

Basal reinforcement of pavement systems has been used for the purposes of: (i) increasing the lifespan of a pavement while maintaining the thickness of the base course, and (ii) decreasing the thickness of the base course while maintaining the lifespan of the pavement. This paper describes a third application of basal reinforcement of pavements, namely, the mitigation of longitudinal cracks induced in pavements constructed over highly plastic, expansive clay subgrades. This includes information showing that: (i) geogrid reinforcement has precluded the development of longitudinal cracks in pavement sections located in projects where unreinforced sections have shown significant cracking, (ii) longitudinal cracks are ‘shifted’ beyond the reinforced pavement zone, avoiding their development within the pavement itself, and (iii) that current specifications, which often rely on geogrid properties defined in isolation, are insufficient to fully characterize the reinforcement requirements for reinforced pavement project. Overall, the field observations highlight the significant benefits associated with the use of geogrids in pavements over expansive clay subgrades, although there is still the need for more rationale design methodologies.