Wheel tracking test

Keyword paving material, asphalt mixture, waste plastics, recycling, Marshall test, wheel tracking test, dynamic stability, bending test. 

Wheel tracking test specimens were prepared by compacting asphalt mixtures into a mold of 300 by 300 mm, and 50 mm in depth, with a roller compactor. The test apparatus is a machine in which a loaded wheel with a solid rubber tire of 200 mm diameter and 50 mm wide is rolled to and fro on a specimen of an asphalt mixture. A photograph of the apparatus is given as Fig. 2. 

Table 3. Dynamic stabilities of asphalt mixtures measured by wheel tracking test...

Table 6 shows the DS values measured by the wheel-tracking test for core samples collected during the present survey, compared with those for core samples collected at... 

Permanent deformation behaviour of asphalts is determined by the wheel tracking test (see Sections 7.6.5 and 7.6.6). From an extensive study, it was found that the wheel tracking parameters such as rate or the wheel tracking slope and the rut depth or the proportional rut depth of the asphalt concrete mixtures (AC 20 mm) with SBS-modified bitumen were, in all cases, lower than those obtained for the AC 20 mm mixtures with 50/70 grade bitumen (Nikolaides and Manthos 2009). 

The resistance to permanent deformation is determined with respect to the wheel-tracking test. The resistance to permanent deformation, expressed accordingly, should be lower than the maximum values of the category (or categories) specified. 

The wheel-tracking test is carried out in accordance to CEN EN 12697-22 (2007), using deferent devices. For an AC, the test conditions per device used are determined in CEN EN 13108-20 (2008). 

The mechanical stability of BBTM is expressed in terms of rutting performance, determined by carrying out the wheel-tracking test (CEN EN 12697-22 2007). 

The simplest test used to study the deformation behaviour of asphalts was the static unconfined uniaxial compression test, termed the creep test, developed in the 1970s by Shell Bitumen (Hill 1973). The specimen was subjected to static axial compressive load over a long period (1 h). The test procedure was very simple and required low-cost equipment. In addition. Shell Bitumen developed a rut prediction procedure based on results of the creep test but soon realised that it underestimated rut depths measured in trial pavements (Hill et al. 1974). This was attributed to the effects of dynamic loading producing higher deformation in the wheel-tracking test (Van de Loo 1974). 

The wheel-tracking test and the cyclic compression tests, apart from determining the resistance to permanent deformation of a bituminous mixture, also make it possible to rank various mixes or to check on the acceptability of a given mix. 

The wheel-tracking test was developed for the determination of asphalt susceptibility to deformation under moving load simulating conditions that exist on the road. The tests are all described in CEN EN 12697-22 (2007). 

Apart from the above alternative testing procedures, if wheel-tracking test is executed by a small-size device, two alternative procedures may be followed. 

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. 

Table 7.6 Limiting wheel-tracking test requirements for dense asphalt concrete for base and binder courses...

Table 7.9 Limiting wheel-tracking test requirements by French design guide ...

The development and use of the wheel-tracking test are relatively recent in the United States. The wheel-tracking test procedures used in the United States for the determination of the resistance to permanent deformation, or susceptibility to rutting, of the bituminous mixtures are (a) the asphalt pavement analyser (APA) test and (b) the Hamburg wheel track (HWT) test. 

The HWT test is one of the first wheel-tracking tests, developed in Germany, and is used in the United States by various agencies. Today, it is not as widely used as the APA tester. The test procedure is specified by AASHTO T 324 (2011). 

Figure 7.24 Specimens during the wheel-tracking test with the APA device. (Courtesy of Pavement Technology Inc.)...

The wheel-tracking test using the APA for evaluating the rut resistance of bituminous mixtures is carried out in accordance to AASHTO T 340 (2010). The test is used as part of fundamental performance tests for Superpave mix design. 

Wheel-tracking test with the use of the Hamburg device... 

This wheel-tracking test with the use of Hamburg device, developed in Germany during the 1970s, is carried out in accordance to AASHTO T 324 (2011). 

AASHTOT 324.2011. Hamburg wheel-track testing of compacted hot mix asphalt ( HMAj. Washington, DC American Association of State Highway and Transportation Officials. 

Markhussen - Paulsen (15) Rotating wheel tracking test. Non-tracking - erosion through thickness of 2mm occurred at 4288 hours. 

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