Publicação
Development of a multifunctional composite sandwich panel for the rehabilitation of building façades
| Resumo: | This PhD thesis presents a research work aiming at the development of a sustainable and multifunctional composite sandwich panel for the rehabilitation of reinforced concrete (RC) buildings from the 1960s to the mid-1980s. The sandwich panel retrofit solution developed in the thesis comprises four main components: (i) thin outer layers of Recycled Steel Fibre Reinforced micro Concrete (RSFRC); (ii) a lightweight core made of polystyrene; (iii) internally distributed glass fibre reinforced polymer (GFRP) connectors; and (iv) steel anchors for fixing the panel to the existing structure. The first part of this work’s experimental program encompassed pushout and pullout tests, carried out on reduced-scale specimens representative of the sandwich panel solution; these tests aimed at assessing the overall composite behaviour of the sandwich panel and analysing the influence of the type of core insulation layer, and of the anchoring conditions and diameter of the GFRP connectors. The tests showed that the adopted structural GFRP connectors are able to adequately ensure shear load transfer between RSFRC layers. The second part of the experimental program involved testing intermediate-scale RC frame specimens, representative of the target building typology, under in-plane cyclic loading conditions. The cyclic tests were performed on different variations of the referred RC frames: (i) a bare RC frame; (ii) an RC frame with a masonry infill wall; and (iii) an RC frame with the incorporation of the sandwich panel prototype developed in the scope of this research work. The results of the tests show that, in comparison with the traditional masonry infill wall solution, the proposed rehabilitation solution enabled a significant improvement of the RC frame’s cyclic performance, providing higher levels of load carrying capacity and energy dissipation. The numerical part of this study included numerical simulations conducted to assist the sandwich panel design process and, more specifically, the modelling of the failure mechanisms observed at the interface between the RSFRC layers and the polystyrene core; good agreement was obtained between experimental and numerical results, with important conclusions being drawn regarding the cohesion and friction angle between these components of the sandwich panel. |
|---|---|
| Autores principais: | Sousa, Christoph Fernandes |
| Assunto: | Rehabilitation RC frame buildings Building façades Sndwich panel Precast concrete Recycled steel fibres GFRP connectors Polystyrene Pushout tests Pullout tests Cyclic tests Finite element method Reabilitação Edifícios porticados Fachadas de edifícios Painéis sanduíche Betão préfabricado Fibras recicladas Conetores GFRP Poliestireno Ensaios de corte Ensaios de arranque Método dos elementos finitos |
| Ano: | 2021 |
| País: | Portugal |
| Tipo de documento: | tese de doutoramento |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | This PhD thesis presents a research work aiming at the development of a sustainable and multifunctional composite sandwich panel for the rehabilitation of reinforced concrete (RC) buildings from the 1960s to the mid-1980s. The sandwich panel retrofit solution developed in the thesis comprises four main components: (i) thin outer layers of Recycled Steel Fibre Reinforced micro Concrete (RSFRC); (ii) a lightweight core made of polystyrene; (iii) internally distributed glass fibre reinforced polymer (GFRP) connectors; and (iv) steel anchors for fixing the panel to the existing structure. The first part of this work’s experimental program encompassed pushout and pullout tests, carried out on reduced-scale specimens representative of the sandwich panel solution; these tests aimed at assessing the overall composite behaviour of the sandwich panel and analysing the influence of the type of core insulation layer, and of the anchoring conditions and diameter of the GFRP connectors. The tests showed that the adopted structural GFRP connectors are able to adequately ensure shear load transfer between RSFRC layers. The second part of the experimental program involved testing intermediate-scale RC frame specimens, representative of the target building typology, under in-plane cyclic loading conditions. The cyclic tests were performed on different variations of the referred RC frames: (i) a bare RC frame; (ii) an RC frame with a masonry infill wall; and (iii) an RC frame with the incorporation of the sandwich panel prototype developed in the scope of this research work. The results of the tests show that, in comparison with the traditional masonry infill wall solution, the proposed rehabilitation solution enabled a significant improvement of the RC frame’s cyclic performance, providing higher levels of load carrying capacity and energy dissipation. The numerical part of this study included numerical simulations conducted to assist the sandwich panel design process and, more specifically, the modelling of the failure mechanisms observed at the interface between the RSFRC layers and the polystyrene core; good agreement was obtained between experimental and numerical results, with important conclusions being drawn regarding the cohesion and friction angle between these components of the sandwich panel. |
|---|