Unique Solution for Mechanical and Energy Retrofit of Existing Buildings by Means of a New Fabric Reinforced Geopolymer Mortar (FRGM)

The built heritage is for the most part old and therefore requires studies by the engineers in order to
design the most suitable retrofit system to improve both mechanical and energy performance. In fact,
recent disasters have highlighted the inadequacy of existing structures. Just think of the earthquakes
that more or less significantly damaged the structures; or climate change has severely tested the
thermal insulation capacity of buildings built over 50 years ago.
Commonly, different interventions are proposed for solving these issues separately. However,
reasonable drawbacks arise when the structural retrofitting requires a direct contact with the targetmember
while the insulation layer is potentially interposed in between. In this scenario, the present
research proposes a novel unique system able to guarantee both the energetic and the structural
retrofitting. Inorganic Matrix Composites (IMCs) are a promising solution in this sense. Among them,
the Fabric Reinforced Cementitous Matrix (FRCM) is one of the most used; or rather a composite
made of a fabric (open grid or mesh) within an inorganic matrix (lime or cement based). Even if the
inorganic matrix has a relevant thickness (if compared with the one of the fabric), its thermal
resistance is inadequate.
The novelty of this work consists in assessing a new geo-polymeric FRCM-system by combining flyash
binder (reused material) and expanded glass aggregate (recycled material). Direct tensile tests,
for measuring the tensile strength, ultimate strain and elastic modulus, were performed in addition to
thermal conductivity tests. The results were compared with those of traditional FRCM (commercially
available). The potentiality of the proposal for structural and energy retrofitting is discussed and
examples of possible application are also reported.