Search results for: construction recovery

Authors: Inas Kamel, Noor Z. Habib

Abstract:

Utilizing construction and demolition wastes in hotmix asphalt (HMA) pavement construction can reduce the adverse environmental effect of its inadequate disposal and reduce the pressure of extracting and processing mineral aggregates (MA). This study aims to examine the viability of replacing MA by recycled construction and demolition waste aggregates (RCDWA) in the wearing course of asphaltic concrete (AC) pavements without compromising its loadbearing capacity. The Marshall Method was used to evaluate the performance of AC wearing course specimens by replacing MA by 10%, 20% and 30% RCDWA. Grade 60/70 bitumen was used in the range 3.0-5.5%, with 05% increments, to generate the optimum bitumen content (OBC). From the volumetric analysis and test property curves, the mixture containing 20% RCDWA was chosen as the preferred mix at 5.1% OBC. It possessed a 10% increase in Marshall Stability compared to the reference specimen, containing 100% MA, and a 6% increase in Marshall flow.

Keywords: aggregate, asphaltic concrete, Marshall method, optimum bitumen content, recycled construction and demolition waste

Procedia PDF Downloads 120

Authors: Sukruthai Sapniwat, Falan Srisuriyachai

Abstract:

Polymer Flooding is one of the most well-known methods in Enhanced Oil Recovery (EOR) technology which can be implemented after either primary or secondary recovery, resulting in favorable conditions for the displacement mechanism in order to lower the residual oil in the reservoir. Polymer substances can lower the mobility ratio of the whole process by increasing the viscosity of injected water. Therefore, polymer flooding can increase volumetric sweep efficiency, which leads to a better recovery factor. Moreover, polymer adsorption onto rock surface can help decrease reservoir permeability contrast with high heterogeneity. Due to the reduction of the absolute permeability, effective permeability to water, representing flow ability of the injected fluid, is also reduced. Once polymer is adsorbed onto rock surface, polymer molecule can be desorbed when different fluids are injected. This study is performed to evaluate the effects of the adsorption and desorption process of polymer solutions to yield benefits on the oil recovery mechanism. A reservoir model is constructed by reservoir simulation program called STAR® commercialized by the Computer Modeling Group (CMG). Various polymer concentrations, starting times of polymer flooding process and polymer injection rates were evaluated with selected values of polymer desorption degrees including 0, 25, 50, 75 and 100%. The higher the value, the more adsorbed polymer molecules to return back to flowing fluid. According to the results, polymer desorption lowers polymer consumption, especially at low concentrations. Furthermore, starting time of polymer flooding and injection rate affect the oil production. The results show that waterflooding followed by earlier polymer flooding can increase the oil recovery factor while the higher injection rate also enhances the recovery. Polymer concentration is related to polymer consumption due to the two main benefits of polymer flooding control described above. Therefore, polymer slug size should be optimized based on polymer concentration. Polymer desorption causes polymer re-employment that is previously adsorbed onto rock surface, resulting in an increase of sweep efficiency in the further period of polymer flooding process. Even though waterflooding supports polymer injectivity, water cut at the producer can prematurely terminate the oil production. The injection rate decreases polymer adsorption due to decreased retention time of polymer flooding process.

Keywords: enhanced oil recovery technology, polymer adsorption and desorption, polymer flooding, reservoir simulation

Procedia PDF Downloads 292

Authors: Anurag Bhambhani, Jan Peter Van Der Hoek, Zoran Kapelan

Abstract:

The food system depends on the availability of Phosphorus (P) and Nitrogen (N). Growing population, depleting Phosphorus reserves and energy-intensive industrial nitrogen fixation are threats to their future availability. Recovering P and N from domestic sewage water offers a solution. Recovered P and N can be applied to agricultural land, replacing virgin P and N. Thus, recovery from sewage water offers a solution befitting a circular economy. To ensure minimum waste and maximum resource efficiency a circularity assessment method is crucial to optimize nutrient flows and minimize losses. Material Circularity Indicator (MCI) is a useful method to quantify the circularity of materials. It was developed for materials that remain within the market and recently extended to include biotic materials that may be composted or used for energy recovery after end-of-use. However, MCI has not been used in the context of nutrient recovery. Besides, MCI is time-static, i.e., it cannot account for dynamic systems such as the terrestrial nutrient cycles. Nutrient application to agricultural land is a highly dynamic process wherein flows and stocks change with time. The rate of recycling of nutrients in nature can depend on numerous factors such as prevailing soil conditions, local hydrology, the presence of animals, etc. Therefore, a dynamic model of nutrient flows with indicators is needed for the circularity assessment. A simple substance flow model of P and N will be developed with the help of flow equations and transfer coefficients that incorporate the nutrient recovery step along with the agricultural application, the volatilization and leaching processes, plant uptake and subsequent animal and human uptake. The model is then used for calculating the proportions of linear and restorative flows (coming from reused/recycled sources). The model will simulate the adsorption process based on the quantity of adsorbent and nutrient concentration in the water. Thereafter, the application of the adsorbed nutrients to agricultural land will be simulated based on adsorbate release kinetics, local soil conditions, hydrology, vegetation, etc. Based on the model, the restorative nutrient flow (returning to the sewage plant following human consumption) will be calculated. The developed methodology will be applied to a case study of resource recovery from wastewater. In the aforementioned case study located in Italy, biochar or zeolite is to be used for recovery of P and N from domestic sewage through adsorption and thereafter, used as a slow-release fertilizer in agriculture. Using this model, information regarding the efficiency of nutrient recovery and application can be generated. This can help to optimize the recovery process and application of the nutrients. Consequently, this will help to optimize nutrient recovery and application and reduce the dependence of the food system on the virgin extraction of P and N.

