Performance Study of Surface Treated Crushed Rock Pavement

The performance of a thin, crushed rock surface treated pavement is predicted using mechano-lattice analysis and the results are compared with actual performance after the passage of the equivalent of 250,000 standard axles. The pavement consisted of 100 mm of crushed rock base overlying a uniformly weak subgrade. Input properties include resilient modulus and deformation determined from repeated loading triaxial testing. Results were compared for transient longitudinal strain, rebound deflection under loading and rutting during service life. Because the moisture conditions of the pavement may have varied during service life analyses were performed at two moisture contents to represent the likely variation in subgrade moisture during the initial period of service. Tensile stresses were predicted by the program. Transient longitudinal tensile strains were underestimated by a factor of from 1–2 while rut depth predictions were reasonable. The predicted rebound deflections were overestimated but approximated the value of the field measured means plus standard deviation.