Nondestructive Deflection Testing And Backcalculation For Pavements PDF Download

This report presents guidelines for selection of asphalt-overlaid concrete (AC/PCC) pavements for rehabilitation, collection of distress data, recognition of AC/PCC pavement distress modes, nondestructive deflection testing, materials sampling, and overall project-level evaluation. Key condition indicators (distress, rutting, roughness, serviceability, and CRS) were examined to address their usefulness in AC/PCC rehabilitation project selection. Critical levels for these indicators were identified, and available prediction models were investigated for use in rehabilitation programming. The project-level evaluation procedure includes guidelines for field and laboratory data collection and analysis for structural evaluation, functional evaluation, drainage evaluation, and AC surface material evaluation. A procedure was developed for backcalculation of AC/PCC pavement layer elastic moduli from deflection measurements, and guidelines were developed for practical interpretation of the backcalculation results. The recommended evaluation procedure relies on conventional testing and evaluation methods (visual surveying, deflection testing, coring, materials testing, etc.). New technologies (e.g., ground-penetrating radar, infrared thermography) are developing which have potential for use in pavement evaluation. These technologies are also reviewed in this report.