Keywords: circular economy, dynamic substance flow, nutrient cycles, resource recovery from water

Procedia PDF Downloads 175

Authors: M. Yakubu, M. B. Isah, S. Bako

Abstract:

This paper presents the findings of a research which sought to investigate the readiness to integrate sustainable construction principles into curriculum design for built environment professional programs in the Nigerian Universities. Developing the knowledge and understanding that construction professionals acquire of sustainable construction practice leads to considerable improvement in the environmental performance of the construction sector. Integrating sustainable environmental issues within the built environment education curricula provide the basis of this research. An integration of sustainable development principles into the universities built environment professional programmes are carried out with a view of finding solutions to the key issues identified. The perspectives of academia have been assessed and findings tested for validity through the analysis of primary quantitative data that has been collected. The secondary data generated has shown that there are significant differences in the approach to curriculum design within the built environment professional programmes, and this reveals that there is no ‘best practice’ that is clearly identifiable. Sequel to the above, this research reveals that engaging all stakeholders would be a useful component of built environment curriculum development, and that the curriculum be negotiated with interested parties. These parties have been identified as academia, government, construction industry and built environment professionals.

Keywords: built environment, curriculum development, sustainable construction, sustainable development

Procedia PDF Downloads 394

Authors: Zarabizan Zakaria, Hayati Zainal

Abstract:

The construction industry is one of the most important sectors that contribute to the nation’s economy and catalyze towards the growth of other industries. However, some construction projects have not been completed on its stipulated time and duration, scope and budget due to several factors. This problem arises due to the weaknesses of human factors, especially from ineffective leadership quality practiced by project managers and contractors in managing project teams. Therefore, a construction project should impose the element of Project Team. The project team is formed in the implementation of the project which includes the project brief, project scope, customer requirements and provided designs. Many organizations in the construction sector use teams to meet today's global competition and customer expectations, however, team effectiveness evaluation is required. In insuring the construction team is successful and effectiveness, the construction department must encourage, measure, set up, and evaluate or review the effectiveness of project team that was formed. In order to produce a better outcome for a high-end project, an effective and efficient project team is required which also help in increasing overall productivity. The purpose of this study is to determine the role of team effectiveness in the construction project team based on the overall construction project performance. It examines several different factors which related to team effectiveness. It also examines the relationship between team effectiveness factor and project performance aspect. Team Effect Review and Project Performance Review are developed to be used for data collection. Data collected were analyzed using several statistical tests. Results obtained from data analysis are validated using semi-structured interviews. Besides that, a comprehensive survey were developed to assess the way construction project teams in order to maintain its effectiveness throughout the project phase. In order to determine a project successful it has been found that Project Team Leadership is the most important factor. In addition, the definition of team effectiveness in the construction project team is developed based on the perspective of project clients and project team members. The results of this study are expected to provide an idea on the factors that are needed to be focused on improving the team's effectiveness towards project performance aspects. At the same time, the definition of team effectiveness from team members and owner views has been developed in order to provide a better understanding of the word team's effectiveness in construction projects.

Keywords: project team, leadership, construction project, project successful

Procedia PDF Downloads 149

Authors: Dong-Ho Kim, Su-Sang Lim, Sang-Won Han, Chang-Taek Hyun

Abstract:

In the construction site, the cost and schedules are the most important management elements. Despite efforts to integrated management the cost and schedule, WBS classification is struggling to differ from each other. The cost and schedule can be integrated and can be managed due to the characteristic of the detail system in the case of Korea around the axis of pressure and official fixture system. In this research, the Work Breakdown Structure (WBS) integrating the cost and schedules around in government office construction, WBS which can be used in common was presented in order to analyze the detail system of the public institution construction and improve. As to this method, the efficient administration of not only the link application of the cost and schedule but also construction project is expected.

