复合地聚物固化高含水率泥浆的回填性能及微观机理研究

硅酸盐通报 ›› 2023, Vol. 42 ›› Issue (10): 3643-3651.

复合地聚物固化高含水率泥浆的回填性能及微观机理研究

冯兴国, 刘宁, 卢向雨

河海大学港口海岸与近海工程学院,南京 210098

收稿日期:2023-06-12 修订日期:2023-07-27 出版日期:2023-10-15 发布日期:2023-10-17
作者简介:冯兴国(1983—),男,博士,副教授。主要从事淤泥减量化、工程渣土利用和固废资源化方面的研究。E-mail: fengxingguo@hhu.edu.cn
基金资助:
江苏省研究生科研与实践创新计划项目(KYCX23_0730);工程结构性能演化与控制教育部重点实验室(同济大学)开放课题(2021KF-4)

Backfilling Performance and Microscopic Mechanism of High Moisture Content Slurry Solidified by Composite Geopolymer

FENG Xingguo, LIU Ning, LU Xiangyu

College of Harbor, Coastal and Offshore Engineering, Hohai University, Nanjing 210098, China

Received:2023-06-12 Revised:2023-07-27 Online:2023-10-15 Published:2023-10-17

摘要/Abstract

摘要： 泥浆广泛存在于河道疏浚、灌注桩、顶管等工程中,其处理是长期困扰工程界的问题。本文以原状煤矸石、高炉矿渣、粉煤灰等多元固废地聚物为基础固化60%(质量分数)含水率的泥浆,研究固化土的力学性能、耐久性和微观机理,评估固化土作回填料的可行性。结果表明,增加固体废弃物和碱性激发剂掺量都可提高固化土强度,固废掺量为20%(质量分数)时固化土7 d黏聚力c为60 kPa,内摩擦角φ为19°,强度可达400 kPa,满足回填土的性能要求;同时地聚物固化土的抗冻融性能明显优于同掺量的水泥固化土;地聚物固化土的胶凝产物主要为水化硅酸钙和斜方钙沸石,其水胶凝产物黏结土颗粒,填充孔隙结构,从而强化土体性能。

关键词: 地聚物, 固体废弃物, 碱性激发剂, 掺量, 抗压强度, 冻融循环, 质量损失, 微观机理

Abstract: Slurry widely existes in river dredging, cast-in-place piles, pipe-jacking construction and other projects, whose treatment is a long-term problem in the engineering field. In this study, solid waste geopolymer which was synthesized by coal gangue, blast furnace slag and fly ash was adopted to solidify the slurry with a moisture content of 60% (mass fraction). The mechanical properties, durability and microscopic mechanism of the solidified soil were investigated. The feasibility of the solidified soil as the backfill material was also estimated. The results show that strength of the solidified soil increases with the content of solid waste and alkaline activator. When 20% (mass fraction) solid waste is added, the cohesion c, the internal friction angle φ and strength of the solidified soil were 60 kPa, 19°, and 400 kPa after 7 d solidification. The solidified soil meets the properties requirements of the backfill soil. In addition, the geopolymer-solidified soil displayes better freeze-thaw resistance than the cement-solidified soil with the same content of cement. The gel products of geopolymer-solidified soil are mainly calcium silicate hydrate and gismondine, which can bind soil particles and fill the pore structure, then strengthenes the solidified soil performance.

Key words: geopolymer, solid waste, alkaline activator, content, compressive strength, freeze-thaw cycle, mass loss, microscopic mechanism

中图分类号:

TU443

冯兴国, 刘宁, 卢向雨. 复合地聚物固化高含水率泥浆的回填性能及微观机理研究[J]. 硅酸盐通报, 2023, 42(10): 3643-3651.

FENG Xingguo, LIU Ning, LU Xiangyu. Backfilling Performance and Microscopic Mechanism of High Moisture Content Slurry Solidified by Composite Geopolymer[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2023, 42(10): 3643-3651.

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