Prefabrication Method Research Articles

Real-scale tests on bundle-bar-filled circular hollow sections (BBFC) under eccentric compression

The escalating demand for innovative, multifunctional, and advanced composite structures stems from the pressing concerns related to cost efficiency and environmental impact, alongside interest in the prefabrication methods within the construction industry. This paper advances a pioneering approach by proposing the utilization of high-strength bundle-bar-filled circular hollow sections (BBFC) as columns. In this method, a bundle comprising high-strength reinforcing bars with an impressive yield strength of 670 N/mm² is strategically placed within a steel tube, varying in related-slenderness values from 0.86 to 2.44. Subsequent to this arrangement, the bundle undergoes grouting with mortar, resulting in the formation of the BBFCs. The composition of the bundle is a critical aspect, with different configurations featuring 1, 3, 7, and 19 high-strength bars. Given the intricacies involved in the fabrication process, this paper meticulously outlines the unique techniques employed to successfully manufacture the BBFCs. To comprehensively evaluate the performance of these innovative columns, a series of ten real-scale tests were conducted. These tests look at various aspects, including capacity, flexural stiffness, deflection, and strain response. In addition to experimental validation, finite element analysis was applied, not only to corroborate the empirical findings but also to lay the foundation for future parametric studies. These subsequent investigations aim to explore and understand the influence of different geometric and material features on the structural behaviour of this innovative composite column, thereby contributing to the advancement of knowledge in the field.

Planning Innovation for Implementing Modular Prefabricated Construction in Housing Development in Indonesia Using A Riskbased ISO 56002:2019 Approach to Improve Project Performance

The development of housing in Indonesia, growing rapidly due to urbanization and population growth, faces challenges in terms of land, labor, and housing backlog. Despite being innovative, modular prefabrication methods are limited by unattractive designs and high costs, slowing down construction, harming the productivity of construction companies, and hindering the growth of the national construction sector. These challenges are prevalent in various countries and are influenced by low knowledge, conservative mindsets, and inhibiting regulations. In Indonesia, additional issues include a lack of mastery of modular prefabrication methods and awareness of long-term benefits. This research identified innovative risk-based applications of modular prefabrication with an ISO approach to improve project performance. The methodology employed includes a literature review, a questionnaire survey, and phased expert validation. The study found that out of 38 risk factors based on the 4 processes of implementing modular prefabrication methods, the average risk assessment is high. As a result, 5 innovations are proposed as efforts to reduce risk assessments. The research analyzed data from various literature, resulting in low inter-data connectivity. However, the processes and outcomes of this research can be relied upon for further understanding in subsequent research. This study combined proposed new innovations with those from external literature that have the potential to be applied in Indonesia for optimizing the cost efficiency of modular prefabrication methods.

A peridynamic model for rail crack initiation with cavity defect

Cavity defects can aggravate the rail crack initiation. To study their effect on rail fatigue crack initiation behaviour, a peridynamic model of rail crack initiation considering the characteristics of the cavity defect was proposed. First, based on the low-cycle fatigue test data, the bond failure criterion of the rail material was derived and verified to characterize the fatigue damage performance. Then, mathematical expressions for circular, triangular and rectangular defect characteristics were proposed, establishing a prefabricated method for rail cavity defects. Based on the ordinary state-based peridynamic fatigue theory, a rail crack initiation model with the cavity defect was constructed. Finally, the behaviour of rail crack initiation with the cavity defect was analysed.

An Automated Method for Generating Prefabs of AR Map Point Symbols Based on Object Detection Model

Augmented reality (AR) technology enables paper maps to dynamically express three-dimensional geographic information, realizing the fusion of virtual and real information. However, in the current mainstream AR development software, the virtual information usually consists of prefabricated components (prefabs), and the content creation for AR maps heavily relies on manual prefabrication. It leads to repetitive and error-prone prefabrication work, which restricts the design of the dynamic, interactive functions of AR maps. To solve this problem, this paper explored the possibility of automatically generating AR map prefabs using object detection models to establish a data conversion interface from paper maps to AR maps. First, we compared and analyzed various object detection models and selected YOLOv8x to recognize map point symbols. Then, we proposed a method to automatically generate AR map prefabs based on the predicted bounding boxes of the object detection model, which could generate prefabs with corresponding categories and positional information. Finally, we developed an AR map prototype system based on Android mobile devices. We designed an interaction method for information queries in the system to verify the effectiveness of the method proposed in this paper. The validation results indicate that our method can be practically applied to the AR map prefabrication process and can quickly generate AR map prefabs with high information accuracy. It alleviated the repetitive workload established through the manual prefabrication method and had specific feasibility and practicality. Moreover, it could provide solid data support for developing dynamic interactive functions of AR maps.