Keywords: WBS, EVMS, integrated cost and schedule, Korea case

Procedia PDF Downloads 345

Authors: Tadewos Awugchew Wudineh

Abstract:

Health and safety issues have always been a major problem and concern in the building construction industry. The health and safety regulations are stated to eliminate the potential hazards and to reduce the consequential risks. However, the importance of the regulations seems to be overlooked in building construction sites of Hawassa City. Accordingly, many companies don’t follow the regulations as construction workers are more likely to be injured and killed by construction accident than any other type of employment. This paper aimed to identify factors that affect the implementation of construction health and safety regulations, their effects and mitigation measures in building construction project sites of Hawassa City. To reach this objective, a review of literature as well as the Ethiopian construction health and safety regulations have been undertaken. Mainly a five-point Likert scale questionnaire was distributed, and statistical analysis was used to summarize, interpret the data, and to find the significances of the responses. In addition, interviews were carried out. Accordingly, the findings indicate that the top factors which affect the implementation of CHS regulations are, availability and development of a clear health and safety policy, health and safety inspections by top management, conducting health and safety training and orientation, provision of healthy and safe working environment and employment of trained safety officers. The study revealed that implementation or non-implementation of CHS regulations have effects on the worker’s productivity, job satisfaction, rate of accidents, and cost greatly. Thus, the suggestion to minimize the impact on worker’s job performance are, developing of a clear health and safety policy, management commitment towards implementation of health and safety regulations, health and safety education and training and conducting regular health and safety inspections. It was concluded from the study that good implementation of health and safety regulations are the results from administrative and management commitment which calls for more attention to be paid to improve the implementation of CHS regulations in building construction sites of Hawassa City.

Keywords: construction health and safety regulations, effects, factors, mitigation

Procedia PDF Downloads 215

Authors: Zhiyuan Jia, Xiuxiu Sun, Yong Chen, Liu Hai, Shuangqing Li

Abstract:

The engine cooling water and exhaust gas contain a large amount of available energy. In order to improve energy efficiency, a steam injection technology based on waste heat recovery is proposed. The models of cooling water waste heat utilization, exhaust gas waste heat utilization, and exhaust gas-cooling water waste heat utilization were constructed, and the effects of the three modes on the performance of steam injection were analyzed, and then the feasibility of in-cylinder water injection steam technology based on waste heat recovery was verified. The research results show that when the injection water flow rate is 0.10 kg/s and the temperature is 298 K, at a cooling water temperature of 363 K, the maximum temperature of the injection water heated by the cooling water can reach 314.5 K; at an exhaust gas temperature of 973 K and an exhaust gas flow rate of 0.12 kg/s, the maximum temperature of the injection water heated by the exhaust gas can reach 430 K; Under the condition of cooling water temperature of 363 K, exhaust gas temperature of 973 K and exhaust gas flow rate of 0.12 kg/s, after cooling water and exhaust gas heating, the maximum temperature of the injection water can reach 463 K. When the engine is 1200 rpm, the water injection volume is 30 mg, and the water injection time is 36°CA, the engine power increases by 2% and the fuel consumption is reduced by 2.6%.

Keywords: cooling water, exhaust gas, extended range engine, steam injection, waste heat recovery

Procedia PDF Downloads 162

Authors: Salam Kodsi

Abstract:

In this research, we sought to focus on constructive play and examine its components in the context of two different educational approaches: Waldorf and normative schools. When they are free to choose, construction is one of the forms of play most favored by children. Its short-term and long-term cognitive contributions are apparent in various areas of development. The lack of empirical studies about play in Waldorf schools, which addresses the possibility of this incidental learning inspired the need to enrich the body of existing knowledge. 90 children (4-6 yrs.old) four preschools ( two normative, two Waldorf) participated in a small homogeneous city. Naturalistic observations documented the time frame, physical space, and construction materials related to the freeform building; processes of construction among focal representative children and its products. The study’s main finding with respect to the construction output points to a connection between educational approach and level of construction sophistication. Higher levels of sophistication were found at the Waldorf preschools than at the mainstream preschools. This finding emerged due to the differences in the level of sophistication among the older children in the two types of preschools, while practically no differences emerged among the younger children. Discussion of the research findings considered the differences between the play environments in terms of time, physical space, and construction materials. The construction processes were characterized according to the design model stages. The construction output was characterized according to the sophistication scale dimensions and the connections between approach, age and gender, and sophistication level.

