Pilot Instrumentation of a Superpave Test Section at the Kansas Accelerated Testing Laboratory;Final rept. Aug 98-Nov 00

摘要

Two Superpave test sections were constructed at the Kansas Accelerated Testing Laboratory (K-ATL) with 12.5 mm (2 in) nominal maximum size Superpave mixture (SM-2A) with varying percentages (15 and 30 percent) of river sand. A 150 kN (34 kip) tandem axle with dual wheels was used for 10,000 repetitions. Next the sections were loaded by three different tandem axle loads and three single axles for more than 30 repetitions in each configuration to estimate the relative pavement damage in the SM- 2A layer due to different axle loads and configurations. All load application was done at a temperature of approximately 38 degrees C (98 degrees F) at the middle of the SM-2A layer. The test sections were instrumented at three locations on each test section with (i) transverse strain gages at the bottom of the SM-2A layer, (ii) pressure cells on the top of the subgrade, and (iii) temperature gages in the aggregate base, subgrade and SM-2A layers (mid-depth and bottom). Data was collected during load applications by the K-ATL tandem axle and a Falling Weight Deflectometer (FWD). After 80,000 applications of the 150 kN (34 kip ) tandem axle loading, severe rutting was observed on both test sections with no visible cracking, and the testing was terminated. The theoretical pavement responses were also calculated with a multi-layer elastic analysis program, ELSYM5 and compared to the test results.