Construction Of Components Research Articles

Directly Reusable Steel Column Base Connection ‐ Concept and Numerical investigation

AbstractConstruction industry as a whole should transform into designs that enable demountability and direct reuse of structural elements to achieve the circularity in construction. Currently, structural connections enabling direct reuse of components in construction are limited. Column base connections are one of the main load transfer units of a steel structure for the magnitude of the forces being transferred from the superstructure. This paper presents an interlocking type of column base connection that enables direct reuse of all associated structural components. The proposed interlocking connection transfers the force through the plate bearing and holding mechanisms and requires minimal number of bolts. In addition to the direct reuse and better load transfer approach, the new interlocking connection enhances and simplifies the mounting procedure that leads to increased productivity in construction. This article discusses the overall concept of the proposed interlocking connection, design philosophy and compares the failure modes with existing conventional bolted column base connections for various loading cases through finite element analyses. Main parameters investigated are the effects of bearing length of connector element and connector element thickness under uniaxial loading. A finite element model of the proposed interlocking connection is built through which the influential parameters are analysed.

AAC building components for modular construction using recycled materials

AbstractThe article presents the results of a study of the use of aggregates from the processing of wastewater treatment plant waste for the manufacture of large‐scale prefabricated building components means large‐scale autoclaved aerated concrete. This aggregate, applied to hydration‐bonded materials, makes it possible to obtain lightweight concretes (density 1400–1600 kg/m3) with increased thermal resistance. In addition, the addition of an aluminosilicate phase to the concrete mix can favorably affect mechanical characteristics and durability. The lightweight aggregate obtained using sewage sludge is characterized by high porosity, resulting from the complete combustion of the organic parts contained in the sludge (more than 90% d.m.), which act as a porophore in the ceramization process. This feature predestines this type of aggregate for use in hydration‐bonded materials that exhibit improved thermal insulation properties. The combination of sludge‐based lightweight aggregate technology with AAC production technology, therefore, implies a synergistic action to obtain a material with improved thermal insulation parameters combined with the mechanical strength expected for structural materials. An important environmental aspect of the proposed approach is the use of waste materials including municipal sewage sludge, which is particularly difficult to manage and dispose of, and the reduction of natural resource exploitation.

Performance analysis of global HYCOM flow field using Argo profiles

ABSTRACT Flow field data generated by ocean models are important for simulating ocean currents and circulation patterns, which are essential components in digital Earth construction. To evaluate the accuracy of model-simulated flow fields, Array for Real-time Geostrophic Oceanography (Argo) float observations can be considered benchmarks. In this study, a novel method for comparing Argo profiles with 3-dimensional trajectories obtained by simulating Argo floats in Hybrid Coordinate Ocean Model (HYCOM)-provided flow fields was proposed. Surface and subsurface trajectories were calculated, and their spatial matching characteristics were analyzed. The results demonstrated that (1) the HYCOM surface and subsurface flow fields generally conform to the basic characteristics and trends of ocean currents; (2) the HYCOM sea surface current field error pattern exhibits a symmetrical distribution centered on the equator in the Northern and Southern Hemispheres and increases with increasing latitude; and (3) the HYCOM subsurface flow field exhibits regional differences, with the largest differences in the Gulf Stream, North Atlantic Warm Current, and Westerly Wind Drift region. Through analysis of the disparities between HYCOM and Argo data, the effectiveness of using model simulation data can be enhanced, and the accuracy and dependability of ocean models can be improved.

HIGH TEMPERATURE PUSH‐OUT TESTS ON DEMOUNTABLE SHEAR CONNECTORS OF STEEL‐CONCRETE COMPOSITE BEAMS

AbstractThere is no denying that there is a growing need for reusable systems in the construction industry. This is not only a by‐product of the increasing demand of materials, but also a necessity to reduce greenhouse gas emissions associated to the manufacturing process of construction components. Reusable systems aim to solidify the transition from a linear economy model to a circular economy model, where the lifecycle of materials is extended overtime. However, there are several factors that might hinder the reusability of structural components, ranging from regular use over a time period to accidental situations, such as earthquakes and fires.This experimental study focuses its efforts on the analysis of demountable shear connectors for composite structural systems under the influence of high temperatures that resemble a situation of fire. The main idea behind this experimental campaign is to combine a standard push‐out test, where a specimen composed by a HEB‐260 steel profile with reinforced concrete slabs connected to its flanges via high strength bolts is subjected to a vertical force by utilizing a hydraulic jack with a simultaneous thermal action.The tests reproduce a previous experimental campaign performed at the University of Luxembourg (cylinder and coupler systems), but subjected to 4 different temperatures (20, 300, 500 and 600 °C). The loss of strength of the connectors with the temperature, the failure mode and the reusability after a situation of fire are discussed in the present study.

