Discussion on relationship between fracture energy and fractured area of concrete-to-concrete surfaces

摘要

Every concrete structure has concrete-to-concrete surfaces as placing joints which are discontinuous planes in concrete produced during construction, which should inseparably adhere to each other for better performance. The adhesion of newly cast concrete with old concrete is the most critical issue for retrofitting existing concrete structure. The first issue to study for improving mechanical properties of interfacial adhesion performance in concrete is the thorough understanding of the mechanism of interfacial fracture. For that purpose, tension softening diagram (TSD) is the best resort. It means that TSD comprises the most fundamental features of fracture mechanics parameters [1] including tension softening initial stress (ft), critical crack width (Wcr) and fracture energy (GF).