Strengthening of Masonry Vaults with Steel Reinforced Grout

Synopsis

In a period characterised by the urgent need to ensure an adequate safety level to the building stock, including architectural heritage, Steel Reinforced Grout (SRG), comprising Ultra High Tensile Strength Steel cords embedded in a mortar matrix, is emerging as a particularly advantageous solution for the externally bonded strengthening of existing structures. Nevertheless, its development is still at a relatively early stage with respect to the already well-established Fibre Reinforced Polymers (which make use of organic matrices) and other mortar-based composite materials, such as Textile Reinforced Mortars or Fabric Reinforced Cementitious Matrix (which comprise carbon, glass, basalt or PBO meshes). Therefore, a deeper knowledge is required on mechanical properties, acceptance criteria and behaviour of reinforced structural members in order to develop suitable design relationships and assessment criteria which would allow for a more confident use of SRG in structural rehabilitation practice.

In this lunchtime talk, experimental data on the use of SRG composites with lime-based mortars for the reinforcement of masonry vaulted structures will be presented. First, direct tensile tests on bare textile specimens and SRG coupons as well as single-lap shear bond tests were performed to investigate the main mechanical properties (tensile strength and stiffness, crack pattern, cord-to-matrix and SRG-to-substrate load transfer capacity, failure modes) and derive fundamental acceptance and design parameters. Then, bond tests were performed on curved substrates to investigate the influence of convex and concave curvatures on the SRG-to-masonry bond behaviour. Both double-lap double-prism test and four point bending tests were performed to study intermediate debonding mechanisms and analyse the effect of testing setups. Simplified relationships were also derived that account for substrate curvature which may be useful for a preliminary estimate of SRG bond strength. Finally, full-scale tests on masonry vaults reinforced either at the extrados or at the intrados with different SRG systems were carried out.

About the speaker

Francesca Roscini is a Civil engineer with a strong background in earthquake engineering, sustainability and energy efficiency. Francesca obtained her BSc and MSc at the University of Perugia, Italy, and she started to develop an interest in the use of innovative solutions for strengthening applications during her BSc dissertation, for which she examined the durability of Steel Reinforced Grout (SRG) systems.
From 2014 to 2017, she carried out her PhD studies on the “Strengthening of masonry vaults with Steel Reinforced Grout” in the Department of Engineering of Roma Tre University. During her PhD, she joined the Department of Civil and Structural Engineering at the University of Sheffield as a visiting PhD Student. In addition to working on her main project, Francesca also coordinated various experimental programmes in the structure laboratory of Roma Tre, including small-scale tests for the mechanical characterisation and certification of FRP and FRCM strengthening systems, as well as full-scale tests to assess their structural performance. After her PhD, Francesca remained at Roma Tre University as a research associate.

From 1st of November 2019, she is a Marie Skłodowska-Curie Individual Fellow (H2020-MSCA-IF-2018) at the Department of Civil and Structural Engineering of The University of Sheffield with the project “GreATeRS: GREen Advanced TEchnologies for the Retrofitting of masonry Structures”. Dr Maurizio Guadagnini is the Project Coordinator.

Registration

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Further information

This online meeting is organised by Young SECED. For further information, please contact Valentina Putrino (This email address is being protected from spambots. You need JavaScript enabled to view it.).

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