Expedient Road Construction Over Soft Soils

This report describes field experiments conducted using a combination of crushed limestone, wood chips, sand, geosynthetics, fiberglass mats, plastic mats, and wood mats for expedient road construction over soft soils. Field sections were constructed and trafficked over two soft subgrades: a CBR less than 0.5 percent, and a CBR between 0.5 and 1.0 percent. Experiment items were trafficked with 2,000 passes of a 41,600-lb, 5-ton military truck. Field experiment results indicated that plastic and wood mats, wood chips, and crushed limestone are capable of providing structural support to military traffic over the two subgrade conditions. The fiberglass mats, geofoam, and ECM geosynthetic were not capable of withstanding the applied traffic and are unsuitable for supporting substantial amounds of military traffic over the very soft subgrade conditions used in this experiment. --Original contains color plates: All DTIC reproductions will be in black and white.