ESCINC-SBIR 21-FH3

According to a survey completed by NCAT in 2019, as part of the NCHRP 20‐07 project, 36 DOTs (out of 43 responded) consider fatigue cracking as the most common failure mode that the agency wants to address. However, in the same survey, 34 of the DOTs also indicated that fatigue cracking test is not required in their mix design specifications. This is primarily because a simple, practical, and robust fatigue test is not available. The current AMPT uniaxial cyclic fatigue and TX overlay cracking tests require gluing specimens to platens. This gluing step can be relatively cumbersome, expensive, and time‐consuming. In this proposed project, the research team will evaluate several innovative ideas to speed up the sample mounting into the AMPT. A few preliminary designs that do not require gluing are discussed in the proposal using clamping systems and screws. Additionally, a preliminary design is proposed for the rapid swap between various fatigue small‐specimens’ geometry conditioned in an external chamber for more efficient testing. Finally, a few preliminary ideas for non‐contact strainmeasurement are proposed in this project. The goal is to speed up testing by minimizing the sample preparation, instrumentation, and temperature equilibrium time.