bluuebunny/crossref_metadata_2025 huggingface dataset:
Additive manufacturing of a stretch forming die using 3D printing technology
Authors: Grigoraș C , Chiriță B , Brabie G
Published: October 2019

3D printing is a maturing technology, that can be used from fast prototyping to industrial scale. A key aspect of 3D printing is the ability to control the material density, thus it’s hardness. This factor assures that 3D printing is not only economical competitive, but it also provides parts with improved mechanical properties. Furthermore, it is a good alternative for manufacturing stretch-forming dies. Implementing 3D printed dies offers an economical advantage, as cost for producing are a fraction of the cost of standard metal die, and the technology behind the process is simpler. Therefore, in this paper we have chosen to study stretch forming on a die that has components 3D printed from polylactic acid (PLA). The length and width of the punch is maintained constant while the radius varied from R180 ÷ R1080 [mm], with an increment of 180 [mm]. A total number of 6 punches were used in these experiments to stretch sheet metal stripes made of aluminium 2024-T0, a material specific for aircraft skin. In addition to the shape of the resulted part, in the present study other process parameters have been investigated (punch force, part radius and deviation from circularity).
Numerical simulation of friction stir welding of pure copper plates
Authors: Constantin M A , Niţu E L , Bădulescu C
Published: October 2019

Friction Stir Welding (FSW) is a joining process which is performed at low temperatures, lower than the melting temperature of the base material, thus it is considered a solid state welding process. This feature makes it suitable for copper welding, material whose thermal diffusivity is higher than that of most steel alloys. Large heat losses identified at copper welding by fusion welding processes are thus reduced using FSW process. Because of the shown efficiency and the innovative character of this process, many actions have been initiated in order to optimize it. The aim of this paper is to develop a three-dimensional coupled thermo-mechanical finite element (FE) model of FSW process for pure copper plates using the Coupled Eulerian-Lagrangian (CEL) formulation given in the FE code ABAQUS V6.13. The CEL formulation is one of the few formulations that are capable of handling with such large deformations. The developed numerical model was validated by comparing its results related to the temperatures calculated in the process time with those measured in performed experiments using the same process parameters. This model was capable of simulating the FSW of copper plates and of anticipating the temperature distribution and burrs formation in the weld bead.
Tensile properties of friction stir welding of three dissimilar aluminium alloys, AA7075, AA2024 and AA6061 versus process parameters
Authors: Grigore J C , Boșneag A , Badulescu C
Published: October 2019

Friction stir welding is a solid-state welding process with a lot of advantages comparing to the traditional arc welding. In the last years, this process was more and more used in industrial environment to joining by welding a large range of materials, similar and dissimilar. Applicability of this process was identified in automotive industry, aeronautics industry, aerospace industry, railway industry, metal working, research and development, electronic industry, machinery and equipment and others. The friction stir welding process is a simple, this are performed in three steps: a tool is rotated and plunge into the materials until the shoulder meets the surface of upper material, after that the tool keeps rotation, start translation movement and traversed along the direction of welding. At the end of welding seams, the tool has a vertically movement to get out of the plates. This paper presents an experimental study for the welding of three dissimilar aluminium alloys, with different mechanical and chemical properties and the results of it. These three materials are: AA7075, AA2024 and AA6061. The samples obtained with the friction stir welding were tested and analysed considering: process parameters and their influence on tensile properties
Porous coatings obtained on titanium after IMPULSE – PEO processes
Authors: Rokosz K , Hryniewicz T , Dudek Ł , Pietrzak K , Raaen S , Malorny W , Ciuperca R
Published: October 2019

The surface stereometry and chemical compositions of porous coatings obtained during Plasma Electrolytic Oxidation, PEO / (Micro Arc Oxidation, MAO) processes with use of impulse regime with different frequencies were the main goal of discussions presented in that paper. All the coatings were characterized by Scanning Electron Microscope (SEM), Energy-dispersive X-ray Spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS). It was found out that the frequencies of voltage signals used in PEO process as well as their duty ratios have a big influence on porosity, roughness and chemical composition of fabricated layers. In addition, it was noted that all the coatings’ compounds contained Ti4+ and Ca2+ or Mg2+ as well as PO4
3–, and/or HPO4
2–, and/or H2PO4
–, and/or P2O7
4–.
Stress/Strain analysis in the bogie in linear motion
Authors: Blanari I , Goanta V
Published: October 2019