Individual differences in empathy in Danish university students: A cross-sectional study.

Empathy is widely recognized as a multi-dimensional construct, involving emotional and cognitive components. These may cause distinct experiences and behaviors that can be both beneficial and deleterious to individuals' well-being and mental health. We wished to examine the association between emotional and cognitive empathy of Danish university students as measured by the multidimensional Interpersonal Reactivity Index (IRI) and study major, sex, age, and parental status. Additionally, we aimed to gauge the validity of the Jefferson Scale of Empathy - Student version (JSE-S) as a measure of primarily cognitive empathy in the context of medical majors by comparing JSE-S scores with IRI cognitive scores. In our national, cross-sectional study, conducted in October 2020, we used survey data from students in their first, third, and final study year. All students from University of Southern Denmark were invited to fill out IRI, and all medical students at Denmark's four medical educations were additionally invited to fill out the JSE-S. Associations were estimated by linear regression models. Of 14,072 invited, 2,595 students completed the questionnaire. Health majors scored statistically significantly higher on cognitive empathy than students from other study majors. The JSE-S correlated significantly with the cognitive empathy subscales of the IRI. Furthermore, the effects found in relation to sex, age-, and parental status were significant. Our study results show that large differences in empathy exist between university students and study majors. Overall, our results highlight (1) the relevance of investigating empathy as a multidimensional versus a global construct in young adult populations (including university students) and (2) the importance of focusing on differences in empathy across different student characteristics.

ANALISA PERMASALAHAN DAN RENCANA PELEBARAN SALURAN DRAINASE DI DAERAH JALAN CIMAHPAR

Flood control buildings or commonly known as drainage channels are a global element of the legacy of infrastructure to help facilitate community activities and are a major component of road support construction. The Jalan Cimahpar area which is the main road that connects to Jalan Pandu Raya, an area where the majority of the people sell and pass through the road is still facing various problems. Problems that are quite disturbing to the community are when there is high rainfall, there is a puddle of water on the shoulders and road bodies as a result of overflowing drainage channels that are not functioning properly, as a result, the busyness of the community and road users falters. The slope of the road and the accumulated sediment is also one of the factors that causes the drainage water to not function properly. Thus, it is necessary to expand the drainage channel that is able to accommodate puddles of water during high rainfall.

Automated reconstruction model of a cross‐sectional drawing from stereo photographs based on deep learning

AbstractThis study presents a novel, deep‐learning‐based model for the automated reconstruction of a cross‐sectional drawing from stereo photographs. Targeted cross‐sections captured in stereo photographs are detected and translated into sectional drawings using faster region‐based convolutional neural networks and Pix2Pix generative adversarial network. To address the challenge of perspective correction in the photographs, a novel camera pose optimization method is introduced and employed. This method eliminates the need for camera calibration and image matching, thereby offering greater flexibility in camera positioning and facilitating the use of telephoto lenses while avoiding image‐matching errors. Moreover, synthetic image datasets are used for training to facilitate the practical implementation of the proposed model in construction industry applications, considering the limited availability of open datasets in this field. The applicability of the proposed model was evaluated through experiments conducted on the cross‐sections of curtain wall components. The results demonstrated superior measurement accuracy, compared with those of current methods of laser scanning or camera‐based measurements for construction components.

Activity-Based Costing Method Application Activity in Determining the Production Cost of Aluminum Ships in the Small Shipyard Industry

In the ship production process, each construction component has a price value that will be taken into account how much raw material costs, labor costs, and other costs will be incurred, producing the finished product of a ship. This study aims to determine the calculation of the Production Cost of aluminum boats using the application of activity-based costing methods. As well as to find out the comparison of the calculation of the Production Cost of aluminum ships with traditional system methods and activity-based costing. At the data analysis stage, this study uses the activity-based costing method. The end result of this study is in the form of data from the results of data analysis from the application of the activity-based costing method, the advantages and disadvantages obtained while using this method. Based on the research results it can be concluded that by using the activity-based costing method, the company will get a positive impact in calculating the Production Cost in imposing factory overhead costs on each product.

