Enhanced Self-healing Properties in Stone Mastic Asphalt with Encapsulated Bitumen Rejuvenators

Abstract

The extensive use of asphalt is generating a special interest in increasing the durability of this material. The development of encapsulated bitumen rejuvenators for self-healing asphalt is a sustainable and automated alternative to prolong the lifespan of asphalt. This paper presents an experimental study about how the strength and size of the encapsulated bitumen rejuvenators affect the mechanical properties of the material. In addition to that, this paper shows how optimum sizes and strengths of encapsulated bitumen rejuvenators are found to maximize the healing properties without compromising the fatigue resistance. Three types of asphalts containing encapsulated bitumen rejuvenator with different sizes and strengths were manufactured for this study. Each type of capsule was mixed in stone mastic asphalt to analyze their influence on fatigue durability and self-healing properties. The encapsulated rejuvenators performance was assessed by carrying out wheel tracking tests in the laboratory. Different loads were applied over the asphalt samples with and without capsules. The results showed that encapsulated bitumen rejuvenators, besides improving the healing properties of the material, are able to maintain and improve, depending on the type of capsule, the asphalt fatigue resistance.