The railway wheel, together with the axle, represents one of the very important parts that support the safe operation of railway vehicles. Wheels support the entire weight of cars. Therefore, the reliability is demanded in terms of accuracy. Accordingly, the most important and fundamental characteristic in designing wheels is strength. The investigation of dangerous area in bogie is one of important area of study in railway manufactured. This essential information is required in structural integrity, failure and fatigue calculation to determine lifetime for scheduling the maintenance and regrinding necessity. The aim of this work is to determine the stress/strain in a bogie to common working in operating conditions using the 3D finite element method (FEM). The FEM results carried out using 3D elements allows the stress/strain distribution with good accuracy. Knowing the maximum stress/strain value in a bogie, prevents an unsafe construction from the design stage, and consequently increases safety in rail traffic.
Design for manufacturing using TEBIS CAM software for milling processing
Authors: But A
Published: October 2019

Complex parts require specific processing. Computer aided manufacturing solutions make their mark and optimize the manufacturing process. Different CAM software’s have different philosophy with different capabilities. TEBIS CAM software brings more facilities and opportunities to manufacturing a complex part. In the paper was presented this capability on real part. It was made the comparison between two different milling strategies: one classical milling strategy-Contour parallel strategy, versus adaptive milling strategy. Was presented the way how was implement the TEBIS CAM software and the results of manufacturing. The time of manufacturing was significantly reduced with 43% using the adaptive milling strategy and the surface accuracy was improved.
Software instrument used as interface in the design of technical installations
Authors: Popa L , Popa V
Published: October 2019

Technical installations can account for up to half of the building costs and it is crucial to have detailed projects for the assembly and maintenance of these systems. This means that workflow can be improved more efficiently and faster. With the help of the installation engineer, the beneficiary can track and control the correct execution of the works. The installation engineer is the link between the beneficiary and the contractor or those who deliver the materials and equipment, people who generally follow works and additional sales. As regards the design of technical installations, the development of versatile low-response software interfaces becomes necessary and appropriate. The article is focused on the interface that has been developed as a software instrument to increase design process productivity and optimization of technical installations by reducing the required work time and the number of clicks made. Inside the application, the Revit design software was used and the number of clicks needed to access the element linking and node troubleshooting of the technical installations was reduced. Two new functionalities have been created within the software application: “connect and copy” and “connect and rotate”.
Design and analysis of side dump bucket for wheel loader using CAD/CAE/CAM technologies
Authors: Debeleac C
Published: October 2019

In this paper the author presents a wheel loader equipped with side dump bucket modelled with modern technologies used in mechanical engineering fields (SolidWorks, Femap and NX 11 manufacturing). The various behaviours that acting on the bucket during technological process were analysed with finite element method. The obtained results validate appropriate dimensioning of main elements of bucket ensemble in proposed constructive variant.
The generation of the worm and wheel gears in a CAD soft
Authors: Popa D , Popa C M
Published: October 2019

In this paper, we present the way to obtain in AutoCAD the solids that materialize the worm and wheel gears. The worm and wheel gears are practically used first of all due to their high transmission ratio. After the state of the art of the worm and wheel gears, we present the manufacturing possibilities of the wheels. Further on, one presents the way to obtain of the solids that materialize the cylindrical and globoid worms, using AutoLisp functions in AutoCAD. By Boolean operations, one extracts from the raw material that approximates the worm, the solid that materializes the tool. One thus generates cylindrical worms with 1, 2, and 3 starts and globoid worms with one start. The obtaining of the wheels is performed in a similar way, the tool being the already obtained worm.
Determining the state of stress in the narrow section of Arcan test specimens, by the FEM method
Authors: Danila N A , Blanari I , Barsanescu P D
Published: October 2019

Mohr-Coulomb failure criterion is used to establish the failure conditions under a compound state of stress. According to this criterion, materials failure is produced to a certain combination of normal and shear stresses. Arcan type tests are an easy way to study the specimens behavior in pure and mixed mode (tensile & shear) respectively. The fixture allows an ARCAN sample to be rotated at 15° increments from 0° to 90° to produce different amounts of mode-mixt during loading; with 0° being pure tension/compression loading to 90° being pure shear loading. The Arcan method, like the Iosipescu method, uses specimens with a predetermined breaking section. A condition for material testing is that the stress in the narrow section to be as uniform as possible. This depends on the shape and depth of the notch. Starting from apriori knowledge about Iosipescu specimen, the modelling will be carried in FEM software to optimize the shape of the specimen, in order to obtain more uniform stress in cross section, A FEM is performed for Iosipescu specimen, designed for pure shear, when it is mounted in Arcan device, so it is need to be studied for some complex states of stress. The studied material is aluminum alloy type 7075, used in aerospace industry. This analysis is necessary before the tests are carried out, in order to adopt an appropriate form of the specimens.
Structural health monitoring of critical zones of small wind turbine blades for domestic users
Authors: Savin A , Iftimie N , Nastac S M , Stanciu M D
Published: October 2019

