Hasil untuk "Construction industry"

Andrezza Maria Moura Calheiros de Novaes

The construction industry, which has historically faced low productivity and high waste, is seeking to improve its performance and adopt sustainable practices. This research suggests analyzing the synergy between Lean Construction (LC) and Building Information Modeling (BIM) to reveal its principles, obstacles, and performance improvements. LC seeks to maximize customer value and eliminate waste (muda) by considering production as an uninterrupted flow. On the other hand, BIM transforms 2D drawings into 3D information systems that can be read by machines, increasing efficiency. Integrating LC with BIM, leveraging its use with Last Planner System (LPS) and Agile Design Management (ADM) tools, provides significant improvements in workflow and productivity, optimizing resource utilization and promoting sustainable construction. This implementation becomes complicated because it encounters cultural barriers within the organization, such as resistance to change and a lack of knowledge of the Lean methodology. It is concluded that the systemic and inclusive (bottom-up) adoption of LC and BIM is a promising path to ensure long-term competitiveness and sustainable growth of the industry.

Ahmad Hadavi, Sepehr Alizadehsalehi

Simon Garoghan, Ayomikun Solomon Adewumi, Eng L. Ofetotse et al.

With commercial refurbishment projects being identified as large contributors to landfill waste in the United Kingdom (United Kingdom), the aim of this paper is to identify effective Sustainable Waste Management strategies that could be implemented by Small and Medium-sized Enterprise (SME) construction businesses, specifically within the commercial refurbishment sector. The study adopted a mixed method approach engaging industry professionals working within SMEs through both questionnaires and interviews. Findings showed that although SME businesses aspire to make improvements, the construction industry is not making clients and consultants equally accountable. However, some of the most effective tactics that could be employed were low cost and easy to implement but it seems that some SME businesses are still averse to them for mostly economic reasons suggesting for better enlightenment of collaborative procurement routes, implementing sustainability regulations and comprehensive engagement of SMEs by industry authorities; substantial improvements can be made in the realm of sustainable waste management.

Donghua Wang, Huichun Ye, Yanan You et al.

Abstract Rubber powdery mildew, caused by the fungal pathogen Oidium heveae Steinm., is a prevalent disease in rubber plantation regions worldwide. This disease significantly impacts the growth and yield of rubber trees, leading to substantial economic losses within the rubber industry. In recent years, due to climate change and adjustments in planting structures, both the geographical spread and severity of the disease have increased. Consequently, there is an urgent need to develop efficient remote sensing monitoring methods for early warning and effective management. To fully exploit disease information within hyperspectral data, this study first extracted spectral features using three methods: spectral mathematical transformations (MT), continuous wavelet transformation (CWT), and vegetation indices (VIs). Subsequently, correlation analysis (CA), least absolute shrinkage and selection operator (LASSO), and principal component analysis (PCA) were employed to select optimal features from each set, resulting in the construction of nine independent basic feature sets. To further enhance model performance, features selected by these three strategies (CA, LASSO, and PCA) were combined to form three fused feature sets. Finally, all basic and fused feature sets were input into a Random Forest (RF) model to evaluate the impact of different feature combinations on the accuracy of disease severity classification. The results revealed that, among the spectral data processing methods, CWT performed the best. Among the feature selection methods, PCA was the most effective. The feature fusion methods significantly improved model performance. Specifically, the fused feature set based on PCA selection (PCA_ALL) achieved the highest classification accuracy, with an overall accuracy (OA) of 98.89% and a Kappa coefficient of 0.98. This OA was 8.89% higher than that of CA_ALL and 4.42% higher than the best-performing basic feature set (PCA_CWT). This study establishes a remote sensing monitoring framework for classifying rubber leaf powdery mildew severity based on the fusion of multi-dimensional hyperspectral features. This framework not only lays a technical foundation for the transition of the natural rubber industry from experience-based control to intelligent decision-making but also provides crucial parameters for large-scale dynamic disease monitoring using UAV and satellite platforms.

Murat Gunduz, Khalid K. Naji, Hadi Al-Marri

Although earlier studies had connected material scarcity and price fluctuation to cost overruns and delays in Qatar’s building projects, the root causes of this volatility had not been investigated. To close this crucial gap, this study looked into these drivers. The research analyzed the factors affecting construction material prices by addressing three key objectives. First, it identified and categorized factors based on a comprehensive literature review. Second, it examined the influence of these factors and categories on material prices using Generalized Structured Component Analysis (GSCA). Third, it proposed strategies for mitigating price volatility within the Qatari construction sector. Fourteen factors were identified and grouped into three constructs: Economic and Regulatory, Logistics, and Market. Data were collected through an online survey, producing 195 responses. The GSCA method was applied to assess the model, which met the goodness-of-fit, reliability, and validity criteria for component-based structural equation modeling. The findings showed that all three constructs positively affected material prices. The Economic and Regulatory construct exerted the most significant influence, with a t-value of 5.987, followed by the Logistics construct with a t-value of 2.292. The Market construct had the lowest impact, with a t-value of 0.099. The model’s R-square value of 0.41 indicated that the three constructs accounted for 41% of the variation in construction material prices in Qatar.

