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The Effect of Electric Arc Furnace Dust (EAFD) on Improving Characteristics of Conventional Concrete
No full textThe steel industry is one of the key industries and its use is inevitable in many industries including construction. In addition to steel, this industry produces massive amounts of electric arc furnace dust (EAFD) that is classified as hazardous waste. Using this material as an admixture can improve the characteristics of concrete, neutralize potential risks and be beneficial to the circular economy. Considering the differences in EAFD between different steel companies, which in turn is caused by the type and percentage of input materials, the optimal percentage and specific application of EAFD from steel companies of each region is unique. In the present study, samples from 11 different sources of EAFD in Khuzestan Steel Company (KSC) were collected. Then, they were classified into three groups depending on the size and origin (fine and coarse, both obtained by filtering those particle sizes directly from furnaces, and a third class obtained in the interior of the steelmaking site close to material handling (MH) belt conveyors) based on their physical and chemical characteristics. To test the effect of EADF as an admixture, several conventional concrete samples were prepared by replacing 0% (control), 2%, 5% and 8% of cement with each EAFD group. Finally, the resulting material was characterized through several tests, namely: (i) compressive strength test at 7, 28 and 90 days, (ii) depth of water penetration under pressure test and (iii) electrical indication of concretes ability to resist chloride ion penetration. The result shows that replacing 2% of the cement with MH caused the largest improvement in compressive strength of 7 day concrete, but also showed negative effect on water penetration, while coarse had a negative effect in almost all tests except in the chloride ion penetration test. The best results were obtained by replacing with 2% of cement with fine EAFD, showing significant improvements in all tests, as well as in the observed trend of increasing compressive strength over time
Development of a new Ni voltammetric sensor for hardened concrete conditions estimate
No full textDeveloping efficient monitoring systems to control reinforced concrete structures (RCS) is still an open research line in the building sector. Thus, in this work was proposed the novelty use of Ni voltammetric sensor to control the concrete conditions by means of PCA model. The efficiency of voltammetric sensors are verified in other sectors like food or wastewater treatment, where the sensors are used in liquid media, in the study was intended verify the high potential use of this sensors in porous materials such as concrete. With this purpouse the sensor response was characterized in three different concretes (w/c = 0.6, w/c = 0.5 and w/c = 0.4) and three different concrete conditions (water satured conditions, presence of chlorides and concrete carbonation). Then, was developed a PCA model, where was verified the capability of the sensor to classify the concrete state. The validation of the model pointed an acceptance range between 78.3% and 95.4% (with a 95% confidence index). © 202
Theoretical Analysis of the Worker’s Movement Prediction in Construction Sites and Their Stress Level for the Dangerous Situation Prevention
No full textThe occupational risk assessment methodology called Level of Preventive Action (Lpac) evaluates the amount of preventive action to obtain an optimal prevention level, measuring the degree of danger concerning the building geometry, the worker position concerning the slab edge and the worker’s emotional states. The mathematical basis of Lpac can be extended to include the perspective of collective behaviour models, which can describe the predictable human behaviour based on the probability of acts. Research in the mathematical field satisfactorily models the movement that individuals follow or will follow in different scenarios (e.g., street crossing, emergency evacuation), including social parameters such as mood and emotions. This paper presents a theoretical case applied to the predictive analysis of behaviours and interactions between individuals working on constructing a slab. It is essential to include the worker’s movement prediction regarding unsafe acts and movements in the risk assessment and add the emotional states. From a case study at the microscopic level, stress can trigger dangerous situations, and its evaluation can prevent them. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG
Degradation Model Applied to the Plasterwork of the Palace of Pedro I (Royal Alcazar of Seville)
No full textThis study proposes a model to evaluate the overall degradation condition of historical plasterworks in three different locations inside the Royal Alcazar of Seville, Spain. A Severity of Degradation Index (Sw) is proposed to establish a priority of intervention while also improving the durability and conservation of plasterworks with exceptional heritage features. The Sw is a numerical index that considers the area affected by the different anomalies, their severity, and the relative importance of each anomaly on the overall conservation condition of the plasterworks, while also considering its influence on the overall performance of the plasterworks and its propensity to generate new anomalies. Visual inspections and non-destructive tests (NDT) were adopted to evaluate the conservation condition of the plasterworks of the Palace of Pedro I, which revealed that cracking and metal fixing elements represent the most common and severe anomalies detected. The method proposed allows for a more rational and cost-effective use of resources in the conservation of patrimonial-built heritage. © 2023 by the authors
BIM Methodology in the Teaching of Graphic Expression in Civil Engineering