The most important part of wind turbine is the blade that must be tested during fabrication and functioning when can be damaged by moisture absorption, fatigue, wind guests or lightning strikes. The fibers can also appear and develop under moderated loads or cracks and delaminating due to the low energy impacts etc. The aim of this paper is to identify the modal behavior of small wind turbine blade in terms of the signal convergence, modal evolutions and frequency spectra. There are numerous methods for monitoring and detecting structural damage of the wind blades, but in this study it was used the impact hammer method. The results emphasized the natural frequencies, the modal shape of structure and the signal coherence captured in different points.
The error assessment in case of using two models for the displacement of a linear spring
Authors: Ibanescu R , Ibanescu M
Published: October 2019

The displacement of the free end of a spring is not always an axial displacement. In some circumstances, the free end of the spring displaces along a circular trajectory, and the spring elongation is considered approximately equal to its axial displacement. Such an approximation is used for modelling the suspension of railway wagons. The present work purpose is to exactly determine the elastic force in case of spring free end circular displacement, in order to compute the error of considering this displacement equal to the spring axial displacement. Then, the real dynamic behavior of the model is compared with the approximate one, by numerical simulation.
Dynamics of employers’ costs for the implementation of the dual model in industrial sectors
Authors: Ogorodnikova E S , Kokovikhin A Yu , Creciun L G , Kochergina T V
Published: October 2019

The introduction of the dual model of education is one of the promising areas for providing personnel with the necessary qualifications of industrial production in Russia. In the framework of this study, the task was to determine the role of the employer in the process of organizing the dual model. The main research method is the analysis of the structure and cost dynamics of industrial enterprises aimed. The purpose of the article is to analyze the dynamics and cost structure of the implementation of the dual model on the example of the industrial sectors of the Sverdlovsk region.
Implementation of tool-technical base of agile manufacturing in Russian industry
Authors: Gromova E A
Published: October 2019

The Fourth Industrial Revolution led to a shift in the strategic orientation of industrial enterprises, which explains the generation of new production concepts. In modern realities, the scale of production has lost its relevance. Minimizing costs and the highest quality of products still play an important role, but such a guideline as speed has come to the fore. The main tool-technical base of agile manufacturing approach is considered in terms of changing of enterprises production systems. The aim of this paper is to prove in practice that the agile manufacturing is promising for Russian industry. The approbation of the concept of agile manufacturing in metallurgy was carried out. In 2017, PJSC Severstal launched a major innovation program aimed at ensuring business growth without a significant increase in production, and focusing on three key areas: innovative products, innovative processes, innovative business model. Summarizing, agile manufacturing approach is offered as effective for Russian industry development.
Ishikawa diagram applied to identify causes which determines bearings defects from car wheels
Authors: Luca L , Luca T O
Published: October 2019

The use of quality management tools plays a great role in improving the quality of products or services offered and helping to ensure the internal efficiency and effectiveness of the organization as well as improving customer satisfaction. Considering the advantages of using quality management tools, the author of this paper presents a study on the application of the Ishikawa diagram for the problem of bearing defects from car wheels. A list of potential causes that generated the studied problem was made. Brainstorming method has also been used in this regard. The identified causes have been classified into four main categories: Man (M), Manufacturing of bearings (M), Service - Bearing replacement (S), Exploitation of the car (E). It resulted a new model of the Ishikawa diagram, that has the formula 2M + S + E. The Ishikawa diagram determined and presented in this paper identifies the causes that generate a non-quality type problem. The diagram provides the advantage of a correct orientation to correct nonconformities, as well as the basis for further studies with other appropriate methods, solutions or measures to eliminate the causes. This case study presented in the paper may be the basis for other studies related to the proposed problem.
Reengineering of the design process: An industrial case
Authors: Boudouh T.
Published: October 2019

In this article, a Business Process Reengineering (BPR) approach is applied to the design process of electric motors. The objective is to improve the quality, reduce costs and duration of the design process by bringing radical change to the process allowing breakthrough improvements rather than obtained by continuous improvement. For this purpose, the Design Structure Matrix (DSM) is used to represent and analyse the design process. This method is particularly adapted to capture the repetitive aspect of design tasks. Indeed, iterations, an inherent feature of the design process, represent a key factor in the determination of the design process duration and cost. In this study, the number of iterative tasks is reduced by 50%. The implementation of the reorganized process needs an organisational change in the design office but the expected benefits are worth the effort.
CFD study of aerodynamic sensitivity to air deviation angle for a hatchback vehicle
Authors: Ilea L , Iozsa D , Stan C , Fratila G
Published: October 2019

