An experimental-numerical study of tensile behavior of reinforced-UHPC members subject to uniaxial tension

• Published in: Structures (Oxford) Vol. 75; p. 108626
• Main Authors: Tong, Teng, Li, Xiaobo, Wang, Tao, Liu, Zhao
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.05.2025
• Subjects: Bond; Cracking; Spacing; UHPC; Width; Cracking; UHPC; Spacing; Bond; Width
• ISSN: 2352-0124; 2352-0124
• DOI: 10.1016/j.istruc.2025.108626

Cracking behavior, including cracking spacing and width, of a reinforced-UHPC (R-UHPC) member is critical to quantitatively evaluate its damage and durability capacity. In this study, totally twenty specimens were loaded to experimentally probe tensile behaviors of R-UHPC specimens, considering the variation of fiber contents and reinforcement ratios. With a given reinforcement ratio, higher fiber content (fracture energy of UHPC) would lead to sparse distribution of main cracks and rapid post-peak strength degradation. Therewith, deliberate selection of reinforcement ratio, tensile strength and fracture energy of UHPC was required to guarantee a R-UHPC specimen’s strength and ductility. On the other aspect, a novel numerical simulation framework is proposed, which integrates concrete damage plasticity (CDP) model for UHPC matrix and user-coded zero-thickness cohesive element for bond behavior between UHPC and rebars. The tensile stress-displacement relation is defined in the CDP model to alleviate mesh sensitivity problem. It proves that numerical results precisely reflect the effects of steel fiber content and reinforcement ratio on a R-UHPC specimen’s tensile strength and ductility, as well as its cracking spacing and width. •Tensile strength of R-UHPC depends on the tensile properties of UHPC and reinforcement ratio.•High fracture energy requires high reinforcement ratio to avoid rapid post-peak strength degradation and poor ductility.•A numerical framework is proposed for the matrix and rebar-matrix interface elements inserted between 2-D and 3-D elements.