<p><p><div><h2>Project Summary/Scope:</h2>A section of Route 30 in Delaware County, PA was to be rehabilitated. FWD analysis was used to perform a structural evaluation of the reconstructed road. The basic construction plan involved reconstructing SR-30, in two large patches, with each patch reconstructed as a designated left and right side.</p><p>Subsurface Conditions: The subgrade had a California Bearing Ratio (CBR) of 4.0% when tested during excavation. The soil was classified A-4 in accordance with AASHTO.</p><p>Because of its instability, the subgrade was first compacted with a roller in static mode. A Class 4 geotextile was then placed over the entire subgrade. The geotextile was covered with a high-strength, uniaxial geogrid. The geocell was then placed. The geocell height was 100 mm and it was formed by 2.4 by 6.1m panels when expanded and staked down. All adjacent panels were connected together using pneumatic staples. The cells were then filled with 2A subbase material. The geocell was filled by dumping the subbase material onto the adjacent existing pavement and pushing the subbase out onto the geocell with a small bulldozer. Once the geocell was backfilled, tri-axle dump trucks could back onto the filled cells and unload material.</p><p>On the following day, 200 mm of (Bituminous Concrete Base Course) BCBC and 50 mm of ID-2 HMA binder were placed. No movement was observed during placement of the first 100-mm lift of BCBC material. During placement of the second 100-mm lift of BCBC, there was very little movement. No movement of material was observed during placement of the 50 mm of ID-2.<br><h2>Complementary Technologies Used:</h2>Geotextile Separator, Geogrid Reinforcement of Pavement Systems<br><h2>Performance Monitoring:</h2>Visual inspection of pavement distress was conducted. FWD tests were performed. Visual inspection of the roadway over three years after reconstruction revealed no sign of pavement distress such as excessive rutting, cracking, or base failure. This indicates that the combinations of different geosynthetics perform adequately.<br><h2>Case History Author/Submitter:</h2>Jitendra Kumar Thakur<br><h2>Project Technical Paper:</h2>Al-Qadi, I. L., and Hughes, J. J. (2000). "Field evaluation of geocell use in flexible pavements." <em>Transportation Research Record: Journal of Transportation Research Board</em>, 1709, 26-35<br><h2>Date Case History Prepared:</h2>November 2012</p><p></div></p></p>