Wheel-tracking test by a small device, , in air

Before the development of CEN EN 12697-22 (2007), the wheel-tracking test was carried out, in some countries, in accordance with BS 598-110 (1996). The procedure specified was quite similar to procedure A, using a small-size device, but with some differences. 

The wheel-tracking test in the BS procedure had gained popularity because of the size and simplicity of the device required to be used and a lot of research has been carried out using this procedure. 

The wheel-tracking parameters are used for the evaluation of conformity of the bituminous mixtures and for the selection of the target mix, during mix design, with respect to their rut resistance. Some countries have determined limiting requirements. 

Site description Test temperature CQ Maximum wheeltracking slope (mm/1000 cycles) Maximum proportional rut depth (%) Maximum rut rate (mm/h) Maximum rut depth (mm) 

1 Moderately to heavily stressed sites requiring high rut resistance 45 WTS, m.o 2.0 4.0 

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