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BULLETIN OF THE CHINESE CERAMIC SOCIETY ›› 2025, Vol. 44 ›› Issue (9): 3137-3146.DOI: 10.16552/j.cnki.issn1001-1625.2025.0184

• Cement and Concrete • Previous Articles     Next Articles

Durability Study of Cement-Sodium Silicate Double Slurry Grout Consolidation Body under Accelerated Erosion by High Chloride Salts

WANG Qianqian1, DAI Hang1, WANG Lichuan2,3,4, ZHANG Chunyu2,5, LI Liping3, WANG Haiyan4, ZHANG Jingjing2   

  1. 1. College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China;
    2. China Railway 18th Bureau Group Co., Ltd., Tianjin 300222, China;
    3. School of Qilu Transportation, Shandong University, Jinan 250061, China;
    4. College of Transportation Engineering, Nanjing Tech University, Nanjing 211816, China;
    5. China Railway 18th Bureau Group Tunnel Engineering Co., Ltd., Chongqing 401135, China
  • Received:2025-02-25 Revised:2025-04-18 Online:2025-09-15 Published:2025-09-19

Abstract: As a grouting material for water plugging and reinforcement, the service performance and degradation mechanism of cement-sodium silicate (C-S) double slurry grout under high chloride salt erosion have not been studied systematically. In this paper, the effects of water-cement ratio (w/c) and water glass concentration on the workability of C-S double slurry grout, the mechanical properties, phase evolution and pore structure of C-S double slurry grout consolidation body (referred to as C-S consolidation body) under high chloride salt curing environment were studied by macroscopic and microscopic tests such as compressive strength, X-ray diffraction (XRD), scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP). The results show that the chemical gelling time of C-S double slurry grout is shortened with the decrease of w/c and water glass concentration in a certain range, and the chemical gelling time is less than 35 s, which meets the demand of rapid water plugging. In the curing environment with chloride concentration greater than 15% (mass fraction), the compressive strength of C-S consolidation body with two optimal mix ratios (w/c of 0.6, water glass concentration of 34°Bé and w/c of 0.7, water glass concentration of 30°Bé) is higher than that of water curing environment before 56 d of curing. In addition, the C-S consolidation bodies of the two optimal mix ratios still show good resistance to chloride salt corrosion after 90 d of curing. Microscopic analysis shows that under high chloride salt concentration, the C-S consolidation body generates Friedel's salt (Fs) in the short-term, and the mechanical properties are improved. However, long-term erosion will lead to decalcification of hydrated calcium silicate (C-S-H) gel and decrease of mechanical properties.

Key words: cement-sodium silicate, double slurry grout, high chloride salt, mechanical property, pore structure, microstructure

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