Measurement of the Dynamic Elastic Modulus of Concrete Pavements in situ Based on Impact Echo Measurements Corrected via Elastic Wave Theory

Abstract Efficient and non-destructive methods for measuring the dynamic elastic modulus of concrete pavements in situ are essential for ensuring durable, safe, and smooth road conditions. However, existing measurement methods are generally suitable only for small-sized road specimens under laboratory conditions. The present work addresses this issue by proposing a novel measurement method that combines elastic wave theory with the wave velocity data collected using the impact echo method to establish a model for measuring the dynamic elastic modulus of concrete pavements in situ. The model includes a correction coefficient function to account for the impact of the structural dimensional parameters of concrete specimens on the measured wave velocity. The validity of the proposed method is demonstrated experimentally for a 40 cm thick large-scale C30 grade concrete pavement slab in conjunction with the measurement results obtained using the conventional resonance method based on corresponding core samples, where the obtained modulus values differ by only 3.48% on average. A similar experimental process employing nine concrete specimens prepared using different water-to-cement ratios, air contents, and aggregate types yields modulus values by the proposed method and the resonance method with differences that do not exceed 1.89%. Accordingly, the proposed measurement methodology provides an effective approach for assessing the dynamic elastic modulus of concrete pavements in situ, offering valuable support for near real time pavement safety evaluations and maintenance planning.