New- Bitumen Degradation Factor
The QED analyser can indicate if the bituminous binder from road surface planings is suitable for re-use.
This QED fingerprint shows road binder made from fresh bitumen stock with no recycled asphalt present.
This QED fingerprint shows bitumen that has been heavily oxidised and degraded
This fingerprint compares degraded (blue line) and undegraded (black line) road binder. Bitumen contains many hundreds of organic compounds that give the material its elasticity, water resistance and stickiness. As the material degrades, these compounds are broken down, as seen by the relative height of the peak on the right to that on the left. This reduces the performance of the bitumen.
The blue shaded area compared to the undegraded bitumen can be used to estimate the amount of degradation. The heights of the small peaks seen can also provide a second indicator of degradation. The combined values allow a Bitumen Degradation Factor to be derived. A BDF of less than 100 indicates an undegraded bitumen, between 100 and 500 a degraded bitumen and above 500 a very degraded bitumen. This sample has a BDF of 926.
In the example on the right, the bitumen is relatively unoxidised, but is showing some degradation compared to the undegraded bitumen. The BDF is 87.