Keywords: constructive play, preschool, design process model, complexity

Procedia PDF Downloads 90

Authors: Ndibarafinia Tobin

Abstract:

Building defect and failure are common phenomena in the Nigerian construction industry. The activities of the inexperienced labor force in the Nigerian construction industry have tarnished the image of practicing construction professionals in recent past. Defects and collapse can cause unnecessary expenditure, delays, loss of lives, property and left many people injured. They are also generating controversies among parties involved. Also, if this situation is left unanswered and untreated, it will lead to more serious problems in the future upcoming construction projects in Nigeria. Quite a number of factors are responsible for collapse of high-rise, reinforced concrete buildings in Nigeria. Government, professional bodies and stakeholders are asking countless questions as to who should be responsible and how solutions could be proffered. Therefore this study is aimed to identify the contributing factors to high-rise buildings defects and failures in Nigeria, which frequently occur in construction project in order to minimize time and cost and also the roles of professionals and other participants play in the industry in terms of the use of building materials, placement and curing of concrete, modification in the use of a building, collapse of building induced by fire and other causes. The data is collected from questionnaire from various players in construction industry in Nigeria. This study is succeeds in identifying the causes of building failure and also suggesting possible measures to be taken by government and other regulatory bodies in the building industry to avert this and also improve the effectiveness of managing appraisal process of failures and defects in the future.

Keywords: building defects, building failures, Nigerian construction industry, professionals

Procedia PDF Downloads 273

Authors: Rashid S. Mohammad, Shicheng Zhang, Sun Lu, Syed Jamal-Ud-Din, Xinzhe Zhao

Abstract:

A compositional reservoir simulation model (CMG-GEM) was used for cyclic CO₂ injection process in unconventional tight reservoir. Cyclic CO₂ injection is an enhanced oil recovery process consisting of injection, shut-in, and production. The study of cyclic CO₂ injection and hydrocarbon recovery in ultra-low permeability reservoirs is mainly a function of rock, fluid, and operational parameters. CMG-GEM was used to study several design parameters of cyclic CO₂ injection process to distinguish the parameters with maximum effect on the oil recovery and to comprehend the behavior of cyclic CO₂ injection in tight reservoir. On the other hand, permeability reduction induced by asphaltene precipitation is one of the major issues in the oil industry due to its plugging onto the porous media which reduces the oil productivity. In addition to asphaltene deposition, solubility of CO₂ in the aquifer is one of the safest and permanent trapping techniques when considering CO₂ storage mechanisms in geological formations. However, the effects of the above uncertain parameters on the process of CO₂ enhanced oil recovery have not been understood systematically. Hence, it is absolutely necessary to study the most significant parameters which dominate the process. The main objective of this study is to improve techniques for designing cyclic CO₂ injection process while considering the effects of asphaltene deposition and solubility of CO₂ in the brine in order to prevent asphaltene precipitation, minimize CO₂ emission, optimize cyclic CO₂ injection, and maximize oil production.

Keywords: tight reservoirs, cyclic O₂ injection, asphaltene, solubility, reservoir simulation

Procedia PDF Downloads 360

Authors: Chris Landorf, Stephen Ward

Abstract:

This paper addresses a virtual environment approach to work integrated learning for students in construction-related disciplines. The virtual approach provides a safe and pedagogically rigorous environment where students can apply theoretical knowledge in a simulated real-world context. The paper describes the development of a 4-dimensional digital construction environment and associated learning activities funded by the Australian Office for Learning and Teaching. The environment was trialled with over 1,300 students and evaluated through questionnaires, observational studies and coursework analysis. Results demonstrate a positive impact on students’ technical learning and collaboration skills, but there is need for further research in relation to critical thinking skills and work-readiness.

Keywords: architectural education, construction industry, digital learning environments, immersive learning

Procedia PDF Downloads 375

Authors: Mohamed T. El-Hawary, Carsten Koenke, Amr M. El-Nemr, Nagy F. Hanna

Abstract:

Sustainable construction materials using solid construction wastes are of great environmental and economic significance. Construction wastes, demolishing wastes, and wastes coming out from the preparation of traditional materials could be used in sustainable concrete manufacture, which is the main scope of this paper. Ceramics, clay bricks, marble, recycled concrete, and many other materials should be tested and validated for use in the manufacture of green concrete. Introducing waste materials in concrete helps in reducing the required landfills, leaving more space for land investments, and decrease the environmental impact of the concrete buildings industry in both stages -construction and demolition-. In this paper, marble aggregate is used as a replacement for the natural aggregate in sustainable green concrete production. The results showed that marble aggregates can be used as a full replacement for the natural aggregates in eco-friendly green concrete.

Keywords: coarse aggregate replacement, economical designs, green concrete, marble aggregates, sustainability, waste management

Procedia PDF Downloads 119

Authors: Kherbache Radhwane

Abstract:

We currently live in the world pressed by technological developments necessary for the construction, where the concept of sustainable development is truly rooted in recent years. Construction or demolitions of buildings necessarily generate environmental pollution, both inside and outside the site. Depending on the size and nature of work and the context surrounding these problems can be more or less important as is the case here in Algeria. They may affect the smooth running of the site. Moreover, there are regulations exist or are under development and should be taken into account by the various players in the act of building. This is, for example, the case of new obligations in terms of sorting and recycling of construction waste. Given this situation, it appears increasingly necessary to integrate the building sites in an effort to better respect the environment and its regulation. Several operations were performed according to this principle. The success of a project is that respects its environment through the involvement of each actor of the operation of the site with a low nuisance. As such, the client assisted by his driver and its operating contractor and the company plays a central role as an initiator of the process. It must ensure the establishment of appropriate means of organizational plans and contract.

