Construction Elements Research Articles

Critical Uncertainty Analysis of the Application of New-Generation Digital Technology in China’s Construction Industry—A Study Based on the LDA-DEMATEL-ISM Improvement Model

As the main driving force for the digital transformation of the construction industry, the uncertainty of digital technology in the application process has seriously hindered the high-quality development of the construction industry. In order to promote the wide application of digital technology in the construction industry and clarify the key uncertainties in its application process, this paper identifies the uncertainty index system of digital technology application based on the LDA topic model and literature analysis; the DEMATEL-ISM method is used to construct the multilevel hierarchical structure model of the uncertainty indicators in the application of digital technology to study the mutual influence among the indicators and to find the key uncertainty indicators. The research results show that the uncertainty indicators of the application of digital technology in the construction industry are divided into five levels: policy, industry, personnel, economy and law, and that the perfection of the policy guarantee system is the key uncertainty indicator for the investment return period of digital technology application. The standard contract model for digital technology is a direct uncertainty indicator for the application of digital technology in the construction industry. The results of this study help researchers and practitioners to focus on the key barriers and provide a list of key elements for construction companies to promote the application of next-generation digital technologies to improve digitalization of the construction industry. This study also provides a policy reference to further promote the digital transformation of the construction industry.

Review on Advances in Bio-based Admixtures for Concrete

Bio-based admixtures (BBAs) are emerging as a promising class of additives for concrete, of- fering a more sustainable and environmentally friendly alternative to conventional chemical admixtures. Derived from various natural or biological sources, including plants, animals, and microorganisms, BBAs have shown potential in enhancing the performance characteristics of concrete in several key areas. This review article provides an in-depth exploration of BBAs, be- ginning with a detailed classification of the different types of BBAs based on their source mate- rial and production methods. It then delves into the various characterization techniques used to assess the properties and performance of BBAs, providing insights into their impact on the workability, strength, durability, and rheology of concrete. The article also discusses the diverse application areas of BBAs, highlighting their versatility and potential for wide-ranging use in the construction industry. It further identifies and discusses the challenges associated with the use of BBAs, such as issues related to compatibility with different types of cement and concrete, storage and shelf-life considerations, quality control and standardization concerns, and cost-effective- ness. In conclusion, the review emphasizes that while BBAs hold great promise as an alternative to conventional chemical admixtures for concrete, there is a need for more interdisciplinary collaboration and research to overcome the identified challenges and fully realize their poten- tial. The paper calls for further studies focusing on optimizing the production and application processes of BBAs, as well as developing standardized testing and quality control procedures.

Analysis of the EU Cybersecurity Governance Model

The EU regards cybersecurity governance as an important development agenda in Europe, establishing a framework mechanism around the three key dimensions of defense, development, and diplomacy, promoting the construction of laws and regulations, facilitating coordinated development of regulatory agencies, creating supporting policy tools, and mobilizing social stakeholders to participate in co-governance, and a unique multi-level cybersecurity governance model has been formed. This article discusses, summarizes, and analyzes the official documents and governance practices of EU cybersecurity governance, and explores its main measures and development mechanisms. Facing the year 2030, the new development trends of EU cybersecurity governance mainly include actively integrating relevant elements of green Europe and digital Europe construction in funding project supply, expanding and strengthening partnerships in the cybersecurity governance framework in external relations processing, and emphasizing the use of multi-level and diversified behavior in comprehensive capacity building, so as to promote the international dissemination of the cybersecurity governance framework and norms it advocates, and at the same time strengthen Europe's autonomy and leadership in global digital governance.

Design Study of a Temporary, Emergencial and Sustentable Shelder in Light Wood Framing and Bamboo

Objective: This article aims to present an architectural proposal for a temporary emergency shelter of a sustainable nature using Wood Frame and bamboo, which allows for easy transport, assembly and disassembly in the event of major tragedies and serves as a shelter for the needy population. Method: This work was developed in two stages: initially data was collected on issues relating to environmental tragedies and their solutions as well as the emergency needs of the victims. In the second stage, a program of these refugees' needs was drawn up, the project was developed and the volumetric model was presented. Theoretical framework: Currently, the socioeconomic conditions in Bolivia, the political instability in Venezuela and the natural disasters in Haiti cause the number of refugees to increase in Brazil. Bolivian immigration to the country has a more continuous flow compared to that from countries like Venezuela and Bolivia. Furthermore, with the increase in natural disasters present in the national territory, it is necessary to promove solutions to aliviate the needs of this population in a state of vulnerability. Results and conclusion: the results presented in this work make up the research project for the development of new materials, products and constructive elements for wooden construction. Implications of the research: along with this discussion, it is expected to expand of the understanding of the concepts and design processes in emergency housing, possible renewable materials application, ease of production and execution to fit vulnerable communities in Brazil. Originality/value: This study explores an important gap in empirical studies carried out in the context of emergency shelter projects for vulnerable communities.

