Search results for: construction supply chain
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 7181

Search results for: construction supply chain

6611 A Review: Recycled Materials Used in Construction

Authors: Oghenerukome Akponovo, Lynda I. Onyebuchukwu

Abstract:

Construction waste, along with that of many other industries, contributes significantly to the world's annual solid waste totals. Most of these materials, such as ash from rice hulls, slags, cement kiln dust, tire ash, plastic waste (PW), and silica fumes, end up in landfills or waterways. Some of them might even end up polluting the air from high in the atmosphere. It's sustainable, cheap, and environmentally friendly to recycle these items into new building supplies. When constructing a "Green" structure, the materials employed have the potential to either exacerbate environmental imbalance or maintain a stable ecosystem. The purpose of this research is to take stock of what is already known about recycling's potential in the construction industry and to identify its deficiencies. Therefore, this study systematically reviews the wide range of recycled materials that go into building construction. Recognizing that the construction industry's use of recycled materials has an influence on the environment and that investigating these materials may have a substantial economic impact if they were discovered

Keywords: building, construction, recycled materials, waste management

Procedia PDF Downloads 92
6610 Growth of Public Listed Construction Companies in Malaysia

Authors: M. C. Theong, F. L. Ang, G. J. Muga

Abstract:

Growth of firms is influenced by environmental changes such as the global and national economy. On the other hand, it indicates the economic situation of a country. Therefore, it is imperative for firms to be sensitive to changes and to stay competitive and remain compatible with the environment. The Malaysian construction industry is prone to environmental changes due to its complexity. In order to survive in the construction industry, focus on the development of the firms themselves to achieve long term their long term goals is vital besides maximizing profits. The objective of this paper is to measure growth of the public listed construction companies in Malaysia and to investigate the development of the companies with highest, moderate and lowest growth. Growth is measured based on the companies' sales between year 2008 and 2012 collected via secondary data collection method. Findings show that the highest average growth created is 235.20 % while the lowest average growth is -22.75%. The construction companies remained active in the construction industry by implementing different sets of strategies and involving in several types of construction projects.

Keywords: growth, Malaysian construction industry, public listed companies, sales

Procedia PDF Downloads 362
6609 A Study of Carbon Emissions during Building Construction

Authors: Jonggeon Lee, Sungho Tae, Sungjoon Suk, Keunhyeok Yang, George Ford, Michael E. Smith, Omidreza Shoghli

Abstract:

In recent years, research to reduce carbon emissions through quantitative assessment of building life cycle carbon emissions has been performed as it relates to the construction industry. However, most research efforts related to building carbon emissions assessment have been focused on evaluation during the operational phase of a building’s life span. Few comprehensive studies of the carbon emissions during a building’s construction phase have been performed. The purpose of this study is to propose an assessment method that quantitatively evaluates the carbon emissions of buildings during the construction phase. The study analysed the amount of carbon emissions produced by 17 construction trades, and selected four construction trades that result in high levels of carbon emissions: reinforced concrete work; sheathing work; foundation work; and form work. Building materials, and construction and transport equipment used for the selected construction trades were identified, and carbon emissions produced by the identified materials and equipment were calculated for these four construction trades. The energy consumption of construction and transport equipment was calculated by analysing fuel efficiency and equipment productivity rates. The combination of the expected levels of carbon emissions associated with the utilization of building materials and construction equipment provides means for estimating the quantity of carbon emissions related to the construction phase of a building’s life cycle. The proposed carbon emissions assessment method was validated by case studies.

Keywords: building construction phase, carbon emissions assessment, building life cycle

Procedia PDF Downloads 734
6608 Comparative Life Cycle Analysis of Selected Modular Timber Construction and Assembly Typologies

Authors: Benjamin Goldsmith, Felix Heisel

Abstract:

The building industry must reduce its emissions in order to meet 2030 neutrality targets, and modular and/or offsite construction is seen as an alternative to conventional construction methods which could help achieve this goal. Modular construction has previously been shown to be less wasteful and has a lower global warming potential (GWP). While many studies have been conducted investigating the life cycle impacts of modular and conventional construction, few studies have compared different types of modular assembly and construction in order to determine which offer the greatest environmental benefits over their whole life cycle. This study seeks to investigate three different modular construction types -infill frame, core, and podium- in order to determine environmental impacts such as GWP as well as circularity indicators. The study will focus on the emissions of the production, construction, and end-of-life phases. The circularity of the various approaches will be taken into consideration in order to acknowledge the potential benefits of the ability to reuse and/or reclaim materials, products, and assemblies. The study will conduct hypothetical case studies for the three different modular construction types, and in doing so, control the parameters of location, climate, program, and client. By looking in-depth at the GWP of the beginning and end phases of various simulated modular buildings, it will be possible to make suggestions on which type of construction has the lowest global warming potential.

