Performance of Flexible Pavements Reinforced with Geogrids: Fid-Bau Portal

Performance of Flexible Pavements Reinforced with Geogrids

B. Kutuk / H. J. Siriwardane

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