Evaluating the fire behaviour of cement-based lightweight materials with textile waste incorporation using a cone calorimeter

The conscientious utilization of natural resources and the efficient waste management have become a matter of great concern in recent years due to the harmful impacts on the environment. The construction sector presents itself as one of the sectors that most contributes to raw materials consumption and waste generation, demanding the investigation of more sustainable and eco-friendly building materials, where the valorisation of wastes originated from other industries can be promising. Following the sustainability concept in construction materials, this work investigates the potential use of textile waste in cement-based lightweight construction material, evaluating the fire reaction of the material using the cone calorimeter equipment. The samples were tested at three different radiant heat fluxes (35 kW/m², 50 kW/m², 75 kW/m²) to simulate different fire situations. For the highest heat flux, the lightweight construction element with textile waste incorporation showed a Heat Release Rate Average ≤ 18 kW/m², a peak Heat Release Rate Average ≤ 60 kW/m², and a Total Heat Release Average ≤ 33 MJ/m². These results reveal a very satisfactory fire behaviour compared to other materials and show the suitability of using textile waste as lightweight cement-based materials.

In-Process Integration of Reinforcement for Construction Elements During Shotcrete 3D Printing

The current state of the art for additive manufacturing often utilises horizontal layer printing approaches for a variety of materials and applications. However, it imposes restrictions on the integration of utilities, mounting fixtures, installations, and reinforcement. Particularly the integration of reinforcement into 3D concrete printing still faces many challenges. It is currently restricted by the nozzle to strand distance, the lack of bond quality, automation, and geometric limitations of the respective 3D concrete printing techniques. The following research presents a case study on additively manufactured concrete construction elements utilising the Shotcrete 3D Printing (SC3DP) technique, focusing on interlayer- and short rebar reinforcement. To demonstrate the potential benefits for an automated reinforcement integration and to uncover further challenges and research questions, a wall segment was produced using a unique combination of Interlayer Reinforcement (ILR) and Short Rebar Insertion (SRI). By incorporating these methods, it was possible to generate three-dimensional continuous reinforcement structures within the wall. The innovative approach showcased takes full advantage of the SC3DP technique, enabling the integration of reinforcement during the printing process itself, thus utilising the geometric freedom, the fast build up rate and the kinetic energy during application. This eliminates the need for premanufactured reinforcement structures, enabling a more efficient and flexible manufacturing process. Furthermore, the discussion includes the potential for surface finishing and attainment of geometrical accuracy through the direct integration of reinforcement. An outlook is given as future construction elements can be produced structurally reinforced without formwork and with a high degree of geometric freedom.

CONCEPTS ON THE RESISTANCE OF ACRYLIC TEETH, PMMA

Artificial acrylic teeth, also known as dentures, are a common solution for replacing missing or damaged teeth. Wear of artificial acrylic teeth can be influenced by several factors, such as: if dentures are ulilized and worn every day, they can suffer from gradual wear over time. Mastication and friction against other hard surfaces can lead to a gradual deterioration of artificial teeth. It is very important how artificial acrylic dental compositions are made, but more importantly it seems that it is the stratification that is of particular importance when we talk about wear resistance. The studies performed so far are quite relative because each tooth lining can withstand depending on the component of the constructive elements.

Experimental and Numerical Evaluation of a Wildland–Urban Interface Fire Scenario

This paper presents the results obtained from a field fire test, aiming to reproduce a wildland–urban interface scenario to collect relevant information concerning the impact of wildfires on the built environment. The objective was to understand heat transfer mechanisms from forest fires to structures. During the fire test, the temperatures at the exposed face of one building component were monitored, as well as those in the vicinity of that component, using thermal imaging. The detailed characterization of the field test and building component and obtained experimental results of the fire test were then used to develop and validate a complex computational fluid dynamics model (full physics models) using the Fire Dynamics Simulator (FDS). Several numerical models were previously developed to reproduce the behaviour of individual shrubs and trees in fires considering available results in the literature. The developed Computational Fluid Dynamics (CFD) models can accurately reproduce the field test, including the fire spread and the temperature evolution on the surface of the exposed construction component. The obtained maximum temperature in the construction element was 1038 °C, whereas the maximum average temperature was approximately 638 °C. According to the results from the numerical model, the construction element was exposed to a very high heat flux (above 40 kW/m2), indicating direct contact of the flames with the construction element. The use of CFD enables the quantification of the characteristics of the fire and the exposure of structures to fire in the wildland–urban interface (WUI), allowing for the definition of a performance-based design approach for buildings in the WUI. This contributes to developing safe and resilient structures, as well as mitigating and reducing the impacts of wildfires in the built environment.

