Assessing the viability of silica fume-based geopolymer paste as a bonding agent for the restoration of historic stone masonry structures
Volume Title: ICASGE2025
Paper ID : 1063-ICASGE-FULL
Authors
Institute of Aviation Engineering and Technology
Abstract
The need for eco-friendly restoration materials has emerged as one of the most appealing alternatives to traditional cement products, owing to their environmental and economic benefits. Contributing to this direction, this study particularly investigated the feasibility of using geopolymer composites to develop bonding agent, particularly for the restoration and rehabilitation of historical stone masonry buildings. Three cement-free geopolymer pastes (GP) were optimized, utilizing silica fume modified with metakaolin, fly ash, and coal ash. A commercially available epoxy mortar (EM) was included for comparison. All the developed geopolymer pastes (GP) and investigated epoxy materials (EM) were employed to bond sandstone and granite blocks typically found in historical buildings. The bonding of stone blocks was carried out in two ways: (i) by applying a thin layer of GP/EM between the faces of the same or different types of stone blocks, simulating the filling of cracks, fractures, and cavities, and (ii) by using GP/EM to anchor fiberglass rebar into two or more blocks. The bonded specimens were tested in shear, flexure, and direct tension. The results indicated that in both repair methods, GPs demonstrated excellent performance in bonding sandstone and granite face-to-face, as well as in anchoring them with fiberglass rebar. They also outperformed EM while being significantly more cost-effective. This highlights GPs' potential as an eco-friendly bonding agent, making them a more economical option for the rehabilitation of historic stone masonry buildings.
Keywords
Silica fume-based geopolymer paste; bonding agent; Rehabilitation; historic stone masonry structures
Subjects