Swelling of sulfate-bearing soil: A case study of A1 highway pavement failure
Lime stabilization is one of the most commonly used methods for improving weak road subgrades, but it becomes very problematic in sulfate-bearing soils. This article presents results of a case study in which the sulfate attack was the most probable reason for a significant deformation of a highway p...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-07-01
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| Series: | Case Studies in Construction Materials |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214509523002619 |
| _version_ | 1797798962244091904 |
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| author | Magdalena Kowalska Bartłomiej Grzesik Zdzisław Adamczyk Jacek Nowak Adam Konsek |
| author_facet | Magdalena Kowalska Bartłomiej Grzesik Zdzisław Adamczyk Jacek Nowak Adam Konsek |
| author_sort | Magdalena Kowalska |
| collection | DOAJ |
| description | Lime stabilization is one of the most commonly used methods for improving weak road subgrades, but it becomes very problematic in sulfate-bearing soils. This article presents results of a case study in which the sulfate attack was the most probable reason for a significant deformation of a highway pavement founded on lime-stabilized Doggerian clay. Macroscopic analysis revealed partial degradation of the concrete structure, a larger extent of stabilization than designed, and large gypsum crystals in the native soil. Chemical tests indicated a very high content of sulfates in the soil (> 10,000 mg/kg of SO4) and in the groundwater (> 3,000 mg/l of SO42-). The maximum free swelling strain (εvolmax = 3–6%) and the swelling pressure (pcmax = 56 kPa) of the clay, determined in the Wasiliew apparatus and the oedometer tests, were not large enough to be considered as the only cause of the pavement damage. Sand-cement and clay-lime mixtures, which simulated stabilized soil layers in the road profile, were observed for several months in oedometric tests, under various loading conditions. The swelling of Sa-Cem was negligible, but the Cl-Lim mixtures turned out to be much more expansive than the natural soil (εvolmax up to 21%, pcmax = 230 kPa) with a much longer duration of volume increase. The samples were flooded with distilled water or hard groundwater to clarify whether the constant access of the material to sulfates is important in the swelling process, but the results were unequivocal. X-ray diffraction revealed that the addition of lime resulted in the formation of secondary minerals: butlerite, portlandite, and ettringite. The presence and swelling of ettringite in the stabilized sub-base soil layers was eventually agreed to be the most probable reason for the pavement deformation. These results indicate the need to introduce an obligatory investigation of the level of sulfates in clayey subbase soils subject to lime stabilization. |
| first_indexed | 2024-03-13T04:11:45Z |
| format | Article |
| id | doaj.art-af2c1111d8f44178920a7e94d56c3b90 |
| institution | Directory Open Access Journal |
| issn | 2214-5095 |
| language | English |
| last_indexed | 2024-03-13T04:11:45Z |
| publishDate | 2023-07-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Case Studies in Construction Materials |
| spelling | doaj.art-af2c1111d8f44178920a7e94d56c3b902023-06-21T06:54:25ZengElsevierCase Studies in Construction Materials2214-50952023-07-0118e02081Swelling of sulfate-bearing soil: A case study of A1 highway pavement failureMagdalena Kowalska0Bartłomiej Grzesik1Zdzisław Adamczyk2Jacek Nowak3Adam Konsek4Silesian University of Technology, Faculty of Civil Engineering, Department of Geotechnics and Roads, ul. Akademicka 5, 44-100 Gliwice, Poland; Corresponding author.Silesian University of Technology, Faculty of Civil Engineering, Department of Geotechnics and Roads, ul. Akademicka 5, 44-100 Gliwice, PolandSilesian University of Technology, Faculty of Mining, Safety Engineering and Industrial Automation, Department of Applied Geology, ul. Akademicka 2, 44-100 Gliwice, PolandSilesian University of Technology, Faculty of Mining, Safety Engineering and Industrial Automation, Department of Applied Geology, ul. Akademicka 2, 44-100 Gliwice, PolandBerger Bau Polska Sp. z o.o., ul. Szczecińska 11, 54-517 Wrocław, PolandLime stabilization is one of the most commonly used methods for improving weak road subgrades, but it becomes very problematic in sulfate-bearing soils. This article presents results of a case study in which the sulfate attack was the most probable reason for a significant deformation of a highway pavement founded on lime-stabilized Doggerian clay. Macroscopic analysis revealed partial degradation of the concrete structure, a larger extent of stabilization than designed, and large gypsum crystals in the native soil. Chemical tests indicated a very high content of sulfates in the soil (> 10,000 mg/kg of SO4) and in the groundwater (> 3,000 mg/l of SO42-). The maximum free swelling strain (εvolmax = 3–6%) and the swelling pressure (pcmax = 56 kPa) of the clay, determined in the Wasiliew apparatus and the oedometer tests, were not large enough to be considered as the only cause of the pavement damage. Sand-cement and clay-lime mixtures, which simulated stabilized soil layers in the road profile, were observed for several months in oedometric tests, under various loading conditions. The swelling of Sa-Cem was negligible, but the Cl-Lim mixtures turned out to be much more expansive than the natural soil (εvolmax up to 21%, pcmax = 230 kPa) with a much longer duration of volume increase. The samples were flooded with distilled water or hard groundwater to clarify whether the constant access of the material to sulfates is important in the swelling process, but the results were unequivocal. X-ray diffraction revealed that the addition of lime resulted in the formation of secondary minerals: butlerite, portlandite, and ettringite. The presence and swelling of ettringite in the stabilized sub-base soil layers was eventually agreed to be the most probable reason for the pavement deformation. These results indicate the need to introduce an obligatory investigation of the level of sulfates in clayey subbase soils subject to lime stabilization.http://www.sciencedirect.com/science/article/pii/S2214509523002619Sulfate-bearing clayGypsumEttringitePavement failureLimeStabilization |
| spellingShingle | Magdalena Kowalska Bartłomiej Grzesik Zdzisław Adamczyk Jacek Nowak Adam Konsek Swelling of sulfate-bearing soil: A case study of A1 highway pavement failure Case Studies in Construction Materials Sulfate-bearing clay Gypsum Ettringite Pavement failure Lime Stabilization |
| title | Swelling of sulfate-bearing soil: A case study of A1 highway pavement failure |
| title_full | Swelling of sulfate-bearing soil: A case study of A1 highway pavement failure |
| title_fullStr | Swelling of sulfate-bearing soil: A case study of A1 highway pavement failure |
| title_full_unstemmed | Swelling of sulfate-bearing soil: A case study of A1 highway pavement failure |
| title_short | Swelling of sulfate-bearing soil: A case study of A1 highway pavement failure |
| title_sort | swelling of sulfate bearing soil a case study of a1 highway pavement failure |
| topic | Sulfate-bearing clay Gypsum Ettringite Pavement failure Lime Stabilization |
| url | http://www.sciencedirect.com/science/article/pii/S2214509523002619 |
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