Mechanical testing and engineering applicability analysis of SAP concrete used in buffer layer design for tunnels in active fault zones
To tackle the challenge of dislocation damage when tunnels traverse active fault zones, this study introduces the concept of using brittle buffer materials for anti-dislocation. Building on this concept, we propose a novel concrete buffer material utilizing large-sized spherical super absorbent poly...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
De Gruyter
2024-04-01
|
| Series: | Reviews on Advanced Materials Science |
| Subjects: | |
| Online Access: | https://doi.org/10.1515/rams-2024-0002 |
| _version_ | 1797208418624208896 |
|---|---|
| author | Jun Cao Zheshu Wu Zhen Cui Xiancheng Mei |
| author_facet | Jun Cao Zheshu Wu Zhen Cui Xiancheng Mei |
| author_sort | Jun Cao |
| collection | DOAJ |
| description | To tackle the challenge of dislocation damage when tunnels traverse active fault zones, this study introduces the concept of using brittle buffer materials for anti-dislocation. Building on this concept, we propose a novel concrete buffer material utilizing large-sized spherical super absorbent polymers (SAP) as a porogen, aimed at ensuring the safety of tunnel structures during active fault dislocations. To investigate the feasibility and superiority of SAP concrete as a buffer material compared to other similar materials, we prepared samples with three different SAP concrete proportions and conducted a series of physical and mechanical tests. The results show that SAP pre-hydrated with 0.2 mol·L−1 sodium carbonate solution exhibits a slower rate of moisture loss in the cement slurry, aiding the hydration reaction of concrete. The permeability coefficient of SAP concrete is approximately 10−7 cm·s−1, slightly lower than foam concrete of the same density level. SAP concrete buffer material demonstrates significant brittleness, in contrast to the mostly ductile nature of other buffers such as foam concrete and rubberized concrete. Utilizing the brittle nature of SAP concrete materials, when applied to tunnels affected by stick–slip active fault dislocations, its instantaneous loss of compressive capacity provides excellent yield performance, thus protecting the tunnel lining from damage. However, under certain circumferential pressure conditions, both the peak and residual strength of SAP concrete significantly increase. High peak and residual strengths do not favor the effective buffering effect of SAP concrete; therefore, an approach involving the intermittent arrangement of precast buffer blocks has been proposed for application. |
| first_indexed | 2024-04-24T09:38:30Z |
| format | Article |
| id | doaj.art-322e1c5cf9c84c13ac5b414f0413a7ab |
| institution | Directory Open Access Journal |
| issn | 1605-8127 |
| language | English |
| last_indexed | 2024-04-24T09:38:30Z |
| publishDate | 2024-04-01 |
| publisher | De Gruyter |
| record_format | Article |
| series | Reviews on Advanced Materials Science |
| spelling | doaj.art-322e1c5cf9c84c13ac5b414f0413a7ab2024-04-15T07:42:22ZengDe GruyterReviews on Advanced Materials Science1605-81272024-04-01631pp. 81382110.1515/rams-2024-0002Mechanical testing and engineering applicability analysis of SAP concrete used in buffer layer design for tunnels in active fault zonesJun Cao0Zheshu Wu1Zhen Cui2Xiancheng Mei3State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071, ChinaChina Railway Siyuan Survey and Design Group Co., Ltd., Wuhan, Hubei, 430063, ChinaState Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071, ChinaState Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071, ChinaTo tackle the challenge of dislocation damage when tunnels traverse active fault zones, this study introduces the concept of using brittle buffer materials for anti-dislocation. Building on this concept, we propose a novel concrete buffer material utilizing large-sized spherical super absorbent polymers (SAP) as a porogen, aimed at ensuring the safety of tunnel structures during active fault dislocations. To investigate the feasibility and superiority of SAP concrete as a buffer material compared to other similar materials, we prepared samples with three different SAP concrete proportions and conducted a series of physical and mechanical tests. The results show that SAP pre-hydrated with 0.2 mol·L−1 sodium carbonate solution exhibits a slower rate of moisture loss in the cement slurry, aiding the hydration reaction of concrete. The permeability coefficient of SAP concrete is approximately 10−7 cm·s−1, slightly lower than foam concrete of the same density level. SAP concrete buffer material demonstrates significant brittleness, in contrast to the mostly ductile nature of other buffers such as foam concrete and rubberized concrete. Utilizing the brittle nature of SAP concrete materials, when applied to tunnels affected by stick–slip active fault dislocations, its instantaneous loss of compressive capacity provides excellent yield performance, thus protecting the tunnel lining from damage. However, under certain circumferential pressure conditions, both the peak and residual strength of SAP concrete significantly increase. High peak and residual strengths do not favor the effective buffering effect of SAP concrete; therefore, an approach involving the intermittent arrangement of precast buffer blocks has been proposed for application.https://doi.org/10.1515/rams-2024-0002sap concretebuffer materialanti-dislocationtunnel |
| spellingShingle | Jun Cao Zheshu Wu Zhen Cui Xiancheng Mei Mechanical testing and engineering applicability analysis of SAP concrete used in buffer layer design for tunnels in active fault zones Reviews on Advanced Materials Science sap concrete buffer material anti-dislocation tunnel |
| title | Mechanical testing and engineering applicability analysis of SAP concrete used in buffer layer design for tunnels in active fault zones |
| title_full | Mechanical testing and engineering applicability analysis of SAP concrete used in buffer layer design for tunnels in active fault zones |
| title_fullStr | Mechanical testing and engineering applicability analysis of SAP concrete used in buffer layer design for tunnels in active fault zones |
| title_full_unstemmed | Mechanical testing and engineering applicability analysis of SAP concrete used in buffer layer design for tunnels in active fault zones |
| title_short | Mechanical testing and engineering applicability analysis of SAP concrete used in buffer layer design for tunnels in active fault zones |
| title_sort | mechanical testing and engineering applicability analysis of sap concrete used in buffer layer design for tunnels in active fault zones |
| topic | sap concrete buffer material anti-dislocation tunnel |
| url | https://doi.org/10.1515/rams-2024-0002 |
| work_keys_str_mv | AT juncao mechanicaltestingandengineeringapplicabilityanalysisofsapconcreteusedinbufferlayerdesignfortunnelsinactivefaultzones AT zheshuwu mechanicaltestingandengineeringapplicabilityanalysisofsapconcreteusedinbufferlayerdesignfortunnelsinactivefaultzones AT zhencui mechanicaltestingandengineeringapplicabilityanalysisofsapconcreteusedinbufferlayerdesignfortunnelsinactivefaultzones AT xianchengmei mechanicaltestingandengineeringapplicabilityanalysisofsapconcreteusedinbufferlayerdesignfortunnelsinactivefaultzones |