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Abstract Resilience of new and existing buildings to climate change is a key research issue. Climate change-related phenomena can considerably affect buildings mechanical and thermal-energy response by contributing to materials degradation and structural safety. Such an impact is even further exacerbated in historical constructions, more vulnerable to such events due to their ancient structure if compared to recent designs. The purpose of this paper is to propose an innovative, integrated, multidisciplinary methodology for assessing construction materials’ degradation in historic masonry buildings and its potential future evolution, providing a risk mapping accounting for interactions between climate change effects and structural damage. Such a replicable approach consists in (i) preliminary site inspections, (ii) damage and degradation surveys, (iii) development and calibration of numerical models predicting structural-thermal response and (iv) prediction of materials degradation accounting for future climate conditions and potential worsening of structural damage. The final output of the procedure is a hierarchical mapping of regions with different degradation severities, by identifying those where a specific type of degradation or damage insists but are likely stable and those where they are expected to get worse due to changes in future climate conditions or to a negative interaction between degradation and damage. The presented approach is applied to an iconic Italian monumental building, the Consoli Palace in Gubbio, where future climate scenarios up to 2080 are simulated according to the IPCC climate change predictions. Results highlight that thermal-energy and structural aspects need to be jointly considered in the preservation of surface materials of historic buildings exposed to climate change severity.

Abstract The presence of mortar attached to the surface of recycled aggregates strongly affect their quality, especially in order to reuse them for making new concrete. In this perspective, an innovative sensor-based quality control strategy was developed using hyperspectral imaging (HSI) in the near-infrared range (1000–1700 nm), to evaluate the residual mortar content on the surface of coarse recycled concrete aggregates. Hyperspectral data processing was carried out applying first principal component analysis (PCA) for data exploration and then partial least square-discriminant analysis (PLS-DA) to build classification models. Micro X-ray fluorescence (micro-XRF) maps were also obtained on the same aggregate samples in order to validate the HSI classification results. The developed procedures allowed to correctly identify the mortar attached on aggregate surface and to quantify its percentage. The proposed approach can be profitably applied to certify recycled aggregates quality, increasing their economic value.

Abstract In the present experimental study, the valorization of construction and demolition (C&D) and industrial wastes, namely ferronickel slag and red mud, through alkali activation is investigated. Specimens were produced by mixing various proportions of the raw materials with NaOH and sodium silicate solutions. The paste was cast in cubic metal moulds with an edge of 5 cm, cured at 80 °C for 24 h and then aged for 7 days at room temperature. The produced specimens were subjected to compressive strength testing. The effect of the molarity of the activating solution, the mineralogy of the raw materials and the ratios of SiO 2 /Al 2 O 3 and SiO 2 /(Al 2 O 3 + CaO) on the compressive strength of the final products was investigated. Also, the effect of high temperature heating (400–800 °C) on the structural integrity of the produced specimens was assessed. The use of analytical techniques, namely X-ray diffraction, Thermogravimetric Analysis, Fourier Transform Infrared Spectroscopy and Scanning Electron Microscopy provided insights on the morphology, structure and thermal resistance of the produced specimens.

Abstract This paper presents an experimental campaign on multi-leaf stone masonry panels, scales 1:1 and 2:3, in both original conditions and strengthened with grout injections. The panels were subjected to horizontal in-plane cyclic loading combined with vertical loading for different pre-compression levels, and provided important information on failure mechanisms, maximum displacement capacity, shear strength and other mechanical parameters, such as shear modulus and tensile strength. Further analysis provided results on other parameters which mainly characterise the behaviour of three-leaf masonry under seismic loads, i.e., stiffness degradation, energy dissipation, and viscous damping. The main aim of this study was to gather information on the static and dynamic behaviour of three-leaf stone masonry structures in non-injected and injected conditions, in order to accurately characterise their mechanical behaviour. In particular, the effectiveness of injections of hydraulic lime-based grout as a reinforcement technique was assessed and validated.

This paper presents a numerical model for nonlinear analysis of masonry structural elements based on Continuum Damage Mechanics. The material is described at the macro-level, i.e. it is modeled as a homogeneous orthotropic continuum. The orthotropic behavior is simulated by means of an original methodology, resulting from the concept of mapped tensors from the anisotropic field to an auxiliary workspace. The application of this idea to strain-based Continuum Damage Models is innovative and leads to several computational benefits. The suitability of the model for representing the behavior of different types of brickwork masonry is shown via the simulation of experimental tests.

Abstract The misunderstanding of the overall behaviour of traditional timber trusses can result in incorrect strengthening interventions or, frequently, on their replacement. Timber roof structures need a more concise knowledge of the real behaviour to determine internal loads and control the load transfer. For that, laboratory tests on scaled or full-scale specimens of members, connections and trusses are needed. In this paper, an accurate geometric and mechanical evaluation of the timber elements of two King-post timber trusses, based on grading results with data gathered from non-destructive tests (NDT), including mechanical evaluation of the modulus of elasticity in bending (MoE), followed by full-scale carrying tests were performed. The trusses were reassembled in laboratory and submitted to a series of symmetric and non-symmetric cyclic tests, according to the Limit States. Strengthening techniques evaluated in precedent research steps were used in a second phase of the load-carrying tests.