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Mechanical behaviour of TRM and FRP-reinforced concrete voussoir masonry specimens
No full textThis research investigates, both experimentally and analytically, the mechanical performance of masonry specimens made with special lightweight concrete voussoirs joined with cement mortar and reinforced with TRM (Textile Reinforced Mortar) made of either fibreglass mesh, TRM with basalt mesh or FRPs (Fiber Reinforced Polymers). The specimens represent a segment of an arch. A total of 18 specimens were tested, with one-third featuring each reinforcement solution. Another variable studied was the number of sides reinforced with TRM or FRP, either one or three. The specimens were tested under eccentric compression to analyze the effectiveness of the reinforcements. An analytical model was calibrated with the experimental results and used to extrapolate the experimental results in terms of strength capacity. The specimens that exhibited the best mechanical behaviours were those reinforced with TRM using basalt mesh. The FRP reinforcement experienced prematurely debonding with the voussoirs
Sustainability Factor for the Cost–Benefit Analysis of Building-Integrated Greenery Systems
No full textBuilding-integrated greenery (BIG) systems, which include green roofs and green facades, are well-established nature-based solutions (NBS) with proven scientific benefits. However, initial costs and economic apprehensions stemming from potential negative outcomes act as adoption barriers. Furthermore, the lack of standardized indicators and assessment methodologies for evaluating the city-level impacts of BIG systems presents challenges for investors and policy makers. This paper addresses these issues by presenting a comprehensive set of indicators derived from widely accepted frameworks, such as the Common International Classification of Ecosystem Services (CICES) and the NBS impact evaluation handbook. These indicators contribute to the creation of a ‘sustainability factor’, which facilitates cost–benefit analyses for BIG projects using locally sourced data. The practical application of this factor to a 3500 m2 green roof in Lleida, Catalonia (Spain) demonstrates that allocating space for urban horticultural production (i.e., food production), CO2 capture, and creating new recreational areas produces benefits that outweigh the costs by a factor value of nine during the operational phase of the green roof. This cost–benefit analysis provides critical insights for investment decisions and public policies, especially considering the significant benefits at the city level associated with the implementation of BIG systems
Enhancing the Accuracy of Low-Cost Inclinometers with Artificial Intelligence
No full textThe development of low-cost structural and environmental sensors has sparked a transformation across numerous fields, offering cost-effective solutions for monitoring infrastructures and buildings. However, the affordability of these solutions often comes at the expense of accuracy. To enhance precision, the LARA (Low-cost Adaptable Reliable Anglemeter) system averaged the measurements of a set of five different accelerometers working as inclinometers. However, it is worth noting that LARA’s sensitivity still falls considerably short of that achieved by other high-accuracy commercial solutions. There are no works presented in the literature to enhance the accuracy, precision, and resolution of low-cost inclinometers using artificial intelligence (AI) tools for measuring structural deformation. To fill these gaps, artificial intelligence (AI) techniques are used to elevate the precision of the LARA system working as an inclinometer. The proposed AI-driven tool uses Multilayer Perceptron (MLP) to glean insight from high-accuracy devices’ responses. The efficacy and practicality of the proposed tools are substantiated through the structural and environmental monitoring of a real steel frame located in Cuenca, Spain
Seasonal field study on thermal comfort in university classrooms in Mediterranean climate
No full textThe assessment of indoor environmental conditions of educational buildings is not only essential to ensure the correct performance of heating, cooling and ventilation systems but it is also fundamental to guarantee a suitable environment. This study aims to analyse the thermal comfort of students in teaching–learning spaces in university buildings with natural ventilation. A field measurement campaign and a questionnaire survey were carried out from September 2021 to June 2022 in educational buildings in southern Spain. The collected data were analysed and the neutral temperature in each season was obtained, based on the thermal sensation votes of 1966. The neutral temperatures found in this study were 23.5°C, 23.1°C, 23.3°C and 23.9°C, for autumn, winter, spring and summer, respectively. The ranges obtained for 90% acceptability in the winter season (21.1°C–25.1°C) provided lower temperature limits than the ranges obtained in the summer months (22.6°C–25.3°C). The highest values for clothing insulation were found in the autumn (0.90 clo) and winter (0.75 clo) seasons, compared to the spring (0.5 clo) and summer (0.4 clo) seasons. An adaptive thermal comfort model was applied. These findings could be used to improve thermal comfort and to optimise energy consumption according to the students’ actual thermal perception
Testing of battery separators: transducers and methods for air-coupled ultrasonic sensing
No full textBattery separator membranes are thin polymeric microporous films placed between battery electrodes. They are a key component that strongly affects both battery performance and security and controlling its main properties is critical for the industry. In particular, the manufacturing process demands tests that allow checking both the mechanical integrity (porosity, thickness, pore size, etc.) of the materials and the consistency of these properties during the construction of the batteries. The use of an air-coupled ultrasonic system is proposed in this work. It is expected that this will make possible the non-destructive and quick testing of these materials, in order to evaluate thickness, stiffness, pore distribution and pore size of the separator. By means of three pairs of transducers, the modulus and phase of the transmission coefficient was measured from 0.35 to 1.4 MHz in different materials. The measurements show a clear modification of the film response produced by the presence of porosity. This suggests that the transmission of ultrasonic waves in battery separators using air-coupled ultrasound may have two contributions: one corresponds to the propagation though the solid part, the other corresponds to propagation in the pores. The former allows to determine properties like film thickness and elastic constants, while the latter allows to determine porosity and pore size and pore tortuosity. This work set the basis for the development of a quality test for the in-line inspection of these materials during their fabrication. The observed ultrasonic response in microporous separators suggest the possibility to use low frequency air-coupled transducers with limited sensitivity, where the use of MEM transducers at industrial scale can be advantageous
