Search Results (3)

The challenge of maintaining ride quality and serviceability in flexible pavements built over expansive soil deposits remains a critical concern for transportation agencies. These expansive subgrades exhibit swell-shrink behavior in response to moisture fluctuations, leading to differential heaving and subsequent costly maintenance. This paper explores the effectiveness of a Hybrid Geosynthetic Reinforcement System (HGRS)—a composite of geocell and geogrid—as a targeted mitigation strategy for differential heaving induced by expansive soils. A large-scale box test was designed to simulate a flexible pavement section, consisting solely of a base course layer and the underlying expansive subgrade. Four test conditions were investigated: an unreinforced control, a geocell-reinforced section, a geogrid-reinforced section, and an HGRS-reinforced section. Vertical displacements on the surface of the base course layer were longitudinally monitored and compared against the control. The results reveal that the use of geosynthetic reinforcements, and HGRS in particular, significantly mitigates both maximum surficial heave and differential swelling. Among the systems tested, flexible pavements featuring HGRS demonstrated the most effective performance in alleviating the challenges posed by expansive soil deposits. Full article

A series of triaxial compression tests with different confining pressures were conducted for gravels, road surface milling materials, and surface–base milling mixtures to investigate the stress–strain relationships of these three kinds of materials. On the basis of the analysis of the test results, the strength and the deformation of the geocell-reinforced surface milling materials and the geocell-encased surface–base milling mixtures were predicted and compared with those of the gravels via the constitutive model of geocell–soil composites. The effects of the geocell pocket size, tensile stiffness, and the peak internal frictional angle on the stress–strain responses of the geocell-reinforced surface–base milling mixtures were examined. Moreover, by employing the finite element strength reduction technique, stability analysis was conducted on the geocell-reinforced retaining wall with the surface–base milling mixtures to investigate the factor of safety and the failure mechanism of the structure. The study results indicated that the surface milling materials exhibited strain hardening, while the gravels and the surface–base milling mixtures exhibited strain softening. The surface milling materials displayed evident shear contraction characteristics, whereas the gravels and surface–base milling mixtures first displayed shear contraction and later dilatancy features. In addition, the strength of the geocell-reinforced surface milling materials is smaller than that of the gravels, but the strength of the geocell-encased surface–base milling mixtures is larger than that of the gravels. Thus, the geocell-reinforced surface–base milling mixtures can be used to replace the gravels in engineering practices. Additionally, the size of the sliding wedge and the factor of safety of the retaining walls increase significantly with reductions in the geocell pocket size. Full article

Porous asphalt pavement is a part of the permeable pavement system, which can be used to mitigate the negative impacts of urbanisation on the water hydrological cycle and environment. This study aims to assess the mechanical and hydrologic characteristics of porous asphalt pavements, with and without geocell composites, using a plate load test, falling weight deflectometer test, and rainfall simulation test. The corresponding results indicate that the elastic modulus of the unreinforced pavement is lower than that of the reinforced pavement. The analysis demonstrates that the use of geocell composites effectively increases the load-bearing capacity of the pavement. When the base layer is reinforced with geocells, its load-bearing capacity increases. Observation of the rainfall simulation tests on the reinforced pavement indicates that the reinforced pavement effectively handles the surface runoff. Full article