Abstract:
At present, budget planning for pavement overlay and road rehabilitation in Thailand is primarily based on International Roughness Index (IRI) as a key indicator of road serviceability level, as well as pavement distresses, pavement age, and traffic volume. However, these factors only present the damage at pavement surface, and do not reflect strength or remaining service life of pavement structure. This research has developed structural deterioration model to predict structural condition in the future. An Elastic Modulus of Base Layer (E2) is used to represent structural condition. The purpose of this research is to provide analytical framework to select appropriate pavement treatment types between pavement overlay and rehabilitation by considering life-cycle cost, based on data from structural deterioration model. The result of this research indicates that the road which has IRI trigger value for pavement maintenance at 3.00, pavement overlay would cost lower than rehabilitation when Cumulative Equivalent Single Axel Load (NE4) is lower than 2.10 msa./Lane. While road which has IRI trigger value at 3.50, pavement overlay would cost lower than rehabilitation when NE4 is lower than 1.90 msa./Lane. This is because more frequency of pavement overlay can help slow down structural deterioration which is effected by the increasing of asphalt surface thickness.