Effects of design and maintenance requirements and axle loads to flexible pavement lifetime performance

Abstract

This thesis aimed to identify sensitivity of flexible pavement roughness (IRI) and maintenance budget on motorway due to design/maintenance criteria and repetition of axle loads. Highway Development and Maintenance Software (HDM) was used as a tool to forecast Long-Term Pavement Performance ( LTPP) and maintenance plan. The literature review showed that roughness is the representative of primary distresses on pavement. Six primary distress-initiated factors including surface thickness, California Bearing Ratio of subgrade (CBR), construction defects, maintenance methods, traffic volume (AADT) and vehicle gross weight, were examined for their effects in IRI and maintenance budget. Using Highway Development and Maintenance Software, a total of 19 case studies were set up for sensitivity test. Two sets of calibration factors were applied in case studies to observe result in upper and lower bounds. The results showed changes in IRI and maintenance budget when each primary distress-initiated factor was changed. This research could be useful for motorway designers and decision makers for establishing strategic design/maintenance program and prepare extra maintenance budget for underestimated traffic volume