Duration : 01.03.2020 – present
Supervisor : Professor Eugen Brühwiler
Doctoral Student : Jian Zhan
Ultra-high performance ﬁbre reinforced cementitious composites concrete (UHPFRC) is a new class of cementitious composite materials with remarkable mechanical properties and dense matrix. The concept of using a robust layer of UHPFRC (usually with rebars) to enhance RC structures has proven to be very efﬁcient and durable, especially for the RC bridge decks subjected to signiﬁcant fatigue loading. This novel concept combines the structural resistance and protective functions of UHPFRC leading to improved durability and increased structural resistance of RC structures. Thus, the UHPFRC layer usually carries significant fatigue stress and is under severe environment. However, only limited research have been conducted on the fatigue behavior of UHPFRC. No research have been conducted on the variable amplitude (VA) fatigue behavior of UHPFRC. Besides, the UHPFRC layer will probably enter strain hardening domain due to built-in stress and service stress, while the importance of strain-hardening behavior of UHPFRC is often neglected by researchers. The objectives of this research are thus to :
- Study the tensile fatigue behavior of UHPFRC and reinforced UHPFRC under variable amplitude loading;
- Conduct numerical analysis on RC slabs strengthened by reinforced UHPFRC considering built-in stress and service stress;
- Conduct fatigue damage modelling on RC deck slabs strengthened by reinforced UHPFRC;
- Validate a conceptual design of UHPFRC joints by means of numerical analysis and bending tests.