Movement is the base of most nowadays activities. For this purpose, vehicles that have specific characteristics for various needs were developed. The current legislation enforces an aerodynamic homologation process to assess a vehicle’s CO2 footprint. This process has to be done in specific conditions, with airflow at 0 degree deviation. The increasing concerns toward pollution will soon lead to the introduction of new rules meant to closely simulate real life vehicle usage, like the RDE test. The current paper has the purpose to analyse, using the CFD method, the influence of the directionality of the airflow (i.e. front-at 0 degree deviation and at various deviation angles) on the aerodynamic performance of a vehicle. The paper studies the airflow behaviour of a hatchback body type vehicle for airflow direction angles between 0 and 20 degrees, through Cd parameter. The focus of the analysis was on air direction (± angles) and simulating time. Due to vehicle asymmetry, the results were different in case of positive and negative values of the airflow angle. The simulation time leads to slightly different Cd due to different averaging periods. Obtained results indicate the necessity of future investigations towards the optimisation of aerodynamic elements in crosswind conditions.
Strategic directions of transport and logistics to ensure the implementation of new industrialization processes
Authors: Ogorodnikova E S , Sidorenko A M , Semenet I I , Morkonosov A G
Published: October 2019

Ensuring the processes of industrialization of the modern economy requires the formation of an efficient transport and logistics infrastructure. The solution of this task is carried out using the tools of strategic management, in particular the formation of strategic goals. The article presents the strategic goals and the corresponding strategic measures in the field of ensuring the availability and quality of transport and logistics services in the field of freight traffic at the level of the needs of the development of the economy of the Sverdlovsk region
Dynamic analysis of a mechanism of an engine with variable compression ratio
Authors: Mănescu B , Stănescu N D
Published: October 2019

Increasing of the energetic performances of an engine and reducing the consumption of fuel, and emissions of carbon oxides may be obtained with the aid of a mechanism with variable compression ratio. In this paper, we perform a numerical study of one mechanism of this kind highlighting the variation of the mechanical parameters and the influence of the geometric dimensions on the compression ratio.
The reduction of the fuel consumption and of the pollution through the city public transport
Authors: Istrate M , Nicolae V , Vîlcan A
Published: October 2019

The public transportation represents the ideal solution that can be offered with the purpose of satisfying the mobility request through an urban area. A highly organized and efficient public transportation system which offers adequate movement possibilities, in a short time and through high safety and comfort conditions, forms the basis of an urban transportation system that improves the sustainable development of a urban area. Over this paperwork it is going to be estimated the optimization effects of the Pitesti urban transportation system, and even more, it is going to be established the „translation” way of the different improvements for the public transportation system as input data into the urban transport model. In this way it will be shown how the renewal of the vehicles and the modernization of the bus stations could get to the increasing of the urban transport share, thus succeeding the decrease of the own vehicles transport. As a consequence, through the private vehicles movements decrease it is get, in the end, a fuel consumption and gas emissions reduction, in the same time resulting a high traffic performance both for the public transportation and for the own private vehicle transportation
Considerations on longitudinal dynamics of passenger trains with blocked wheelsets during braking
Authors: Cruceanu C , Crăciun C
Published: October 2019

The aim of the study is to highlight the fact that, besides the other well-known aspects, wheelsets blocking during braking actions performed in poor wheel/rail adhesion conditions has important influence on the longitudinal dynamics of the train. The study is based on MATLAB numerical simulations, performed for passenger trains consisting of four vehicles. There were considered the possible operational situations specific in low adhesion condition braking, determined by the pitch effect, i.e. the possible blocking of one up to all wheelsets of the vehicle. The results presented in the paper cover two situations: train set composed of identical vehicles, considering only the braking forces and, respective, classical configuration train hauled by a locomotive with a larger weight compared to each coach, resistances being also taken into account in simulations in that case. The outcomes indicate important dynamic effects in the train body, highlighting the importance of using performant wheel slide protection devices, essential not only for traffic safety reasons, but also useful in terms of in-train level of forces. It is to mention that these results represent the initial step of a more comprehensive ongoing study.
Development of a thermal self-diagnostics system for a digital current and voltage instrument transformer
Authors: Parfenov G I , Gotovkina E E , Lebedev V D , Smirnov N N , Tyutikov V V
Published: October 2019

Ivanovo State Power Engineering University (ISPEU) staff have developed and put into operation innovative designs of digital current and voltage instrument transformers (DCVT) based on resistor dividers performing technical and commercial electric power accounting, and also participating in work of relay protection and automation systems. Thermal self-diagnostics systems working in real time for instrument transformers do not exist in electric power engineering, while thermal examination is often conducted according to maintenance schedules, which negatively impacts the reliability of electrical equipment functioning. Development and building of new systems of self diagnostics for instrument transformer thermal state, revealing temperatures at several points, including values for the most heated up part, in real time, is therefore a vital task, especially for controlling operation of “smart” grids. Based on the results of physical and mathematical simulation of the process of heat exchange between a transformer and its environment at different values of ambient temperature, insolation and grid voltage, methods have been developed to determine the impact of the above factors on the thermal mode of DCVT operation. Algorithm has also been developed for thermal self-diagnostics and thermal protection against overheating of instrument transformers. System of thermal self diagnostics has been developed for 6-220 kV.
Numerical investigation for high lifetime solar-powered airport signal unit development
Authors: Tarasenko A B , Fedotov A A
Published: October 2019

