Abstract:
The road pavement construction industry of consumes a large amount of virgin aggregate and Solid
waste material has impacts on environmental problem. Therefore, this investigation aims to explore
the suitability of filter cake powder as a filler in hot mix asphalt. FCP is taken from alum factory
from awash melkasa town. The study used purposive method of sampling materials. Marshall mix
design method was used for designing both conventional and filter cake powder mixtures. For
conventional four percent of bitumen content (4.3,4.8,5.3 and 5.8%) and three crushed stone filler
content 5.5,6.5 and 7.5% were used to determine optimum bitumen content and optimum filler
content. Optimum bitumen content and optimum filler content was used to prepare Marshall
Specimen with mixture of filter cake by replacement 0,10,20,30,40 and 50%. Marshall Immersion
test method was used to determine tensile strength ratio of both fillers (conventional and filter cake)
to evaluate Moisture susceptibility of the mix. The results show that adding filter cake by partially
in hot mix asphalt improves its mechanical properties. The optimum filter cake ratio gives the
maximum stability of HMA is at 30% FCP. The values of stability, flow, bulk specific gravity, voids
filled with asphalt, air voids and voids filled in mineral aggregates at 30% optimum filter cake
powder content were, 11.49 kN, 3.21 mm,2.253 g/cm3, 72.7%, 3.84%, and 14.06%, respectively.
While the 0,10,20,40 and 50% FCP fulfill the requirements of Ethiopian Road Authority and
Asphalt Institute standard specifications. Marshall Immersion test resulted, tensile strength ratio
was 83.6 and 90.2% for mix with fully crushed stone dust and replaced filter cake at 30%
respectively. Result showed that resistance of moisture induced damage of filter cake is higher than
crushed stone dust filler in hot mix asphalt. This study concluded, all the mixes with partial
replacement of filter cake has significant effect on performance of hot mix asphalt concrete
production. Therefore, based on this study, filter cake powder can be considered as an alternative
to conventional filler in hot mix asphalt. The amounts of waste filter cake can be removed from
factory and significantly environmental damage can be reduced
