| Summary: | 碩士 === 國立高雄第一科技大學 === 營建工程系碩士專班 === 106 === ABSTRACT
Rutting, oil, cracks, spalling and potholes often occur earlier than expected in Taiwan. In order to effectively improve the quality of asphalt pavement, the Directorate General of Highway has initiated studies regarding performance-base testing. However, there is no sound information on the correlation between rutting behavior of laboratory-mixed and plant-mixed HMA mixtures, neither the correlation between rutting, compaction, and filler. This study investigated 19mm(3/4 inches)/AC-20 HMA mixtures, both laboratory-mixed and plant-mixed, with the Hamburg wheel tracking device (HWTD). The results are to understand how HWTD rutting results are affacted by: 1 compaction(air void %); 2 rolling temperatures; 3 fillers type. The influence of mixture sampling error on oil content, stability/flow and the rutting depth is also examined.
For laboratory-mixed HMA, the stability and flow of mixture using Portland cement as filler are slightly better than those using Ground Granulated Blast-Furnace Slag (GGBFS). However, in the results of HWTD, HMA mixture with GGBFS showed better anti-rutting performance. The alternative cause is GGBFS particle is extremely fine, therefore it can filled in the pores of asphalt concrete, to make it more resistant to rutting.
For plant-mixed mixture, the higher the air void, the lower the resistance to rutting, which means appropriate compaction is important for anti-rutting performance. If sampling error makes the gradation of HMA mixture become coarser, the oil content will be lower for the mixture, but the resistance to rutting is better. On the contrary, if the gradation of HMA becomes finer, the oil content is increased, and the resistance to rutting is relatively worse.
In addition, the resistance to rutting is worse when the rolling temperature is lower than the expected temperature. It is because the lower the temperature, the more difficult for the roller compacting the HMA pavement. The poor adhesion results in high air void and reduces the resistance to rutting.
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