Cost Analysis and Economical Suitability of Prefabricated Concrete Structures in Building Construction

Construction industry of Pakistan has a great contribution in uprising the GDP of the country. When compared with the construction industries of some developed countries of the world it still lacks in utilizing the modern methods of construction. Most of the organizations are relying on traditional ways of construction and are not ready to equip themselves with the advanced techniques of construction that may help them do their projects more effectively and efficiently. Prefabrication is the future of modern and sustainable construction which can maximize the capability of constructing the structures without compromising not only the time, cost and quality of project but also the environment. Prefabrication is rapidly increasing in construction, and previous researchers have identified various positive impacts of prefabrication on projects. However, prefabricated construction is less preferred over traditional methods of construction in Pakistan. Therefore, a comparison is required between conventional RCC building and a prefabricated (precast RCC) building to unearth the potential benefits of adopting prefabrication on overall cost of project. To achieve this, a BIM based multi-dimensional model of conventional and prefabricated building is developed using Autodesk Revit. A detailed comparison between both the methods of construction with respect to material, labor, transportation and time made the benefits of prefabricated construction clear over conventional construction. Prefabrication method is 84% faster and costs about 13.46% less than conventional method of construction. This comprehensive contrast will help to better understand and encourage the construction industry to move towards the prefabricated construction.

Comparative Study of Light Steel Roof Frame Construction Methods with Conventional Methods and Prefabricated Methods

Technology of house construction method have been experiencing development from time to time. In general, there are two construction methods that can be applied to lightweight steel roof truss which are the conventional method and the prefabricated method. The assembly of the lightweight steel roof truss using the conventional method is assembled directly on site, but the prefabricated method was done off site and then carried to the house unit using heavy equipment. With heavy equipment, the prefabricated method is considered to be more cost friendly and time efficient. This research is intended to compare the working methods, costs and time of lightweight steel roof truss using conventional methods and prefabricated methods. The research method used is Qualitative Method where the conventional method's data were collected from site observation on Cluster Type A. The results show that the lightweight steel roof truss using prefabricated method has a faster working time by 67% or three times faster than using conventional method. Meanwhile, the cost of using conventional methods is cheaper by 25% on average than using prefabricated methods.

Preparation Scheme Optimization of Thermosetting Polyurethane Modified Asphalt.

To solve the issue of the poor temperature stability of conventional modified asphalt, polyurethane (PU) was used as a modifier with its corresponding curing agent (CA) to prepare thermosetting PU asphalt. First, the modifying effects of the different types of PU modifiers were evaluated, and the optimal PU modifier was then selected. Second, a three-factor and three-level L9 (33) orthogonal experiment table was designed based on the preparation technology, PU dosage, and CA dosage to prepare the thermosetting PU asphalt and asphalt mixture. Further, the effect of PU dosage, CA dosage, and preparation technology on the 3d, 5d, and 7d splitting tensile strength, freeze-thaw splitting strength, and tensile strength ratio (TSR) of the PU asphalt mixture was analyzed, and a PU-modified asphalt preparation plan was recommended. Finally, a tension test was conducted on the PU-modified asphalt and a split tensile test was performed on the PU asphalt mixture to analyze their mechanical properties. The results show that the content of PU has a significant effect on the splitting tensile strength of PU asphalt mixtures. When the content of the PU modifier is 56.64% and the content of CA is 3.58%, the performance of the PU-modified asphalt and mixture is better when prepared by the prefabricated method. The PU-modified asphalt and mixture have high strength and plastic deformation ability. The modified asphalt mixture has excellent tensile performance, low-temperature performance, and water stability, which meets the requirements of epoxy asphalt and the mixture standards.

Application of Segmental Prefabrication Method in Railway Bridge Construction

Segmental prefabrication construction method is a bridge construction technology that divides a span bridge into several segments along the axis direction, prefabricated in batch at the beam yard and transported to the construction site for assembly. This method has been gradually popularized for its advantages of rapid construction, green environment protection and strong adaptability. In this paper, the application status of this method at home and abroad, the key points of construction technology are summarized, and the technical characteristics, advantages and disadvantages are summarized, so as to provide a reference for the project using this method.

