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

2021 ◽  
Vol 11 (21) ◽  
pp. 10137
Author(s):  
Limin Lu ◽  
Shaohua Wu ◽  
Yuwen Qin ◽  
Guanglin Yuan ◽  
Qingli Zhao ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Elevated Temperatures ◽  
Coupling Effect ◽  
Basalt Fiber ◽  
Chloride Ion ◽  
Fiber Reinforced Concrete ◽  
Ion Permeability ◽  
Ion Content ◽  
Chloride Ion Penetration ◽  
Ion Penetration

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.

MEASURING CRACK WIDTH IN RC AND R/FRC TIES THROUGHT LASER SCANNER

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Nicola Critelli ◽  
Alessandro Cesetti ◽  
Alessandro P. Fantilli ◽  
Francesco Tondolo
Keyword(s):  
Reinforced Concrete ◽  
Crack Width ◽  
Laser Scanner ◽  
Chloride Ion ◽  
Fiber Reinforced Concrete ◽  
Fundamental Parameter ◽  
Concrete Carbonation ◽  
Rc Structure ◽  
Chloride Ion Penetration ◽  
Conoscopic Holography

Durability of reinforced concrete (RC) structure is strictly connected to the capacity of concrete mass to protect the embedded reinforcement from corrosion. As cracks are almost inevitable, crack width is a fundamental parameter that needs to be controlled during the serviceability stage of RC members. In fact, not only the direct ingress of aggressive agents, such as oxygen and water, is a function of crack width, but also concrete carbonation and the chloride ion penetration are accelerated by the presence of wide cracks. Accordingly, the aim of present research project is to assess the width by using a new system, based on the optical conoscopic holography. It provides the non-contact measure of crack profile, taken at the end of each loading cycle, in ties subjected to sets of repeated loads. Both in plain and fiber-reinforced concrete (FRC), more than one crack width can be measured for the same crack.

Structure Characteristics and Mechanical Properties of Fiber Reinforced Concrete

2010 ◽  
Vol 168-170 ◽  
pp. 1556-1560
Author(s):  
Wen Qin Deng ◽  
Jing Zhao
Keyword(s):  
Reinforced Concrete ◽  
Glass Fiber ◽  
Polypropylene Fiber ◽  
Basalt Fiber ◽  
Chloride Ion ◽  
Sem Analysis ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Ion Diffusion ◽  
Glass Fiber Reinforced

Mechanical properties of fiber reinforced concrete with polypropylene fiber, alkali-resistant glass fiber and basalt fiber separately were studied in this paper. The internal structure of fiber reinforced concrete was researched by testing chloride ion diffusion coefficient and scanning electron microscope (SEM) analysis. The results show that adding a certain amount of three fibers separately into concrete have all increased splitting strength. Compared with referenced concrete, compressive strength of alkali-resistant glass fiber reinforced concrete and basalt fiber reinforced concrete are both improved. According to analysis, the effect of srengthening and toughening for basalt fiber is particularly significant. The order of chloride ion diffusion coefficient from lower to higher is alkali-resistant glass fiber reinforced concrete, referenced concrete, basalt fiber reinforced concrete, polypropylene fiber reinforced concrete. This result indicates that alkali-resistant glass fiber bonds cement paste best and makes internal structure densest by SEM analysis.

scholarly journals Durability Investigation of Carbon Fiber Reinforced Concrete under Salt-Freeze Coupling Effect

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6856
Author(s):  
Yongcheng Ji ◽  
Wenchao Liu ◽  
Yanmin Jia ◽  
Wei Li
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Coupling Effect ◽  
Chloride Ion ◽  
Chloride Ions ◽  
Fiber Reinforced Concrete ◽  
Ion Concentration ◽  
Fiber Reinforced ◽  
Ion Distribution ◽  
Carbon Fiber Reinforced

