Mechanical insights into the behavior of cement stabilized aggregates during compaction and failure using smart aggregate: Experiments and DEM simulations

Abstract

Smart aggregate (SA) is a new type of sensor that has been employed recently in pavement health monitoring (PHM). However, the interaction mechanism between the sensor and the surrounding granular media and how to evaluate the pavement health are still unknown and need to be investigated before its wide application in PHM. In this study, laboratory uniaxial compaction and unconfined compression tests are undertaken on SA-based cement stabilized aggregates (CSA) and an index is proposed to characterize the physical and mechanical properties of CSA. Simultaneously, the discrete element method is employed to investigate the grain-scale evolution mechanisms of aggregates for spherical and irregular particles under loading. The results show that the micro-structural evolution inside the CSA can be observed more intuitively by means of SA combined with the new indicator Sv and can be used to monitor and assess the compaction and damage degree of the mixture. The variation of grain-scale parameters such as coordination number (CN) and normal contact force are the main reasons altering the SA sensor readings.