scholarly journals IDENTIFIKASI FAKTOR PENGARUH DOMINAN KETERLAMBATAN PROYEK AKIBAT RANTAI PASOK PADA PENGADAAN PELAT BETON PRACETAK

2020 ◽  
Vol 3 (4) ◽  
pp. 1295
Author(s):  
Firena Bian Saputri ◽  
Basuki Anondho
Keyword(s):  
Supply Chain ◽  
Human Error ◽  
Concrete Slab ◽  
Precast Concrete ◽  
Influence Factors ◽  
Concrete Slabs ◽  
Literature Study ◽  
Factors Affecting ◽  
Project Duration ◽  
Speed Up

One way that can be done to speed up the duration of the project is to use precast concrete slabs. However, the use of precast concrete slab elements in the project can be ineffective if in the order stage, production stage, until the delivery stage of precast concrete elements to the project site is not managed properly, which can cause delays in project duration. Therefore, the use of precast concrete slabs is very dependent on the supply chain management. To anticipate this risk, it is necessary to identify what are the dominant factors in the supply chain that affect the procurement of precast concrete slabs which can cause delays in project duration. The initial influence factors were collected through a literature study and interviews with a number of practitioners, followed by a survey using a questionnaire to a number of project actors in projects using precast concrete slabs. The Likert scale 1-5 is used to measure the level of influence of a factor identified on project delays. By using factor analysis techniques, as many as three groups of dominant supply chain factors affecting the procurement of precast concrete slabs were found, namely special factors, technical factors, and human error factors.ABSTRAKSalah satu cara yang dapat dilakukan demi mempercepat durasi proyek adalah menggunakan pelat beton pracetak. Namun, penggunaan elemen pelat beton pracetak di proyek bisa tidak efektif apabila dalam tahap pemesanan, tahap produksi, hingga tahap pengiriman elemen beton pracetak ke lokasi proyek tidak dikelola dengan baik, sehingga dapat menyebabkan keterlambatan durasi proyek. Oleh sebab itu, penggunaan pelat beton pracetak sangat bergantung pada manajemen rantai pasokannya. Untuk mengantisipasi risiko tersebut, perlu adanya identifikasi mengenai faktor dominan apa saja pada rantai pasok yang mempengaruhi pengadaan pelat beton pracetak yang dapat menyebabkan keterlambatan durasi proyek. Faktor pengaruh awal dikumpulkan melalui studi literatur dan wawancara kepada sejumlah praktisi, dilanjutkan dengan survei menggunakan kuesioner kepada sejumlah pelaku proyek di proyek yang menggunakan pelat beton pracetak. Skala Likert 1-5 digunakan untuk mengukur tingkat pengaruh suatu faktor yang diidentifikasi terhadap keterlambatan proyek. Dengan menggunakan teknik analisis faktor, sebanyak tiga kelompok faktor dominan rantai pasok yang berpengaruh pada proses pengadaan pelat beton pracetak ditemukan, yaitu faktor khusus, faktor teknis, dan faktor human error.

scholarly journals Development of Narrow Loop Joint for Precast Concrete Slabs with Fiber-Reinforced Mortar: Experimental Investigation of Material Properties and Flexural Behavior of Joint

2021 ◽  
Vol 11 (17) ◽  
pp. 8235
Author(s):  
Shuichi Fujikura ◽  
Minh Hai Nguyen ◽  
Shotaro Baba ◽  
Hiromi Fujiwara ◽  
Hisao Tategami ◽  
...  
Keyword(s):  
Concrete Slab ◽  
Precast Concrete ◽  
Highway Bridges ◽  
Flexural Behavior ◽  
Concrete Slabs ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slab ◽  
Suitable Material ◽  
Girder Bridges ◽  
Steel Girder Bridges

In the replacement of the reinforced concrete slab in existing steel girder bridges, a loop joint is commonly used to join precast concrete slabs on site. However, a relatively wide joint is needed, and considerable time and effort are consumed to construct the joint due to the addition of transverse reinforcements to the joint on site. These disadvantages affect the progress of on-site construction and should be addressed, especially when this method is applied to highway bridges, where early traffic opening is necessary in many cases. This study proposes a narrow loop joint that has fiber-reinforced mortar without transverse reinforcements. Several material tests were conducted to determine a suitable material for the joint. A series of flexural loading tests of slabs was conducted to investigate the flexural behavior of the proposed loop joint with the selected material (polyvinyl alcohol (PVA) fibers). The results showed that the flexural capacity and deformation performance of the proposed joint with PVA fibers are equivalent to those of the conventional loop joint.

