COMPARISON BETWEEN WIDE BASE SINGLE TIRE AND DUAL TIRES ASSEMBLYBASED ON EXPERIMENTAL PAVEMENT RESPONSE AND PREDICTED DAMAGE

摘要

Past studies suggest that Wide-Base Single Tires (WBST: 455/55R22.5) induce pavement strains,which are different than duals of similar sizing, some higher and some lower depending on thedirection and the location in the pavement. An experimental assessment of strain basins occurring atvarious positions within the hot-mix asphalt (HMA) layer as well as within the pavement unboundlayers was undertaken to further this understanding. The method and results of this assessment alongwith the pavement damage predicted using available models is presented in this paper. Four failuremechanisms were considered; HMA rutting, bottom-up and top-down fatigue cracking, and structuralrutting. Testing was conducted at two sites on a total of four different roads over a range of loads,pressures, and temperatures, using WBST and different sizes of dual tires. Analysis of data showedseveral critical strain zones near the tire edges and at the tire center. Optic fiber sensors allowedanalyzing these phenomena. HMA rutting was calculated considering vertical shear strain near thesurface under the edge of the tires. The other failure mechanisms were calculated using maximumstrain. The results predict that the WBST tested may induce less damage in the upper part of the HMAlayer and more damage considering fatigue cracking and rutting of soils and unbound materials. Thedata collected was from specific tires and all tests were conducted only under smooth, steady-staterolling conditions. Thus, results should not be generalized to all tires nor extrapolated to predict actualfield performance.