Technology hype, promises, and expectations: The discussion on small modular reactors in the Finnish newspaper ‘Helsingin Sanomat’ in 2000–2022

While the construction of collective promises is vital to the success of any techno-scientific innovation, it also entails the risk of overpromising and cycles of hype and disappointment. This article explores the discursive construction of the nuclear sector’s latest promise concerning small modular reactors (SMRs), using Finland as an example. It provides a brief overview of the Finnish context of SMR development and analyzes it's coverage in the leading Finnish daily newspaper Helsingin Sanomat 2000–2022. Efforts at promise construction have so far been aimed at building legitimacy for SMRs, while strengthening credibility – another key element of successful promise construction – has only just begun. The increasing number of SMR-related articles indicates a growing hype, but the absence of a corresponding ‘hype language’ suggests that the considerable media attention does not automatically translate into emphatic media coverage and discursive hyping.

Comparative life cycle assessment of traditional timber jack arch slab refurbishment solutions: Eco-efficient proposal versus conventional ones

Abstract Purpose In the context of worldwide efforts to reduce plastic waste, the authors of this document patented a cement mortar floor slab interjoist prefab vault incorporating recycled plastic. This piece was designed to be used for the refurbishment of Spanish traditional timber jack arch floor slabs. Taking into account nowadays context, it is essential to assess the environmental benefits of this product. Methods A cradle to gate LCA has been performed following ISO 14044 and ISO 15804 recommendations. Thus, the aim of this research is both to provide a measure of the environmental improvement that this material adds to the building process and to compare it with current most used construction elements used for the same function. It is stressed that this study is based mainly on primary data obtained from Spanish producers. Results The results obtained show that the reference scenario, corresponding to the new patented vault, is the system with lower impacts in six out of the seven categories assessed. Furthermore, when adding the LCA normalisation step, the conducted analysis show that for the most influential impact categories, GWP100a and AD fossil fuels, the reference scenario bears the lowest scores. Conclusions It can be concluded that the new patented vault has a better environmental performance than the assessed commercial vaults. Therefore, in this research, the benefits for the construction sector to incorporate recycled plastics are shown. Furthermore, these results can encourage the research on construction products that include recycled plastics in their composition. Bearing in mind that this study assesses the impacts corresponding to the production of a prototype of the newly vault, it is considered that there is room for further improvement through the optimisation of the production process.

INFLUENCE OF ANNUAL GROWTH RING STRUCTURE REGULARITIES AND NATURAL DEFECTS ON PHYSICAL AND MECHANICAL PROPERTIES OF CARPATHIAN SPRUCE

In the process of technical inspection of buildings and structures constructed with the use of both solid logs and Carpathian spruce lumber massively observed processes of deplanation of the wall fence, exit from functional state of constructive elements of inter-storey floors and rafter systems. During inspection calculations of existing construction elements, which are in exploitation for all types of stress-deformed state, there are often questions to the accepted constructive solutions of cross-sections and nodal joints of building structures made of solid wood. This fact can only be due to the discrepancy between the strength and deformation properties of Carpathian spruce and the declared characteristics in normative documents. The presence of natural defects and structural features of the Carpathian spruce structure indicate that the unequal physical and mechanical properties of the two coniferous species that grow in the northern latitudes and the Carpathian region of Ukraine are not entirely true. The distribution of the ratio of latewood to earlywood has a direct influence on the physical and mechanical properties of wood. This fact is caused by rather cellular structure of wood with large annual growth of early and late wood. Such characteristics can have both positive and negative effects on the properties of Carpathian spruce as a building material. This type of wood with a high degree of natural moisture content and cellular structure requires a special pre-drying procedure for the production of building structures. To establish the factual physic-mechanical properties of Carpathian spruce, the current normative documents were analysed and the existing scientific research on this issue was studied. In the process of conducting a comparative analysis of the results of comprehensive studies of standard samples of Carpathian spruce for compression along the fibres and control samples made from the base species - pine, the fact of partial inconsistency of physical and mechanical parameters of the two varieties of conifers was established. In general view, recommendations are made for changes to the current norms for the construction of solid timber structures. Keywords: : physic-mechanical properties, bulk weight, wood defects, temporary resistance.

