TY - JOUR

T1 - Compression performance of ultra-high performance concrete filled steel tube(UHPCFST) columns exposed to elevated temperature during construction

AU - Wang, T.

AU - Yu, M.

AU - Liao, W.

AU - Yu, C.

AU - Ye, J.

N1 - Export Date: 8 January 2025 CODEN: ENSTD Correspondence Address: Yu, M.; School of Civil Engineering, China; email: ceyumin@whu.edu.cn Funding details: National Natural Science Foundation of China, NSFC, 52178157 Funding details: National Natural Science Foundation of China, NSFC Funding text 1: This study was supported financially by the National Natural Science Foundation of China (Grant NO. 52178157).

PY - 2025/3/1

Y1 - 2025/3/1

N2 - To investigate the residual mechanical performance of ultra-high performance concrete filled steel tube (UHPCFST) columns exposed to high temperatures during construction, in this research, an experimental study on 27 UHPCFST columns is conducted to examine the impact of fire scenarios, age of the core UHPC exposed to elevated temperature, and volume ratio of coarse aggregates on the post fire behavior of the UHPCFST columns. Detailed analyses are carried out on the failure modes, the historical maximum temperatures in the cross-sections, the axial load-deformation curve, the residual compressive strengths, and the residual stiffness of the columns. The findings indicate that both the steel tubes and the bearing capacity UHPC cores show increases in the historical maximum temperatures with the increase in the aging of the core UHPC. For columns exposed to fire sources at greater distances, a significant enhancement in bearing capacity was observed following high-temperature exposure at varying ages. The bearing capacity demonstrated an increasing trend with the aging of the UHPC subjected to high temperatures. In contrast, when exposed to nearby fire sources, a decline in strength was noted, and the overall bearing capacity of the columns decreased as the age of UHPC exposed to elevated temperature increased. Furthermore, a predictive model for the residual bearing capacity of UHPCFST columns subjected to high temperatures during construction was developed and validated. This research is expected to provide valuable insights for the post-fire evaluation and reinforcement of UHPCFST structure in construction settings.

AB - To investigate the residual mechanical performance of ultra-high performance concrete filled steel tube (UHPCFST) columns exposed to high temperatures during construction, in this research, an experimental study on 27 UHPCFST columns is conducted to examine the impact of fire scenarios, age of the core UHPC exposed to elevated temperature, and volume ratio of coarse aggregates on the post fire behavior of the UHPCFST columns. Detailed analyses are carried out on the failure modes, the historical maximum temperatures in the cross-sections, the axial load-deformation curve, the residual compressive strengths, and the residual stiffness of the columns. The findings indicate that both the steel tubes and the bearing capacity UHPC cores show increases in the historical maximum temperatures with the increase in the aging of the core UHPC. For columns exposed to fire sources at greater distances, a significant enhancement in bearing capacity was observed following high-temperature exposure at varying ages. The bearing capacity demonstrated an increasing trend with the aging of the UHPC subjected to high temperatures. In contrast, when exposed to nearby fire sources, a decline in strength was noted, and the overall bearing capacity of the columns decreased as the age of UHPC exposed to elevated temperature increased. Furthermore, a predictive model for the residual bearing capacity of UHPCFST columns subjected to high temperatures during construction was developed and validated. This research is expected to provide valuable insights for the post-fire evaluation and reinforcement of UHPCFST structure in construction settings.

KW - During construction

KW - Early-age UHPC

KW - Post fire

KW - Residual bearing capacity

KW - Ultra-high-performance concrete-filled steel tube

KW - Columns (structural)

KW - Compressive strength

KW - Fires

KW - Pressure vessels

KW - Tubular steel structures

KW - Concrete filled steel tube columns

KW - Concretefilled steel tubes (CFST)

KW - Early age UHPC

KW - Exposed to

KW - High-performance concrete

KW - Post-fire

KW - Residual bearing capacities

KW - Ultra high performance

KW - Ultra-high performance concrete

U2 - 10.1016/j.engstruct.2024.119553

DO - 10.1016/j.engstruct.2024.119553

M3 - Journal article

VL - 326

JO - Engineering Structures

JF - Engineering Structures

SN - 0141-0296

M1 - 119553

ER -