Experimental Study on Dynamic Mechanical Performance of Post-Fire Concrete Confined by CFRP Sheets

Jingya Liu; Jingsi Huo; Haitao Wang; Zhongping Tang; Qingyan Zhang; Shixiang Yi

doi:10.3390/ma17092076

Experimental Study on Dynamic Mechanical Performance of Post-Fire Concrete Confined by CFRP Sheets

Materials (Basel). 2024 Apr 28;17(9):2076. doi: 10.3390/ma17092076.

Authors

Jingya Liu¹, Jingsi Huo², Haitao Wang^{3

4}, Zhongping Tang¹, Qingyan Zhang¹, Shixiang Yi¹

Affiliations

¹ Institute of Structural Material Failure and Strengthening Technology, Ningbo Polytechnic, Ningbo 315800, China.
² Fujian Provincial Key Laboratory of Intelligent Infrastructure and Monitoring, Huaqiao University, Xiamen 361021, China.
³ College of Civil and Architecture Engineering, Chuzhou University, Chuzhou 239000, China.
⁴ Engineering Research Center of Low-carbon Highway Building Materials of Anhui Province, Chuzhou 239000, China.

Abstract

Impact tests on post-fire concrete confined by Carbon Fiber-Reinforced Polymer/Plastic (CFRP) sheets were carried out by using Split Hopkinson Pressure Bar (SHPB) experimental setup in this paper, with emphasis on the effect of exposed temperatures, CFRP layers and impact velocities. Firstly, according to the measured stress-strain curves, the effects of experiment parameters on concrete dynamic mechanical performance such as compressive strength, ultimate strain and energy absorption are discussed in details. Additionally, temperature caused a softening effect on the compressive strength of concrete specimens, while CFRP confinement and strain rate play a hardening effect, which can lead to the increase in dynamic compressive strength by 1.8 to 3.6 times compared to static conditions. However, their hardening mechanisms and action stages are extremely different. Finally, nine widely accepted Dynamic Increase Factor (DIF) models considering strain rate effect were summarized, and a simplified model evaluating dynamic compressive strength of post-fire concrete confined by CFRP sheets was proposed, which can provide evidence for engineering emergency repair after fire accidents.

Keywords: CFRP-confined; DIF; SHPB; dynamic mechanical performance; post-fire concrete.

Grants and funding

This research was funded by 2022 Construction Research Project (self-funded) of Zhejiang department of housing and urban rural construction (Grant Number 2022K186), 2023 Social Investment Construction Scientific Research Project of Ningbo (Grant Number 20230103), the Open Fund Funding by National Engineering Laboratory for Applied Technology of Forestry & Ecology in South China (Grant Number 2023NFLY02), and 2022 Construction Research Project (self-funded) of Zhejiang department of housing and urban rural construction (Grant Number 2022K040), as well as Research Start-up Fund Project of Chuzhou University (Grant Number 2023qd52).