Research on development mechanism of early-stage strength for cold recycled asphalt mixture using emulsion asphalt

This paper aims at investigating the development mechanism of early-stage strength for cold recycled asphalt mixture using emulsion asphalt. The influence parameters of early-stage strength development for cold recycled mixture by emulsion and cement (CRME) is firstly studied, and then the direct tensile test is used to determine the early-stage strength development law of emulsion asphalt-cement mortar. Lastly, the image analysis is used to identify the fracture morphology of cross-section of cold recycled mixture, and the development mechanism of cold recycled mixture is revealed. The results indicate that the cement plays the predominant role in strength of CRME in first 3 days, while emulsion asphalt plays the predominant role in both early-stage and final strength. Moreover, the adhesion between mortar and aggregate provide the strength for CRME in earth-stage, while the cohesion in emulsion-cement mortar provides the strength for CRME after curing. The findings in the paper provide new approaches to improve the early-stage strength of CRME. (C) 2015 Elsevier Ltd. All rights reserved.