REHEATING AND COMPACTION TEMPERATURE OF HOT MIX ASPHALT

Different studies discussed about the effect of temperature on hot mix asphalt and found significant effect on the performance of asphalt concrete pavement. This study was intended to investigate the effect of reheating and remolding on the hot mix asphalt tested at different cooling time and effect of temperature on the asphalt pavement road compaction also evaluated and analyzed by compacting the Hot Mix Asphalt at different compaction temperature and the difference has been studied with reference to the normal Marshall Mix Design preparation procedures. The effect of temperature on compaction of hot mix asphalt has been studied at different compaction temperature starting from 60oC to 160oc in the laboratory. While the effect of reheating is studied by cooling the HMA at different cooling hours 0Hrs, 5Hrs, 12Hrs and 24Hrs and reheating to a compaction temperature. The test result shows that temperature does have an effect on the compaction asphalt and on the performance of the paved asphalt road. This thesis presents the statement of the problem, objectives, literature review; test methodology of Design Analysis and evaluation of effects of temperature on the hot mix asphalt in accordance to the most commonly used Hot Mix Asphalt Concrete Mix Design Methods used in Ethiopian highway Roads. From various mix design methods of hot mix asphalt Marshal Mix design is a default method in Ethiopia. Even if this mix design methods performed considering actual traffic flow, actual weather condition, reliable expected compaction and compaction methods, Design aggregate structures, Design Asphalt binder content it is observed that some roads are failed to serve for the required design period. iii Therefore, evaluating and analyzing the mix design method in use considering the actual condition will increase the performance period of the road, minimizes unwonted periodic maintenance and damage of the road. The ultimate goal of this thesis is to analyze and evaluate the temperature of hot mix asphalt design method, and recommend some conditions that have to be kept in mind while preparing mix design and working with hot mix asphalt. Accordingly, 22 samples are prepared to analyze the compaction temperature of hot mix asphalt, to be compacted at different compaction temperature and the figured effect is significant. Whereas 10 samples are also analyzed for the effect of reheating and remolding which practiced at different cooling temperature and the result is found to be significant