Keywords: evolution, sustainable development, construction, demolition, building, nuisance, environmental, tailings, construction, regulations

Procedia PDF Downloads 241

Authors: Shu-Hui Jan, Hui-Ping Tserng, Shih-Ping Ho

Abstract:

Construction project control attempts to obtain real-time as-built schedule information and to eliminate project delays by effectively enhancing dynamic schedule control and management. Suitable platforms for enhancing an as-built schedule visually during the construction phase are necessary and important for general contractors. As the application of building information modeling (BIM) becomes more common, schedule management integrated with the BIM approach becomes essential to enhance visual construction management implementation for the general contractor during the construction phase. To enhance visualization of the updated as-built schedule for the general contractor, this study presents a novel system called the Construction BIM-assisted Schedule Management (ConBIM-SM) system for general contractors in Taiwan. The primary purpose of this study is to develop a web ConBIM-SM system for the general contractor to enhance visual as-built schedule information sharing and efficiency in tracking construction as-built schedule. Finally, the ConBIM-SM system is applied to a case study of a commerce building project in Taiwan to verify its efficacy and demonstrate its effectiveness during the construction phase. The advantages of the ConBIM-SM system lie in improved project control and management efficiency for general contractors, and in providing BIM-assisted as-built schedule tracking and management, to access the most current as-built schedule information through a web browser. The case study results show that the ConBIM-SM system is an effective visual as-built schedule management platform integrated with the BIM approach for general contractors in a construction project.

Keywords: building information modeling (BIM), construction schedule management, as-built schedule management, BIM schedule updating mechanism

Procedia PDF Downloads 344

Authors: Mehrab Gholami Zangalani, Siavash Rajabpour

Abstract:

In compliance with the Statistical Centre of Iran (SCI)’s results, construction and housing section in Iran is consuming 40% of energy, which is 5 times more than the world average consumption. By considering the climate in Iran, the solutions in terms of design, construction and exploitation of the buildings by utilizing the LEED rating system (LRS) is presented, regarding to the reasons for the high levels of energy consumption during construction and housing in Iran. As a solution, innovative Work Break Structure (WBS) in accordance with LRS and Iranian construction’s methods is unveiled in this research. Also, by amending laws pertaining to the construction in Iran, the huge amount of energy and cost can be saved. Furthermore, with a scale-up of these results to the scale of big cities such as Tehran (one of the largest metropolitan areas in the middle east) in which the license to build more than two hundred and fifty units each day is issued, the amount of energy and cost that can be saved is estimated.

Keywords: costs reduction, energy statistics, leed rating system (LRS), work brake structure (WBS)

Procedia PDF Downloads 501

Authors: Dhafer Alqahtani

Abstract:

Total quality management (TQM) has become a widely accepted approach in the modern industry over recent years. There is a general consensus that by adopting TQM, the overall effectiveness and performance of an industry can be improved. It is also proved that as long as TQM is adopted fully and practiced effectively in the industry, potential benefits of TQM will be delivered. But despite the benefits of TQM as articulated by many quality gurus and academicians, these benefits are not achieved in practice. Many service industries have found it difficult to implement TQM successfully. This paper, therefore, explores the barriers to TQM’s successful implementation in construction firms. The aim is to identify and rank the barriers to successful TQM implementation in order to make them know and get a better understanding by the managers and practitioners of the Construction Industries. The research methodology adopted in this study was an extensive literature review on barriers to TQM implementation followed by a survey of selected construction firms using the self-administered instrument. The results also showed that only lack of effective communication and lack of top management support were not significantly associated with the level of implementation of TQM.

Keywords: total quality management, construction firms, barriers, successful implementation

Procedia PDF Downloads 65

Authors: Evelyn Lami Ashelo Allu, Fidelis A. Emuze

Abstract:

This study aims to contribute to the pursuit of environmental sustainability through the built environment practices of design and construction. Activities within the built environment and particularly within the construction industry have a significant role in ensuring environmental sustainability. The adoption of Lean principles and approaches would ensure that project deliverables are sustainable. This is because the processes that integrate lean principles reduce waste, add value to productivity, ensures customer satisfaction and are mindful of future productivity. Additionally, the lean principles for development are sustainable in themselves and thus promotes environmental sustainability. The study encourages further research with other methodologies and recommends the development of monitoring and evaluation mechanisms in order to promote the global concern for environmental sustainability.