In order to study the durability behavior of CFRP (carbon fiber reinforced polymer) reinforced concrete, three category specimens (plain, partially reinforced, and fully reinforced) were selected to investigate its performance variation concerning chlorine salt and salt-freeze coupled environment, which included the microscopic examination, the distribution of chloride ion concentration, and the compressive properties. By observing the microscopic of the specimens, the surface and cross-section corrosion deterioration was examined with increasing exposure time, and the physical behavior of CFRP and core concrete were discussed. The chloride ion diffusion test exerted that the chloride ion concentration in plain specimens is at least 200 times higher than that of fully reinforced specimens. Therefore, the effectiveness of CFRP reinforcement will be proved to effectively hinder the penetration of chloride ions into the core section. The formula of the time-dependent effect of concrete diffusivity with salt-freeze coupling effect was presented and its accuracy verified. A time-varying finite element model of chloride ion distribution was established by using ABAQUS software. It can be seen from the axial compression test that the strength loss rate of three categories of specimens was varied when subjected to the corrosion environment. Therefore, it is proved that CFRP reinforcement can effectively reduce the deterioration of the specimen’s mechanical properties caused by the exposure environment. The research results can provide technical reference for applying the CFRP strengthened concrete in a severe salt-freeze environment.

Penetration Behavior of Chloride Ions into Concrete in Coastal Areas

2006 ◽  
Vol 302-303 ◽  
pp. 584-590
Author(s):  
Yoshihiro Masuda ◽  
F.-R. Wu ◽  
S. Nakamura ◽  
S. Sato
Keyword(s):  
Chloride Ion ◽  
Concrete Specimen ◽  
Chloride Ions ◽  
Ion Content ◽  
Exposure Test ◽  
Total Chloride ◽  
Chloride Ion Penetration ◽  
Apparent Diffusion ◽  
Penetration Behavior ◽  
Ion Penetration

Exposure test on chloride ion penetration behavior into Concrete in coastal area was implemented. The distances between concrete specimens and coast were changed in the range from 50 to 150 meters, and water-cement ratios (W/C) were 45, 55, 60 and 65 %. The total chloride ion content at each different depth from surface of concrete specimen was measured at the age of 1, 2, 3, 5, 7, 8 and 10 years. In this paper, apparent diffusion coefficient (D) and chloride ion content on surface of concrete (C0) were calculated by inverse analyses from the measured total chloride ion content, and the chloride ion penetration behavior was simulated using the calculated D and C0. As a result, the chloride ion penetrated in concrete with a W/C of 60 % at a point 50 m from the sea for 10 years was estimated approximately 0.2 kg/m3.

Examining the Effect of Asphalt Plant Surplus Filler on Water and Chloride Ion Permeability of Cement Mortar

2018 ◽  
Vol 765 ◽  
pp. 383-390
Author(s):  
Hadi Vafaeinejad ◽  
Mahdi Kioumarsi
Keyword(s):  
Electrical Resistivity ◽  
Reinforced Concrete ◽  
Electrical Resistance ◽  
Cement Mortar ◽  
Concrete Structures ◽  
Chloride Ion ◽  
Partial Replacement ◽  
Reinforced Concrete Structures ◽  
Ion Permeability ◽  
Chloride Ion Penetration

The penetration of water and chloride ion into the concrete is of factors that cause rust and corrosion in rebars by reaching the existing reinforcement surface in reinforced concrete structures. In this study, effect of using Asphalt Plant Surplus Filler as a partial replacement of cement with replacement values of 0, 5, 10, 15 and 20% on permeability and electrical resistance of cement mortar were investigated with the aim of decreasing cement consumption. In order to determine the penetration of water, 10 cubic specimens with the size of 150 mm were made and tested. In order to determine chloride ion penetration, 20 cylindrical specimens with a length of 50 and a diameter of 100 mm were studied at the ages of 28 and 56 days. To test the electrical resistivity of cement mortar, 30 cubic specimens with the size of 100 mm were tested at the ages of 7, 28 and 56 days. According to the results of the experiments, adding filler to the cement mortar enhances the penetration of water and chloride ion. Electrical resistivity generally increases with the increase of specimen age. Furthermore, the filler increment indicates the reduction of electrical resistivity.

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