TRC SANDWICH SOLUTION FOR ENERGY RETROFITTING

Concerning energy improvement of existing façades, a favourable system involves prefabricated multilayer panels, made of internal insulation core and outer textile reinforced concrete layers. It is a convincing alternative to external thermal insulation composite systems (ETICS) and ventilated façades, and it meets all the requirements for façade systems. The main advantage is the possibility to apply the panel using a crane, without any scaffolding. The paper considers two solutions: the former uses expanded polystyrene (EPS) as insulating material; the latter substitutes EPS with an innovative green insulation material made of inorganic diatomite. The paper aims at comparing the solutions in terms of mechanical properties of the components and behaviour of the composite sandwich at lab-scale level. Numerical models, previously calibrated, will be instrumental for the discussion

TRC sandwich solution for energy retrofitting

Concerning energy improvement of existing façades, a favourable system involves prefabricated multilayer panels, made of internal insulation core and outer textile reinforced concrete layers. It is a convincing alternative to external thermal insulation composite systems (ETICS) and ventilated façades, and it meets all the requirements for façade systems. The main advantage is the possibility toapply the panel using a crane, without any scaffolding. The paper considers two solutions: the former uses expanded polystyrene (EPS) as insulating material; the latter substitutes EPS with an innovative green insulation material made of inorganic diatomite. The paper aims at comparing the solutions in terms of mechanical properties of the components and behaviour of the composite sandwich at lab-scale level. Numerical models, previously calibrated, will be instrumental for the discussion

Erratum to: Textile Reinforced Concrete: experimental investigation on design parameters

Textile Reinforced Concrete (TRC) is an advanced cement-based material in which fabrics used as reinforcement can bring significant loads in tension, allowing architects and engineers to use thin cross-sections. Previous research projects, developed during the last 10 years mainly in Germany, Israel and the USA, have shown the capabilities of such a material. In this paper an extensive experimental investigation of TRC is presented: tensile tests were carried out to obtain a complete mechanical characterization of the composite material under standard conditions, considering the influence of different variables such as reinforcement ratio, fabric geometry, curing conditions, displacement rate and specimen size. ******* Due to an unfortunate turn of events this article was published with wrong citations in the text to the references at the end of the article. In order to provide the correct information this article is hereafter published in its entirety with the correct citations and should be regarded as the final version by the reader

Analytical and numerical prediction of the bending behaviour of textile reinforced concrete sandwich beams

This paper concerns the investigation of the behaviour of sandwich beams previously tested in four point bending through analytical and numerical models. Modelling is a fundamental resource to predict the mechanical response of the element and to investigate the mechanisms that act during the evolution of the test. The sandwich beams here taken into account are characterised by external textile reinforced concrete (TRC) layers and an insulation material (expanded polystyrene, EPS) able to transfer shear stresses. Bond between the layers is obtained during production thanks to an in-pressure casting technique, and no particular device is used in order to transfer shear stresses between the layers. Two beam slenderness values are taken into account. An analytical and a numerical approach have been used in order to predict the experimental behaviour: concerning the analytical approach, a model based on the Stamm and Witte sandwich theory has been developed including material non-linearity; concerning the numerical analysis, a finite element (FE) model has been built in ABAQUS including material and geometry non-linearity. The assumption of perfect bond is used in both cases. The non-linear analytical and finite element models have been validated, as a good agreement with experimental results has been achieved. The experimental identification of material parameters - TRC in tension, mortar in compression and EPS in tension, compression and shear - is crucial for the definition of proper constitutive laws for the models and is here presented and discussed. For both approaches, the assumptions of modelling TRC in bending as homogeneous and assuming perfect bond between TRC and EPS (even when behaviour becomes highly non-linear) have been proved to be reliable. Analytical and FEM results show that EPS non-linear behaviour and TRC membrane and bending behaviour govern the response. The FE analysis also highlights the mechanisms involved in specimen failure

Dysregulated copper transport in multiple sclerosis may cause demyelination via astrocytes

