Bearing Capacity Improvement of Asphalt Paved Road Constructions Due to the Use of Geocells —Falling Weight Deflectometer and Vertical Stress Measuresments

Abstract

To evaluate the influence of a geocell layer on the load-deformation behavior of the soil large scale static load tests were carried out. Geocells with different aspect ratios made of different materials filled with sand had been tested. To simulate soft subgrade material an artificial mixed soil called “Glyben” was used. The test results showed that a geocell layer increased the bearing capacity of the infill materials and reduced the vertical stresses on the subgrade about 30 percent compared to an unreinforced soil. To verify the results of model tests, geocell reinforced, unreinforced and also hydraulic bounded base (HBB) in-situ test fields were carried out within different asphalt paved road constructions. After finishing the road construction vehicle crossing tests with a 40-tons truck and falling weight deflectometer measurements were carried out while the vertical stresses on the subgrade were measured by earth pressure cells. Compared to an unreinforced test section the stresses beneath the geocell layer were reduced by about 30 percent. Falling weight deflectometer measurements showed that the deflections measured in geocell reinforced test section were significantly smaller than in the unreinforced section. Back calculated layer modules were significantly higher in the geocell reinforced section compared to an unreinforced section.