Foamed-In-Place Polyurethane Insulated Traffic Test Sections for Expedient Roads.

摘要

Foamed-in-place polyurethane was tested as an expedient road surface insulation and load distributing structural layer with T15 aluminum airfield landing mat as a trafficking surface. The insulation was sprayed on leveling courses of either woodchips or gravel with thicknesses of about 15 cm. Various thicknesses of insulation with two densities were used singly and in combinations of layers. Total insulation thicknesses ranged from 2.5 to 28 cm. The test sections were constructed in April 1970 and trafficked during the thaw seasons of 1970 and 1971 with a military dump truck loaded with gravel. The total test vehicle weight was 12,270 kg with a maximum single wheel load of 2,415 kg. The test sections withstood over 1,000 passes of the test vehicle without suffering complete failure. Observations by surface level measurements showed settlements of 0.0 to 14.0 cm. Sugrade temperature observations by thermocouples showed thaw depths in the subgrade from 24.0 to 99 cm. This method of expedient road construction would provide satisfactory service throughout two thaw seasons and possibly longer without deleterious effects to the subgrade and adjacent environment.