Autonomous solar-powered small light and signal units can help solve many navigation and transportation problems for sufficient solar energy potential regions. Even in case of centralized grid presence the additional consumers’ integration can be an issue due to construction works and power availability. Electrochemical accumulator is a traditional solution for such devices, but its application usually faces lifetime and stable operation at low temperatures problems. Electrochemical double-layer supercapacitor (EDLC) possess high cyclic resource and stable operation down to minus 40-45°C. Low specific energy capacity, high specific energy costs and high self-discharge rates are main drawbacks for this technology. The paper is devoted to airport signal unit operation numerical simulation in case of lead-acid accumulator and EDLC application. Using developed software based on energy balance calculation and satellite solar energy data, optimal configurations of signal units were derived for Rostov and Saratov climate conditions. Technical and economical estimations for both configurations were made from the 100% operation availability and minimum service during 20 years – typical lifetime for monocrystalline photovoltaic module. Maximum power point tracking (MPPT) charge controller features typical for such application are also considered. Target parameters for EDLC commercially attractive application were evaluated.
A pilot station using renewable resources to rehabilitate the inefficient small-hydro power plants
Authors: Radulescu V
Published: October 2019

In Romania, based on a complex plan elaborated during 1980-1990 were built over 600 SHP-Small Hydropower Plant to assure the power supply in isolated localities. After 30 years, less than 200 are still functional, mainly due to a lack of investments or improper utilization. Nowadays a permanent campaign concerning intensive use of renewable resources is implemented. Firstly is mentioned the economically favorable solution from the selected zone to achieve the photovoltaic power plant connected to an existent SHP, which needs to be rehabilitated. The paper presents such a pilot plant realized between 2015 and 2017, built near an SHP decommissioned in 1998. Firstly was implemented a wind turbine which starts immediately producing energy. After two months, the photovoltaic power plant was interconnected. The main steps of the hydropower plant rehabilitation are presented, beginning with the selection of the necessary parameters to establish the opportunity and the pilot station efficiency. The theoretical model and the physical realization in coupling these power plants based on three different energy resources are mentioned. Some obtained results for six months are illustrated. Finally, some of the appeared problems during the execution are mentioned, considering that similar projects in the other four sites will be developed.
Prediction of the atmospheric boundary layer in wind power plants by proper selection of the main air parameters
Authors: Radulescu V
Published: October 2019

Romania, based on UE reports has a high wind potential, representing more than 14,000 MW. The main scope of the paper is to estimate the distribution of the horizontal component of wind velocity in the vertical direction and its influence on wind turbines efficiency. The selected domain for analysis is located in the Southeast part of Romania until an altitude of 600 m. Firstly is presented the impact of the boundary layer’s separation in the vertical wind distribution. The database of the main measured parameters is realized with two masts of 80 m high, situated at 20 km distance each other, during for 24 months. Firstly are presented theoretical aspects allowing estimation of the vertical Boundary Layer separation influence on the wind distribution. An altimetry model for the selected area, based on approximations of the soil roughness is calibrated. There are established the necessary corrections for average and variable roughness. Secondary parameters as the air density, pressure, and temperature, also have an essential role in the proper functioning of the wind turbines. The numerical results allow establishing a long-term prediction of the vertical air distribution. The paper ends with conclusions and references.
Implementing Three-Variance Approach for Project Time and Cost Control in a Building Construction Project (Case Study: A Project in West Java)
Authors: Friescilia L , Gondokusumo O
Published: October 2019

Earned Value Method (EVM) is one of project controlling methods. This method has been widely used in many projects since long time ago. However, this traditional EVM still has some shortcomings that related to time aspect, such as the use of monetary units, also the time aspect and work aspect are not measured separately. To overcome these shortcomings, several researches have been carried out and one of them is Three-Variance Approach (TVA). This paper proposed the use of EVM and TVA and compared the result from those methods. This paper also aimed to identify the strengths and problems that may arise when using TVA in a real project. The results are visualized with graphs, then be gathered into three categories; project status, forecasting, and trend. Project status determines the condition of the project in each period. Forecasting enables one to estimate the final condition of a project. The improvement of project condition from time to time can be seen in trend.
Finance-based scheduling using integer programming method for building construction project in Jakarta
Authors: Ervina  , Gondokusumo O
Published: October 2019