Data Base for Punching Shear Strength of Reinforced Concrete Slabs and Evaluation for CCES Equation

2011 ◽  
Vol 90-93 ◽  
pp. 933-939 ◽  
Author(s):  
Qiu Ning Yang ◽  
Ming Jie Mao ◽  
Sumio Hamada
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Reinforced Concrete Slab ◽  
Factors Affecting ◽  
Reinforced Concrete Slabs ◽  
Numerous Test ◽  
Rc Slabs

Several equations for punching shear strength of the reinforced concrete slab have been proposed in the world. These equations have their own factors affecting the strength. There are numerous test data for punching shear strength of RC slabs, which have been obtained by numerous researchers. A database with approximately 300 specimens has been structured through the present study. In the present study seven equations for punching shear strength are evaluated based on the database. CCES equation is also evaluated from the present database.

scholarly journals Structural Behavior of Steel-Concrete Composite Beam using Bolted Shear Connectors: A Review

2018 ◽  
Vol 203 ◽  
pp. 06010
Author(s):  
Nadiah Loqman ◽  
Nor Azizi Safiee ◽  
Nabilah Abu Bakar ◽  
Noor Azline Mohd Nasir
Keyword(s):  
Composite Beam ◽  
Concrete Slab ◽  
Precast Concrete ◽  
Composite Beams ◽  
Reinforced Concrete Beams ◽  
Structural Behavior ◽  
Concrete Slabs ◽  
Steel Beam ◽  
Shear Connectors ◽  
Beam System

Conventional steel-concrete composite beams have been recognized to exhibit stronger structural characteristics, in terms of strength and stiffness, when compared to pure steel or reinforced concrete beams. However, currently most steel beam is fully attached to the concrete slab; this means that the shear connectors are welded through the steel decking on to the steel beam and cast into concrete slab to fulfill the necessary shear connection. Recently, the deconstruction and reuse of the components almost impossible. In order to achieve a sustainable structural system, precast concrete slabs are attached to a steel beam using bolted shear connectors in prefabricated holes have been introduced as an alternative to the conventional connectors in steel – concrete composite beam system. This paper reviews the structural behavior of composite beam system such as the strength, stiffness, slip behavior, failure mode and sustainability obtained by experiment and numerical studies in order to address the applicability and efficiency of the composite beams having precast concrete slabs and bolted shear connectors.

scholarly journals THE FUTURE OF PASSENGER AIR TRANSPORT – VERY LARGE AIRCRAFT AND OUT KEY HUMAN FACTORS AFFECTING THE OPERATION AND SAFETY OF PASSENGER AIR TRANSPORT

2017 ◽  
Vol 12 ◽  
pp. 104
Author(s):  
Petra Skolilova
Keyword(s):  
Human Factors ◽  
Human Error ◽  
Operating Cost ◽  
Aircraft Design ◽  
Air Transport ◽  
Final Decision ◽  
Factors Affecting ◽  
Fuel Burn ◽  
The Future ◽  
The Impact

