Diffusion and Consolidation of Slag-Based Geopolymer for Concrete Pavement Rehabilitation

Homogenized micro-crack crushing is an optimal rehabilitation technology for concrete pavement; however, when there are weak road base issues, some measures need to be taken to treat the diseases. Grouting is a common technique for addressing weak road base issues. This study developed a new visual...

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Main Authors: Wenjie Li, Jinchao Yue, Bin Liang
Format: Article
Language:English
Published: MDPI AG 2025-04-01
Series:Applied Sciences
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Online Access:https://www.mdpi.com/2076-3417/15/8/4373
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author Wenjie Li
Jinchao Yue
Bin Liang
author_facet Wenjie Li
Jinchao Yue
Bin Liang
author_sort Wenjie Li
collection DOAJ
description Homogenized micro-crack crushing is an optimal rehabilitation technology for concrete pavement; however, when there are weak road base issues, some measures need to be taken to treat the diseases. Grouting is a common technique for addressing weak road base issues. This study developed a new visual indoor grouting test system to analyze the diffusion and consolidation of slag-based geopolymer slurry. The reactants of the geopolymer and the consolidation state of the slurry and aggregate were observed. Moreover, the reinforcement effect of the slurry on a weak road base was studied through the on-site grouting and excavation of the test pit. The results show that, during indoor grouting tests, as the size of the aggregate decreases, the slurry diffusion depth gradually decreases: only 9.5–4.75 mm aggregate formed a complete cylindrical specimen. In the tests of unformed cylindrical specimens, the 9.5–4.75 mm aggregate will develop 20–50 mm splitting surfaces, while the 4.75–2.36 mm aggregate will develop slurry bulbs and veins of different sizes, but the development is not obvious in the 2.36–1.18 mm aggregate. Fine aggregate grouting will exhibit the pressure filtration effect—especially for the 2.36–1.18 mm aggregate, the pressure filtration effect is the most obvious. An SEM microstructural analysis demonstrated that the geopolymer with a water–slag ratio of 0.4 has a faster hydration and dissolution, which results in a decrease in the density of local reactants. However, the polymerization of geopolymers is more complete. The pores of the coarse aggregate are larger and the slurry filling is denser, while the pores of the fine aggregate are smaller and the consolidation is loose locally. The consolidation of aggregates has cracks at local locations, but the width of the cracks is relatively small. On-site grouting applications revealed that the geopolymer slurry filled the bottom voids of pavement slabs and deep gaps in the road base layers, and the average deflection of the driveway decreased from 104.8 (0.001 mm) to 48 (0.001 mm) after grouting. Weak road base conditions were successfully treated, leading to a significant improvement in bearing capacity.
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spelling doaj-art-aaad03820d1742038dbc7187346a4bc32025-08-20T02:24:39ZengMDPI AGApplied Sciences2076-34172025-04-01158437310.3390/app15084373Diffusion and Consolidation of Slag-Based Geopolymer for Concrete Pavement RehabilitationWenjie Li0Jinchao Yue1Bin Liang2School of Civil Engineering and Architecture, Henan University of Science and Technology, Luoyang 471000, ChinaYellow River Laboratory, Zhengzhou University, Zhengzhou 450001, ChinaSchool of Civil Engineering and Architecture, Henan University of Science and Technology, Luoyang 471000, ChinaHomogenized micro-crack crushing is an optimal rehabilitation technology for concrete pavement; however, when there are weak road base issues, some measures need to be taken to treat the diseases. Grouting is a common technique for addressing weak road base issues. This study developed a new visual indoor grouting test system to analyze the diffusion and consolidation of slag-based geopolymer slurry. The reactants of the geopolymer and the consolidation state of the slurry and aggregate were observed. Moreover, the reinforcement effect of the slurry on a weak road base was studied through the on-site grouting and excavation of the test pit. The results show that, during indoor grouting tests, as the size of the aggregate decreases, the slurry diffusion depth gradually decreases: only 9.5–4.75 mm aggregate formed a complete cylindrical specimen. In the tests of unformed cylindrical specimens, the 9.5–4.75 mm aggregate will develop 20–50 mm splitting surfaces, while the 4.75–2.36 mm aggregate will develop slurry bulbs and veins of different sizes, but the development is not obvious in the 2.36–1.18 mm aggregate. Fine aggregate grouting will exhibit the pressure filtration effect—especially for the 2.36–1.18 mm aggregate, the pressure filtration effect is the most obvious. An SEM microstructural analysis demonstrated that the geopolymer with a water–slag ratio of 0.4 has a faster hydration and dissolution, which results in a decrease in the density of local reactants. However, the polymerization of geopolymers is more complete. The pores of the coarse aggregate are larger and the slurry filling is denser, while the pores of the fine aggregate are smaller and the consolidation is loose locally. The consolidation of aggregates has cracks at local locations, but the width of the cracks is relatively small. On-site grouting applications revealed that the geopolymer slurry filled the bottom voids of pavement slabs and deep gaps in the road base layers, and the average deflection of the driveway decreased from 104.8 (0.001 mm) to 48 (0.001 mm) after grouting. Weak road base conditions were successfully treated, leading to a significant improvement in bearing capacity.https://www.mdpi.com/2076-3417/15/8/4373homogenized micro-crack crushingconcrete pavementindoor grouting test systemslag-based geopolymerdiffusion and consolidation characteristics
spellingShingle Wenjie Li
Jinchao Yue
Bin Liang
Diffusion and Consolidation of Slag-Based Geopolymer for Concrete Pavement Rehabilitation
Applied Sciences
homogenized micro-crack crushing
concrete pavement
indoor grouting test system
slag-based geopolymer
diffusion and consolidation characteristics
title Diffusion and Consolidation of Slag-Based Geopolymer for Concrete Pavement Rehabilitation
title_full Diffusion and Consolidation of Slag-Based Geopolymer for Concrete Pavement Rehabilitation
title_fullStr Diffusion and Consolidation of Slag-Based Geopolymer for Concrete Pavement Rehabilitation
title_full_unstemmed Diffusion and Consolidation of Slag-Based Geopolymer for Concrete Pavement Rehabilitation
title_short Diffusion and Consolidation of Slag-Based Geopolymer for Concrete Pavement Rehabilitation
title_sort diffusion and consolidation of slag based geopolymer for concrete pavement rehabilitation
topic homogenized micro-crack crushing
concrete pavement
indoor grouting test system
slag-based geopolymer
diffusion and consolidation characteristics
url https://www.mdpi.com/2076-3417/15/8/4373
work_keys_str_mv AT wenjieli diffusionandconsolidationofslagbasedgeopolymerforconcretepavementrehabilitation
AT jinchaoyue diffusionandconsolidationofslagbasedgeopolymerforconcretepavementrehabilitation
AT binliang diffusionandconsolidationofslagbasedgeopolymerforconcretepavementrehabilitation