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535 bytes added ,  23:00, May 20, 2008
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There have been many minor changes to the types of asphalt mixes since the turn of the millenium. These changes were needed to ensure that the performance of HMA meets today's traffic counts and loads. All of these changes, described different mix criteria, aggregate types and sizes, and asphalt binder (liquid asphalt), but all these changes continued to use the outdated Marshall method of mix design.
 
There have been many minor changes to the types of asphalt mixes since the turn of the millenium. These changes were needed to ensure that the performance of HMA meets today's traffic counts and loads. All of these changes, described different mix criteria, aggregate types and sizes, and asphalt binder (liquid asphalt), but all these changes continued to use the outdated Marshall method of mix design.
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SuperPave is a new design method was developed to adopt a national standard for HMA pavements. This standards allows our industry to measure HMA performance on a national level. Therefore a new design method was needed that better simulated the traffic loads expected; one that would perform better under those loads.
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It was also decided that the asphalt binder used needed to do a better job of fitting to the climate in which the mix was to be laid. This resulted in the development of the "performance graded" (PG) asphalt binder.
    
[[Category:Construction]]
 
[[Category:Construction]]

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