2019 : Bonding Mechanism Study of Fly Ash Based Geopolymer for Repair Material Application towards Ternary Interface

Ir. Muhammad Sigit Darmawan M.Eng.Sc
Raden Buyung Anugraha Affandhie ST., MT.

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Repair materials are used to restore the original conditions of concrete structures. The commercial repair materials required proper curing condition (moisture condition) and it was reported half of the repaired structures fails due to weak bonding. Bonding strength is the fundamental properties that act as a measuring tool for the bonding performance of repair materials. However, the existing repair material is reported as weak link to the old concrete substrate. A rapid and strong adhesion to the concrete substrate is therefore, a subject of interest in this study. Therefore, geopolymer is proposed for use as repair material to enhance bonding strength cured at ambient temperature. Geopolymers also contribute to reducing the carbon dioxide emission by the use of industrial by-products as raw materials, such as fly ash. In addition, N-A-S-H and C-A-S-H product of geopolymer binders have superiority on commercialize repair materials in terms of mechanical and durability properties. A number of researchers have tried to utilize geopolymer as a repair material where its only focus on slant shear, pull-out and direct shear test. However, several researchers highlight the calcium additive is needed to enhance the early strength development. Therefore, in this study, fly ash is used as precursor for geopolymer repair materials without addition of calcium additives. In order to optimize the properties as an excellent repair material, various mixing ratio and surface preparation will be studied. The testing and characterization of geopolymer repair materials such as physical, mechanical, phase analysis, and surface morphology are examined. Lastly, the identification of phase composition through ternary diagram is discussed. Thus, this study will become a fundamental study reporting on the formulation and mechanism of geopolymer repair materials. Fly ash based geopolymer can be embodies a rapid and high strength repair materials to extend the service life of existing structures. Keywords: Geopolymers; Repair Materials;Bonding Mechanism;