| dc.description.abstract | The study investigated cracks in flexible pavement on a section of Kampala-Masaka Road. The continuous occurrence of cracks which has affected the riding quality, increase in travel times as the vehicles be moving at a slow speed rather than the design speed and eventually the road in future will become not motorable. To realise the study objectives, primary data from the field comprising surface condition survey, traffic counts, FWD test and coring of the pavement for laboratory tests using, Marshall Test, indirect tensile stress test and secondary data for axle load data were acquired from UNRA. The PCI of the subject pavement section was 46.8% which falls between the limit of Poor (41-55) %. Therefore, the condition of the selected pavement section was qualitatively rated as poor. The estimated traffic loading of 54.0 MESA determined was not significantly different from the actual design value of 44.1 MESA indicating that the pavement structure was strong enough to carry the current traffic loading. FWD deflection bowl for the Subgrade layer was still in sound structural condition and for Base layer and Asphalt concrete layers were in warning structural condition. The materials characteristics were within the acceptable specification requirements except for the air voids which were at 5.7% being greater than 5.0% which is the maximum value provided for in the specification. Finally, the study concludes that for the section of the road being along the swamp and the road rehabilitation, which was completed in 2013, much attention was not catered for to strengthen the subgrade, therefore the underground movements in the swamp contributed to the cracks on the asphalt. It is recommended that the existing asphalt layer should be milled off and reconstructed with strict quality control regimes in place. | en_US |