A novel steel bulkhead based on the method of prefabrication and assembly and its first application to the Yuliangzhou immersed tunnel

Temporary bulkheads installed at the end of each tunnel element are indispensable for immersed tunnel elements to be watertight and float. Currently, welded steel bulkheads and cast-in-place concrete bulkheads have been applied in the installation of most immersed tunnels; however, these bulkheads have many inherent drawbacks. For example, existing cast-in-place concrete bulkheads are bulky and cannot be recycled after demolition. In addition, existing welded steel bulkheads, which cannot be fully reused, are installed and dismantled with a large number of on-site welding operations. Relying on the Yuliangzhou Immersed Tunnel in China, a novel steel bulkhead based on the method of prefabrication and assembly, namely, a piece-assembled steel bulkhead, was developed to address the abovementioned problems. The structural components of the new steel bulkhead applied to realize full recycling mainly include steel bulkhead panels, ethylene-propylene-diene-monomer (EPDM) sealing gaskets, steel bearings, and steel connecting bolts. The water tightness function of the new bulkhead was achieved through the compression deformation of the designed EPDM sealing gaskets inside the assembly seams, which were designed as multihole structures to save manufacturing material. Nonlinear finite element simulations were conducted to investigate the gasketed seam mechanical and sealant behavior. It was concluded that the control threshold value of gasketed seam compression displacement needed to satisfy the design requirement for a 250 kPa waterproof capacity could be taken as 15 mm, while that for seam offset displacement was set to 40 mm. To achieve the fast and efficient construction of the new steel bulkhead, a strategy of symmetrically installing and removing steel bulkhead panels piece by piece at one carriageway bore was proposed, and an automatic installation trolley that adjusts the bulkhead panel position in three directions was designed and developed. Finally, the on-site monitoring of the assembly seam displacements and the stress and deformation of the H-shaped steel beam verified that the new steel bulkhead was in a safe state and displayed good watertightness. This bulkhead was successfully applied in the Yuliangzhou Immersed Tunnel project, and this test application supports the use of these technologies in immersed tunnel construction.

Impacts of Prefabrication in the Building Construction Industry

Interest in sustainable construction has been increasing due to recent events. The limitations of natural resources and the scale of global impacts, specifically as a result of the effects of global climate change, have consequences for the construction sector. These changes are giving rise to a need to reassess the way we face the built environment and rethink new solutions for construction systems or methods that contribute to mitigating negative consequences, among which we highlight the prefabrication method. This new scenario, characterised by the need to meet the decarbonisation goals set for 2050, as well as the effects of the spread of the pandemic crisis, emphasizes the importance of understanding the impacts that may occur in the construction industry, which are essentially understood as increases in sustainability, productivity, quality and, consequently, as reductions in deadlines, costs, and dependence on labour. Therefore, this entry seeks to study on the existing literature on prefabrication, seeking to gather relevant information on the new advances, challenges, and opportunities of this construction method whose approach has been mostly focused on partial or specific aspects for case studies, both highlighting the potential and identifying the gaps and opportunities of prefabrication in this new context. The prefabrication method brings benefits compared to the conventional method, and may be an alternative, as it has more positive global impacts on the environment, the economy, and society, and consequently on the sustainable development of construction, despite some limitations that have been reported and that should be looked into in the future.

Study on prefabrication method for housing in Indonesia by utilization undegradable waste for building material

Study on prefabrication method for housing in Indonesia by utilization undegradable waste for building material

Innovation of Prefabrication Construction Methods for Cost and Time Efficiency in The High Rise Building Project of Perum Perumnas

Prefabrication has been widely used in construction projects. Prefabrication improves construction speed, architectural quality, material efficiency, and worker safety while limiting construction's environmental impact than conventional construction practices built on site. This research explains the advantages of prefabricated construction methods and offers an alternative method for innovation for the High Rise Building Project of Perum Perumnas. The prefabrication method is an alternative solution based on the SWOT analysis, and software for modeling and structural design is STAAD.Pro V8.I by Bentley System, inc. The research results have shown that prefabrication methods in the High Rise Building Project of Perum Perumnas can save 7% (deviation = 868.47 million) more than the current construction method (conventional). In terms of time, the prefabrication method is faster than traditional methods, with a time difference of 371 days. The estimated time required to complete upper structure work using conventional methods is 557 days. In comparison, the time needed to complete upper structure work with prefabricated methods is only 186 days, assuming the working time is eight hours per day. And the risk analysis is generally mentioned. Therefore, based on the calculation results, it can be concluded that the prefabrication method can increase the number and quality of development production in the High Rise Building Project of Perum Perumnas.

