6. LPC Bituminous Mixtures Design Guide, Sept 2007. - Aapaq.org

LPC Bituminous Mixtures Design Guide- Relationships between laboratory and field résults -4.2 Large device wheel tracking test4.2.1 The studies conducted in FranceThe comparative studies performed on the basis of sample preparation protocol (inthe laboratory, mixed – i.e. mixing plant production and laboratory compaction, andfrom mix plate samples extracted on worksites) systematically demonstrate theenhanced rutting resistance of field materials. This deviation however is inconsistentand depends on material sensitivity to rutting.As an initial approximation, the following may be adopted:- a rather close similarity in results, provided the mix design displays decent ruttingresistance (e.g. less than 5% at 30000 cycles): deviation of 1% to 2% lower in favorof the worksite;- a major deviation in the formula sensitive to rutting (e.g. 10% at 3000 cycles); thisdifference could reach tenfold in terms of number of cycles, for a given level ofpermanent deformation, which could (as an illustration) reflect a laboratory rut depthof 10% at 3000 cycles, in comparison with a 10% onsite rut depth after 30000 cycles.Figures 32, 33 and 34 show examples of results obtained during wheel trackingexperiments conducted in 1992 on the LCPC-Nantes accelerated test carousel.Figure 31: LCPC Fatigue Carousel- 132 -