David Ojimaojo Ebiloma, Opeoluwa Akinradewo, Clinton Ohis Aigbavboa et al.

Blockchain is a decentralised system based on cryptographic procedures and smart contracts that records every transaction and shares it with all parties involved, thereby handling issues of delays and trust. However, as identified in past studies, there are barriers to its adoption in the construction industry, especially in developing countries. There are no studies that assessed the impact of these barriers on the various procurement systems used in Nigeria; hence, this study is aimed at developing the statistical impact models of these barriers on critical procurement systems in Nigeria, with a view of identifying the most available and least-affected system that is best fit for blockchain adoption. The study adopted the quantitative research approach through a questionnaire survey. Data was collected from 182 stakeholders in the Nigerian construction industry through a snowball sampling technique; these stakeholders were grouped as clients, contractors and consultants. The retrieved data were analysed using descriptive statistics and linear regression, while Cronbach’s alpha was used to test for reliability. The R2 and the significance level of the three models indicated that they are significant, and the barriers significantly influence the use of blockchain smart contracts for the three procurement systems. The findings also predicted that the design and build (DB) procurement system is best suited for the easier adoption of blockchain smart contracts in the Nigerian architectural, engineering and construction (AEC) industry. This novel study has developed statistical impact models of blockchain barriers on the critical procurement systems in the Nigerian AEC industry, giving a road map for blockchain smart contracts usage.

Tinoapei Dhliwayo , Innocent Musonda , Trynos Gumbo et al.

The sustainability of small and medium-sized contractors (SMCs) is vital, considering the critical role they play in socio-economic development globally. SMCs in Namibia have been consistently grappling with high failure rates over the years, largely due to a dearth of robust policy frameworks to guide SMC development and sustainability in the country. This study investigates the critical success factors (CSFs) for SMCs’ sustainability in Namibia. Using a qualitative approach, data were collected from 60 purposively selected construction industry participants, comprising owner-managers of contracting firms, policymakers, and construction professional consultants. Interviews were conducted with the participants, using a semi-structured interview tool. Data were then analysed using reflexive thematic analysis. The findings revealed six CSFs, including public and private institutions’ collaborative support, skills training, an enabling construction business environment, access to adequate and affordable finance, consistent work opportunities, and firm owner’s entrepreneurial skills. The identified CSFs culminated in the development of a framework for guiding the development of SMCs in Namibia. By incorporating the six CSFs in the framework, SMCs could be effectively developed and sustained. The framework may assist policymakers in making fundamental policy reforms and developing appropriate and context-specific interventions to sustain SMCs in Namibia and similar contexts.

Nwadike Gerald, Chimezie, Anikelechi, Ijeoma Genevieve

This study examines the effects of immigrants on wage and cost in the Nigerian construction industry, from 1980- 2020. The objectives are to; examine the effect of immigrants on wage in the Nigerian construction industry, ascertain the effect of immigrants on cost in the Nigerian construction industry and investigate the impact of immigrants on the Nigerian construction industry growth and performance. The study employed the econometric and statistical techniques; Augmented Dickey-Fuller (ADF) and Phillips-Perron (PP) tests, Co-integration Test, Vector Error Correction Model (VEC), Impulse response analysis in VEC models and Granger Causality. Based on the above econometric and statistical techniques conducted, it was observed that there is a significant effect of immigrant’s on wage in the Nigerian construction industry. Our results indicated significant positive effect of immigrants on cost in the Nigerian construction industry within the sample period. Furthermore, there is significant effect of immigrants on the Nigerian construction industrial growth performance and bidirectional nature of causality relationship between the variables in the model within the sample period 1980-2020. The empirical results do support that increase in the supply of labour resulting from immigrant’s, caused wages decline in the Nigerian construction industry and as well, support that the cost of building decreased as result of increase in stock of immigrants’ labours that leads to 21% decrease in cost in Nigeria construction industry. Based on these findings, the researcher recommends that; Yes wage for native’s worker in the construction industry declined by a relatively small amount, the societal effects of reduced wages and prices for all purchasers should be considered in the conversation. The construction industry should uphold the fact that these immigrant’s laborers are substitutes for native’s worker in the construction industry, yet it doesn't avoid the likelihood that they are supplements also. Nigeria construction industry should take advantage of presence of the immigrant’s workers, and expatriates’ companies in the industry to gain transfer of knowledge and advance in the construction technical knowhow.

