Highway Asset Management Framework for Longevity of Infrastructure – A Case Study for China-Pakistan Economic Corridor

Abstract

Pavement management system (PMS) affords objective information and useful data analysis to make consistent, cost-effective, and defensible decisions related to the pavement preservation at network and project level. Pavement functional and structural evaluations using performance indicators such as international roughness index (IRI), surface distress, rutting, deflection data etc. are the key element of PMS. A departure from exiting stand-alone evaluation practices, this research presents project-level functional and structural evaluation and its integration into a PMS framework for more accurate and realistic forecasting of the pavement needs over the analysis period. A case study of an in-service pavement is presented to demonstrate the applicability of proposed framework. Owing to the non-availability of time-series performance data at present, pavement serviceability and structural capacity data before and after of an in-service pavement rehabilitation was explored for overlay treatments (conventional and crumb rubber- modified (CRM) asphalt mixtures) effectiveness analyses. Results of functional evaluation quantified the extent to which CRM improves the functional performance of the pavement, in terms of the drop in IRI. CRM asphalt mixture exhibited relatively superior functional performance in contrast to conventional asphaltic wearing course by a margin of 8% higher drop in IRI, on average. Non-destructive testing technique for pavement structural evaluation using falling weight deflectometer (FWD) data was employed to assess structural capacity of pavements. A computer-aided program was developed for estimation of structure number effective (SNeff) to be used as an input for overlay design using AASHTO empirical method. Moreover, mechanistic-empirical (M-E) design method was employed using evaluation of layer moduli and overlay design (ELMOD) program for overlay thickness design and pavement remaining service life (RSL). Comparison of pre- and post-rehabilitation deflection data endorsed roadbed soil stiffness and structural adequacy. RSL estimated through traffic data (truck load repetitions) validated the results obtained using empirical and M-E methods. Application of KENPAVE program for evaluation of pavement overlay thickness design was also demonstrated by conducting damage analysis. Integrating structural evaluation with functional evaluation into an overall framework of PMS is envisaged to provide systematic and objective procedures for monitoring and evaluating pavement performance, selecting optimal type of treatment and its thickness design.