Feasibility study of ECC with self-healing capacity applied on the long-span steel bridge deck overlay

Engineered Cementitious Composites (ECC) with high ductility has been recognised to be a high performance and durable alternative to the construction material in civil engineering field. In this paper, ECC material was proposed to be applied on the long-span steel bridge deck overlay. Herein we studied the feasibility of this application via integration of ECC's material performances and stress response of structure using finite element analysis. The results show that ECC material could overcome the brittleness of normal concrete, featuring high tensile strain/deformability capacity under tension/flexural load, as well as higher flexural strength and fatigue life, compared with normal asphalt/concrete materials. Furthermore, the self-healing capacity in ECC helps the crack seal itself, as a result, recovers its water permeability coefficient and resistance to chloride ion penetration to nearly the same level as undamaged ones. By integrating ECC's flexural fatigue behaviour and finite element analysis, it can be concluded that ECC is feasible to be a candidate material for the steel bridge overlay. The application of ECC is expected to greatly extend the service life of steel bridge overlay meanwhile be with thinner thickness compared with normal bridge deck overlay structure, resulting in a more sustainable overlay.