Performance of Flexible Pavements Reinforced with Geogrids

摘要

The main objective of this research work was to evaluate the effectiveness of the211u001euse of geogrids as a reinforcement material for flexible pavement systems. This 211u001ereport presents the results of an investigation on the effectiveness of glass 211u001efiber grids as a reinforcement of the asphalt base layer in flexible pavements. 211u001eThe study involved both laboratory experimental work and computer analysis of 211u001epavement sections. As part of the experimental work, twenty flexible pavement 211u001esections with and without glass fiber grids were constructed and tested in the 211u001elaboratory. The experimental pavement sections were built in a rectangular 211u001econtainer with dimensions of 4 feet x 6 feet x 2.5 feet (1.2 m x 1.8 m 0.8 m). 211u001eTwo containers were constructed of steel for testing flexible pavement sections. 211u001eFive analog dial gages (1-inch (25 mm)) were placed on top of the asphalt surface 211u001eto measure permanent vertical displacements. Two earth pressure cells were 211u001elocated at the top of the subgrade soil in each soil container (test box). the 211u001edepth of the buried pressure cells was 8.5 inches (215.9 mm) below the 211u001easphalt/gravel base interface. For the test sections, the maximum applied load on 211u001ethe asphalt surface was 9 kips (40 kN) over a 12-inch (305 mm) diameter loading 211u001eplate, simulating a tire pressure of 80 psi (551 kN/m(squared)). Test sections 211u001ewere subjected to 1,000,000 load applications at a frequency of 1.2 Hz. Static 211u001eloading tests were conducted at intervals of 100,000 load applications. Factors 211u001esuch as permanent (cumulative) displacement of the asphalt surface, change in 211u001epavement stiffness with number of load cycles, resistance to cracking, strain in 211u001ethe glass fiber grid.