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硅酸盐通报 ›› 2026, Vol. 45 ›› Issue (7): 2299-2311.DOI: 10.16552/j.cnki.issn1001-1625.2025.1257

• 水泥混凝土 • 上一篇    下一篇

盐冻环境下CO2养护生物炭再生混凝土的损伤规律与寿命预测

王梦瑶1(), 赵远卓2, 杜文风2, 赫中营2()   

  1. 1.黄河水利职业技术大学土木与交通工程学院,开封 475004
    2.河南大学建筑工程学院,开封 475004
  • 收稿日期:2025-12-16 修订日期:2026-01-22 出版日期:2026-07-15 发布日期:2026-08-13
  • 通信作者: 赫中营,博士,教授。E-mail:3792097137@qq.com
  • 作者简介:王梦瑶(1989—),女,讲师。主要从事混凝土力学性能的研究。E-mail:2541052037@qq.com
  • 基金资助:
    国家自然科学基金(52478166)

Damage Law and Life Prediction of CO2 Curing Biochar Recycled Concrete under Salt Freezing Environment

WANG Mengyao1(), ZHAO Yuanzhuo2, DU Wenfeng2, HE Zhongying2()   

  1. 1.Civil Engineering and Transportation Engineering,Yellow River Conservancy Technical University,Kaifeng 475004,China
    2.School of Civil Engineering and Architecture,Henan University,Kaifeng 475004,China
  • Received:2025-12-16 Revised:2026-01-22 Published:2026-07-15 Online:2026-08-13

摘要:

为提升寒冷盐碱地区再生混凝土的耐久性,以C30再生混凝土为对象,设置 0%、2.0%、4.0%、6.0%、8.0%(质量分数)五个生物炭掺量梯度,并采用普通养护与CO2养护两种方式,通过硫酸盐冻融循环试验测定了质量损失率、相对动弹性模量及抗压强度损失率等宏观指标,结合核磁共振技术对孔隙结构进行微观分析,并基于Weibull 分布构建了损伤模型,用于预测混凝土在盐冻环境下的服役寿命。结果表明:生物炭可显著改善再生混凝土抗盐冻性能,最优掺量为4.0%,在该掺量下,普通养护试件经300次冻融循环后,质量损失率、相对动弹性模量及抗压强度损失率较基准组分别改善46.8%、58.0%与22.7%;采用CO2养护可进一步提升性能,同掺量下质量损失率与抗压强度损失率较普通养护组分别降低36.8%、33.1%。生物炭多孔吸附特性与CO2养护碳化致密化作用协同优化了混凝土的孔隙结构,减少有害孔比例。基于Weibull分布的损伤模型拟合效果良好,预测华北地区该最优组合试件服役寿命可达9 288 d,较基准组提升175.4%。研究证实,生物炭与CO2养护的协同作用对再生混凝土抗盐冻性能具有“1+1>2”的增强效果,可显著延长其在寒冷盐碱环境下的服役寿命。

关键词: 生物炭, 再生混凝土, CO2养护, 硫酸盐冻融, Weibull概率分布

Abstract:

To enhance the durability of recycled concrete in cold saline-alkaline regions, this study focused on C30 recycled concrete with five biochar incorporation levels (0%,2.0%,4.0%,6.0%, and 8.0%,mass fraction). Two curing methods,standard curing and CO2 curing,were applied. Sulfate freeze-thaw cycle tests were conducted to measure macroscopic indicators including mass loss rate, relative dynamic elastic modulus, and compressive strength loss rate. Microscopic pore structure analysis was performed using nuclear magnetic resonance (NMR) technology. A damage model based on the Weibull distribution was established to predict service life of concrete under salt freezing environment. The results show that biochar significantly improves the salt-freeze resistance of recycled concrete, with an optimal incorporation rate being 4.0%. After 300 freeze-thaw cycles under standard curing, the mass loss rate, relative dynamic elastic modulus, and compressive strength loss rate of the 4.0% biochar group improve by 46.8%, 58.0%, and 22.7%, respectively, compared with the reference group. CO2 curing further enhances the performance, reducing the mass loss rate and compressive strength loss rate by 36.8% and 33.1%, respectively, compared with the standard-cured group at the same biochar content. The porous adsorption characteristics of biochar, combined with the densification effect of CO2 curing through carbonation, synergistically optimize the pore structure and reduce the proportion of harmful pores. The damage model based on the Weibull distribution exhibits a good fit and predicte that the service life of the optimal combination (4.0% biochar with CO2 curing) in North China could reach 9 288 d, which is 175.4% longer than that of the reference group. The study confirms that the synergistic effect of biochar and CO2 curing produces a “1+1>2” enhancement effect on the salt-freeze resistance of recycled concrete, significantly extending its service life in cold saline-alkaline environments.

Key words: biochar, recycled concrete, CO2 curing, sulfate freeze-thaw, Weibull probability distribution

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