Influence of gauge length on the measurement of resilient modulus of bituminous mixtures

This paper investigates the influence of gauge length on the measurement of resilient modulus of bituminous mixtures with modified and unmodified binders tested at 25 °C. From this investigation, it is clear that for the tests carried out using a quarter-gauge length, the cumulative vertical deformations at the end of 200 preconditioning load cycles stays within 0.025 mm as stipulated in ASTM D7369-11. In the case of half-gauge length, the cumulative vertical deformation exceeds 0.025 mm after the application of 200 preconditioning load cycles. It was seen that the resilient modulus and Poisson’s ratio computed from the deformations measured using quarter-gauge length exhibited better repeatability when compared to half-gauge length.