Choice of Healing Agent for Self-Healing Asphalt Concrete

The choice of a substance as a healing agent for asphalt concrete is determined by the scientific experience of researchers and the results of exploratory studies. There are no standard approaches for selecting healing agents or assessing their compatibility with the matrix components in asphalt concrete. However, such methods would make it possible to systematize research in the field of self-healing asphalt concrete and significantly expand the list of healing agents potentially suitable for encapsulation and ensuring the formation of a healing effect. An approach has been proposed for studying a substance and assessing the suitability of its use as a healing agent during encapsulation, using alginate technology in terms of solubility, homogeneity in a system with bitumen, and adhesive strength. This set of indicators can be used in the development and design of self-healing asphalt concrete, as well as for expanding the list of healing agents that can be used to implement self-healing technology. This article discusses sunflower oil and AR polymers as healing agents for self-healing asphalt concretes. The substances under consideration are capable of forming a homogeneous system ∆δ → 0 with bitumen, and the double systems “SfO-bitumen” and “ARP-bitumen” have a Gibbs energy value ∆G < 0, which confirms this. The studied healing agents are able to form an emulsion in alginate aqueous solutions, which was confirmed by the structuring effect and the extreme influence of their concentration on viscosity. The strength of the adhesive bonds under the influence of SfO was 14.2% of the initial value of the tensile strength during splitting. Under the influence of ARP, the strength of the adhesive bonds was 5.8% of the initial value of the tensile strength at splitting. The use of an activator in asphalt concrete makes it possible to increase the strength of the adhesive bonds to 25–45% of the initial splitting strength.