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硅酸盐通报 ›› 2026, Vol. 45 ›› Issue (1): 346-358.DOI: 10.16552/j.cnki.issn1001-1625.2025.0660

• 道路材料 • 上一篇    下一篇

高掺量磷石膏-水泥-固化剂稳定碎石基层材料的性能及强度形成机理

何兆益1(), 邹萌2(), 姚启文3, 曹东伟4, 秦猛2   

  1. 1.重庆交通大学交通运输学院,重庆 400074
    2.重庆交通大学土木工程学院,重庆 400074
    3.中冶建工集团有限公司,重庆 400084
    4.交通运输部公路科学研究院,北京 100088
  • 收稿日期:2025-06-19 修订日期:2025-08-30 出版日期:2026-01-20 发布日期:2026-02-10
  • 通信作者: 邹 萌,硕士研究生。E-mail:622220951078@mails.cqjtu.edu.cn
  • 作者简介:何兆益(1965—),男,博士,教授。主要从事路面结构与新材料方面的研究。E-mail:hzyzwb@cqjtu.edu.cn
  • 基金资助:
    国家自然科学基金(52478444);重庆市研究生科研创新项目(CYS23486)

Performance and Strength Formation Mechanism of High Dosage Phosphogypsum-Cement-Curing Agent Stabilized Crushed Stone Base Layer Material

HE Zhaoyi1(), ZOU Meng2(), YAO Qiwen3, CAO Dongwei4, QIN Meng2   

  1. 1. School of Traffic & Transportation,Chongqing Jiaotong University,Chongqing 400074,China
    2. School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China
    3. China Metallurgical Construction Engineering Group Co. ,Ltd. ,Chongqing 400084,China
    4. Research Institute of Highway Ministry of Transport,Beijing 100088,China
  • Received:2025-06-19 Revised:2025-08-30 Published:2026-01-20 Online:2026-02-10

摘要:

本文采用高掺量磷石膏搭配水泥、自研固化剂稳定级配碎石制备路面基层材料,研究不同水泥、磷石膏、固化剂掺量对基层材料各龄期无侧限抗压强度及路用性能的影响,结合XRD、FTIR、SEM-EDS等测试方法探讨材料的水化机制和微观特性,并测试其浸出毒性。结果表明,水泥与磷石膏的质量比增大会提升基层材料的力学性能,且使用自研地聚物固化剂替代20%(质量分数,下同)水泥后基层材料的力学性能会进一步增强。以7 d无侧限抗压强度为评价指标,结合实际工程需求,提出高掺量磷石膏-水泥-固化剂稳定碎石基层材料最优配合比:35%磷石膏+4%水泥+1%三元碱激发固化剂+60%级配碎石。相对未掺入固化剂对照组,最优配合比下基层材料7、28和60 d无侧限抗压强度分别提升了69.2%(达到6.6 MPa)、106.7%(达到9.3 MPa)和88.3%(达到11.3 MPa)。主要水化产物为水泥水化形成的水化硅酸钙(C-S-H)凝胶和钙矾石(AFt),碱性固化剂不仅激发了水泥活性,还与磷石膏中的Ca2+通过火山灰反应进一步生成C-S-H凝胶和水化硅(铝)酸钙(C-(A)-S-H)凝胶,二者共同为基层材料提供强度。基层材料中的F-、PO43-和重金属元素的毒性浸出浓度均符合我国现行的污水排放标准。

关键词: 磷石膏, 路面基层, 固化剂, 水化特性, 无侧限抗压强度, 形成机理

Abstract:

This study investigated the use of high dosages of phosphogypsum in combination with cement and a self-developed curing agent for the stabilization of graded crushed stone, with the objective of preparing pavement base layer material. The study encompassed a comprehensive investigation into the effects of varying dosages of cement, phosphogypsum and curing agent on the unconfined compressive strength and pavement performance of base layer material at various ages. The hydration mechanism and microscopic properties of the materials were investigated by XRD, FTIR, SEM-EDS and other testing method, and its leaching toxicity was also tested. The results indicate that increasing the mass ratio of cement to phosphogypsum enhances the mechanical properties of the base layer material. Moreover, the mechanical properties of the base layer material are further optimised through the incorporation of a geopolymer curing agent, self-developed, replacing 20%(mass fraction, the same below) of the cement. The 7 d unconfined compressive strength is selected as the evaluation index, and the optimal mix ratio of high dosage phosphogypsum-cement-curing agent stabilized crushed stone base layer material is determined by combining this with the actual engineering requirements. The proposed optimal mix ratio is 35% phosphogypsum + 4% cement + 1% ternary alkali activated curing agent + 60% graded crushed stone, and the ratio of 7, 28 and 60 d unconfined compressive strengths increases by 69.2% (reaches 6.6 MPa), 106.7% (reaches 9.3 MPa) and 88.3% (reaches 11.3 MPa), respectively, in comparison with the control group without a curing agent. The primary hydration products are calcium silicate hydrate (C-S-H) gel and ettringite (AFt), which are formed by the hydration of cement. The alkaline curing agent not only activated the cement but also reacted with the Ca2+ from the phosphogypsum via a pozzolanic reaction, further promoting the formation of C-S-H and calcium silicate (aluminate) hydrate (C-(A)-S-H) gels, the collective formation of these gels contributes to the overall strength of the base layer material. In addition, the toxic leaching concentrations of F-, PO43-, and heavy metal elements in base layer material are in accordance with the current standards established by China for sewage discharge.

Key words: phosphogypsum, road base, curing agent, hydration characteristic, unconfined compressive strength, formation mechanism

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