Construction project management consists of planning, scheduling, and controlling. Planning is important because it’s set down the target of project to achieve successfulness. Successfulness of a project consists of several aspects, including: cost, quality, time, and HSE (Health, Safety, and Environment). In many cases, scheduling is optimized with minimum costs for achieving a project’s goal. This doesn’t necessarily guarantee that contactors can provide the budget according to the scheduling. This paper will focus on optimizing scheduling by considering financial capabilities. The method used to optimize scheduling by considering financial capabilities is called Finance-based Scheduling Method. The stages to do finance-based scheduling method, are: arranging initial scheme, arranging extension scheme, and formulating an integer programming model. This study have purpose to obtain optimal scheduling by considering contractor’s financial capabilities. Analysis of this study uses integer programming to find the most optimal solution. However, integer programming requires different modeling for each case and result from it must be simplifying become a bar chart so it’s make easier to understand.
Factors Affecting Design and Management of Residential Community for Enhancing Well-being of Thai Early Stage Elderly
Authors: Ruengtam P
Published: October 2019

This article presents factors related to environmental perception, residential community, and design of the healing environment, which affect Thai early stage elderly perceptions and requirements. Structural equation modeling was used to assess influences among the factors. Empirical data were collected from 419 samples of Thai early stage elderly. The research revealed that requirements of the residential community were classified into three groups including (1) general facilities and activities, (2) facilities related to health and security, and (3) facilities related to physical exercise. Results showed that factors of the elderly’s requirements have direct effects on willingness to join in with project activities of the residential community. The result led to formulating policies in design and management of the residential community which enhanced the quality of life both physically and mentally for the Thai early stage elderly.
The effect of heavy equipment management on the performance of the construction project and the construction company
Authors: Nugraha A S , Putranto L S
Published: October 2019

The appropriate use of heavy equipment will affect the progress of a construction project. An inappropriate choice of heavy equipment will result in low productivity and at the end will incur additional costs. Previous studies have been observing separately the effect of heavy equipment management on the performance of the construction project and the effect of heavy equipment of the performance of the construction company. In this present paper, using structural equation modelling (SEM), both relationships will be studied simultaneously and additionally direct effect of performance of construction project on the performance of construction company will be observed as well. It was found that both relationships were significant and positive.
Evaluation of Ground Anchor Design on Man-made Cut Slope of Cemented Sand: A Case Study
Authors: Bahsan E , Sopandji B S , Sagitaningrum F H
Published: October 2019

A system of ground anchor and horizontal drain on a steep cut-slope in Bogor, West Java was designed to stabilize the slope below a bridge structure spanning across a river. Due to the difficulties in the construction of the ground anchor, the design of the ground anchor was evaluated and analyzed for its effect on the stability of the slope. The slope is assumed to have three layers of soil consist of sandy clay (medium stiff), sandy silt (hard), sandy silt (medium stiff), and cemented sand gravel. Four scenarios were evaluated to examine the slope stability: initial stage, the addition of horizontal drain, construction of bored piles with horizontal drain, and addition of ground anchor after the construction of bored piles and horizontal drain. Analysis were done with evaluating the Factor of Safety (FS) of the slope. It was found that the addition of horizontal drain played a big part in stabilizing the slope from initial stage (FS = 0.933 to FS = 1.546), whereas the addition of ground anchor and bored piles were not apparent after the addition of horizontal drain (FS = 1.545 and FS = 1.555), indicating that the main problem of the slope was the high groundwater level. Other than the constructed solutions, shortcrete should also be given at the critical slip surface at the top and surface of the slope in order to reduce erosion by run-off water.
Analysis of The Stability of Dam Building After Counterweight Additions (A Case Study: Gonggang Dam, Magetan Regency)
Authors: Kuntoro P , Surjandari N , Hadiani R
Published: October 2019

The Gonggang Dam was first planned to be a rock filled dam, but due to the economic consideration, in the construction, the materials were changed from rock piles to random heaps with the fixed degree of slope. After being operated for a year with the observation on the possibility of seepage, no seepage was found. Therefore, to increase the stability of the dam body, a counterweight in the form of random pile completed with a filter and rip-rap was added to the lower part of the body of dam. The height of counterweight was determined based on the safety needs from the flow (surface) of the seepage line and the stability of the dam. The calculation results of stability analysis of the dam body with counterweights was considered effective as the downstream safety. Safety factors obtained from empty conditions, flood water levels and rapid drawdown without seismic load show the equation: security factor ≥1.2, which was in accordance to the permitted safety factor: sf ≥1.2. Meanwhile, the calculation result of the analysis of stability of the dam body with Operation Base Earthquake (OBE) and Maximum Design Earthquake (MDE) in empty condition and flood water level, the safety factors obtained were still above the permitted limit, ≥1.2. However, for rapid drawdown conditions with the effect of the MDE seismic load was not yet safe (collapse), so it was necessary to modify the design of the upstream leg section. The design modification was carried out by adding a random land fill structure that blends with the body of the main dam. The method was expected to be able to withstand the tension occurring upstream, thus increasing the stability of the dam body. This was proven to be effective based on the calculation results obtained by the safety factor of 1.115. The number was still included in the permitted Maximum Design Earthquake (MDE) safety number of load effect (sf ≥1).
Effect of Compaction to Increase the Critical Height of a Slope without any Support
Authors: Susilo A.J , Sumarli I , Sentosa G.S. , Prihatiningasih A , Wongkar E
Published: October 2019

