Three-level performance evaluation of high RAP asphalt surface mixes

To support an increased use of reclaimed asphalt pavement (RAP) and innovative materials, appropriate laboratory performance tests are required. There exists a wide selection of performance tests with varying complexity, reliability, and cost. However, there is no consensus on which tests are best suited to support the design and quality assessment of asphalt mixtures. The main purpose of this effort was to assess the impact of testing complexity on the estimated performance of asphalt pavements through a comprehensive evaluation of four different highly recycled surface mixes produced and placed in Virginia. For that purpose, the research team defined a three-level testing framework herein referred to as basic, intermediate, and advanced. Each level was characterized by an increasing degree of complexity and cost and included tests to characterize both the cracking resistance and the rutting resistance of the evaluated mixtures. Under the performance evaluation process, it was possible to investigate the features of the various laboratory tests. Through the review of the theoretical background, the evaluation of the test procedures, and statistical analysis of the results, it was possible to identify the strengths and weaknesses of each test. Based on the test results, recommendations were provided on the design of highly recycled surface mixes. Also, it was possible to provide guidelines to develop appropriate quality assessment criteria and mix design methodology.