Carlos Manterola-Barroso, Daniela Padilla Contreras, Gabrijel Ondrasek et al.

The hard-shelled seed industry plays an important role in the global agricultural economy. In fact, only considering hazelnut and walnut, the global nut supply is over 5.6 tons. As a result considerable amounts are produced year by year, burnt or discarded as waste, bypassing a potential source of valuable compounds or features. This review deals with the recent scientific literature on their chemical composition as well as functional applications as an approach to sustain the utilization of the main byproduct derived from industry. Indeed, nutshells have received great interest due to their lignin, antioxidant, physical and mechanical features. It was found that these properties vary among cultivars and localities of plantation, influencing physical and structural features. The inconsistencies regarding the above-mentioned properties of nutshells lead to exploring the status of hazelnut and walnut shell applications in sustainable bio-economy chains. In fact, in terms of potential applications, the state of the art links their use to the construction industry and the manufacture of materials, such as resin or plastic composites, particleboards or construction panels, or vital infrastructure and as a filler in cement pavements. However, their current use continues bypassing their great antioxidant potential and their interesting chemical and mechanical features.

Christopher Borg Costanzi, Benedikt Waldschmitt, Ulrich Knaack et al.

Guangjie Wang, Wenfu Peng, Lindan Zhang

We estimated the population density and quantified its characteristics using remote sensing, census data, and Geographic Information System (GIS). The interactive influence of these factors on population density was quantified based on geographic detectors to identify the differentiation mechanisms in the Chengdu metropolitan area of China. We identified the key factors that contribute to population density growth. The models used to simulate population density had the highest R2 values (>0.899). Population density tended to increase with time, with a multicentre spatial agglomeration pattern; the centre of gravity of the spatial distribution tended to move from the southeast to the northwest. Industry proportions, Normalised Difference Vegetation Index (NDVI), land use, distance to urban centers or construction land, and GDP per capita can satisfactorily explain population density changes. The combined impact of these elements on population density variation exhibited mutual and non-linear strengthening, with the mutual effect of the two elements intensifying the impact of each individual element. Our study identified the key driving forces that contribute to the differentiation of population density, which can provide valuable support for the development of effective regional and targeted population planning guidelines.

Siyang LIU, Yunfei ZHANG

Based on the development status and industry challenges of intelligent connected vehicles (ICV), the concepts and development strategies of ICV 1.0 and ICV 2.0 were proposed.Pan-V2X which aimed to achieve the breakthrough of ICV 1.0 and the vehicle-city coordination platform which was the core platform of ICV 2.0 were introduced.The vision of ICV 2.0 was to build transport real-time digital twin based on ICV and real-time digital twin city for coordinated development of ICV and smart city.The construction methods and innovative practices of real-time digital twin city for coordinated development of ICV and smart city were finally introduced.

Tatyana V. Konovalova, Yury D. Shevtsov, Sofia L. Nadiryan et al.

With the growth of production volumes of transport products, the effective management of the logistics costs of the enterprise forces us to look for new approaches in the management of enterprise resources. Logistics costs are directly dependent on logistics operations in the supply chain. Optimizing the logistics costs of an enterprise in the new competitive environment involves the search and implementation of innovative solutions in the field of transport technologies. The article discusses the development of methods for improving the efficiency of transport and logistics processes by optimizing the logistics costs of the enterprise, through the optimization of vehicle control systems. Purpose – development of a methodology for assessing the effectiveness of ISAS. Method or methodology of the work. The article used mathematical and statistical methods of analysis. Results. The most informative parameters for evaluating the functioning of ISAS were determined, which should include a calculated assessment of power, economic, environmental and reliability indicators for various control modes or their combinations, as well as for various operating modes. Scope of the results. Applied research in the field of evaluating the effectiveness of transport and logistics processes; carrying out research work aimed at creating new science-intensive technologies for optimizing transport and technological systems.

Mohammad Sadra Rajabi, Mohammad Rezaeiashtiani, Afiqah R. Radzi et al.

