A comprehensive approach for the assessment of HMA compactability using GPR technique

Abstract

With the focus on quality assurance practices during pavement construction, the present research aims at investigating the compactability of hot mix asphalt using the ground-penetrating radar technique. Thus, density as an indicator of the compactability of hot mix asphalt is predicted using three different electromagnetic-mixing-theory-based density models (namely, the complex refractive index model, Rayleigh model, and Al-Qadi, Lahouar and Leng model), and the prediction performance is also investigated. The investigations are based on experimental data acquired, both in the laboratory and field, from new full-scale asphalt pavement sections with varying asphalt mixture compositions. The laboratory experiment, which involved the compaction of asphalt mixtures using the steel-segmented roller compactor, indicated that compaction mode affects the compactability of hot mix asphalt, whereas the analysis of field ground-penetrating radar experimental data revealed that the estimated electric permittivity ε HMA during the compaction process could be considered a measure of the asphalt mix field compactability. The prediction performance of the three density models was evaluated using different methodological approaches with respect to the backcalculation of ε s of the mix aggregates. The results indicated that, by utilizing the ground-penetrating radar field measured ε HMA for the assessment of ε s , the predicted G mb values from the implementation of the above density models closely approach the ground-truth field-core bulk densities. Comparative evaluation of the three density models showed that the Al-Qadi, Lahouar, and Leng model exhibits the best prediction performance, which is comparable to nuclear/non-nuclear methods. In light of this, it could be argued that the ground-penetrating radar methodology coupled with novel algorithms can be an effective and efficient tool to improve the asphalt mix compaction process and assessment of in situ density.

Rapid Detection Methods for Asphalt Pavement Thicknesses and Defects by a Vehicle-Mounted Ground Penetrating Radar (GPR) System

“…Besides, Kassem et al proved that there was very good correlation between the density and permittivity obtained from GPR [27]. Similarly, Plati et al argued that the GPR coupled with novel algorithms could be an effective tool to improve the asphalt mix compaction process and assessment of in situ density [28]. However, all of these studies were carried out on the basis of density prediction models that required some prior typical parameters.…”

Approach to Determination of Risk-Based Inspection Workload for Highway Construction Projects

“…For example, Texas DOT applies three levels of owner verification testing to specific materials and properties, which are based on a perceived residual risk after completion of construction. Compaction control was in the highest level of risk, where it depends on various factors such as compaction equipment, mixing process, and type of compacted materials ( 13 , 27 ). The results from two common daily scenarios illustrate how the proposed framework can be used to deal with different inspection workload challenges in highway construction projects.…”