The article outlines some human factors affecting the operation and safety of passenger air transport given the massive increase in the use of the VLA. Decrease of the impact of the CO2 world emissions is one of the key goals for the new aircraft design. The main wave is going to reduce the burned fuel. Therefore, the eco-efficiency engines combined with reasonable economic operation of the aircraft are very important from an aviation perspective. The prediction for the year 2030 says that about 90% of people, which will use long-haul flights to fly between big cities. So, the A380 was designed exactly for this time period, with a focus on the right capacity, right operating cost and right fuel burn per seat. There is no aircraft today with better fuel burn combined with eco-efficiency per seat, than the A380. The very large aircrafts (VLAs) are the future of the commercial passenger aviation. Operating cost versus safety or CO2 emissions versus increasing automation inside the new generation aircraft. Almost 80% of the world aircraft accidents are caused by human error based on wrong action, reaction or final decision of pilots, the catastrophic failures of aircraft systems, or air traffic control errors are not so frequent. So, we are at the beginning of a new age in passenger aviation and the role of the human factor is more important than ever.

scholarly journals Effect of the Geometrical Constraints to the Wenner Four-Point Electrical Resistivity Test of Reinforced Concrete Slabs

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4622
Author(s):  
Kevin Paolo V. Robles ◽  
Jurng-Jae Yee ◽  
Seong-Hoon Kee
Keyword(s):  
Experimental Investigation ◽  
Electrical Resistivity ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Plain Concrete ◽  
Electrode Spacing ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
Spacing Ratio ◽  
Geometrical Constraints

The main objectives of this study are to evaluate the effect of geometrical constraints of plain concrete and reinforced concrete slabs on the Wenner four-point concrete electrical resistivity (ER) test through numerical and experimental investigation and to propose measurement recommendations for laboratory and field specimens. First, a series of numerical simulations was performed using a 3D finite element model to investigate the effects of geometrical constraints (the dimension of concrete slabs, the electrode spacing and configuration, and the distance of the electrode to the edges of concrete slabs) on ER measurements of concrete. Next, a reinforced concrete slab specimen (1500 mm (width) by 1500 mm (length) by 300 mm (thickness)) was used for experimental investigation and validation of the numerical simulation results. Based on the analytical and experimental results, it is concluded that measured ER values of regularly shaped concrete elements are strongly dependent on the distance-to-spacing ratio of ER probes (i.e., distance of the electrode in ER probes to the edges and/or the bottom of the concrete slabs normalized by the electrode spacing). For the plain concrete, it is inferred that the thickness of the concrete member should be at least three times the electrode spacing. In addition, the distance should be more than twice the electrode spacing to make the edge effect almost negligible. It is observed that the findings from the plain concrete are also valid for the reinforced concrete. However, for the reinforced concrete, the ER values are also affected by the presence of reinforcing steel and saturation of concrete, which could cause disruptions in ER measurements

scholarly journals Decisions and Coordination in E-Commerce Supply Chain under Logistics Outsourcing and Altruistic Preferences

Mathematics ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 253
Author(s):  
Yuyan Wang ◽  
Zhaoqing Yu ◽  
Liang Shen ◽  
Runjie Fan ◽  
Rongyun Tang
Keyword(s):  
Supply Chain ◽  
Supply Chains ◽  
Stackelberg Game ◽  
Consumer Preferences ◽  
Third Party ◽  
Altruistic Behavior ◽  
Fixed Cost ◽  
Equilibrium Solutions ◽  
Factors Affecting ◽  
Dual Channel

Considering the peculiarities of logistics in the electronic commerce (e-commerce) supply chain (ESC) and e-commerce platform’s altruistic preferences, a model including an e-commerce platform, third-party logistics service provider, and manufacturer is constructed. Based on this, three decision models are proposed and equilibrium solutions are obtained by the Stackelberg game. Then, an “altruistic preference joint fixed-cost” contract is proposed to maximize system efficiency. Finally, numerical analysis is used to validate the findings of the paper. The article not only analyzes and compares the optimal decisions under different ESC models, but also explores the intrinsic factors affecting the decisions. This paper finds that the conclusions of dual-channel supply chains or traditional supply chains do not necessarily apply to ESC, and that the effect of altruistic behavior under ESC is influenced by consumer preferences. Moreover, there is a multiparty win–win state for ESC, and this state can be achieved through the “altruistic preference joint fixed-cost” contract. Therefore, the findings of this paper contribute to the development of an e-commerce market and the cooperation of ESC members.