Building information modeling (BIM) has a significant role in the architecture, engineering, construction, and operation (AECO) industries. Most BIM benefits have not been grasped due to the lack of organizational BIM capabilities (OBIMCs). Accordingly, organizations must develop intuitive strategies to support BIM implementation and to fulfill the promised benefits. This study investigates the impact of different capability factors on OBIMC and the underlying strategies to improve OBIMC in Iran. Particularly, this study builds a structural equation model to explain the links between the capability factors and strategies linked to OBIMC in Iran. A systematic literature review of twenty-six papers and semi-structured interviews with fifteen BIM specialists identified nineteen capability factors and fourteen strategies. A survey of 126 BIM professionals was used to assess the importance of the capability factors and strategies. To analyze the collected data, first, an Exploratory Factor Analysis (EFA) was performed. Then, Partial Least-Squares Structural Equation Modeling (PLS-SEM) was employed. The EFA generated two constructs for the capability factors: OBIMC and organizational capabilities (OCA). Furthermore, it categorized the strategies into two constructs: BIM capability requirement (BIMCR) and organizational culture (OCU). The structural equation model demonstrates that BIMCR and OCU enhance OCA and OBIMC. These two elements are also positively impacted by BIMCR. Industry professionals and policymakers can use these findings to develop strategic plans and to prioritize efforts. The significant contribution of this study is to illuminate the interrelationship between capability factors and strategies related to OBIMC in Iran.

Dominika Sereda, Hubert Nieścior, Aleksandra Metelska et al.

Introduction and purpose  Infectious keratitis represents the leading cause of corneal blindness worldwide, particularly in developing countries. Both risk factors and etiological patterns vary between economically developed and developing regions, with bacterial predominance in the former and fungal predominance in the latter. This review aims to provide an updated overview of the risk factors in relation to infectious keratitis. Description of the state of knowledge  Infectious keratitis is a painful and potentially vision-threatening ophthalmic condition characterized by decreased vision, photophobia and eye redness. In severe cases, it may require hospital admission for intensive medical treatment or surgical interventions. It can be caused by a wide array of organisms, including bacteria, fungi, viruses, parasites or polymicrobial infection. The most commonly observed predisposing factors for infectious keratitis include contact lens wear, trauma, ocular surface diseases, post-corneal surgery and systemic or local immunosuppression. Manual workers in construction or agricultural industry, exposed to vegetative matter, organic materials and animal products are particularly at risk. Higher rate of incidence is also observed in regions with poor environmental and personal hygiene, low level of education, poor access to sanitation and healthcare facility. Summary  Persistent prevalence of infectious keratitis in both developed and developing countries makes it a serious medical problem. Prevention, proper diagnosis and effective treatment are crucial for positive visual outcome.

Deatra Walsh, Michael Haan, Christopher Hewitt

Working without fixity, while historically prevalent, has been on the rise in Canada and throughout the world due to processes associated with advanced capitalism. Moreover, it implies mobility to, from, and within work, which in a time of COVID-19, is problematic for workers and communities alike. In this paper, we argue that our pre-COVID statistical knowledge of workers without a fixed place of work in Canada is inadequate. Using the best source of available data—the 2016 Census—we provide a thorough account of these workers as compared to those with a set place of work. We find that most individuals without a fixed workplace are male, have low income, are likely to be self-employed, have a higher proportion of employment insurance (EI) and self-employment income, and have college or on-the-job training skill levels. They are also likely to live in rural areas, and work in the construction or transportation industry. We argue that documenting which workers are most likely to be working without fixity is necessary to understand how a COVID-19 world will play out for these workers and their communities as the pandemic continues and beyond. Keywords: COVID-19, labour, mobility, gender, Canada, Census ________________________________________  Travailler sans fixité: Comptabiliser une main-d'oeuvre mobile Résumé Le travail sans fixité, bien qu'historiquement répandu, est à la hausse au Canada et dans le monde entier en raison des processus associés au capitalisme avancé. De plus, cela implique une mobilité vers, depuis et au sein du travail, ce qui, à une époque de la COVID-19, est problématique pour les travailleurs et les communautés. Dans cet article, nous soutenons que notre connaissance statistique pré-COVID des travailleurs sans lieu de travail fixe au Canada est inadéquate. En utilisant la meilleure source de données disponibles, le Recensement de 2016, nous fournissons un compte rendu détaillé de ces travailleurs par rapport à ceux dont le lieu de travail est défini. Nous constatons que la plupart des personnes sans lieu de travail fixe sont des hommes, ont un faible revenu, sont susceptibles d'être des travailleurs autonomes, ont une proportion plus élevée de revenus d'assurance-emploi (AE) et de travail autonome, et ont suivi une formation collégiale ou sont en formation pratique par niveaux de compétence. Ils sont également susceptibles de vivre dans des zones rurales et de travailler dans l'industrie de la construction ou des transports. Nous soutenons que documenter quels travailleurs sont les plus susceptibles de travailler sans fixité est nécessaire pour comprendre comment un monde COVID-19 se déroulera pour ces travailleurs et leurs communautés alors que la pandémie se poursuit et au-delà. Mots-clés: COVID-19, main-d'oeuvre, mobilité, le sexe, Canada, Recensement

CUI Fan, KOU Xinyue, FENG Youbin et al.

