Abstract
This study investigated the chloride transport performance of basalt‐polypropylene fiber reinforced concrete (BPFRC) subjected to drying‐wetting cycles. The effects of the strength grade, basalt fiber (BF), polypropylene fiber (PF), and hybrid BF‐PF on the pore solution pH, chloride concentration distribution, chloride peak concentration (Cmax), and apparent chloride diffusion coefficient (Da) of the BPFRC were analyzed, and a multifactor model of Da was established. Moreover, the microstructures of BPFRC were studied to explore the effect of fibers on chloride transport performance of concrete in terms of theoretical pore volume, fiber‐matrix interface, fiber bonding properties, and corrosion morphology. The results showed that the chloride concentration of the BPFRC increased and the pore solution pH of the BPFRC decreased with the increase in the exposure time. The chloride concentration and Da of the BPFRC decreased with the increase in the strength grade. At a fiber volume content of 0.1%, the addition of BF and PF reduced the chloride concentration and Da of the BPFRC; at a fiber volume content of 0.2%, the addition of hybrid BF‐PF increased the chloride concentration and Da of the concrete. The chloride peak concentration appeared at the depth of 2 mm inside the concrete, and the change of the chloride peak concentration with exposure time followed the power function model. The theoretical pore volume of the BPFRC specimens decreased initially and then increased with the increase in the exposure time. FE‐SEM observed that the bonding property between BF and matrix was better than that of PF, which could effectively control the development of microcracks.
Highlights
Concrete is one of the most widely used building materials in the world [1]
The pH gradually decreases with an increase in the exposure time. is is because, in order to balance the anion charge during the erosion, OH− ions dissolve out while chloride ions enter the concrete through capillary adsorption and diffusion, leading to a continuous decrease in the pore solution pH [30]. e higher strength grade for the basalt-polypropylene fiber reinforced concrete (BPFRC) results in a higher pH value. e pH value at the 1 mm depth of C50 concrete is 2.43%–3.77% higher than that of the C30 concrete
A tropical ocean tidal zone was simulated using a drying-wetting cycle test system in a high-temperature environment. e effects of the strength grade, fiber type, and fiber content on the chloride transport performance of BPFRC were investigated. e main conclusions are as follows: (1) e pore solution pH of the BPFRC specimens decreased with the increase in the exposure time, and the pore solution pH of the surface concrete decreased rapidly
Summary
Concrete is one of the most widely used building materials in the world [1]. its typical quasibrittle characteristics, low tensile strength, and low strain capacity have a significant effect on the application and development of concrete structures [2, 3]. e addition of short and disorderly distributed fibers can inhibit the generation and development of microcracks in concrete, control the stress at the crack tip, and play a bridging role, thereby significantly improving the toughness of the concrete [4,5,6] and increasing its application. Two types of fibers are mixed into concrete—rigid fibers and flexible fibers Rigid fibers, such as steel fiber, carbon fiber, and basalt fiber (BF), have high elastic modulus and can improve the strength and bearing capacity of concrete, and steel fiber can increase the ductility of concrete [7, 8]. BF is a new type of environment-friendly fiber that has the advantages of excellent chemical stability, large elastic modulus, good wear resistance, and low cost [13] It is a suitable replacement for steel fibers in hybrid fiber systems in marine environments. The microstructures of BPFRC before and after erosion, such as theoretical total pore volume (P), the bonding performance between fiber and concrete matrix, and corrosion morphology, were evaluated by thermogravimetry (TG) and field emission scanning electron microscope (FE-SEM)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
