Abstract
This paper presents an experimental study on the interface bonding properties of polyvinyl alcohol (PVA) fiber in alkali-activated slag/fly ash (AASF) pastes. Three interface bonding properties (i.e., the chemical bonding energy Gd, the initial frictional bond strength τ0, and slip-hardening behavior) were determined using single-fiber pullout tests. The microstructure and chemical composition of the reaction products in the fiber/matrix interfacial transition zone (ITZ) and the nearby matrix were also characterized to reveal the influence of PVA fiber to its surrounding matrix. It is found that Gd increases primarily with increasing Ca/(Si+Al) ratio of C-(N-)A-S-H gel. Unlike that in cementitious materials, the inclusion of PVA fiber in AASF pastes promotes the formation of a high-Ca C-(N-)A-S-H phase rather than crystalline portlandite near the fiber surface. This study provides useful guidance for tailoring the interface bonding properties of AASF and also the development of high-performance composites such as strain-hardening geopolymer composites.
Original language | English |
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Article number | 107308 |
Number of pages | 12 |
Journal | Cement and Concrete Research |
Volume | 173 |
Early online date | 24 Aug 2023 |
DOIs | |
Publication status | Published - Nov 2023 |
Bibliographical note
Funding Information:This research was carried out in Microlab, Delft University of Technology and was financially supported by the Netherlands Organisation for Scientific Research (NWO), Grant No. 729.001.013 and National Natural Science Foundation of China (NSFC), Grant No. 5151101050. The authors would like to thank Dr. Lupita Sierra-Beltran, Dr. Jishen Qiu, and Dr. Haoliang Wu for the discussion on the single-fiber pullout tests set-up, Prof. Victor C. Li, Prof. Erik Schlangen, and Dr. Jorge Dolado for the discussion on interface properties, and Paul Veerman for helping with the set-up of single-fiber pullout tests. Additionally, the authors wish to acknowledge Kuraray Co. Ltd. Japan for supplying the PVA fiber.
Publisher Copyright:
© 2023 The Authors
Keywords
- Alkali-activation
- Bonding
- Fiber pullout
- Fly ash
- Interface
- PVA
- Slag
ASJC Scopus subject areas
- Building and Construction
- General Materials Science