Although many field trials have been undertaken to examine the benefits and drawbacks of the use of tyres with reduced inflation pressure on heavily loaded haul vehicles typical of central tyre inflation (CTI) systems, few carefully controlled, full-scale laboratory tests have been performed. The results of one such laboratory test program indicated that low inflation pressures had relatively little influence on subgrade stresses and strains, so attention was focused on the tyre tread - road surface interface. A full scale test apparatus was used to measure normal and shear stresses at the interface: these stresses were found to be especially non-uniform when the inflation pressure was low and the tyre load was heavy. On the basis of the test results, conclusions are drawn regarding the benefits of the low inflation pressures typical of CTI systems. (a)
Abstract