# Acoustic-based detection of debonding in thin-layer semi-rigid base asphalt pavements using a-weighted sound pressure levels

## TL;DR

This paper introduces a new acoustic method to detect small-scale debonding in asphalt pavements, which is more sensitive than traditional techniques like ground-penetrating radar.

## Contribution

The novel use of A-weighted sound pressure levels and a DEVD Maxwell model for detecting thin-layer debonding in pavements.

## Key findings

- A-weighted acoustic metrics strongly correlate with the debonding area in pavements.
- The method detects thin debonding layers that ground-penetrating radar cannot.
- The approach shows high sensitivity for early pavement damage detection.

## Abstract

Thin-layer interlayer debonding in semi-rigid base asphalt pavements is difficult to detect with conventional techniques due to their limited sensitivity. This study proposes a novel acoustic-based detection approach that utilizes a distributed elastic variable damping (DEVD) Maxwell model and introduces an A-weighted sound pressure level (SPL) index to enhance detection of small-scale debonding. Comprehensive numerical simulations were integrated with full-scale experiments to analyze acoustic signals under different excitation modes and debonding scenarios. The results show a strong correlation between the A-weighted acoustic metrics and debonding area, and the proposed method reliably distinguishes thin debonding layers that ground-penetrating radar (GPR) could not detect. Our acoustic method demonstrated superior sensitivity to thin-layer debonding, highlighting its potential as a non-destructive tool for early pavement damage detection and improved road maintenance.