A major distress problem in rigid concrete pavements is early deterioration of near-surface layers. The quality of near-surface material governs the long-term performance of concrete pavement. If the near-surface material of concrete layer is cured sufficiently well at an appropriate moisture and temperature, the concrete pavement system can be expected to endure fatigue loading of traffic throughout its design lifespan. In this paper, a field measurement device, referred to as a pavement integrity scanner (PiScanner), was developed for use in quality control and quality assurance programs for concrete layers of pavement systems. PiScanner is based on the enhanced resonance search (ERS) technique, which evaluates the vertical variation of elastic modulus or compressive strength of the concrete layer in pavement systems. This information can be used in the construction period of a concrete pavement to evaluate curing process of near-surface materials. In the implementation of PiScanner, two design schemes were incorporated: a dedicated hardware device to perform measurements and an automated analysis algorithm to minimize user expertise required for analysis. The resulting PiScanner allows ERS measurements to be performed in about two minutes with complete analysis of the measurements in about three minutes. Two field investigations were performed on a concrete test slab and at an express highway in order to prove the reliability and feasibility of PiScanner. Vertical variations of elastic modulus of concrete layer were successfully obtained by PiScanner.
Abstract