Optical Parameters of Aluminum Alloy Samples Irradiated by High Current Relativistic Electron Beams

The aluminum alloys D16, D16AT are widely used as construction materials in the aircraft industry. Questions connected with the enhancement of the properties of the construction elements made of the alloys through surface modification are of great interest now. The objects of the study in our paper are the samples of the aluminum alloy D16AT subjected to irradiation by high-current relativistic electron beams. Leaving aside the material science aspects, in this work we focused on modeling the optical properties of the samples. The problem is relevant because optical methods for surface analysis have become widespread due to their versatility and efficiency. Through the treatment of the preliminary measured ellipsometry data, we obtain the optical constants of the samples and their dispersion in the visible region of wavelength. The method used consists of an approximation of the reflection coefficient calculated from the ellipsometry data by finding the values of the parameters in the model. The last is performed by the least squares method. The reflection coefficient is assumed to correspond to the semibounded uniaxial medium with the optical axis perpendicular to the interface between the medium and the homogeneous and dielectric ambient medium. The dielectric function of the semibounded medium is approximated by the Drude-Lorentz model. The possibility of birefringence of the samples caused by the irradiation with electron beams is discussed.

Adaptation 4D and 5D BIM for BIM/GIS data integration in construction project management

Construction project management contains a sequence of activities such as planning, completing, scheduling and cost estimation. Building Information Modelling (BIM) is one of the technologies that can be used to manage the complexity of construction documentation. BIM provides a digital visualization of building structures in three dimensional (3D) and store all the geometric and semantic data likes construction element, material properties, construction details, and schedules but lacking feature like geospatial analyses. Geographic Information System (GIS) can apply in construction project to overcome the limitation because GIS can offer advantages in route design, cost estimation, site layout, material layout design and construction planning. Therefore, integration BIM/GIS is recommended to produce an operational of construction project management. This paper presents the advantages of BIM-based in term of scheduling (4D BIM) and cost estimation (5D BIM) in the scope of project management to control the time efficiency and cost saving during the construction process. 4D and 5D BIM data were examine during data integration between BIM and GIS by using Feature Manipulation Engine to bring the gap in construction project management. 4D BIM data develop using Naviswork while 5D BIM developed using Autodesk Revit. GIS data management was used to maintain and update the construction database to assist the project planning.

Victoria Cozmolici's creation, the subtle universe of nature and femininity

The work of the painter Victoria Cozmolici is the fruit of her plastic investigations based on the formal-stylistic principles morphologically originating from a series of currents of modern and contemporary European art in which the principle of abstraction remains a priority. Approaching the means and methods of figurative abstractionism and abstract expressionism, pop-art style in combination with constructive elements that belong to her own artistic language, the painter carefully approaches the chromatic relationships of the pictorial surfaces as the decorative elements of form configuration. Integrated into nature, the characters and objects represented in the paintings signed by Victoria Cozmolici are often transfigured into silhouettes and female faces, creating original visual rhythms of a particular constructive logic. The theme is focused on everyday life, nature is both the background and part of this life, and the woman, with her soft face repeating the undulations of the plates – bearer of meaning, beauty and spirituality.

Additive manufacturing technology for the continuous production of precision concrete elements

AbstractThis work reports about a combined additive manufacturing technology – concrete spraying and extrusion – for a continues production of precision concrete elements for modular civil construction. In order to achieve the goal, a fine‐grained concrete mix was developed that covers the technical production properties for both spraying and extrusion. In a next first step, a spray‐extrusion multi‐tool nozzle was developed and tested for spraying and extrusion of the fine‐grained concrete mixture. In addition to complete the robot‐assisted flow production process, force transmission elements were developed, which can be automatically integrated into the extruded concrete matrix in the non‐cured green state in accordance with the load. This holistic automated production technology opens new fields of application in the construction industry that were previously not possible with classic methods.

Concrete with clinker‐efficient cements ‐ Robustness to variations in water content and temperature

AbstractThe use of multi‐component cements (CEM II‐CEM VI), which contain main constituents other than Portland cement clinker in significant quantities, can significantly help to reduce the CO2 footprint of the cement or concrete industry. Clinker‐efficient cements (CEM II/C‐M) have been standardized in the current version of DIN EN 197‐5. In a systematic experimental program, the influence of water content variations and temperature on the robustness of concrete with clinker‐efficient cements with high contents of granulated blast furnace slag or fly ash and limestone (CEM II/C‐M (S‐LL) and CEM II/C‐M (V‐LL)) was studied. As a reference, concretes representative for construction elements used indoor (XC1) or in protected outdoor environment (XC3) with standard Portland composite cement (CEM II/A‐M) and blast furnace slag cement (CEM III/A) were investigated. The influence of variations in water content and temperature on fresh (rheological properties, bleeding) and mechanical concrete properties (compressive strength, elastic modulus) were investigated. The results obtained show similar performance and robustness of such concretes with clinker‐efficient cements compared to the reference concretes.