Demyelination is a key pathogenic feature of multiple sclerosis (MS). Here, we evaluated the astrocyte contribution to myelin loss and focused on the neurotrophin receptor TrkB, whose up-regulation on the astrocyte finely demarcated chronic demyelinated areas in MS and was paralleled by neurotrophin loss. Mice lacking astrocyte TrkB were resistant to demyelination induced by autoimmune or toxic insults, demonstrating that TrkB signaling in astrocytes fostered oligodendrocyte damage. In vitro and ex vivo approaches highlighted that astrocyte TrkB supported scar formation and glia proliferation even in the absence of neurotrophin binding, indicating TrkB transactivation in response to inflammatory or toxic mediators. Notably, our neuropathological studies demonstrated copper dysregulation in MS and model lesions and TrkB-dependent expression of copper transporter (CTR1) on glia cells during neuroinflammation. In vitro experiments evidenced that TrkB was critical for the generation of glial intracellular calcium flux and CTR1 up-regulation induced by stimuli distinct from neurotrophins. These events led to copper uptake and release by the astrocyte, and in turn resulted in oligodendrocyte loss. Collectively, these data demonstrate a pathogenic demyelination mechanism via the astrocyte release of copper and open up the possibility of restoring copper homeostasis in the white matter as a therapeutic target in MS

How future surgery will benefit from SARS-COV-2-related measures: a SPIGC survey conveying the perspective of Italian surgeons

COVID-19 negatively affected surgical activity, but the potential benefits resulting from adopted measures remain unclear. The aim of this study was to evaluate the change in surgical activity and potential benefit from COVID-19 measures in perspective of Italian surgeons on behalf of SPIGC. A nationwide online survey on surgical practice before, during, and after COVID-19 pandemic was conducted in March-April 2022 (NCT:05323851). Effects of COVID-19 hospital-related measures on surgical patients' management and personal professional development across surgical specialties were explored. Data on demographics, pre-operative/peri-operative/post-operative management, and professional development were collected. Outcomes were matched with the corresponding volume. Four hundred and seventy-three respondents were included in final analysis across 14 surgical specialties. Since SARS-CoV-2 pandemic, application of telematic consultations (4.1% vs. 21.6%; p < 0.0001) and diagnostic evaluations (16.4% vs. 42.2%; p < 0.0001) increased. Elective surgical activities significantly reduced and surgeons opted more frequently for conservative management with a possible indication for elective (26.3% vs. 35.7%; p < 0.0001) or urgent (20.4% vs. 38.5%; p < 0.0001) surgery. All new COVID-related measures are perceived to be maintained in the future. Surgeons' personal education online increased from 12.6% (pre-COVID) to 86.6% (post-COVID; p < 0.0001). Online educational activities are considered a beneficial effect from COVID pandemic (56.4%). COVID-19 had a great impact on surgical specialties, with significant reduction of operation volume. However, some forced changes turned out to be benefits. Isolation measures pushed the use of telemedicine and telemetric devices for outpatient practice and favored communication for educational purposes and surgeon-patient/family communication. From the Italian surgeons' perspective, COVID-related measures will continue to influence future surgical clinical practice

Bending behaviour of Textile Reinforced Concrete sandwich beams

A prefabricated concrete sandwich panel, with insulating material acting as a structural layer able to transfer the shear stresses, is discussed. The use of an in-pressure casting technique allows to avoid the use of glue and to prevent the debonding between the layers thanks to the good bond obtained during the production. Sandwich beams characterized by a thick internal expanded polystyrene foam core and by two thin external Alkali-Resistant glass Textile Reinforced Concrete layers are experimentally investigated according to four point bending scheme. The significant role played by the tangential non linear behaviour of the EPS foam is show

Pannello Multi-strato prefabbricato di facciata: ottimizzazione strutturale per l'adeguamento energetico

Existing buildings are characterized by a large energy consumption due to heating and air- conditioning. Hence, their energy retrofitting has to be considered with a high priority. In this perspective a multi-layer prefabricated façade sandwich panel characterized by an internal insulation layer and by two external layers of Textile Reinforced Concrete (TRC) is proposed for the application on existing building walls. Just the insulating material is used to transfer the shear between the two structural TRC layers. The main goal of the work is to provide the mechanical characterization of this panel. The research is developed at material, cross- section and full-structure level. In this paper the global sectional behaviour is investigated: results concerning bending tests on sandwich beams are proposed together with the developed numerical simulations