Flexural behavior and design of high-strength I-shaped steel-UHPC composite beams

• Published in: Advances in structural engineering Vol. 28; no. 10; pp. 1877 - 1889
• Main Authors: Lai, Zhichao, Yao, Pengyu, Yang, Xiaoqiang, Li, Shihui, Zhao, Qiu
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01.07.2025
• Subjects: Flexural behavior; Design; UHPC; Composite beam; High strength steel
• ISSN: 1369-4332; 2048-4011
• DOI: 10.1177/13694332251319094

High-strength materials and corresponding composite members are gradually accepted in the bridge industry to achieve the purposes of large span and lightweight. Three simply supported I-shaped steel-concrete composite beams were tested to investigate their flexural behavior when different combinations of materials were used, i.e., high-strength steel-ultra high performance concrete (HS-UHPC), high-strength steel-conventional strength concrete (HS-CC), and conventional strength steel-ultra high performance concrete (CS-UHPC). The test finds that the HS-UHPC composite beam has the highest flexural strength and reasonable plastic deformation ability as compared to the other two beams. A finite element (FE) model was also constructed and benchmarked. Subsequently, the model was utilized to conduct parametric studies, aimed at exploring in-depth the flexural behavior of steel-concrete composite beams. The results from the tests and FE analyses were employed to assess the suitability of existing design specifications (i.e., AISC 360-22, GB 50017-2017, and Eurocode 4) in estimating the flexural strength of HS-UHPC composite beams. The evaluations indicated that GB 50017-2017 can reasonably estimate the flexural strength of HS-UHPC composite beams. This research provides valuable insights into the design and construction of HS-UHPC composite beams in bridges.