Investigation on road damage due to vehicle overloading in Ipoh state road

Abstract

Traffic load is a major factor in thickness design due to the main function of pavement which is to resist traffic load. Although efforts to repair the road damage have been done continuously, the recovering effects are almost meaningless if the road is continuously receiving overloading from vehicles. Issues of road damage due to vehicle overloading have been addressed by most agencies in developing countries. However, there is no available study to address this issue on Perak state road. Therefore, this research aims to investigate the effects of vehicle overloading to road damage at Ipoh state road by reviewing the adequacy of existing pavement thickness to withstand current overloading and the reduction of road pavement service life due to overloading using AASHTO and Arahan Teknik (Jalan) 5/85. The selected study area was at Jalan Tuanku Abdul Rahman, Ipoh. Data were employed which acquired from traffic count survey, axle load survey, coring test and dynamic cone penetrometer test. Assessment on existing vehicle loads revealed that more than 50% of vehicles from 4-axle, 5-axle and 6-axle exceeded the maximum permissible gross vehicle weight (PGVW). The analysis on the Equivalency Factor (E.F.) shows that primary and secondary directions have gained E.F. value of 2 and 3 times higher than the E.F. design value respectively. This also denotes that additional overlay pavement thickness is required which is about 50mm and 70mm for primary and secondary direction respectively to ensure the target design life is archived. This study also discovered the reduction of service life of 6 and 7 years for both directions respectively.