Keywords: modular construction, offsite construction, life cycle analysis, global warming potential, environmental impact, circular economy

Procedia PDF Downloads 159
6607 Anti-Corruption, an Important Challenge for the Construction Industry!

Authors: Ahmed Stifi, Sascha Gentes, Fritz Gehbauer

Abstract:

The construction industry is perhaps one of the oldest industry of the world. The ancient monuments like the egyptian pyramids, the temples of Greeks and Romans like Parthenon and Pantheon, the robust bridges, old Roman theatres, the citadels and many more are the best testament to that. The industry also has a symbiotic relationship with other . Some of the heavy engineering industry provide construction machineries, chemical industry develop innovative construction materials, finance sector provides fund solutions for complex construction projects and many more. Construction Industry is not only mammoth but also very complex in nature. Because of the complexity, construction industry is prone to various tribulations which may have the propensity to hamper its growth. The comparitive study of this industry with other depicts that it is associated with a state of tardiness and delay especially when we focus on the managerial aspects and the study of triple constraint (time, cost and scope). While some institutes says the complexity associated with it as a major reason, others like lean construction, refers to the wastes produced across the construction process as the prime reason. This paper introduces corruption as one of the prime factors for such delays.To support this many international reports and studies are available depicting that construction industry is one of the most corrupt sectors worldwide, and the corruption can take place throught the project cycle comprising project selection, planning, design, funding, pre-qualification, tendering, execution, operation and maintenance, and even through the reconstrction phase. It also happens in many forms such as bribe, fraud, extortion, collusion, embezzlement and conflict of interest and the self-sufficient. As a solution to cope the corruption in construction industry, the paper introduces the integrity as a key factor and build a new integrity framework to develop and implement an integrity management system for construction companies and construction projects.

Keywords: corruption, construction industry, integrity, lean construction

Procedia PDF Downloads 366
6606 Cost Overrun Causes in Public Construction Projects in Saudi Arabia

Authors: Ibrahim Mahamid, A. Al-Ghonamy, M. Aichouni

Abstract:

This study is conducted to identify causes of cost deviations in public construction projects in Saudi Arabia from contractors’ perspective. 41 factors that might affect cost estimating accuracy were identified through literature review and discussion with some construction experts. The factors were tabulated in a questionnaire form and a field survey included 51 contractors from the Northern Province of Saudi Arabia was performed. The results show that the top five important causes are: wrong estimation method, long period between design and time of implementation, cost of labor, cost of machinary and absence of construction-cost data.

Keywords: cost deviation, public construction, cost estimating, Saudi Arabia, contractors

Procedia PDF Downloads 461
6605 Evaluation of Traditional Methods in Construction and Their Effects on Reinforced-Concrete Buildings Behavior

Authors: E. H. N. Gashti, M. Zarrini, M. Irannezhad, J. R. Langroudi

Abstract:

Using ETABS software, this study analyzed 23 buildings to evaluate effects of mistakes during construction phase on buildings structural behavior. For modelling, two different loadings were assumed: 1) design loading and 2) loading due to the effects of mistakes in construction phase. Research results determined that considering traditional construction methods for buildings resulted in a significant increase in dead loads and consequently intensified the displacements and base-shears of buildings under seismic loads.

Keywords: reinforced-concrete buildings, construction mistakes, base-shear, displacements, failure

Procedia PDF Downloads 257
6604 Radio Frequency Identification System and Its Effect on Retailing Sector

Authors: Ayşe Çoban, Orhan Çoban, Murat Birekul

Abstract:

In this study, the effects of radio frequency identification system on the retailing sector were theoretically analysed. The technology of Radio Frequency Identification (RFID) is a method enabling to identify the objects individually and automatically, using radio frequency. RFID generally consists of a tag and reader. RFID tags can be programmed to receive, store, and send the information of object such as Electronic Product Code (EPC). Having read the tags placed on product by the reader, the information associated with the management of supply chain can be automatically recorded and replaced. Recently, RFID technology used in many areas has particularly important effects on the businesses that are active in the retailing sector. The most important disadvantage of this technology is that the cost of installation and operation is higher compared to its alternatives. However, it provides important advantages to the business enterprises in the application process. At present, it is especially adopted by the large sized enterprises and with chain stores in the international areas. The application results point out that RFID technology provides business enterprises with the important competitive advantage.

