The Chloride Ion Penetration Mechanism in Basalt Fiber Reinforced Concrete under Compression after Elevated Temperatures

Limin Lu,Shaohua Wu,Qingli Zhao,Yuwen Qin,Jeung-Hwan Doh,Guanglin Yuan

doi:10.3390/app112110137

Abstract

Chloride ion penetration frequently leads to steel corrosion and reduces the durability of reinforced concrete. Although previous studies have investigated the chloride ion permeability of some fiber concrete, the chloride ion permeability of the basalt fiber reinforced concrete (BFRC) has not been widely investigated. Considering that BFRC may be subjected to various exposure environments, this paper focused on exploring the chloride ion permeability of BFRC under the coupling effect of elevated temperatures and compression. Results demonstrated that the chloride ion content in concrete increased linearly with temperature. After exposure to different elevated temperatures, the chloride ion content in BFRC varied greatly with increasing stress. The compressive stress ratio threshold for the chloride ion penetration was measured. A calculation model of BFRC chloride ion diffusion coefficient under the coupling effect of elevated temperatures and mechanical damage (loading test) was proposed.

Highlights

Elevated temperatures and chloride ion erosion are affecting the durability of concrete structures [1]
Sim et al [15] and High et al [16] conducted experimental studies on the high-temperature performance of basalt fiber reinforced concrete (BFRC) and found that the basalt fiber can improve the performance of concrete exposed to elevated temperatures
2.5 mm, the chloride ion content was decreased by 3.85%, 13.7% and 16.9% at stress ratios

Summary

Introduction

Elevated temperatures and chloride ion erosion are affecting the durability of concrete structures [1]. It is necessary to evaluate the chloride ion penetration resistance of structural concrete after a disaster. Adding fly ash and slag to concrete could improve pore structure and resistance to chloride ion penetration [4]. To clarify the permeability of BFRC under long-term axial load after elevated temperatures, a chloride ion penetration test of BFRC specimen under axial compression was conducted. A calculation model for the chloride ion diffusion coefficient of BFRC under the coupling effect of elevated temperatures and loads was proposed to provide a basis for evaluating the durability and service life of BFRC. The water-soluble chloride ion content of different depth layers of the concrete specimen was measured after the erosion process. The concrete powder for depth layers from the surface counts: 0–5 mm, 5–10 mm, 10–15 mm, 15–20 mm, 20–25 mm, and 25–30 mm were measured by the DY-2501B chloride ion meter

Loading System

Results and Discussion

Effect of Stress Level on Chloride Ion Diffusion Coefficient

Effect of Erosion Time on Chloride Ion Diffusion Coefficient

Conclusions