Combination of Non-contact and Contact Measuring Methods for Analyzing Structural Conditions of Dry Transformers

Abstract The article describes the non-contact and contact analysis of 1-MVA dry power transformers with epoxy-resin insulation using an acoustic camera and frequency analyzer with automatic sweeping for low-middle frequency areas. Power transformers are most commonly used for construction component (core, windings, taps) analysis. The electrical, non-rotating machine generates electromagnetic and acoustic emissions that can be used to analyze dry transformers during their operation. Non-contact online diagnostic methods have many advantages over offline methods because it is not necessary to shut down the transformer, and also, the condition and behaviour of the machine are analyzed during its normal operation. The article presents the analysis and comparison of structural parts of the distribution dry transformers of the same type and power. The problem of insufficient or incorrect clamp-screw connection was identified using the SFRA (Sweep Frequency Response Analysis) method.

Hermite Finite Element Method for Variable Coefficient Damping Beam Vibration Problem

Beam is the most common component in mechanical equipment and construction. The heterogeneous beam and the variable cross-section beam both have good structural performance. In this study, a Hermite finite element method is proposed for variable coefficient damping beam vibration. The first-order time derivative is approximated by the Richardson format, the second-order time derivative is approximated by the central difference method, and the fully discrete scheme is obtained. The variable coefficients are processed, the error estimate is analyzed in detail. Finally, we verify the validity of the scheme by Matlab and observe influence of damping coefficient variation on beam vibration.

THE DIALECTIC STRENGTH IN SOCIAL CONSTRUCTION OF URBAN COMMUNITY FOR PREVENTING STUNTING DURING THE COVID-19 PANDEMIC

In Palembang, Indonesia, toddlers who suffer from stunting, a condition marked by a failure to develop, are the subject of this study. This study analyses and assesses the function of urban social construction in avoiding infant stunting during the first 1,000 days of life using a qualitative approach and Berger and Luckmann's theory of social construction. According to the study's findings, this social construction is influenced by socioeconomic elements like education, the surrounding community, and cleanliness, as well as the reality of pregnancy, delivery, and raising children. This study stresses the importance of dialectics in this social construction by demonstrating how clashes and interactions between social systems and people have an impact on efforts to prevent stunting. This work is groundbreaking because it recognises dialectics as a fundamental component of social construction that affects stunting prevalence and prevention. The dialectic offers fresh perspectives for preventing stunting in urban areas like Palembang and highlights the social factors that affect preventative efforts. Keywords: Social Construction; Urban Community; Stunting Prevention; Dialectic Strength

Shape transformation of 4D printed edible insects triggered by thermal dehydration

Insect-based food was fabricated by 3D printing of edible insect inks (cricket; CK or silkworm; SW) aiming to produce an alternative and sustainable food with high protein for a variety of consumers. CK and SW of 30% (w/v) together with 5%(w/v) sodium alginate can be 3D-printed into several designed geometries with fine resolution. 4D shape transformation as triggered by thermal stimuli at 80 °C of the printed insect-based objects was found to be varied with infill angle and infill pattern. The ability to form the CK/SW bilayer structure of which shape transformation upon thermal dehydration was similar to that of the structure of a single component suggesting that the culinary applications of the developed edible insect inks can be extended to other 4D-printed multi-nutrient structures. Analysis by gas chromatography-mass spectrometry verified that main components of all 4D-printed insect-based constructs were preserved with diminished nutty-like odor verifying that 3D-printing and heating are non-destructive.