Keywords: RFID, retailing sector, RFID technologies, electronic product code

Procedia PDF Downloads 373
6603 Development of Intelligent Construction Management System Using Web-Camera Image and 3D Object Image

Authors: Hyeon-Seung Kim, Bit-Na Cho, Tae-Woon Jeong, Soo-Young Yoon, Leen-Seok Kang

Abstract:

Recently, a construction project has been large in the size and complicated in the site work. The web-cameras are used to manage the construction site of such a large construction project. They can be used for monitoring the construction schedule as compared to the actual work image of the planned work schedule. Specially, because the 4D CAD system that the construction appearance is continually simulated in a 3D CAD object by work schedule is widely applied to the construction project, the comparison system between the real image of actual work appearance by web-camera and the simulated image of planned work appearance by 3D CAD object can be an intelligent construction schedule management system (ICON). The delayed activities comparing with the planned schedule can be simulated by red color in the ICON as a virtual reality object. This study developed the ICON and it was verified in a real bridge construction project in Korea. To verify the developed system, a web-camera was installed and operated in a case project for a month. Because the angle and zooming of the web-camera can be operated by Internet, a project manager can easily monitor and assume the corrective action.

Keywords: 4D CAD, web-camera, ICON (intelligent construction schedule management system), 3D object image

Procedia PDF Downloads 498
6602 An Evaluation of the Effectiveness of Health and Safety Induction Practices in the Zambian Construction Industry

Authors: Josephine Mutwale-Ziko, Nonde Lushinga, Inonge Akakandelwa

Abstract:

The study discusses the effectiveness of health and safety induction practices on construction sites against the background of the Zambian construction industry experience. The research design included the literature review of relevant literature. Questionnaires and interviews were administered to regulatory bodies, health, and safety personnel. Observation was also employed on construction sites to assess the health and safety practices being used. Health and safety in the construction industry are not something to be ignored or overlooked. The construction industry needs to take heed of the serious consequences of inadequate health and safety induction practices. The implications of inadequate health and safety induction procedures included among others threats to profitability, corporate social responsibility and increased turnover of the workforce leading to poor productivity. Adequate health and safety practices can improve the health and wellbeing of employees, reduce financial implications on firms and encourage productivity on construction sites. Despite this, accidents are still prevalent on construction sites in Zambia. The overall result of this research denotes that the implementation of health and safety induction practices is inadequate, as indicated by the negligent and non-adherent attitude to health and safety induction aspects on the sites by most stakeholders on construction sites. Therefore, health and safety induction practices are ineffective as preventive measures for reduction of accidents on construction sites in Zambia.

Keywords: accidents, health and safety, inadequate, induction

Procedia PDF Downloads 426
6601 Familiarity With Civil Engineering and Types of Construction and Its Methods

Authors: Mokhtar Nikgoo

Abstract:

Civil engineering is one of the disciplines that shows the application of science in creating construction and civil engineering. That is, everything that returns to the population of a country, such as dams, airports, roads, bridges, towers, tunnels, telecommunication towers, buildings resistant to earthquakes, floods and fires, power plants and light, cheap and quality materials for construction. And the construction is included in the scope of work of the civil engineer. Civil engineering covers a wide range of tasks. That is, for the construction of buildings, bridges, towers, tunnels, roads, silos, or sewage networks, an efficient civil engineer is needed at the beginning, in addition to complying with the technical and operational aspects, he also works economically. Because being economical is a principle in civil engineering. Is. This field at the undergraduate level has three majors: civil-building, civil-mapping and civil-water.

Keywords: civil engineering, construction, surveying, mapping, pile

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6600 Integrating Blockchain and Internet of Things Platforms: An Empirical Study on Immunization Cold Chain

Authors: Fawzia Abujalala, Asma Elmangoush, Majdi Ashibani

Abstract:

The adoption of Blockchain technology introduces the possibility to decentralize cold chain systems. This adaptation enhances them to be more efficient, accessible, verifiable, and data security. Additionally, the Internet of Things (IoT) concept is considered as an added-value to various application domains. Cargo tracking and cold chain are a few to name. However, the security of the IoT transactions and integrated devices remains one of the key challenges to the IoT application’s success. Consequently, Blockchain technology and its consensus protocols have been used to solve many information security problems. In this paper, the researchers discussed the advantages of integrating Blockchain technology into IoT platform to improve security and provide an overview of existing literature on integrating Blockchain and IoT platforms. Then, presented the immunization cold chain solution as a use-case that could apply to any critical goods based on integrating hyperledger fabric platform and IoT platform.

