Development of microstructure and early-stage strength for 100% cold recycled asphalt mixture treated with emulsion and cement

This paper aims at investigating the microstructure and early-stage (<14 days) strength formation for 100% Cold Recycled Asphalt Mixture treated with Asphalt Emulsion and Cement (CRME). First, the factors influence on early-stage strength of CRME are carefully discussed. The microstructure formation of CRME in early-stage are identified by means of Environmental Scanning Electron Microscope (ESEM) and SEM. Moreover, two approaches including accelerating the hydration of cement and accelerating the integration of asphalt emulsion are proposed to improve the early-stage strength of CRME. The results indicate that the early-stage strength formation depends mainly on integration between emulsion particles in CRME. The early-stage strength of CRME can be improved by both accelerating the hydration of cement by additives and accelerating the demulsification of asphalt emulsion by surfactant, and the addition of surfactant in CRME has better effect in improving the early-stage strength. The method of accelerating the demulsification of asphalt emulsion by surfactant is recommended in practical application, which will help to enlarge the application range of CRME in winter or cold regions.