY OF GRANITE STONE DUST MODIFIED ASPHALT MIXTURE

Abstract

In this experimental work, the effect of hydrated lime on the workability and performance of the GSD (Granite Stone Dust) Modified Asphalt Mixture is investigated. In GSD Modified Asphalt Mixture, the problem of compaction in GSD is addressed. GSD Modified Asphalt Mixture, which is structurally superior in nature, in many instances, turns out to be stiff and difficult to compact due to poor density and resistance to the environmental effects of the constructed pavement. In this case, the workability of GSD can be improved by adding hydrated lime. Lab work was carried out on mixes that had 0%, 1%, 2%, 3% and 4% hydrated lime compared to the weight of filler (the total mass of the aggregate). Hydrated lime physical and chemical analysis, Marshall Mix Design, Indirect Tensile Strength (ITS), assessment of resistance to moisture damage, and workability analysis based on Marshall Flow, Air Voids, VMA, and VFB were done. From the above results, it can be noted that the addition of hydrated lime has increased the physical and chemical properties of the mixes significantly. The values of VMA and VFB gradually increase with the addition of lime, showing better compaction of mixes at the microscopic level and higher density of the mastic portion of the mixes. ITS increases from 1,092 kPa in the unmixed (neat) mixes to 1,288 kPa in mixes containing 3% lime, and this indicates higher binding properties of the mixes due to addition of lime. Meanwhile, the Marshall Stability increases with higher contents of lime and Marshall Flow reduces from 3.8 mm in the control mixes to 3.6 mm at 3% lime content, showing the mixes to be stiffer and less deformable. In general, the combination that imparted the optimal strength properties and stability at the same time had a lime content of 3% hydrated lime, in spite of requiring higher compaction effort. Conclusion: Hydrated lime can be considered an effective active filler in improving the performance properties of GSD-modified asphalt mixes in the tropics, and it is recommended that it be used in controlled proportions to achieve durable and well-compacted roads