Implementation of a simple performance test procedure in a hot mix asphalt quality assurance program

In current pavement construction, it is traditionally typical Quality Assurance (QA) practice to evaluate the as-constructed asphalt mix quality based upon individual asphalt mixture material parameters which are used to empirically determine the incentive/disincentive to contractors, considering key variables to play a role to have the intended quality in the mixture. Recognizing the limit of this empirical-based QA practice, effort to implement performance-based QA methodology has been exerted. At present, however, it has been known to be quite difficult to establish the most precise relationship between the actual pavement performance and the magnitude of pay adjustments.;One of the ultimate goals in the National Cooperative Highway Research Program (NCHRP) 9-22 project was essentially to develop a quality assurance tool for Hot Mix Asphalt (HMA) based upon the Performance Related Specification (PRS) which tied the performance to the payment system. A new software package named Quality Related Specification Software (QRSS) was developed as a deliverable of the project. This computer program has a capability to predict the performance of both as-design and as-constructed mixes in terms of projected service life, based upon the major HMA quality indicators: dynamic modulus and creep compliance estimated by the key HMA volumetric properties.;A new, innovative quality assurance tool was developed in this dissertation study to expand the capability of the QRSS by implementing the Simple Performance Test (SPT). The asphalt pavement performance in the developed SPT program is evaluated by directly measuring the SPT with the as-constructed HMA, rather than estimating with the volumetrics. To properly implement the SPT technology in the developed program, two prototype SPT procedures were developed: E* SPT procedure for the AC rutting and fatigue distress evaluation, and D(t) SPT procedure for the thermal fracture evaluation.;The QRSS developed under NCHRP 9-22 was used to validate the developed SPT QA program and it was found that the SPT program properly was operated and produced overall quite similar results as the QRSS did. Further validation of the SPT procedures/program is completed with real projects under the NCHRP 9-22A project which is currently on-going.;The SPT protocols and accompanying computer program developed under this doctoral research is a more rational, accurate, and practically useful methodology to replace the current empirical QA practice; and envision the next generation of the asphalt pavement quality assurance.