Distributed Embedded System for Multiparametric Assessment of Infrastructure Durability Using Electrochemical Techniques
No full textWe present an autonomous system that remotely monitors the state of reinforced concrete structures. This system performs real-time follow-up of the corrosion rate of rebars (iCORR), along with other relevant parameters such as temperature, corrosion potential (ECORR), and electrical resistance of concrete (RE), at many of a structure’s control points by using embedded sensors. iCORR is obtained by applying a novel low-stress electrochemical polarization technique to corrosion sensors. The custom electronic system manages the sensor network, consisting of a measurement board per control point connected to a central single-board computer in charge of processing measurement data and uploading results to a server via 4G connection. In this work, we report the results obtained after implementing the sensor system into a reinforced concrete wall, where two well-differentiated representative areas were monitored. The obtained corrosion parameters showed consistent values. Similar conclusions are obtained with ECORR recorded in rebars. With the iCORR follow-up, the corrosion penetration damage diagram is built. This diagram is particularly useful for identifying critical events during the corrosion propagation period and to be able to estimate structures’ service life. Hence, the system is presented as a useful tool for the structural maintenance and service life predictions of new structures
Design and materials of the auteur social housing: the case study of Santa María Micaela housing complex by Santiago Artal Ríos
No full textIn Spain, although with a certain delay compared to other countries, social housing has had a singular evolutionary history through the design experiments of famous architects and the adoption of innovative technologies for the construction of the most important works considered today the architectural heritage of every city. The contribution will illustrate peculiarities and original solutions present in Iberian social housing through an in-depth study of a case study carried out in Valencia in the late 1950s by architect Santiago Artal Ríos. In the Santa María Micaela complex, the relationships between the formal component, principles of the Modern Movement and technical-constructive aspects were skillfully highlighted, paying particular attention to the use of materials both in terms of formal characterization and performance contribution. Artal Ríos arranges and shapes the three building blocks following the shape of the lot, thus creating a closure from the outside, emphasized by the single entrance placed along the lowest building, to guard the large interior common spaces. In his design he skillfully achieves more than one balance between different subsystems (technological-constructive, organizational-distributive, environmental-climatic, figurative-formal), which in turn generate others between the supporting structure and aesthetic expression. The resisting frame masterfully punctuates the metrics of the elevations. Within the grid, formed by exposed concrete beams and pillars with 45-degree chamfered edges and a pitch of 4.80 m x 4.80 m, fixed elements (yellow exposed bricks and red under-window panels), movable elements (iron window frames and wooden shutters) and lattice elements (white concrete perforated square screens) are inserted, creating a constant alternation and movement between opacity, transparency and color
Evaluation of the Implementation of Project-Based-Learning in Engineering Programs: A Review of the Literature
No full textProject-Based Learning (PBL), as an experiential methodology, improves learning outcomes and competencies (technical and non-technical) in engineering students. The Conceive–Design–Implement–Operate (CDIO) approach, adopted globally in engineering education, is based on PBL but expands the curriculum framework. Developed by MIT and the Royal Institute of Technology (KTH) in Sweden, CDIO focuses on the entire life cycle of engineering projects to train engineers so that they are capable of applying knowledge in real-life situations. Integrating CDIO and PBL into engineering curricula requires changes in teaching methodologies, teacher training and workspaces. The literature has explored their combination, highlighting shared values and mutual reinforcements. An assessment model is crucial for implementing PBL and evidencing improvement in student and course skills. Only through assessment and the cycle of continuous improvement will the adoption of PBL in engineering programs be advanced. A systematic review of the literature is proposed to identify effective methods in the evaluation of educational programs based on PBL, analyzing related research areas and evaluations according to the CDIO approac
A comparison between the use of cork and synthetic aggregates in the production of geopolymer composites
No full textInnovative and multifunctional building materials with low embodied energy and reduced CO2 emissions have attracted considerable attention. Herein, a comprehensive comparison between the use of cork and commercial synthetic aggregates (expanded vermiculite, expanded polystyrene (EPS), and lightweight expanded clay (Leca®)) in the production of geopolymer composites was performed. Additionally, composites containing rubber coming from the recycling of end-of-life tires were also studied. The impact of the aggregate nature and amount on the geometric density, compressive strength, thermal conductivity, sound absorption coefficient, and thermal stability of the composites was evaluated. This investigation demonstrates the feasibility of tuning the geopolymer composites properties according to the envisioned application, cork-composites being the most suitable approach for sound absorbing panels (α = 0.8, 2000single bond3150 Hz), while Leca® and expanded vermiculite containing composites are the best option when considering fire resistant applications
The Architecture Competition in the Age of AI: Emulation or Collective Revolution?
No full textArchitectural competitions have historically been instances where individual genius is celebrated, shaping the prestige and identity of their protagonists -evident, for example, in the prominence of awards like the Pritzker Prize. However, competitions are undergoing a profound transformation in the digital age. Artificial intelligence, machine learning, and other digital technologies challenge the humanist tradition of singular authorship, favoring more collaborative and participatory models. By tracing this shift, this article raises key questions about the tension between technological innovation and the persistence of individualistic practices. It offers an incisive reflection on the role of algorithm-driven processes and their potential to redefine both architectural practice and the collective production of space