Keywords: built environment, construction, design, lean, sustainability

Procedia PDF Downloads 235

Authors: Aynur Kazaz, Yusif Inusah

Abstract:

In the bid to improve transparency and efficiency as well as to reduce the cost of the public procurement process, Ghana started implementing an electronic Government Procurement System, known as the Ghana Electronic Procurement System (GHANEPS) in November 2019. The implementation of e-tendering technology is new to the stakeholders. Therefore, this research is aimed to identify the critical barriers to e-tendering implementation in the Ghanaian construction industry. Examples of barriers to e-tendering implementation were first identified through a literature review, and questionnaires and interview questions were prepared to gather the data. This study contributes to the in-depth understanding of global e-tendering barriers in the Ghanaian construction industry. The findings could help researchers, practitioners, and governments make strategic investment decisions and overcome e-tendering challenges.

Keywords: barriers, challenges, construction industry, e-procurement, e-tendering

Procedia PDF Downloads 90

Authors: Atousa Khodadadyan, Ali Rostami

Abstract:

The objective of off-site construction manufacturing is to utilise the workforce and machinery in a controlled environment without external interference for higher productivity and quality. The usage of prefabricated components can save up to 14% of the total energy consumption in comparison with the equivalent number of cast-in-place ones. Despite the benefits of prefabrication construction, its current project practices encompass technical and managerial issues. Building design, precast components’ production, logistics, and prefabrication installation processes are still mostly discontinued and fragmented. Furthermore, collaboration among prefabrication manufacturers, transportation parties, and on-site assemblers rely on real-time information such as the status of precast components, delivery progress, and the location of components. From the technical point of view, in this industry, geometric variability is still prevalent, which can be caused during the transportation or production of components. These issues indicate that there are still many aspects of prefabricated construction that can be developed using disruptive technologies. Practical real-time risk analysis can be used to address these issues as well as the management of safety, quality, and construction environment issues. On the other hand, the lack of research about risk assessment and the absence of standards and tools hinder risk management modeling in prefabricated construction. It is essential to note that no risk management standard has been established explicitly for prefabricated construction projects, and most software packages do not provide tailor-made functions for this type of projects.

Keywords: project risk management, risk analysis, risk modelling, prefabricated construction projects

Procedia PDF Downloads 150

Authors: Eugueni Romantchik, Gilbero Lopez, Diego Terrazas

Abstract:

The residual wind energy recovery from axial air extractors in greenhouses represents a constant source of clean energy production, which reduces production costs by reducing energy consumption costs. The objective of this work is to design, build and evaluate a residual wind energy recovery system. This system consists of a wind turbine placed at an optimal distance, a cone in the air discharge and a mechanism to vary the blades angle of the wind turbine. The system energy balance was analyzed, measuring the main energy parameters such as voltage, amperage, air velocities and angular speeds of the rotors. Tests were carried in a greenhouse with extractor Multifan 130 (1.2 kW, 550 rpm and 1.3 m of diameter) without cone and with cone, with the wind turbine (3 blades with 1.2 m in diameter). The implementation of the system allowed recovering up to 55% of the motor's energy. With the cone installed, the electric energy recovered was increased by 10%. Experimentally, it was shown that changing in 3 degrees the original angle of the wind turbine blades, the angular velocity increases 17.7%.

Keywords: air energy, exhaust fan, greenhouse, wind turbine

Procedia PDF Downloads 139

Authors: M. Shahzad Kamal, Abdullah S. Sultan, Usamah A. Al-Mubaiyedh, Ibnelwaleed A. Hussein

Abstract:

Oil recovery from reservoirs using conventional oil recovery techniques like water flooding is less than 20%. Enhanced oil recovery (EOR) techniques are applied to recover additional oil. Surfactant-polymer flooding is a promising EOR technique used to recover residual oil from reservoirs. Water soluble polymers are used to increase the viscosity of displacing fluids. Surfactants increase the capillary number by reducing the interfacial tension between oil and displacing fluid. Hydrolyzed polyacrylamide (HPAM) is widely used in polymer flooding applications due to its low cost and other desirable properties. HPAM works well in low-temperature and low salinity-environment. In the presence of salts HPAM viscosity decrease due to charge screening effect and it can precipitate at high temperatures in the presence of salts. Various strategies have been adopted to extend the application of water soluble polymers to high-temperature high-salinity (HTHS) reservoir. These include addition of monomers to acrylamide chain that can protect it against thermal hydrolysis. In this work, rheological properties of various water soluble polymers were investigated to find out suitable polymer and surfactant-polymer systems for HTHS reservoirs. Polymer concentration ranged from 0.1 to 1 % (w/v). Effect of temperature, salinity and polymer concentration was investigated using both steady shear and dynamic measurements. Acrylamido tertiary butyl sulfonate based copolymer showed better performance under HTHS conditions compared to HPAM. Moreover, thermoviscosifying polymer showed excellent rheological properties and increase in the viscosity was observed with increase temperature. This property is highly desirable for EOR application.

