Experimental investigation on the resilient response of unbound graded aggregate materials by using large-scale dynamic triaxial tests

Resilient modulus is an important response index for unbound graded aggregate materials (UGAM) as a drainage layer in pavement structure. In this paper, a large-scale dynamic triaxial test (300 mm in diameter and 600 mm in height) is conducted with four gradations under conditions of repeated loading tests to investigate the resilient responses with various stress levels and water contents. Then, a model is introduced to quantify the moisture sensitivity of the resilient response of UGAM with the consideration of stress level, fine fraction porosity and gradation. Through comparison between experimental and predicted values, the proposed model is validated and shows that the resilient modulus at certain water content level can be predicted well when the resilient modulus at other water content level is known by experiment.