摘要: |
As mad owners around the world look for lower-carbon and longer-lasting roads, the list of ingredients that go into a mix design gets ever longer. It could include recycled asphalt pavement (RAP), crumb rubber, warm-mix additives, rejuvenators or polymer modified bitumen (PMB), to name but a few. Yet, in many markets, the testing regime remains unchanged. "Traditional testing is very popular, but it only allows a ranking of the mix," explained Andrea Carlessi, product manager at testing equipment specialist CONTROLS. "The big limitation is that it does not allow you to understand the behaviour of the mix, it cannot detect the properties that come from adding these new materials." An alternative approach is performance testing. Rather than check that the various elements of a mix meet set criteria and then combining them in specified volumetric proportions, performance testing aims to look at how the mix will actually perform on a particular road. |