Keywords: rheology, polyacrylamide, salinity, enhanced oil recovery, polymer flooding

Procedia PDF Downloads 381

Authors: Lars Laußat, Manfred Helmus, Kamil Szczesny, Markus König

Abstract:

As one result of the project “Reactive Construction Project Scheduling using Real Time Construction Logistic Data and Simulation”, a procedure for using data about uncertain resource availability assumptions in reactive scheduling processes has been developed. Prediction data about resource availability is generated in a formalized way using real-time monitoring data e.g. from auto-ID systems on the construction site and in the supply chains. The paper focuses on the formalization of the procedure for monitoring construction logistic processes, for the detection of disturbance and for generating of new and uncertain scheduling assumptions for the reactive resource constrained simulation procedure that is and will be further described in other papers.

Keywords: auto-ID, construction logistic, fuzzy, monitoring, RFID, scheduling

Procedia PDF Downloads 487

Authors: Kenneth O. Otasowie, Matthew Ikuabe, Clinton Aigbavboa, Ayodeji Oke

Abstract:

Subcontracting has become a fundamental feature in the construction industry, particularly as most projects in South Africa (SA) are executed by subcontractors. However, the sector in SA contributes to the high level of occupational hazards and injuries recorded, despite Health and Safety (H&S) regulations being enforced in the industry. Hence, this study aims to evaluate the barriers to health and safety practices by subcontractors in SA Construction Industry. A survey design was adopted. A total number of one hundred and forty-four (144) questionnaires were administered to quantity surveyors, construction managers, construction project managers, project managers, architects, and civil and structural engineers, who are owners or work in small and medium enterprises in Guateng Province, SA and eighty-three (83) were returned and found suitable for analysis. Collected data were analysed using percentage, mean item score, standard deviation, and one-sample t-test. The findings show that lack of skilled workers, lack of safety training, and insufficient safety awareness are the most significant barriers to health and safety practices in SA Construction Industry. Therefore, the study recommends the improvement in skills of staff and adequate training for the safe execution of work be provided to all employees and supervisors in these subcontracting firms. These will mitigate the rate of accident occurrence on construction sites.

Keywords: barriers, health and safety, subcontractors, South Africa

Procedia PDF Downloads 78

Authors: Young Min Kim, Dong Gil Shin, Assmelash Assefa Negash

Abstract:

This study describes the application of a single loop organic Rankine cycle (ORC) for recovering waste heat from an excavator. In the case of waste heat recovery of the excavator, the heat of hydraulic oil can be used in the ORC system together with the other waste heat sources including the exhaust gas and engine coolant. The performances of four different cases of single loop ORC systems were studied at the main operating condition, and critical design factors are studied to get the maximum power output from the given waste heat sources. The energy and exergy analysis of the cycles are performed concerning the available heat source to determine the best fluid and system configuration. The analysis demonstrates that the ORC in the excavator increases 14% of the net power output at the main operating condition with a simpler system configuration at a lower expander inlet temperature than in a conventional vehicle engine without the heat of the hydraulic oil.

Keywords: engine, excavator, hydraulic oil, organic Rankine cycle (ORC), waste heat recovery

Procedia PDF Downloads 278

Authors: Kimberly Joyce A. Roguis, Mica Lorraine L. Fernando, Alan Vito B. Macadangdang, Jennina Mari C. Mijares, Maria Carinnes A. Gonzalez

Abstract:

The paper showcases the vulnerability of the tourism industry especially the inevitable occurrence of natural disasters, implicating the necessity for post-disaster analysis on tourist attractions. This study discusses the aftermath of the super typhoon ‘Yolanda’ incident in the locality of Coron Island, Palawan, assessing its general effect on the community and its tourism livelihood through the analysis of responses from key role-players in the tourism industry of the area gathered through semi-structured interviews and direct observation. The local government’s instigation of recovery programs to their locality has been a pivotal factor in reviving the vitality of their tourism industry and the involvement of the community has been the determining condition that shifted the industry towards revival a year after the incidence. The study illuminates the disaster mitigation processes in the local tourism livelihood perspective, predominantly the diving industry. It did not suffer physical damage to a great extent but was affected because of the public imagery the disaster brought upon. Collaboration between the local government and the community is the highlight of the research for they maneuvered recovery revealing that cooperation between these two parties bridged the correlation of recovery to tourism development. The disaster paved way to a stance towards promoting progressive tourism outlooks, raising awareness among the public and private sectors and re-assessment of the tourism vitality in their locality. The mayhem and destruction proved to be a liberating creative process to give way to progression and was deemed to be of high significance in the over-all tourism system process despite its impediments in the case of the tourism industry in Coron, Palawan.