In order to resolve the contradiction between the high demand for water resources,water ecology and water environment in the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) and the insufficient supervision capabilities in the water conservancy industry,and achieve the transformation from passive management to active management of key drinking water sources in the GBA,this paper carries out supervisory monitoring of key drinking water sources through remote sensing macro monitoring,UAV cruise monitoring,fixed-point monitoring and other intelligent monitoring technology system.The results show that:①After application of a supervisory monitoring technology system for key drinking water sources,the full-coverage,dynamic and quasi-real-time monitoring of 35 key water sources in the GBA is realized,and the risk sources and water problems can be identified efficiently.②For identifying five suspected risk sources in water source areas,namely construction projects,key river (reservoir) tributaries,temporary shipping stops,material stacking places,agricultural production activities by remote sensing macro monitoring and UAV cruise monitoring,the accuracy rate is 65.7%.③For the chlorophyll a and COD_Mnmonitoring of the water source of main Guangzhou-Dongguan-Huizhou Dongjiangbei River by remote sensing macro monitoring and artificial fixed-point monitoring during the same period,the monitoring results of the two technical means are in good agreement.Therefore,with application of the technology system in supervision and management of key drinking water sources,the smart water conservancy supervision and business management are deeply integrated,and the effective technical means for supervision and management are available.

Izabela Rojek, Marek Macko, Dariusz Mikołajewski et al.

Artificial intelligence (AI) is changing many areas of technology in the public and private spheres, including the economy. This report reviews issues related to machine modelling and simulations concerning further development of mechanical devices and their control systems as part of novel projects under the Industry 4.0 paradigm. The challenges faced by the industry have generated novel technologies used in the construction of dynamic, intelligent, flexible and open applications, capable of working in real time environments. Thus, in an Industry 4.0 environment, the data generated by sensor networks requires AI/CI to apply close-to-real-time data analysis techniques. In this way industry can face both fresh opportunities and challenges, including predictive analysis using computer tools capable of detecting patterns in the data based on the same rules that can be used to formulate the prediction.

Blas Cantero, Miguel Bravo, Jorge de Brito et al.

Acceptance by the construction industry of recycled concrete as a sustainable alternative material is contingent upon a reliable assessment of its permeability to corrosive agents. This study analyses the transport mechanisms associated with chloride (Cl⁻), oxygen (O₂) and carbon dioxide (CO₂) ions in concrete with cement made with 10% or 25% ground recycled concrete (GRC) separately or in combination with 50% mixed recycled aggregate (MRA). The findings show that, irrespective of aggregate type, concrete with GRC exhibited lower resistance to ingress than conventional concrete due to its greater porosity. Nonetheless, O₂ permeability was consistently below 4.5 × 10⁻¹⁷ m² and CO₂ penetration, under 4 mm/year^0.5, indicative of concrete with high quality. Resistance to CO₂ and Cl⁻ penetration in the materials with 10% GRC was similar to the values observed in conventional concrete. On the other hand, the incorporation of 25% GRC increased the penetration of CO₂ and Cl^- by 106% and 38%, respectively. Further to those findings in normal carbonation environments, reinforcement passivity would be guaranteed in such recycled materials over a 100 year service life.

Chunxiang Qian, Xiaomeng Wang, Yudong Xie et al.

The application of microbial mineralization in cement-based materials has broad prospects, especially in strengthening the surface layer, improving the microstructure, and healing the cracks. This paper mainly studies the interaction between the mineralizing process by Bacillus mucilaginosus fixing CO2 from air and the hydration process of cement-based materials after addition of microorganisms. The coupling model described the interaction of the hydration of C3S and the microbial mineralization is established. This model is used to predict the contents of hydration products, the microbe induced bio-CaCO3 and the porosity distribution in hardened pastes of C3S. The calculated results revealed that the hydration degree of C3S, the contents of C-S-H gel and bio-CaCO3 increased and the remained C3S, the content of Ca(OH)2, the porosity decreased in certain depth of the surface layer of the hardened pastes of C3S after the addition of microorganisms. Moreover, the calculated results are in good agreement with the experimental.