Short- and long-term ageing of bituminous binders - simulation with the RCAT method

Abstract

Both the short-term ageing (in construction) and long-term ageing (in service) of the bituminous binder are important factors in the performance of bituminous materials. Short-term ageing can be adequately simulated with the RTFOT method, which has been standardized at the European level. For long-term ageing, BRRC has developed - as an alternative to the less well accepted PAV test - the RCAT (Rotating Cylinder Ageing Test) method, which has aroused much interest over the past few years. In the marketed version of the RCAT apparatus, provision has been made to simulate the two types of ageing. To establish equivalence between ageing times, a systematic comparison between RTFOT and RCAT tests both conducted at 163 degrees C was made with several bituminous binders. The measurements of penetration and ring-and-ball temperature as well as the infrared spectra of the binders have shown that 210-240 min of RCAT ageing approximately correspond to 75 min of RTFOT ageing. As a result, the RCAT apparatus appears to be a very practical device with many possibilities for short- and/or long-term ageing tests on normal or modified binders or even on mastics. For the covering abstract see ITRD E117423.