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However, embedded BFRP rebars may degrade over time within the alkaline concrete pore solution. While extensive literature has scrutinized BFRP degradation under highly alkaline conditions (e.g., pH~13 in normal concrete), comparatively few studies have addressed its behavior under lower alkalinity (e.g., pH~11\u201312 in carbonated\/green concrete). To address this issue, this study systematically investigates the degradation mechanism of BFRP rebars under coupled factors of pH (7, 11, 12, and 13), temperature (23, 40, and 60 \u00b0C), and aging time (30, 60, and 90 days). Research outcomes indicate that a decrease in pH from 13 to 11 at 23 \u00b0C results in a reduction in diffusion coefficient from 7.071 \u00d7 10\u22127 mm2\/s to 5.876 \u00d7 10\u22127 mm2\/s. Moreover, lowering the temperature from 60 \u00b0C to 23 \u00b0C at pH 12 leads to a decline in the diffusion coefficient from 7.547 \u00d7 10\u22127 mm2\/s to 6.758 \u00d7 10\u22127 mm2\/s. Furthermore, following a 90-day immersion at 60 \u00b0C, decreasing the exposure pH from 13 to 11 can significantly improve tensile strength retention from 25.357% to 71.933%. In the same scenario, flexural strength retention (or interlaminar shear strength retention) increases from 20.930% to 87.638% (or 23.464% to 76.592%) in such a mildly alkaline environment. A comprehensive degradation mechanism is uncovered, linking macroscopic mechanical properties to microscopic characteristics (encompassing fiber corrosion, matrix cracking, and interfacial debonding). This degradation process can be expedited by alkali attack and thermal activation. These findings contribute valuable insights into the alkali-induced degradation process and furnish a comprehensive dataset regarding the durability performance of BFRP rebars.<\/jats:p>","DOI":"10.3390\/ma18174170","type":"journal-article","created":{"date-parts":[[2025,9,5]],"date-time":"2025-09-05T12:18:18Z","timestamp":1757074698000},"page":"4170","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Time-Dependent Degradation Mechanism of Basalt Fiber Reinforced Polymer (BFRP) in a Low-Alkalinity Environment"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9533-6575","authenticated-orcid":false,"given":"Weiwen","family":"Li","sequence":"first","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, Shenzhen University, Shenzhen 518060, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Murong","family":"Zou","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, Shenzhen University, Shenzhen 518060, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Meilin","family":"He","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, Shenzhen University, Shenzhen 518060, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wanye","family":"Li","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, Shenzhen University, Shenzhen 518060, China"},{"name":"Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2234-6892","authenticated-orcid":false,"given":"Peng","family":"Wang","sequence":"additional","affiliation":[{"name":"Guangdong Provincial Key Laboratory of Durability for Marine Civil Engineering, Shenzhen University, Shenzhen 518060, China"},{"name":"Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yihong","family":"Tang","sequence":"additional","affiliation":[{"name":"Department of Civil and Environmental Engineering, The Hong Kong University of Science and Technology, Hong Kong, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2461","DOI":"10.1016\/j.conbuildmat.2008.09.026","article-title":"Modeling corroded section configuration of steel bar in concrete structure","volume":"23","author":"Yuan","year":"2009","journal-title":"Constr. 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