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.
===PG Graded Asphalt Binder===
'''Binder''' is the new name for asphalt cements. It is the glue that holds the aggregate together and makes asphalt black. PG graded asphalt binder is a new method of specifying binder appropriate for the climate where the asphalt mixture is to be laid. The binder is tested to make sure it gives the greatest amount of flexibility during cold temperatures (to resist cracking) and the greatest amount of rigidity during warmer temperatures (to resist rutting).<br>The type of PG graded asphalt binder used depends on the temperatures of the area. For example, in Florida, binders need to be able to deal with extended periods of heat. In Alaska binders need to deal with prolonged periods of cold. In Wisconsin the binders need to have flexibility to deal with both types of climates.<ref>http://auto.ihs.com/document/abstract/BGMEIBAAAAAAAAAA</ref>
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[[Category:Construction]]