Punching shear of reinforced concrete slabs bonded with reactive powder after exposure to fire

Abstract Reactive powder concrete (RPC) is one of the most recent and significant advancements in the world of building. Due to its higher concrete characteristics, it has a common excessive benevolence happening in the globe at the moment, excessive ductility, shrinkage resistance, and corrosion and abrasion resistance. Investigated is the method for amending the RPC experimentally in punching shear slab action and the properties of construction material to investigate properties of volumetric ratios of steel fiber, and silicas fume, tensile steel ratio, the most important component for construction is reinforced concrete, which works well with other materials to create structures in any shape that is needed. In the present research, investigational work of RC slab with (1,000 × 1,000 × 60) mm dimensions was tested. This study aims to see how the relative volume of steel fibers (Vf) and silica fume content (Sf) affect the actions of RC slabs after being exposed to fire. It originated that a concrete mix containing 2% steel fibers improved the RPC slab's cracking and final punching shear. The existence of reactive powder increases fire resistance. This study's experiment aimed to see how reactive powder and Slab's ultimate punching shear strength were affected by replacement ratio. Whenever a fire is present. After fire exposure, the initial and subsequent stiffness of reinforced concrete slabs reduced considerably the temperature grew from 25 to 750°C.

The study of color as a component of urban cultural construction: A theoretical reflection and methodological proposal

AbstractThis article presents a theoretical reflection and a methodological proposal for the study of urban color as an element of experience and urban cultural construction. The purpose is to propose a methodology based on the analysis of the relationships between the objective and subjective aspects of color in the city. To this end, we aim to understand the objective visual perceptions and relate them to the subjective associations that the inhabitants identify from the urban experience. Additionally, a methodological crossover is carried out that considers the study of urban color from the perceptual and objective analysis of color with the methodologies of imaginaries and urban anthropology. Thus, the proposed chromatic approach links the objective and subjective aspects of color with the tangible and intangible elements of the city. By so doing, this article underlines how the results are not limited to the objective terms of the study of urban color but are enriched by the identification of subjective aspects, such as the analysis of the historical and social contexts in which the colors were chosen, as well as the perceptions that their inhabitants have about them. This research aims to deepen and broaden the view of a city from a chromatic study's perspective. The conclusions invite us to make a reading of the representations and perceptions of the inhabitants of a city who, through the questioning of color, can express their needs, desires and emotions for the place they inhabit and thus transmit a particular cultural construction of the city.

The registration of multi-modal point clouds for industrial inspection

ABSTRACT This study presents a complete solution for multi-modal inspection of industrial components, including a processing pipeline for registering consecutive multi-modal point clouds comprising thermal and visible sensors’ data. A comparative evaluation of optimisation and learning-based registration methods is provided as part of the processing pipeline. Moreover, a benchmark dataset of point cloud data from different FOVs of industrial and construction component samples is provided (LeManchot-Points), having data from five point clouds with depth, colour and thermal information at each point. The experimental campaign with different objects demonstrates the proposed solution’s applicability for the multi-modal inspection of industrial components.

Numerical and Experimental Analysis of Mechanical Properties in Hybrid Epoxy-Basalt Composites Partially Reinforced with Cellulosic Fillers.

The current work is focused on numerical and experimental studies of woven fabric composites modified by hybridisation with biological (cellulosic) filler materials. The mechanical performance of the composites is characterized under tensile, bending and impact loads and the effect of hybridisation is observed with respect to pure and nonhybrid composites. Numerical models are developed using computational tools to predict mechanical performance under tensile loading. The computational prediction results are compared and validated with relevant experimental results. This research is aimed at understanding the mechanical performance of basalt-epoxy composites partially reinforced with micro-/nano-sized bio-fillers from cellulose and intended for various application areas. Different weave structures, e.g., plain, twill, matt, etc., were investigated with respect to the mechanical properties of the hybrid composites. The effects of hybridizing with cellulose particles and different weave patterns of the basalt fabric are studied. In general, the use of high-strength fibres such as basalt along with cellulosic fillers representing up to 3% of the total weight improves the mechanical performance of the hybrid structures. The thermomechanical performance of the hybrid composites improved significantly by using basalt fabric as well as by addition of 3% weight of cellulosic fillers. Results reveal the advantages of hybridisation and the inclusion of natural cellulosic fillers in the hybrid composite structures. The material developed is suitable for high-end applications in components for construction that demand advanced mechanical and thermomechanical performance. Furthermore, the inclusion of biodegradable fillers fulfills the objectives of sustainable and ecological construction materials.