scholarly journals Survey on Public Psychological Intervention Demand and Influence Factors Analysis

2021 ◽  
Vol 18 (9) ◽  
pp. 4808
Author(s):  
Fang Su ◽  
Bingjie Fan ◽  
Nini Song ◽  
Xue Dong ◽  
Yanxia Wang ◽  
...  
Keyword(s):  
Risk Perception ◽  
Family Size ◽  
Psychological Intervention ◽  
Control Period ◽  
Influence Factors ◽  
Negative Influence ◽  
Internet Survey ◽  
Psychological Status ◽  
Factors Affecting ◽  
Epidemic Period

Major public health emergencies would have a negative influence on the psychology of the public, and an effective psychological intervention can help them to relieve some emotions, such as tension and panic. However, differences in individual environments affect people’s psychological intervention demands and intervention mode choices. Therefore, it is of great theoretical and practical value to analyze and identify the key factors affecting these demands and choices. Based on a nationwide sample of 24,188 respondents from the “Internet Survey of Residents’ Behavioral Changes and Psychological Conditions during the Epidemic,” the different characteristics of public psychological intervention demands and choices under different factors are explored in this paper. The results demonstrate that: (1) the psychological status of Chinese people was relatively stable during the epidemic period, and there were 1016 respondents who had subjective demands for a psychological intervention, (2) age, gender, occupation type, residence, family size, risk perception, psychological status, education level, and fixed expenditure all significantly affect public psychological intervention demands, and (3) risk perception, psychological status, age, gender, and family size will impact the choice of psychological intervention methods. The above results can provide a decision-making basis for the construction of a psychological intervention system in psychological crisis management during the post-epidemic prevention and control period, as well as reference and suggestions for handling psychological stress of similar sudden crisis events in the future.

scholarly journals Evaluation of Bleeding Resistance in Chip Seal and Asphalt Emulsion Residue Rheology

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 670
Author(s):  
Preeda Chaturabong
Keyword(s):  
Influence Factors ◽  
Application Rate ◽  
Test Methods ◽  
Test Results ◽  
Asphalt Emulsion ◽  
Aggregate Gradation ◽  
Factors Affecting ◽  
Promising Tool ◽  
Chip Seal ◽  
Asphalt Emulsions

Chip seal bleeding is influenced by many factors, including design inputs, material properties, and project-specific conditions. It reduces the surface texture of the pavement and thus compromises the safety of the traveling public. Even though factors that bring about premature bleeding are known, currently, no laboratory test methods for evaluating bleeding in chip seals have been specified. The objective of this paper is to present the results of an investigation of the influence factors of asphalt emulsion residue properties measured by the ASTM D7405 multiple stress creep and recovery (MSCR) test, as well as other factors related to chip seal bleeding resistance as measured by the modified loaded wheel test (MLWT). In this study, the MSCR test was used as a tool for evaluating the performance of asphalt emulsions because it has been identified as a potential test related to bleeding in the field. In addition, MLWT was selected as a tool for evaluating chip seal bleeding performance in the laboratory. The results of the MLWT showed that the emulsion application rate (EAR), aggregate gradation, and emulsion properties were significant factors affecting bleeding. The MSCR test was found to be a promising tool for the performance evaluation of asphalt emulsion residue, as the test was able to differentiate between emulsion chemistries and modifications in terms of sensitivity to both temperature and stress. In relation to chip seal bleeding resistance, only the creep compliance (Jnr) obtained from the MSCR test results was identified as a significant property affecting potential for bleeding.

Factors affecting RFId adoption in a vertical supply chain: the case of the silk industry in Italy

2012 ◽  
Vol 23 (4) ◽  
pp. 315-331 ◽  
Author(s):  
Cristina Quetti ◽  
Federico Pigni ◽  
Alessandro Clerici
Keyword(s):  
Supply Chain ◽  
Factors Affecting ◽  
Silk Industry
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