Embankment is a common way to raise ground level of any construction. Raising the ground level will also help structure from being flooded, flood especially in major city such as in Capital City of Indonesia, Jakarta, is a yearly problem. On the other hand, embankment will also be a problem if not handle carefully. Clay and sand can be used as materials. Properties of material that should be investigate before the materials being used are cohesion and angle of friction. Beside selection of high quality materials, compaction can also help embankment from failure. When the materials get well-compacted the chance of sliding should be lower. This study analyse the correlation whether well-compacted material can have higher critical height and the result can be imply on the construction site as not every embankment need retaining structure to be stable but only by compaction the embankment can withstand by it self.
Durability of Reactive Powder Concrete
Authors: Kushartomo Widodo , Octavivia
Published: October 2019

Concrete is a generally used material in building construction. The construction will be built on the ground and could also be in places exposed to sea water. Sulfate contained in ground water and sea water could cause sulfate aggression to concrete itself. Therefore, the research used Reactive Powder Concrete which is one of the concretes that is currently popular and has a high durability. The research was done by doing a constant repetition of saturated sulfate submersion and specimen abstersion. The varieties of specimen used along with the research such as Type I, Type II, and PCC variations of cements, also varieties fas 0.2 and fas 0.25. Research shown that Reactive Powder Concrete which is contained type II cement has the best resistance because the compressive strength does not reduced to 30% and the reduced weight is less than 1% when exposed to high concentration of sulfate.
Infiltration of chloride ion in the self compacting concrete with calcium stearate
Authors: Maryoto Agus , Gan Buntara Sthenly , Hermanto Nor Intang Setyo , Setijadi Rachmad
Published: October 2019

Corrosion rates in reinforced concrete can be detected by the amount of chloride ions present in concrete. This study aims to determine the effect of calcium stearate use on self compacting concrete on the infiltration of chloride ions. The calcium stearate content used is 0, 1, 5 and 10 kg per 1 m3 of self-compacting concrete (SCC). The concrete quality tested includes 20, 30 and 40 MPa. The parameters tested in this study were compressive strength and infiltration of chloride ions. Compressive strength specimen is in the form of cylinder 15 mm in diameter and 150 mm in height, while chloride ion infiltration specimen is in the form of cubes with sides of 150 mm. The results show that calcium stearate concrete with 10 kg / m3 of concrete when compared to normal concrete, the compressive strength decreases by -6.69%, 16.16% and 18.74% for concrete 20, 30 and 40 MPa respectively. Whereas the infiltration of chloride ions in concrete on 10 mm depth from the concrete surface was 0.153, 0.061 and 0.012% in the concrete of 20, 30 and 40 MPa. These infiltration of chloride ion in concrete 20, 30 and 40 MPa are lower around 287, 252, and 626% compared to concrete without calcium stearate.
Multi-storey Modular Cold-Formed Steel Building in Hong Kong: Challenges & Opportunities
Authors: Andy Prabowo Pho
Published: October 2019

Modular building construction has become widely popular across the continents, such as in America, Europe (United Kingdom), Asia (Singapore), and more recently in Australia. Promoting sustainability in construction, the application of modular construction has been successfully implemented in very broad range building functionalities. These include student residences, private housings, hotels, commercial buildings, military accommodation, health facilities, as well as other services units attached to the main buildings. Several low-rise buildings (6 to 10 stories) as well as high-rise buildings (20 to 30 stories) have used this type prefabricated off-site building system as an alternative construction method. Among those existing projects, modular steel building brings significant advantage on the manufacturing process and erection speed. These will be beneficial for Hong Kong which has very high pressure on housing demands. Due to its excellence on strength and durability, the modular integrated construction (MiC) in Hong Kong is looking to the direction of using cold-formed steel as structural component. Some challenges and opportunities are exist and these will be discussed in this paper.
Loading Test and Temperature Effect on Steel Arch Bridge
Authors: Sumargo  , Harahap Ahmad H S
Published: October 2019

