Between September 2022 and March 2023, Transportation Association of Canada (TAC) Mechanistic Empirical (ME) Pavement Design Subcommittee completed five sets of design trials using the AASHTOWare Pavement ME Design (PMED) software to assess the effects of portland cement concrete (PCC) mix properties, coefficient of thermal expansion (CTE), slab thickness, dowel diameter, joint spacing and traffic loading on the predicted distresses in jointed plain concrete pavement (JPCP). The trial results using software v2.6 indicated that a better quality concrete results in improved performance in terms of predicted international roughness index (IRI), faulting and cracking. Only a high CTE of >8.0×10‐6/ºC seems to affect the predicted transverse cracking. Varying climate was shown to have significant effect on the predicted IRI, a lesser effect on the predicted faulting and no or negligible effect on the predicted transverse cracking. The trial results also showed some inconsistencies and significant differences in the predicted distresses between software v2.6 and v3.0.
The trial results using software v3.0 showed that an increase in the PCC thickness results in an increase in the predicted IRI and faulting, which is not expected. An increase in the PCC thickness showed a reduction in the predicted transverse cracking. The trial results also showed that thicker dowels provide a significant reduction in the predicted faulting and IRI, but have no or minimal effect on the predicted transverse cracking. PCC joint spacing showed no or minimal effect on the predicted IRI, a significant effect on the predicted joint faulting for PCC layer thicker than 200 mm and for high CTE values and a significant effect on the predicted transverse cracking. Traffic loading has a small effect on the predicted IRI. The minimum PCC thickness should be 205 mm and CTE should be 8.0×10‐6/ºC to produce an impact of traffic loading on the predicted faulting. Transverse cracking is highly sensitive to traffic loading with thinner concrete. Overall, a high CTE value has shown a greater impact on the predicted performance than joint spacing and PCC thickness, which seems to be unreasonable and requires further investigation.
