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ORIGINAL RESEARCH article

Front. Mater.
Sec. Structural Materials
Volume 12 - 2025 | doi: 10.3389/fmats.2025.1527502

Study of interfacial bonding properties and shrinkage deformation of cement-alkali activated gradient-structured composite in complex environments with temperature-humidity changes

Provisionally accepted
Shenzhe Li Shenzhe Li 1Ganyou Jiang Ganyou Jiang 2Naishuang Wang Naishuang Wang 1Yisong Wei Yisong Wei 1Zheng Chen Zheng Chen 3*Jing Li Jing Li 3Ben Chen Ben Chen 3Jiamin Yu Jiamin Yu 3
  • 1 Guangxi Road and Bridge Engineering Group Co, Nanning, China
  • 2 Guangxi Guanglu Industrial Investment Group Co, Nanning, China
  • 3 Guangxi University, Nanning, China

The final, formatted version of the article will be published soon.

    The paper prepared ordinary Portland cement-alkali-activated slag (OPC-AAS) and ordinary Portland cement-alkali-activated metakaolin (OPC-AAMK) gradient-structured composite by stacking cement and alkali-activated materials together. The effects of temperature difference cycling and wet-dry cycling extremes on the early shrinkage strain and splitting strength of OPC-AAS and OPC-AAMK composites, as well as the structure of the bond interface and the micromorphology of the hydration products, were comparatively analyzed. The results demonstrated that the temperature difference cycling affected the early deformation and bond strength of the gradient-structured composite interfaces more significantly than the dry-wet cycling. The maximum expansion strains of OPC-AAS and OPC-AAMK were 1130.88 μm and 1399.25 μm, respectively, under the effect of temperature difference cycling; the splitting strengths of OPC-AAS and OPC-AAMK after three cycles of temperature difference cycling were reduced by 26.37% and 31.32%, respectively, compared with that after three cycles of wet-dry cycling. In addition, the OPC-AAS composites showed better interfacial bonding properties after extreme environmental cycling compared to the OPC-AAMK composites. The early splitting strengths under the two extreme environmental effects increased and then decreased, and the maximum splitting strengths of OPC-AAS were 2.66 MPa and 3.65 MPa under the temperature difference cycling and dry-wet cycling, respectively, which were 5.14% and 35.69% higher than those of OPC-AAMK, respectively. Scanning electron microscopy (SEM) characterization analysis showed that the temperature difference cycling resulted in more severe product decomposition of the AAMK cementitious material, and obvious cracks and holes appeared at the bonding interface of OPC-AAMK. This study provides some references for the optimal design of the early shrinkage-deformation properties and mechanical properties of gradient-structured composites under extreme environments as well as the assessment of service life.

    Keywords: Gradient-structured composite, Alkali-activated mortar, Temperature difference cycling, Wet-dry cycling, Shrinkage strain, Splitting strength

    Received: 13 Nov 2024; Accepted: 13 Jan 2025.

    Copyright: © 2025 Li, Jiang, Wang, Wei, Chen, Li, Chen and Yu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Zheng Chen, Guangxi University, Nanning, China

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.