Keywords: blockchain, hyperledger fabric, internet of things, security, traceability

Procedia PDF Downloads 135
6599 Assessment of Health and Safety Item on Construction Site in Ondo State

Authors: Ikumapayi Catherine Mayowa

Abstract:

The well-being of humans on a construction site is critical; abundant manpower had been lost through accidents which kill or make workers physically unfit to carry out construction activities, these, in turn, have multiple effects on the whole economy. Thus, it is necessary to put all safety items and regulations in place before construction activities can commence. This study was carried out in the Ondo state of Nigeria to investigate and analyze the state of health and safety of construction workers in the state. The study was done using first-hand observations, 50 construction project sites were visited in ten major towns of Ondo state, questionnaires were distributed, and the results were analyzed. The result shows that construction workers are being exposed to many construction site hazards due to lack of inadequate safety programs and lack of appropriate safety equipment for workers on site. From the data gotten from each site visited and the statistical analysis, it can be concluded that occurrences of an accident on construction sites depend significantly on the available safety facilities on the sites. The result of the regression statistics shows that the dependence of the frequency of occurrence of an accident on the availability of safety items on the site is 0.0362 which is less than 0.05 maximum significant level allowed. Therefore, a vital way of sustaining our building strategy is given a detail attention to the provision of adequate health and safety items on construction sites which will reduce the occurrence of accident, loss of manpower and death of skilled workers.

Keywords: construction sites, health, safety, welfare

Procedia PDF Downloads 316
6598 Appraisal of Incentive Schemes for Employees: A Case of Construction Smes

Authors: B. M. Arthur-Aidoo, C. O. Aigbavboa, W. D. Thwala

Abstract:

The performance of construction employees cannot be underestimated if the success of construction projects are to be achieved. This is because the construction industry has been characterised as labour oriented sector, which most of its activities being executed by labour. In the construction sector, employees are driven by incentive schemes which perform encourage and motivate workers for higher efficiency and higher output. The construction sector, however, depends mainly on its labour. In view of the sector's high dependency on its employees, that there must be a significant incentive scheme which must be established to act as a stimulus to drive high performance from employees among the various known incentive packages. This study, therefore, seeks to appraise the incentive packages adopted by construction SMEs. To establish reliable findings that will contribute to knowledge, the study utilised an exploratory approach via semi-structured interviews among sampled construction professionals with the requisite expertise on employees' incentive schemes. The study further established that although incentive schemes are classified in various ways and mediums that act as stimuli to encourage high performance among employees, some are more influential and impacts performance than others. Additionally, the study concludes that medical allowance, holiday with pay, free working tools, and training for employees were ranked the most influential incentives that promote high outputs by workers within the construction SME sector.

Keywords: appraisal, construction, employees, incentive, small and medium-sized enterprises, SMEs

Procedia PDF Downloads 126
6597 Union-Primes and Immediate Neighbors

Authors: Shai Sarussi

Abstract:

The union of a nonempty chain of prime ideals in a noncommutative ring is not necessarily a prime ideal. An ideal is called union-prime if it is a union of a nonempty chain of prime ideals but is not a prime. In this paper, some relations between chains of prime ideals and the induced chains of union-prime ideals are shown; in particular, the cardinality of such chains and the cardinality of the sets of cuts of such chains are discussed. For a ring R and a nonempty full chain of prime ideals C of R, several characterizations for the property of immediate neighbors in C are given.

Keywords: prime ideals, union-prime ideals, immediate neighbors, Kaplansky's conjecture

Procedia PDF Downloads 122
6596 A Genetic Based Algorithm to Generate Random Simple Polygons Using a New Polygon Merge Algorithm

Authors: Ali Nourollah, Mohsen Movahedinejad

Abstract:

In this paper a new algorithm to generate random simple polygons from a given set of points in a two dimensional plane is designed. The proposed algorithm uses a genetic algorithm to generate polygons with few vertices. A new merge algorithm is presented which converts any two polygons into a simple polygon. This algorithm at first changes two polygons into a polygonal chain and then the polygonal chain is converted into a simple polygon. The process of converting a polygonal chain into a simple polygon is based on the removal of intersecting edges. The merge algorithm has the time complexity of O ((r+s) *l) where r and s are the size of merging polygons and l shows the number of intersecting edges removed from the polygonal chain. It will be shown that 1 < l < r+s. The experiments results show that the proposed algorithm has the ability to generate a great number of different simple polygons and has better performance in comparison to celebrated algorithms such as space partitioning and steady growth.

Keywords: Divide and conquer, genetic algorithm, merge polygons, Random simple polygon generation.

