Journal of South China University of Technology(Natural Science Edition) ›› 2025, Vol. 53 ›› Issue (4): 50-60.doi: 10.12141/j.issn.1000-565X.240310

• Architecture & Civil Engineering • Previous Articles     Next Articles

Modified Calculation of Axial Compressive Bearing Capacity of Ultra-High-Strength Concrete Precast Column Considering Constraint Effect of Stirrup

WANG Suguo1, QIU Wei1, CHEANG I2, FAN Binghui1   

  1. 1.College of Civil Engineering,Fuzhou University,Fuzhou 350108,Fujian,China
    2.Jian Tong Consulting Group,Guangzhou 511466,Guangdong,China
  • Received:2024-06-13 Online:2025-04-25 Published:2024-07-22
  • About author:王素裹(1984—),女,博士,副教授,主要从事结构设计理论、结构抗震研究。E-mail: wangsuguo@foxmail.com
  • Supported by:
    the Natural Science Foundation of Fujian Province(2024J01355)

Abstract:

To study the effect of stirrup confinement on the axial compressive bearing capacity of ultra-high-strength concrete (UHSC) precast columns, this paper first conducted an axial compression contrast experiment between full-size UHSC column and ordinary column, and investigated the difference of crack development, failure pattern and ultimate bearing capacity of these two type columns. Based on the experimental results, further finite element analysis was conducted to simulate 36 full-scale UHSC columns. The study focused on analyzing the effects of stirrup configuration, stirrup spacing, and stirrup diameter on the axial compressive performance of UHSC columns. Combining the experimental findings and parametric analysis results, a modified calculation formula for the axial compressive bearing capacity of UHSC columns considering stirrup confinement was proposed. The proposed formula was then compared with the calculation formula in the current Code for Design of Concrete Structures. The results show that: the ultimate bearing capacity of equal-strength designed UHSC column is higher than that of ordinary concrete column, but it is more brittle than ordinary concrete, especially when reaching the ultimate bearing capacity; the confinement effect of stirrups on the core concrete enhances the axial compressive bearing capacity of UHSC columns. Changes in stirrup configuration, stirrup spacing, and stirrup diameter have a significant impact on the ultimate bearing capacity and peak compressive strain of UHSC columns; the proposed axial compressive bearing capacity correction formula for UHSC columns incorporates the differences between UHSC columns and ordinary concrete columns, considering the confinement effect of stirrups on the core concrete. Compared to the calculation formula provided in the code, which does not account for stirrup confinement and is primarily applicable to ordinary concrete columns, this formula better utilizes the material’s potential while ensuring safety margins. It can serve as a useful reference for practical engineering design.

Key words: ultra-high-strength concrete, axial compression, constraint of stirrup, modified bearing capacity formula, confined concrete

CLC Number: