Evaluation of the structural condition of composite pavement

Abstract

One of the road tolls at the borderline of Jakarta, the capital of Indonesia, i.e., Tangerang-Merak toll road, was found in a damaged condition in several locations. The toll’s pavement structure comprises an asphalt layer (blacktopping) over a concrete slab (or a composite structure). An evaluation is required to find out the last condition of the pavement to propose the remedy for the problem. An eight-step evaluation was conducted systematically in this study, and the 1993 AASHTO method was the method used to analyze the results. The first step was to conduct traffic analysis by calculating ADT from toll gate transaction data validated with CCTV data, while vehicle axle loads were measured by static load surveys to calculate the vehicle equivalent factor.Another analysis of the pavement’s structural conditionwas conducted using backcalculation analysis using FWD deflection data to produce the moduli of subgrade reaction and the elastic modulus of the concrete pavement. The analysis showed that several locations of the toll road suffered a medium to severe deterioration as indicated by high deflection values. This fact was also supported by the findings that the pavement system’s remaining life is 22% on average. Two recommendations were made by implementing 7.12 in. or 18 cm overlay thickness on the in-service pavement for road segments with good prediction of moduli, and 2 in. or 5 cm repairing treatment to strengthen the existing pavement may be considered as planned stage of construction for the rest. Before the overlay and treatments were conducted, various repairs were taken place on the damaged spots along the road segment.