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6595 The Influence of Construction Workers Wages and Working Conditions on Productivity in Ghana

Authors: Emmanuel Donkor

Abstract:

Aim/Purpose – This paper examines the influence of construction workers wages and working conditions on productivity in Ghana. Design/methodology/Approach - The study adopted a quantitative research approach with purposive sampling techniques where data was collected using surveys. The data were analyzed using SPSS software version 20.0, which enables the findings of the study to be examined under thematic areas.Findings: - The study revealed that good wages and working condition of workers have a positive correlation on productivity in the construction industry. Increase and improved wages and working conditions can results in higher productivity in the construction industry.Originality/value - This paper is exceptional in the sense that, it does examine the influence of construction workers wages and working conditions on productivity in Ghana. Social value/implications - The paper concludes that workers’ wages and their conditions have a high influence on productivity. It is then recommended that government should train, educate, give good wages to workers and improve on their working condition, give incentives and reduce tax importation on building or construction materials to aid in good productivity of construction firms.

Keywords: construction firms, construction industry, productivity, workers’ wages, working conditions

Procedia PDF Downloads 125
6594 Hybrid Risk Assessment Model for Construction Based on Multicriteria Decision Making Methods

Authors: J. Tamosaitiene

Abstract:

The article focuses on the identification and classification of key risk management criteria that represent the most important sustainability aspects of the construction industry. The construction sector is one of the most important sectors in Lithuania. Nowadays, the assessment of the risk level of a construction project is especially important for the quality of construction projects, the growth of enterprises and the sector. To establish the most important criteria for successful growth of the sector, a questionnaire for experts was developed. The analytic hierarchy process (AHP), the expert judgement method and other multicriteria decision making (MCDM) methods were used to develop the hybrid model. The results were used to develop an integrated knowledge system for the measurement of a risk level particular to construction projects. The article presents a practical case that details the developed system, sustainable aspects, and risk assessment.

Keywords: risk, system, model, construction

Procedia PDF Downloads 157
6593 Delay Studies in Construction: Synthesis, Critical Evaluation, and the Way Forward

Authors: Abdullah Alsehaimi

Abstract:

Over decades, there have been many studies of delay in construction, and this type of study continues to be popular in construction management research. A synthesis and critical evaluation of delay studies in developing countries reveals that poor project management is cited as one of the main causes of delay. However, despite such consensus, most of the previous studies fall short in providing clear recommendations demonstrating how project management practice could be improved. Moreover, the majority of recommendations are general and not devoted to solving the difficulties associated with particular delay causes. This paper aims to demonstrate that the root cause of this state of affairs is that typical research into delay tends to be descriptive and explanatory, making it inadequate for solving persistent managerial problems in construction. It is contended that many problems in construction could be mitigated via alternative research approaches, i.e. action and constructive research. Such prescriptive research methods can assist in the development and implementation of innovative tools tackling managerial problems of construction, including that of delay. In so doing, those methods will better connect research and practice, and thus strengthen the relevance of academic construction management.

Keywords: construction delay, action research, constructive research, industrial engineering

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6592 Maximum Distance Separable b-Symbol Repeated-Root γ-Constacylic Codes over a Finite Chain Ring of Length 2

Authors: Jamal Laaouine, Mohammed Elhassani Charkani

Abstract:

Let p be a prime and let b be an integer. MDS b-symbol codes are a direct generalization of MDS codes. The γ-constacyclic codes of length pˢ over the finite commutative chain ring Fₚm [u]/ < u² > had been classified into four distinct types, where is a nonzero element of the field Fₚm. Let C₃ be a code of Type 3. In this paper, we obtain the b-symbol distance db(C₃) of the code C₃. Using this result, necessary and sufficient conditions under which C₃ is an MDS b-symbol code are given.

Keywords: constacyclic code, repeated-root code, maximum distance separable, MDS codes, b-symbol distance, finite chain rings

Procedia PDF Downloads 131
6591 Analysis of the Impact of Suez Canal on the Robustness of Global Shipping Networks

Authors: Zimu Li, Zheng Wan

Abstract:

The Suez Canal plays an important role in global shipping networks and is one of the most frequently used waterways in the world. The 2021 canal obstruction by ship Ever Given in March 2021, however, completed blocked the Suez Canal for a week and caused significant disruption to world trade. Therefore, it is very important to quantitatively analyze the impact of the accident on the robustness of the global shipping network. However, the current research on maritime transportation networks is usually limited to local or small-scale networks in a certain region. Based on the complex network theory, this study establishes a global shipping complex network covering 2713 nodes and 137830 edges by using the real trajectory data of the global marine transport ship automatic identification system in 2018. At the same time, two attack modes, deliberate (Suez Canal Blocking) and random, are defined to calculate the changes in network node degree, eccentricity, clustering coefficient, network density, network isolated nodes, betweenness centrality, and closeness centrality under the two attack modes, and quantitatively analyze the actual impact of Suez Canal Blocking on the robustness of global shipping network. The results of the network robustness analysis show that Suez Canal blocking was more destructive to the shipping network than random attacks of the same scale. The network connectivity and accessibility decreased significantly, and the decline decreased with the distance between the port and the canal, showing the phenomenon of distance attenuation. This study further analyzes the impact of the blocking of the Suez Canal on Chinese ports and finds that the blocking of the Suez Canal significantly interferes withChina's shipping network and seriously affects China's normal trade activities. Finally, the impact of the global supply chain is analyzed, and it is found that blocking the canal will seriously damage the normal operation of the global supply chain.

