Developing a Model for Resilient Modulus Estimation of Recycled Layer with Bitumen Emulsion and Cement Stabilization

Due to maturation, the resilient modulus (Mr) of recycled mixes with bitumen emulsion and cement will increase upon curing. Therefore choosing a design Mr for these mixtures will be more complex than conventional hot mixes. Furthermore the Mr test apparatus is not accessible in many project plants and developing a model for estimating the Mr with an inexpensive and accessible method will be desirable. In this research using the results of indirect tensile strength (ITS) and Mr tests at different temperatures (-10, 5 and 25oC) and curing times (7, 28 and 120 days), two models have been developed for recycled mixture with bitumen emulsion containing type I and pozzolanic cements. Based on the results, first the relation between ITS and Mr in similar conditions (temperature and curing time) for each cement was correlated by a linear relation. Then by considering the effects of temperature and curing on Mr, the aforementioned models were modified for estimating Mr in different conditions.