Drop Plan Drop Location Coordinates and Comments
To be able to make comparisons between different FWD-HWD equipment, a defined test plan is necessary. A test plan using a total of 33 test locations was developed for this project. Testing on the concrete pavement consists of drop locations as follows: directly over strain gage locations, center of slabs, corner of slabs, and along center of joints. For the flexible pavement, drop locations are either directly on or near the various sensors embedded within the pavement.
Testing locations were not enough to define the testing plan. Other factors were involved in developing the test plan and led to the development of two cycles for testing. The intent of Cycle 1 was to collect a baseline of data at each test location. Understanding that the data for a given drop location could change based on the direction of testing, it was determined to specify testing directions and to utilize two testing directions. As such, Cycle 1 requires testing at each drop location traveling first from west to east and then from east to west. The number of drops for Cycle 1 totaled 66. The intent of Cycle 2 was to investigate repeatability of test results. As such, a small sample of the first drop locations was chosen to be repeated in both test direction. The number of drops for Cycle 2 totaled 22.
Testing Load Levels
At each test location, participants performed a seating drop and three test drops. The load levels for testing were dependent upon the type of equipment being used. To simulate FWD testing, the three test drops were 9k, 12k, and 16k lbs. To simulate HWD testing, the three test drops were 12k, 24k, and 36k lbs. The physical setup of any particular equipment dictates what testing levels could be demonstrated during the testing. Equipment capable of testing at either testing level only tested at one.