Keywords: disaster recovery, tourism development, diving, Palawan

Procedia PDF Downloads 353

Authors: Khorief Ouissem, Sassi Boudmagh Souad, Mahimoud Aissa

Abstract:

The health and safety problem in the construction companies has been a major subject of research in Algeria for many years. The latest statistics of the Algerian National Social Security Fund (CNAS) shows that a third of accidents recorded at the national level are originated from construction activities. It is becoming increasingly essential and urgent to investigate and address its causes in order to find measures to overcome the deficiencies in this area. Thus, this paper takes in investigating this problem through a study conducted in the city of Skikda, Algeria. The study was carried out through questionnaire where twenty construction companies were taking into consideration. First, the study identifies the regulations and the laws related to the health and safety in the construction sector in Algeria. Then it goes on to assess and evaluate the implementation of the identified regulations in the companies selected. The result of the assessment indicates that the majority of the construction companies considered do not meet the health and safety standards and regulations. To extract the main causes of the failure of the system to control this industry, the observations and the evaluation were analyzed using the 5M or Ichikawa diagram method. This method is based on identifying the causes of the problem in terms of purpose, the list of potential causes for families. These families often correspond to 5M (Labor, Material, Methods, Middle, and Management). Finally, having identified the primary motives, the present authors propose a list of actions to move towards a more controlled and effective health and safety system for the construction industry.

Keywords: health and safety, construction industry, performance measurement, Algeria

Procedia PDF Downloads 305

Authors: David Nantes, George Gilbert

Abstract:

There are a lot of risks that might crop up as a tunneling project develops, and it's crucial to be aware of them. Due to the unexpected nature of tunneling projects and the interconnectedness of risk occurrences, the risk assessment approach presents a significant challenge. The purpose of this study is to provide a hybrid FDEMATEL-ANP model to help prioritize risks during tunnel construction projects. The ambiguity in expert judgments and the relative severity of interdependencies across risk occurrences are both taken into consideration by this model, thanks to the Fuzzy Decision-Making Trial and Evaluation Laboratory (FDEMATEL). The Analytic Network Process (ANP) method is used to rank priorities and assess project risks. The authors provide a case study of a subway tunneling construction project to back up the validity of their methodology. The results showed that the proposed method successfully isolated key risk factors and elucidated their interplay in the case study. The proposed method has the potential to become a helpful resource for evaluating dangers associated with tunnel construction projects.

Keywords: risk, prioritization, FDEMATEL, ANP, tunneling construction projects

Procedia PDF Downloads 64

Authors: Tirtha Raj Dhakal, Brian Davidson, Bob Farquharson

Abstract:

Institutional design is an important aspect in efficient water resource management. In Nepal, the water supply in both farmers’- and agency-managed irrigation systems has become sub-standard because of the weak institutional framework. This study characterizes both forms of the schemes and links existing institution and governance of the schemes with its performance with reference to cost recovery, maintenance of the schemes and water distribution throughout the schemes. For this, two types of surveys were conducted. A management survey of ten farmers’-managed and five agency-managed schemes of Chitwan valley and its periphery was done. Also, a farm survey comprising 25 farmers from each of head, middle and tail regions of both schemes; Narayani Lift Irrigation Project (agency-managed) and Khageri Irrigation System (farmers’-managed) of Chitwan Valley as a case study was conducted. The results showed that cost recovery of agency-managed schemes in 2015 was less than two percent whereas service fee collection rate in farmers’-managed schemes was nearly 2/3rd that triggered poor maintenance of the schemes and unequal distribution of water throughout the schemes. Also, the institution on practice is unable to create any incentives for farmers for economical use of water as well as willingness to pay for its use. This, thus, compels the need of refined institutional framework which has been suggested in this paper aiming to improve the cost recovery and better water distribution throughout the irrigation schemes.

Keywords: cost recovery, governance, institution, schemes' performance

Procedia PDF Downloads 232

Authors: Mokhtar Nikgoo

Abstract:

Definition of bridge: A bridge is a structure that allows people to pass through the communication road with two points. There are many different types of bridges, each of which is designed to perform a specific function. This article introduces the concept, history, components, uses, types, construction methods, selected factors, damage factors and principles of bridge maintenance. A bridge is a structure to cross a passage such as a water, valley or road without blocking another path underneath. This structure makes it possible to pass obstacles that are difficult or impossible to pass. There are different designs for bridge construction, each of which is used for a particular function and condition. In the old definition, a bridge is an arch over a river, valley, or any type of passage that makes traffic possible. But today, in the topic of urban management, the bridge is considered as a structure to cross physical barriers, so that while using space (not just the surface of the earth), it can facilitate the passage and access to places. The useful life of bridges may be between 30 and 80 years depending on the location and the materials used. But with proper maintenance and improvement, their life may last for hundreds of years.

Keywords: bridge, road construction, surveying, transportation

Procedia PDF Downloads 484