Keywords: global shipping networks, ship AIS trajectory data, main channel, complex network, eigenvalue change

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6590 A Semi-Markov Chain-Based Model for the Prediction of Deterioration of Concrete Bridges in Quebec

Authors: Eslam Mohammed Abdelkader, Mohamed Marzouk, Tarek Zayed

Abstract:

Infrastructure systems are crucial to every aspect of life on Earth. Existing Infrastructure is subjected to degradation while the demands are growing for a better infrastructure system in response to the high standards of safety, health, population growth, and environmental protection. Bridges play a crucial role in urban transportation networks. Moreover, they are subjected to high level of deterioration because of the variable traffic loading, extreme weather conditions, cycles of freeze and thaw, etc. The development of Bridge Management Systems (BMSs) has become a fundamental imperative nowadays especially in the large transportation networks due to the huge variance between the need for maintenance actions, and the available funds to perform such actions. Deterioration models represent a very important aspect for the effective use of BMSs. This paper presents a probabilistic time-based model that is capable of predicting the condition ratings of the concrete bridge decks along its service life. The deterioration process of the concrete bridge decks is modeled using semi-Markov process. One of the main challenges of the Markov Chain Decision Process (MCDP) is the construction of the transition probability matrix. Yet, the proposed model overcomes this issue by modeling the sojourn times based on some probability density functions. The sojourn times of each condition state are fitted to probability density functions based on some goodness of fit tests such as Kolmogorov-Smirnov test, Anderson Darling, and chi-squared test. The parameters of the probability density functions are obtained using maximum likelihood estimation (MLE). The condition ratings obtained from the Ministry of Transportation in Quebec (MTQ) are utilized as a database to construct the deterioration model. Finally, a comparison is conducted between the Markov Chain and semi-Markov chain to select the most feasible prediction model.

Keywords: bridge management system, bridge decks, deterioration model, Semi-Markov chain, sojourn times, maximum likelihood estimation

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6589 Necessity of Using Cellular Lightweights Concrete in Construction Sector

Authors: Soner Guler, Fuat Korkut

Abstract:

Recently, the using of lightweights concretes in construction sector is rapidly increasing all over the world. Faster construction, low density and thermal transmitting coefficient and high fire resistance are the remarkable characteristics of the lightweight concretes. Lightweight concrete can be described as a type of concrete which enhance the volume of the mixture while giving additional advantages such as to reduce the dead weight of the structures. It is lighter than the conventional concrete. The use of lightweight concrete has been widely spread across countries such as USA, United Kingdom, and Sweden. In this study, the necessity of the using of lightweights concretes in the construction sector is emphasized and evaluated briefly for the architectures and civil engineers.

Keywords: lightweights concretes, low density, low thermal coefficient, construction sector

Procedia PDF Downloads 501
6588 Progress of Research on Community Canteens and Reflections on Planning in China

Authors: Xi Zuo

Abstract:

Against the background of the aging population and changing family structure in China, community canteens have become an important vehicle for community-based home care services and a new space for social interaction. In this paper, we review past studies and the actual construction situation in China, firstly sort out the social interaction of the elderly and the types of places, and on this basis, we find that there is an obvious disconnection between the current construction and the academic research, and the contradiction between social benefit and cost-effectiveness, and therefore we put forward the relevant construction planning and thinking, in order to provide a disciplinary basis and academic support for the construction of community canteens and the construction of elderly-friendly cities. In order to provide disciplinary basis and academic support for the construction of community canteens and the construction of senior-friendly cities.

