Effect of alkalinity on the shear performance degradation of basalt fiber-reinforced polymer bars in simulated seawater sea sand concrete environment

2021 ◽  
Vol 299 ◽  
pp. 123957
Author(s):  
Yong Yi ◽  
Shuaicheng Guo ◽  
Sheng Li ◽  
Md Zillur Rahman ◽  
Linlin Zhou ◽  
...  
2020 ◽  
Vol 12 (3) ◽  
pp. 168781402091288
Author(s):  
Suraksha Sharma ◽  
Daxu Zhang ◽  
Qi Zhao

Although numerous experimental and analytical investigations on the environmental effects on basalt fiber–reinforced polymer bars were carried out, degradation of the basalt fiber–reinforced polymer bar in seawater and sea sand concrete environment has been insufficiently analyzed. This work presents two distinct numerical approaches, degradation rate–based approach and diffusion-based approach, to investigate the durability of basalt fiber–reinforced polymer bars in seawater and sea sand concrete solution subjected to various temperatures (32°C, 40°C, 48°C, and 55°C). The degradation of the material was quantified using a simplified two-dimensional model of a homogenized basalt fiber–reinforced polymer bar in COMSOL Multiphysics software. Fickian diffusion provides basis for modeling diffusion-based approach. The findings from both the approaches suggested that the basalt fiber–reinforced polymer bar becomes more susceptible to degradation as the exposure temperature increases and results in greater geometrical deformities. The comparisons of experimental data, analytical solutions, and numerical results showcase that the present numerical models can predict the degradation of a basalt fiber–reinforced polymer bar in a seawater and sea sand concrete environment.


2021 ◽  
pp. 136943322110262
Author(s):  
Zhiqiang Dong ◽  
Gang Wu ◽  
Hong Zhu ◽  
Yang Wei ◽  
Xiao-Ling Zhao ◽  
...  

This article proposes a new type of basalt fiber–reinforced polymer (BFRP) bar–reinforced seawater sea sand glass aggregate concrete (SSGC) beam with broad application prospects in ocean engineering. Crushed tempered glasses were utilized as coarse aggregates in the concrete mixture to realize the efficient and harmless recycling of waste glass. First, the bond behaviors between the BFRP bars and SSGC with different glass aggregate replacement ratios were investigated. Then, four-point bending tests were conducted to investigate the flexural performance of the SSGC beams completely reinforced with BFRP bars. Based on this, the tested flexural strengths were compared with the calculated strengths to evaluate whether the existing specifications were still applicable to the design of the BFRP bar–reinforced SSGC beams. Test results showed that although the compressive strength of the SSGC gradually decreased with increased glass aggregate content, the bond performance between BFRP bars and SSGC did not follow the same degradation pattern. There were no obvious differences in the form of the bond–slip curves between BFRP bars and different types of SSGC. With increasing glass aggregate content, the ultimate bearing capacity and energy consumption of BFRP bar–reinforced SSGC beams decreased. All calculated ultimate flexural capacities were higher than the experimental values, which shows that the application of existing specifications to BFRP bar–reinforced SSGC beams needs to be studied further.


2018 ◽  
Vol 765 ◽  
pp. 355-360 ◽  
Author(s):  
Sakol Suon ◽  
Shahzad Saleem ◽  
Amorn Pimanmas

This paper presents an experimental study on the compressive behavior of circular concrete columns confined by a new class of composite materials originated from basalt rock, Basalt Fiber Reinforced Polymer (BFRP). The primary objective of this study is to observe the compressive behavior of BFRP-confined cylindrical concrete column specimens under the effect of different number of layers of basalt fiber as a study parameter (3, 6, and 9 layers). For this purpose, 8 small scale circular concrete specimens with no internal steel reinforcement were tested under monotonic axial compression to failure. The results of BFRP-confined concrete specimens of this study showed a bilinear stress-strain response with two ascending branches. Consequently, the performance of confined columns was improved as the number of BFRP layer was increased, in which all the specimens exhibited ductile behavior before failure with significant strength enhancement. The experimental results indicate the well-performing of basalt fiber in improving the concrete compression behavior with an increase in number of FRP layers.


2016 ◽  
Vol 51 (9) ◽  
pp. 1275-1284 ◽  
Author(s):  
Jianzhe Shi ◽  
Xin Wang ◽  
Huang Huang ◽  
Zhishen Wu

Relaxation is a key factor that controls the application of prestressing fiber-reinforced polymer tendons. This paper focuses on the evaluation of the relaxation behavior of newly developed basalt fiber-reinforced polymer tendons through an approach considering anchorage slippage. A series of relaxation tests on basalt fiber-reinforced polymer tendons subjected to three levels of initial stresses (0.4 fu, 0.5 fu, and 0.6 fu, where fu = ultimate strength) were conducted using a specially designed test setup that eliminates the impact of slippage at the anchor zone. An additional group of tests was conducted to validate the enhancement effect of pretension on the relaxation behavior. The relaxation rates at one million hours were predicted based on experimental fitting. Finally, the relaxation rates at 1000 h were predicted using the correlation between the relaxation and creep and were validated with the experimental relaxation rates. The results demonstrate the effectiveness of the proposed setup in measuring the relaxation loss of specimens and reveal that the relaxation rates of untreated basalt fiber-reinforced polymer tendons at 1000 h are 4.2%, 5.3%, and 6.4% at 0.4 fu, 0.5 fu, and 0.6 fu, respectively. Pretension treatment performs effective in relaxation loss controlling. BFRP tendons are recommended to be applied at an initial stress of 0.5 fu after pretension treatment, with one-million-hour relaxation rate equal to 6.7%. Furthermore, the relaxation rate at 1000 h can be predicted accurately based on the creep behavior. The conclusions of this study can provide guidance for the prestressing applications of basalt fiber-reinforced polymer tendons.


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