Laboratory evaluation of geogrid-reinforced flexible pavements

• Published in: Transportation engineering (Oxford) 2021-06, Vol.4, p.100070, Article 100070
• Main Authors: Sharbaf, MohammadReza, Ghafoori, Nader
• Format: Article
• Language: English
• Subjects: Flexible pavement; Geosynthetics; Punched and drawn geogrid; Rutting depth; Traffic Benefit Ratio
• ISSN: 2666-691X; 2666-691X
• DOI: 10.1016/j.treng.2021.100070

•Use of geogrids were effective in reducing vertical stresses when used in strong soil.•The stresses at the subgrade and base layer of goegrid A-reinforced test sections were less than that for unreinforced tests.•The geogrid B-reinforced tests experienced less pressure in all locations as compared to that of the geogrid A test sections.•The Traffic Benefit Rations of the geogrid B-reinforced test sections were higher than for the geogrid A test sections.•The geogrid B (triaxial) was more effective than the geogrid A (biaxial) in reducing the thickness of the base layer. This study assessed the effectiveness of flexible pavements reinforced with two types of punched and drawn geogrids to reduce roadway base course thickness. Six laboratory tests were conducted using a steel cylindrical mold. Instrumentation included pressure cells placed at various locations of the test sections and a linear variable differential transformer which was placed on top of the loading system. A hydraulic actuator provided 40 kN (9 kips) cyclic load through a 305 mm (12 in) circular steel plate at a frequency of 0.77 Hz. Test results revealed that inclusion of both geogrid types in flexible pavement showed reductions in surface rutting and vertical stresses at the subgrade-base interface. Using the results for rutting depth, the use of geogrids increased the number of load applications by a factor of 1.5 to 7.5, depending on the test section properties and geogrid type, as well as the rutting depth experienced at various loading applications. Using the base course reduction values based on vertical stress results, the inclusion of geogrid in strong soil resulted in the reduction of base course thickness by nearly 7 percent.