Seismic plus energy upgrading of masonry buildings using advanced materials
Analysis of a combined structural and thermal retrofitting
Upgrading existing masonry buildings in the EU has become very important due to their poor performance during earthquakes resulting in significant human and economic losses, and on the other hand, their low energy performance which significantly increases their energy consumption. Therefore, a holistic approach with a concurrent seismic and energy retrofitting is necessary and has been explored in this project. Namely, SPEctRUM investigated a hybrid structural-plus-energy retrofitting solution to achieve cost effectiveness, which combines inorganic textile-based composites with thermal insulation systems for masonry building envelopes. Specifically, textile reinforced mortar (TRM) composites are used to reinforce unreinforced masonry (URM) buildings enhancing their seismic capacity, while thermal insulation is added to improve the buildings’ energy performance. The EU policy context of energy efficiency and sustainability and safeguarding of cultural heritage is benefitted by the project as discussed in chapter 1.
Firstly in chapter 2, a thorough review of the experimental investigations applying textiles in inorganic mortars is carried out and conclusions are drawn regarding its efficiency. A substantial increase in the in-plane and the out-of-plane strength and displacement capacity can be seen in all the test campaigns despite the different experintal techniques and strengthening materials. Moreover, the hybrid composite material made of layers of TRM and thermal insulation was found advantageous and capable to fulfil its structural and energy targets if the various layers are carefully bonded.
Then, numerical models and design solutions were developed to facilitate the application of the proposed system. The investigation in the first place focused on a new homogenisation model for masonry to reduce the complexity of the simulation. Indeed, in a retrofitted masonry wall there exist at least four different materials (masonry units, masonry mortar, strengthening mortar and textile) built in-situ with an internal structure which has many imperfections. Therefore, there are a lot of interaction levels and parameters which are not easily to predict in a micro-modelling approach. The homogenisation of masonry offers a viable solution to simplify masonry in one material. To this end, the proposed homogenisation model includes a gradient term to represent the internal structure of masonry. The proposed gradient elastic homogenisation model (GREHM) is furnished with easy-to-apply charts to simplify its application on masonry walls.
In the following chapter 4 the numerical modelling of the strengthened masonary with TRM is attempted. Two approaches for a detailed modelling are followed: (i) an implicit model for quasi-static loading and, (ii) an explicit model for dynamic loading. The former model includes the homogenised properties of masonry to limit the numerical cost of the analysis. Moreover, the interaction of the textile with the inorganic matrix is accounted for introducing in the model effective material properties with the aid of an empirical equation specifically designed for this aim. This empirical equation has been calibrated using an experimental campaign on the out-of-plane performance of masonry walls strengthened with TRM. It can distinguish between coated and uncoated textiles. Parametric investigations show that the capacity can be increased substantially even when less strong textiles from natural fibres are used. The exp
KOURIS Leonidas;
BOURNAS Dionysios;
POHORYLES Daniel;
VALSAMOS Georgios;
SAVVAS Triantafyllou;
MADUTA Carmen;
2024-09-24
Publications Office of the European Union
JRC123617
978-92-76-28603-5 (online),
1831-9424 (online),
EUR 30563 EN,
OP KJ-NA-30563-EN-N (online),
https://publications.jrc.ec.europa.eu/repository/handle/JRC123617,
10.2760/66556 (online),
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