Influence of dimensional and connection characteristics of CLT building elements on predictive calculations

The ISO 12354-1 standard provides different calculation methods for evaluating lateral transmission depending on the vibroacoustic behavior of building structures; the standard classifies them into types A and B depending on whether the structural reverberation time of the considered element depends or not on the connecting elements. Although some construction elements are composed of the same material, they can belong to the first or second type, according to the technology of assembly or installation. CLT panels, generally belonging to type A, may sometimes behave as type B elements. This study deals with some of these cases through calculation examples based on experimental data collected on a real-scale building mockup.

Thermo-accelerated curing of transparent glass-glass bondings through in-situ heat generation in the adhesive joint

ABSTRACT Bonding glass is challenging due to the brittle properties of the material. At the same time, it is interesting for transparent architectural applications, as the entire construction appears as a uniform surface without disturbance. Many adhesives are available for this purpose, whereby epoxy resins and polyurethanes fulfill the highest structural requirements due to their crosslinking properties. In addition, the curing of both can be accelerated by heat, so that short economic cycle times can be achieved. However, in conventional heating the entire construction element, often several meters long, has to be placed in an oven. This results again in long curing cycles, high-energy consumption and high costs. Induction or resistance methods achieve more targeted heating, but these require components at the adhesive joint that can be activated. Electrically conductive or magnetizable fillers are non-transparent and metallic substrates such as brackets or fixings do not exist on glass-glass bondings. Therefore, this study investigated heat generation on little-visible, metallic inserts and glass coatings. Different adhesives were analyzed for their accelerated heat curing properties and the resulting bond strength. A fast cured, highly transparent joint could be achieved with the combination of an epoxy resin and the resistant heating of a silver coating.

Citizens’ knowledge of and perceptions of multi-storey wood buildings in seven European countries

ABSTRACT This study examined public attitudes towards multi-storey wood buildings (MSWBs) in seven European countries. A questionnaire was distributed to online panellists in Austria, Denmark, Finland, Germany, Norway, Sweden and the United Kingdom. Results from 7007 complete questionnaires indicate that respondents knew less about MSWBs in countries where brick, stone and concrete are the most commonly used house frame elements in construction (United Kingdom, Germany and Denmark) compared to countries with a stronger wood building tradition (Austria, Finland, Norway and Sweden). Respondents in Finland and Sweden had the most positive attitudes towards MSWB. The number of respondents, who considered a prospective apartment in an MSWB appealing, was approximately equal to the number that considered it an unappealing alternative. The factors most influencing the respondents’ perception of MSWBs as a nice place to live were (i) vulnerability to fire, (ii) material solidity and durability, (iii) healthy indoor environment and (iv) vulnerability to moisture. The results from this study add new knowledge to the understanding of cross-country differences of preferences among the public for living in MSWBs. The results can be used to support the MSWB planning and marketing efforts in the countries involved.

PRODUCTION OF PLASTIC INCORPORATED CONCRETE AND STABILIZED MUD BLOCK

Rapidly escalating plastic consumption has led to a significant surge in plastic waste, causing notable repercussions for environmental well-being due to the non-biodegradable nature of plastics. In order to mitigate the environmental impact of plastic, it is imperative to explore alternative approaches to recycling plastic. In the present day, several industries repurpose plastic waste to create a wide array of products, including domestic items, clothing, household materials, textiles, construction elements, and even convert waste plastic into fuel. Among these options, the utilization of plastic waste in the creation of building materials has garnered significant focus. This practice not only reduces the amount of plastic waste discarded as litter or sent to landfills but also diminishes the necessity for mining raw materials used in construction. This, in turn, contributes to mitigating the adverse environmental impacts associated with the construction industry. Within this endeavor, the initiative involves partially substituting plastic waste for the fine aggregate in both concrete blocks and stabilized mud blocks. A comparative analysis is conducted between the compressive strength of these integrated plastic blocks and conventional standard blocks. The outcomes unequivocally demonstrate the viability of recycling plastic waste in a constructive manner, achieved through the incorporation of waste plastics in the production of building blocks. Notably, incorporating plastic waste by approximately 3%-6% to replace fine aggregates in Fly-Ash blocks results in enhanced strength compared to regular Fly-Ash blocks