Before the bridge is operated, it is necessary to do a test to find out whether the bridge has met the applicable requirements and regulations and works properly with the service load. Tests include static and dynamic loading of bridges on the Water Front City bridge, Bangkinang, Riau. Static load test in the form of measurement of deflection and strain of the bridge structure when carried out the load on the bridge in a controlled and measurable manner. The given load is at least equal to the bridge service load according to specifications and service defects that occur do not exceed the specified limits. While the dynamic load test is in the form of recording bridge behavior when receiving dynamic loads. Static loading is carried out by placing several truck vehicles with measured dimensions and loads on each wheel to determine the amount of deflection and stress at ¼ - ½ - ¾ spans. Static load test results on the structure of the bridge, the maximum strain that occurs in reinforcing steel and concrete in loading conditions with a load of 2 trucks (50 tons), 4 (100 tons), 6 (150 tons), 8 (200 tons), 10 (250 tons) and 12 trucks (300 tons) respectively 17.62 MPa, 52.82 MPa, 61.95 MPa, 51.08 MPa, 105.49 MPa and 128.48 MPa. In unloading conditions, the maximum strain is 51.31 MPa, 70.38 MPa, 52.47 MPa, 88.71 MPa,75.20 MPa and 13.21 MPa respectively. The temperature difference of 15°C in arch element gives camber in the middle of the span of 15 mm for the arc and 13 mm for the girder. The natural frequency of the WFC bridge is 1,127 Hz which occurs in the vertical direction at a span of 100 meters.
Characteristics Comparison on Mechanical Properties of Mortars using Agriculture Waste as a Cement Replacement Materials
Authors: Saleh F , Prayuda H , Monika F , Pratama M M A
Published: October 2019

Excessive use of cement makes the price of construction projects expensive. Mortar making using high amounts of cement also has the potential to increase the price of the construction. This study discusses the use of agricultural waste as a substitute for cement in mortar production. The waste used in this study was bagasse ash, fuel ash palm oil, and rice husk ash. Each waste is added as much as 25%, 50% and 75% which are then tested for mechanical properties such as water content, unit weight, absorption, and IRS. Compressive strength was tested when the mortar was 28 days old with a cube-shaped specimen with a size of 50 mm x 50 mm x 50 mm. From the test results, it was found that all of this waste can be used as a substitute for cement. To produce a compressive strength of 100 kg/cm2 can add each waste with a percentage range of 10-12% of the weight of cement.
Vulnerability Assessment on Non-Engineered Building in Earthquake Prone Area. Case Study: Klaten District, Central Java, Indonesia
Authors: Zufiar M H , Prayuda H , Monika F
Published: October 2019

Most of the houses in Indonesia are still categorized as non-engineered buildings which do not use good structural analysis in the manufacturing process. The level of education and knowledge about the construction of simple houses is certainly the main cause. The geographical conditions of Indonesia which are quite prone to disasters such as earthquakes, eruptions and cause this condition is one of the real threats to the population of Indonesia. This study discusses the level of vulnerability of buildings in the Klaten area to earthquake hazards. This area is one of the areas affected by the earthquake in 2006, and the community living was rebuilt with funds from the Indonesian government. The results showed that at the time of the initial construction 95% of this building had been calculated to withstand earthquake loads, this was seen from the main building which had a fairly strong structural component and was equipped with a fairly good structural drawing. Along with the growth of the population, most of the buildings have undergone a change of shape, many people have added their own buildings without considering the strength of the construction to withstand earthquake loads. So that buildings that were initially categorized as resistant to earthquake forces are very dangerous if an earthquake occurs.
Temperature sensitivity effect in asphalt modification with natural rubber sir20
Authors: Utami R , Suherman
Published: October 2019

The use of asphalt material is needed so that surface layer could be water-resistant. Asphalt material also improves tensile stress which means enhancing support capacity for traffic load. Asphalt modification can be done by adding certain materials, such as natural rubber, to improve asphalt performance. Experimental methods were taken in this study. Asphalt tests which carried out are specific gravity, softening point and penetration with natural rubber variation 2%, 4%, 6%, 7%, 8%, 9%, 11% and 13%. Results were shown that the higher addition of natural rubber SIR20, asphalt more hardened and more insensitive to changes in temperature. This hardness characteristic of asphalt could be the initial parameter for making asphalt mixtures that more resistant to rutting and permanent deformation.
Study of willingness to pay the Jakarta-Bandung highspeed train: a case study of Argo Parahyangan train passangers
Authors: Putri A L , Widyastuti H
Published: October 2019

Currently the increase in vehicle volume in the cities of Bandung and Jakarta has grown very rapidly. This is accompanied by an increase in the volume of vehicles traveling from Jakarta to Bandung and vice versa. High Speed Train (HST) becoming the government’s choice as a form of mass transportation modernization in Indonesia in building inter-city connectivity and regional development. Study or research on willingness to pay (WTP) is needed to find out the prices that are desired by prospective users. The method used in this study are distribution of questionnaires and interviews with stated preference techniques. The result that the highest probability value is in scenario 1 frequency with a probability value of 96.00%. Or it can be interpreted that as many as 96.00% of respondents of Argo Parahyangan train users will use the HST if the facilities offered are the frequency of train departures once an hour. The biggest WTP is in the scenario conditions offered, namely intermodal accessibility connected with the LRT (Light Rail Transit) mode, and also once a hour frequency scenario where the WTP value reaches.