Keywords: urban and rural planning, community canteens, elderly people, senior-friendly

Procedia PDF Downloads 47
6587 Productivity of Construction Companies Using the Management of Threats and Opportunities ‎in Construction Projects of Iran

Authors: Nima Amani, Ali Salehi Dastjerdi, Fatemeh Ahmadi, Ardalan Sabamehr

Abstract:

The cost overrun of the construction projects has always been one of the main problems of the construction companies caused by the risky nature of the construction projects. Therefore, today, the application of risk management is inevitable. Although in theory, the issue of risk management is divided into the opportunities and threats management, in practice, most of the projects have been focused on the threats management. However, considering the opportunities management and applying the opportunities-response strategies can lead to the improved profitability of the construction projects of the companies. In this paper, a new technique is developed to identify the opportunities in the construction projects using an improved protocol and propose the appropriate opportunities-response strategies to the construction companies to provide them with higher profitability. To evaluate the effectiveness of the protocol for selecting the most appropriate strategies in ‎response to the opportunities and threats, two projects from a construction company in Iran were ‎studied. Both projects selected were in mid-range in terms of size and similar in terms of time, ‎run time and costs. Finally, the output indicates that using the proposed opportunities-response strategies show that the company's profitability in the future can be increased approximately for similar projects.

Keywords: opportunities management, risk-response strategy, opportunity-response strategy, productivity, risk management

Procedia PDF Downloads 216
6586 Research on the Calculation Method of Smartization Rate of Concrete Structure Building Construction

Authors: Hongyu Ye, Hong Zhang, Minjie Sun, Hongfang Xu

Abstract:

In the context of China's promotion of smart construction and building industrialization, there is a need for evaluation standards for the development of building industrialization based on assembly-type construction. However, the evaluation of smart construction remains a challenge in the industry's development process. This paper addresses this issue by proposing a calculation and evaluation method for the smartization rate of concrete structure building construction. The study focuses on examining the factors of smart equipment application and their impact on costs throughout the process of smart construction design, production, transfer, and construction. Based on this analysis, the paper presents an evaluation method for the smartization rate based on components. Furthermore, it introduces calculation methods for assessing the smartization rate of buildings. The paper also suggests a rapid calculation method for determining the smartization rate using Building Information Modeling (BIM) and information expression technology. The proposed research provides a foundation for the swift calculation of the smartization rate based on BIM and information technology. Ultimately, it aims to promote the development of smart construction and the construction of high-quality buildings in China.

Keywords: building industrialization, high quality building, smart construction, smartization rate, component

Procedia PDF Downloads 56
6585 Creation of a Test Machine for the Scientific Investigation of Chain Shot

Authors: Mark McGuire, Eric Shannon, John Parmigiani

Abstract:

Timber harvesting increasingly involves mechanized equipment. This has increased the efficiency of harvesting, but has also introduced worker-safety concerns. One such concern arises from the use of harvesters. During operation, harvesters subject saw chain to large dynamic mechanical stresses. These stresses can, under certain conditions, cause the saw chain to fracture. The high speed of harvester saw chain can cause the resulting open chain loop to fracture a second time due to the dynamic loads placed upon it as it travels through space. If a second fracture occurs, it can result in a projectile consisting of one-to-several chain links. This projectile is referred to as a chain shot. It has speeds similar to a bullet but typically has greater mass and is a significant safety concern. Numerous examples exist of chain shots penetrating bullet-proof barriers and causing severe injury and death. Improved harvester-cab barriers can help prevent injury however a comprehensive scientific understanding of chain shot is required to consistently reduce or prevent it. Obtaining this understanding requires a test machine with the capability to cause chain shot to occur under carefully controlled conditions and accurately measure the response. Worldwide few such test machine exist. Those that do focus on validating the ability of barriers to withstand a chain shot impact rather than obtaining a scientific understanding of the chain shot event itself. The purpose of this paper is to describe the design, fabrication, and use of a test machine capable of a comprehensive scientific investigation of chain shot. The capabilities of this machine are to test all commercially-available saw chains and bars at chain tensions and speeds meeting and exceeding those typically encountered in harvester use and accurately measure the corresponding key technical parameters. The test machine was constructed inside of a standard shipping container. This provides space for both an operator station and a test chamber. In order to contain the chain shot under any possible test conditions, the test chamber was lined with a base layer of AR500 steel followed by an overlay of HDPE. To accommodate varying bar orientations and fracture-initiation sites, the entire saw chain drive unit and bar mounting system is modular and capable of being located anywhere in the test chamber. The drive unit consists of a high-speed electric motor with a flywheel. Standard Ponsse harvester head components are used to bar mounting and chain tensioning. Chain lubrication is provided by a separate peristaltic pump. Chain fracture is initiated through ISO standard 11837. Measure parameters include shaft speed, motor vibration, bearing temperatures, motor temperature, motor current draw, hydraulic fluid pressure, chain force at fracture, and high-speed camera images. Results show that the machine is capable of consistently causing chain shot. Measurement output shows fracture location and the force associated with fracture as a function of saw chain speed and tension. Use of this machine will result in a scientific understanding of chain shot and consequently improved products and greater harvester operator safety.

