Andrew LaCroix

Crossroad Pavemnent Consulting

The objectives of the research were: (1) to investigate possible modifications to the existing TSR test protocol or develop an alternate test method, and a conditioning procedure that can quantify the adhesive and cohesive damage in asphalt mixtures due to moisture; (2) to quantify adhesive damage in asphalt mixture using the boil test along with c...

Asphalt emulsions are used extensively in tack coats and preservation surface treatments. The current specifications for asphalt emulsion residue recovery in AASHTO PP 72 are based on low-temperature evaporative drying. The shortest residue recovery procedure included in AASHTO PP 72 requires 6 h of conditioning in an oven to dry an emulsion. The a...

Moisture damage to asphalt pavements continues to be a major concern after decades of research. Two of the most common moisture failure modes in asphalt mixtures are adhesive failures between the aggregate and binder and cohesive failures in the binder or mastic. The challenge in conditioning asphalt mixtures for moisture sensitivity is developing...

Performance-related specifications base pay rates on tests that measure and predict the performance of the mixture. This study evaluated several methods for predicting the rutting resistance of asphalt mixtures. The mixtures and field performance data came from the National Center for Asphalt Technology test track. The pavement sections evaluated w...

The MEPDG (ARA, Inc., "NCHRP 1-37A Final Report: Guide for Mechanistic-Empirical Design of New and Rehabilitated Pavement Structures," NCHRP Program 1-37A Project, National Research Council, Washington, D.C., 2004) introduces the dynamic modulus as the material property to characterize asphalt concrete. One of the challenges of acquiring the dynami...

Research project NCHRP 9-19 identifies the confined dynamic modulus as one of three favorable indicators for evaluating the rutting potential of a mixture. Though important, dynamic modulus testing at multiple confining pressures takes too long for state highway agencies to use it routinely. Therefore, several methods have been suggested to measure...

This paper presents a laboratory study to refine the impact resonance (IR) test to measure the dynamic modulus (|E*|) and phase angle (φ) of hot-mix asphalt (HMA). Kweon and Kim (1) presented analytical solutions for the determination of the |E*| and φ from the IR test and verified the solutions at high reduced frequencies (i.e., low temperatures)...

The NCHRP Project 1-37A "Guide for Mechanistic–Empirical Design of New and Rehabilitated Pavement Structures" introduces the dynamic modulus (|E*|) as the material property for the characterization of hot-mix asphalt mixtures. This is a significant change from the resilient modulus used in the previous AASHTO "Guide for the Design of Pavement Struc...

The NCHRP 1-37A Guide for Mechanistic-Empirical Design of New and Rehabilitated Design Structures introduces the dynamic modulus as the material property to characterize asphalt concrete. This is a significant change from the resilient modulus used in the previous AASHTO pavement design guide. This paper presents an analytical method of calculating...