Abstract Manager

Tetra Tech was retained by the City of Calgary to complete pavement data collection and analysis of the roadway segments subjected to load bans to validate and confirm the spring load bans and year-round load bans imposed by The City. The load ban assessment effort consisted of the collection of the pavement strength test data using a Falling Weight Deflectometer (FWD), existing pavement structure determination (using Ground Penetrating Road Radar testing and asphalt pavement coring) and analysis of the collected data to determine required load bans and structural adequacy of the existing pavement structures. A total of 49 roadway segments were included in this study. FWD data was collected in three rounds to evaluate seasonal variations and ground penetrating radar data processed following quality assurance standards. Mean Benkelman Beam Deflections (MBD) were estimated from the FWD data, and the Maximum Tolerable Deflections (MTD) were calculated for the calculated design traffic. The load bans or weight restrictions (Spring and Year-Round) were established based on the relationship between the MBD and MTD as provided in the Transportation Association of Canada Guide to Load Management for Weak Pavement Structures.

Structural asphalt overlay required to convert the roads subjected to load bans to all season roads (with no load ban restrictions) were proposed using current Asphalt Institute (AI) and AASHTO design standards.