Triaxial experimental study of effect of loading rate on mechanical properties of asphalt concrete

Abstract

In order to study the influence of loading rate on the mechanical properties of asphalt concrete, Static triaxial tests of asphalt concrete are conducted under four different loading rates. The results show that loading rate has a significant effect on the mechanical properties of asphalt concrete and the stress-strain curve changes regularly with the loading rate and confining pressure. Under the same test temperature and confining pressure conditions, the deviator stress increases with the increase of loading rate, and the change of loading rate has obvious influence on the maximum deviator stress of asphalt concrete under different confining pressure conditions. Under the same loading rate and temperature conditions, the deviator stress increases with the increase of confining pressure, and the maximum deviator stress also increases gradually with the increase of confining pressure, and basically presents a linear relationship. The loading rate has significant influence on the parameters of model concluded by Duncan-Chang Model. With the loading rate increases, model parameters k, n and cohesion force c increase, while the internal friction Angle φ decreases with the loading rate increasing and gradually becomes stable. The comparison between the parameter calculation curve and the test curve shows that the Duncan tensor model cannot reflect the strain softening characteristics of the material.

Keywords

asphalt concrete / static triaxial tests / stress-strain curve / Duncan-Chang model