Keywords: chain shot, safety, testing, timber harvesters

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6584 Admission Control Policy for Remanufacturing Activities with Quality Variation of Returns

Authors: Sajjad Farahani, Wilkistar Otieno, Xiaohang Yue

Abstract:

This paper develops a model for the optimal disposition decision for product returns in a remanufacturing system with limited recoverable inventory capacity. In this model, a constant demand is satisfied by remanufacturing returned products which are up to the minimum required quality grade. The quality grade of returned products is uncertain and remanufacturing cost increases as the quality level decreases, and remanufacturer wishes to determine which returned product to accept to be remanufactured for reselling, and any unaccepted returns may be salvaged at a value that increases with their quality level. Accepted returns can be stocked for remanufacturing upon demand requests, but incur a holding cost. A Markov decision problem is formulated in order to evaluate various performance measures for this system and obtain the optimal remanufacturing policy. A detailed numerical study reveals that our approach to the disposition problem outperforms the current industrial practice ignoring quality grade of returned products. In addition, we identify conditions under which this improvement is the highest.

Keywords: green supply chain management, matrix geometric method, production recovery, reverse supply chains

Procedia PDF Downloads 303
6583 Mobile Application for Construction Sites Management

Authors: A. Khelifi, M. Al Kaabi, B. Al Rawashdeh

Abstract:

The infrastructure is one of the most important pillars of the UAE, where it spends millions of dollars for investments in the construction sectors. The research done by Kuwait Finance House (KFH) Research showed clearly that the UAE investments in the construction sectors have exceeded 30 billion dollars in 2013. There are many construction companies in the UAE and each one of them is taking the responsibilities to build different infrastructures. The large scale construction projects consist of multi human activities which can affect the efficiency and productivity of the running projects. The Construction Administration System is developed to increase the efficiency and productivity at the construction sites. It runs on two platforms: web server and mobile phone and supports two main users: mobile user and institution employee. With Construction Administration Mobile Application the user can manage and control several projects, create several reports and send these reports in Portable Document Format (PDF) formats through emails, view the physical location of each project, capturing and save photos. An institution employee can use the system to view all existing workers and projects, send emails and view the progress of each project.

Keywords: construction sites, management, mobile application, Portable Document Format (PDF)

Procedia PDF Downloads 368
6582 The Role of Supply Chain Agility in Improving Manufacturing Resilience

Authors: Maryam Ziaee

Abstract:

This research proposes a new approach and provides an opportunity for manufacturing companies to produce large amounts of products that meet their prospective customers’ tastes, needs, and expectations and simultaneously enable manufacturers to increase their profit. Mass customization is the production of products or services to meet each individual customer’s desires to the greatest possible extent in high quantities and at reasonable prices. This process takes place at different levels such as the customization of goods’ design, assembly, sale, and delivery status, and classifies in several categories. The main focus of this study is on one class of mass customization, called optional customization, in which companies try to provide their customers with as many options as possible to customize their products. These options could range from the design phase to the manufacturing phase, or even methods of delivery. Mass customization values customers’ tastes, but it is only one side of clients’ satisfaction; on the other side is companies’ fast responsiveness delivery. It brings the concept of agility, which is the ability of a company to respond rapidly to changes in volatile markets in terms of volume and variety. Indeed, mass customization is not effectively feasible without integrating the concept of agility. To gain the customers’ satisfaction, the companies need to be quick in responding to their customers’ demands, thus highlighting the significance of agility. This research offers a different method that successfully integrates mass customization and fast production in manufacturing industries. This research is built upon the hypothesis that the success key to being agile in mass customization is to forecast demand, cooperate with suppliers, and control inventory. Therefore, the significance of the supply chain (SC) is more pertinent when it comes to this stage. Since SC behavior is dynamic and its behavior changes constantly, companies have to apply one of the predicting techniques to identify the changes associated with SC behavior to be able to respond properly to any unwelcome events. System dynamics utilized in this research is a simulation approach to provide a mathematical model among different variables to understand, control, and forecast SC behavior. The final stage is delayed differentiation, the production strategy considered in this research. In this approach, the main platform of products is produced and stocked and when the company receives an order from a customer, a specific customized feature is assigned to this platform and the customized products will be created. The main research question is to what extent applying system dynamics for the prediction of SC behavior improves the agility of mass customization. This research is built upon a qualitative approach to bring about richer, deeper, and more revealing results. The data is collected through interviews and is analyzed through NVivo software. This proposed model offers numerous benefits such as reduction in the number of product inventories and their storage costs, improvement in the resilience of companies’ responses to their clients’ needs and tastes, the increase of profits, and the optimization of productivity with the minimum level of lost sales.

Keywords: agility, manufacturing, resilience, supply chain

Procedia PDF Downloads 81