No full textThe inclusion of the BIM (Building Information Modeling) methodology in civil engineering degrees is an unavoidable fact. Although BIM is a work methodology that has been implemented mainly in the final-years subjects, it has a very important graphic component. One of the most interesting consequences of BIM related to Graphic Expression is the internal coherence of the project, since it is no longer a series of independent views. Now, we are working with a single model, and each of the generated planes will be always connected to that model and to that geometry. Therefore, BIM teaching implies updating the teaching of Graphic Expression, with innovative strategies that impact student learning. But, it is not the same to teach Graphic Expression through BIM than through traditional methodologies. Some authors state that the need for students to know how to ‘draw’ should be replaced by the ability to ‘model’ structures and their components. However, certain traditional techniques that are still effective should not be rejected, as they could also reinforce BIM learning in the future. Education, therefore, is polarizing into two points of view, which tend to reject and exclude the theories of the contrary, the traditionalist or analogical and the progressive or digital. In the Teaching Unit of Graphic Expression of the ETSI de Caminos, Canales y Puertos de Madrid we think that both points of view are compatible and necessary. In fact, we implement both throughout different subjects, since there is a very wide range of exercises about constructions of great geometric complexity that previously require the study of geometric drawing and classic representation systems, prior to the use of software. This does not mean using the same tools in the same way but supporting the traditional manual process of generating elevations and sections as an intrinsic part of capturing the mental model of the project. In this way, when the volumetric comprehension is complete, modeling with 3D BIM software (within the limits that, at least for now, software involves) is possible. To that end, we teach students how to use the program so that they can adapt the software to their purposes through the generation of their own parametric families. At this point the software becomes useful, since, if we know how to use it, we can model almost any structure, its construction and/or maintenance. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG
An Experimental Study of the Sound Reduction Index of Windows with Small Apertures Between the Frame and Window Panel
No full textThis document presents a synthesis of the held research on the sound reduction index in windows both with and without trickle vents, with small openings for permanent natural ventilation between the frame and the windowpane. These devices are invisible to the users and do not affect the natural light from the window. In the case of windows with shutter incorporated the measurements were made with the shutter either fully open or closed
Comparative Study of Building Energy Simulation Software Applied to Research Projects. Cases of Study in Spain and Portugal
No full textArchitecture, Engineering and Construction are currently undergoing an energy-digital transition towards a decarbonised and sustainable scene. Energy assessment of buildings through Building Energy Modelling tools allows for in-depth analyses for energy optimization and establishing quantitative proposals for building improvement. This paper shows a comparative study of three programs used for energy simulation of buildings: TRNSYS, HULC and SG SAVE. They have been applied to four Research and Development (R&D) Projects: the energy assessment of a hospital, the energy behaviour of two partially recycled construction materials, and the cost-effectiveness study of energy efficiency measures and renewable energy at the district level, to validate their handling, precision, and result reliability. The comparative assessment shows SG SAVE is the best-valued software: it is free and easy to use, complies with the Spanish energy regulations more easily than HULC, and along with Open Studio makes complex calculations similar to TRNSYS
Els fons Next Generation per a la rehabilitació energètica. De l’eufòria a la inquietud
No full textEls programes de rehabilitació energètica dels Fons Next Generation no acaben d’engegar. La lentitud de l’administració, la complexitat dels requisits imposats per la UE i la manca d’agilitat en la presa de decisions per les comunitats de propietaris posen en risc que es pugui complir l’objectiu de rehabilitar 58.000 habitatges abans de juny de 2026
Manufacture and characterisation of a new lightweight plaster for application in wet rooms under circular economy criteria
No full textThe use of circular economy criteria for designing new materials is becoming a key factor for the sustainable development of the building sector and the improved performance of construction companies. This research introduces a new plaster composite material in which the original raw material is partially replaced by expanded polystyrene waste in solution and end-of-life tyre textile fibre. This new material has been tested to verify its behaviour in humidity-drying cycles, recording good mechanical properties with strengths well above the values required by current regulations, even after being subjected to the severe effects of these accelerated ageing cycles. A lightened plaster composite has therefore been developed in which the recycled material is fully integrated into the matrix, thereby obtaining a technically viable product for the manufacture of prefabricated products for wet rooms. In addition, a simulation has been carried out using FlexSim 3D modelling and analysis software, which has corroborated the improvement in the further distribution process of a prototype of a prefabricated false ceiling panel made with this new product, as well as the reduction in costs due to more efficient transportation and a lower environmental impact. © 202
Reflections on workflow and standards for the graphic survey of architectural and archaeological heritage
No full textDuring the first decade of the millennium, a slow evolution in the digitalisation of architectural surveying took place. The qualities achieved at first were difficult to compete with analogue systems, so they had to mature until being definitively established. In any case, it was technological development in the following decade that brought about a true revolution in digitisation. Thus, it was during the last ten - twelve years that we have witnessed a true revolution in the methods used within the three-dimensional graphic survey of architectural and archaeological heritage. The incorporation of multi-image photogrammetry (SfM, Structure from Motion) and the new 3D laser scanners broke through in a rather short period of time, allowing us to speak about the advent of a new paradigm. All of this has not only favoured the obtaining of hyper-realistic three-dimensional models, but also the popularisation of such methods due to their extreme simplicity, economy and the visual appeal of their outcomes. In consequence, we can state that these technological advances have triggered a genuine revolution in the documentation of architectural and archaeological heritage