Drip Irrigation Cyber-physical System with Remote Control

In today's reality, the pace of people's lives is much higher than it was 30 years ago and it is still growing. At the same time, the amount of information is also growing. This information should be processed constantly, daily, as soon as it is received. Production volumes are not also standing still. Such a lively pace of life requires process consistency and continuity and these processes must be provided by a man.
 This article describes the system of watering which should automate the process of growing plants. Also, the analysis of a new branch, that is cyber-physical systems, is carried out. The analysis of modern systems of autonomous irrigation, principles of their construction and organization of their work is conducted. A method of implementing a system that provides the possibility of constant monitoring of the growing environment and provides an opportunity to influence it is suggested. The choice of components for system construction is made. The algorithm of the system operation is described. An analysis of the relationship between system components and the user's relationship with the system is performed.

Development of affordable hot box calorimeter to determine the U-value of inhomogeneous building material

In recent years, the use of three-dimensional printing to create construction components has advanced quickly; it is possible now to simplify construction, increase speed, and lower cost while using natural resources responsibly. It also allows us to use recycled material to produce building envelopes while increasing design flexibility. However, the thermal performance of building materials must be characterized to achieve the necessary energy efficiency of the building envelopes. This study aims to develop, produce, and calibrate a hot box calorimeter at a reasonable price for thermal testing components building envelope. The heat loss through these components using a hot box can be measured in a lab to get an idea of the thermal performance of the building envelopes. In order to evaluate and analyze the thermal performance of various 3D-printed building brick samples made in the labs, this study explains the design and creation of an inexpensive hot box. The hot box can conduct a conventional thermal experiment, which involves monitoring heat flux, surface temperatures, and air temperatures. The testing process, instrumentation, test conditions, and validation of the new metering box are all covered in the article. The U-value of the brand-new lattice-based 3D printed building blocks was afterward determined using the validated new hot box. It was observed that the U-values values of 1.04 W/m2.K and 0.99 W/m2.K, respectively, for small components utilizing developed hot box and larger lattice panels using commercial equipment, with a maximum variance of 5%. It highlights the dependability of the hot box apparatus, which is also made affordable to operate by using less material for specimen preparation and less energy to maintain the temperature in the hot and cold chambers. Its small size also makes setup and thermal testing of construction materials simple.

Lightweight Flame-retardant Material Reinforced with Hevea Brasiliensis Ash Intumescent Agent

Flame retardant materials play an important role in many building construction components. The ability of building components to resist fire is crucial to the safety and well-being of the occupants. This research examines a lightweight flame-retardant material-Vermiculite (V) reinforced with a renewable Hevea Brasiliensis Biomass Ash Intumescent Agent (HBAIA) in different compositions. Four specimens of vermiculite reinforced with HBAIA (V/HBAIA) with standard size 200 mm x 200 mm x 10 mm (W x Lx H) were fabricated for investigations. All V/HBAIA specimens were assessed in terms of their density, fire-resistant, fire endurance and smoke, char surface morphology, and flexural toughness. Data disclosed V/HBAIA-2 with the composition of 90% vermiculite reinforced with 10% HBAIA obtained the most prominent outcomes in overall. V/HBAIA-2 attained the lightest density of 37.5 kg/m3 and weight of 0.20 kg, with lowest end temperature of 122 °C after exposure to one-hour of 1000 °C fire. This indicated the best fire-resistant performance in V/HBAIA-2. No structural deformation and only mild smoke and odor were observed in V/HBAIA-2 during the fire endurance examination. V/HBAIA-2 was able to resist the maximum loading force of 67.4 N before and 52.5 N after the fire resistant, with the higher flexural toughness value of 1.47 MPa. Scanning electron microscopy revealed a more uniform, denser, closely connected air cavities char cell quality in V/HBAIA-2 explained its superior outcomes in fire-resistant and flexural toughness as compared to the rest of specimens.

A Workability of Fresh Concrete with Micro Silica Enclosed in Recycled Aggregate

Abstract: The most essential material utilised in the construction sector is concrete. Concrete contains a lot of natural aggregates, which harms the environment. Nowadays, a lot of buildings are torn down and rebuilt, which creates issues with the dumping of waste. Recycling or reusing construction and demolition debris is a crucial component of sustainable construction. It will continue to provide a welcoming, green environment. Concrete using recycled aggregates has low strength and poor workability due to the microcracks on its surface. Micro silica can be used to get around this drawback. In this study, experimental findings for the incorporation of recycled aggregate with micro silica were presented.