Durability of an UHPFRC under mechanical and chloride loads

• Autor(a) principal: Matos, Ana Mafalda
• Data de Publicação: 2021
• Outros Autores: Figueiredo, Stefan Chaves, Nunes, Sandra, Schlangen, Erik, Aguiar, J. L. Barroso de
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: https://hdl.handle.net/1822/76066
• topic: Bending; Chlorides ingress; Cracked UHPFRC; Durability; Ultra-high performance fibre reinforced cementitious composites (UHPFRC); Cementitious composites (UHPFRC); Ultra-high performance fibre reinforced; Science & Technology

The high cost of UHPFRC is a limitation on the practical application in real construction projects. However, a very competitive UHPFRC approach is the hybrid structural elements, where thin layers of UHPFRC are employed to rehabilitate/strengthen damage cover concrete. New layers subjected to harsh conditions (loads and/or environmental) can eventually crack under service conditions, changing the local transport properties and thus, a faster ingress of detrimental substances occur, such as chlorides ions. Most of the studies on chloride penetration in UHPFRC have focused on determining the transport properties of sound, non-cracked specimens. Thus, an experimental campaign was carried out to assess chloride ingress in loaded and/or cracked UHPFRC and the effect of such ions on mechanical performance. Typical service cracks patterns were imposed on UHPFRC specimens and then exposed to wetting?drying cycles in a chloride solution. After 1-year chloride exposure, UHPFRC specimens were in good condition with no significant losses in flexural strength; however, stiffness might be affected. The chloride contents up to 20 mm depth were superior to the European standards critical chloride content. A minimum cover depth of 20 mm of new UHPFRC is recommended to protect a concrete substrate in hybrid structures for exposure classes XS3.