Environmental life cycle evaluation of prefabricated residential construction in China

Due to rapid urbanization, the construction industry in China consumes a significant quantity of material and is responsible for considerable greenhouse gas emissions. Prefabricated construction methods are promoted by the Chinese government because of their potential environmental and economic benefits towards enhancing the productivity and quality of built structures and on-site construction-related pollution. This research investigates the environmental tradeoffs offered by prefabrication methods compared to traditional cast in-situ methods using life cycle assessment (LCA), focusing on primary non-renewable energy, global warming, terrestrial acidification, human carcinogenic toxicity, fine particulate matter formation and eutrophication using a cradle-to-final construction system boundary. Primary data collected from two residential projects under construction in 2019–2020 and built by prefabrication and traditional construction methods in China were compared. This study investigates parameter uncertainty on regional greenhouse gas (GHG) emissions related to electricity production. The results reveal that except for marine eutrophication, prefabrication methods offer more environmental advantages compared to traditional methods for all impact categories. The uncertainty analysis showed that the GHG emission factor for electricity production is not significant within the system boundary. Future research should investigate uncertainty among other parameters related to the building materials in the context of Chinese production. The findings of the study can provide a basis for policy makers in promoting sustainable construction in the context of China.

Challenges Faced in Prefabrication or Modular Construction

Abstract: The prefabricated materials used in construction has indeed been hailed amongst the most efficient approaches, there is a difficulty in implementing this process in the construction industry. The article included an outline of the obstacles and factors that influence prefabrication or modular construction in India. The issues of prefabrication and modular construction were investigated through case studies. Prefabricated elements have been demonstrated to be an efficient and efficient approach for improving productivity and the process of construction, as well as assuring the quality of construction & reducing time and cost. However, there are a number of issues with this strategy in practise, including initial high building costs, lack of understanding of the prefabricated method of construction, technical and installation hurdles, and the inability to find prefabrication businesses locally. Because of the nature of the city and also the growing population, the use of such prefabricated materials in the construction of buildings is beneficial. Keywords: Prefabricated construction, Challenges, fabricated elements, Installation hurdles

Container House using GFRG Panels

In India the demand for housing is ever increasing and hence there is an increase in demand for building materials. Providing affordable housing is a challenge for developing country like India. India have an shortage of millions houses. Now days, more than 17 million retired shipping containers are stacked on the port worldwide. Container building still facing the various challenges. To avoid this challenges GFRG panels use as a Walls and Roofs of container house. So, Container house using GFRG panels provide an adequate solutions to the various problems. Building materials which are energy efficient strong and durable at an affordable cost are in great demand GFRG panels are of much relevance in India where there is tremendous need for cost effective mass scale and rapid housing. They are not only eco-friendly, but also resistant to termites, heat, rot, corrosion, water and fire. Concrete infill with vertical reinforcement rods enhances its vertical and lateral load capabilities. Comparative studies of GFRG and conventional buildings have been carried out in the present investigation. Rapid wall panel provides speedier construction and leads to environmental protection. Subsequently, it is a perfect option building material to replace bricks or concrete blocks. GFRG wall is a green product which can erect a building fast in prefabricated method. This paper highlights the positive aspects of GFRG panels with respect to Time, cost of construction Strength, affordability, energy efficiency over the conventional construction materials and its suitability in the Indian Housing Scenario. This research aims in providing adequate shelter for all individuals that is one among the recent challenges long faced by the developing countries. Economical plan and development of structures, utilizing green material is an option in contrast to exhaustion of totals and increment in cost of concrete. Glass fiber reinforced gypsum panel (GFRG) is a green material, which is a rapid wall construction method and a cost effective construction process. With the end goal to enhance the productivity, and decrease of waste, the lean the development has been presented as another administration rule for better execution. In India, the usage of lean administration in the development industry is a noteworthy errand. Because of the absence of consideration and uneducated towards the lean administration guideline the proprietor, contractual worker, engineers and so on are as yet creating a stage to actualize this standard in their task. This venture primarily centers on to recognize the potential outcomes of execution of lean administration in the development industry. This paper shows the probabilities of compelling usage of lean administration guideline in the development industry, which can definitely diminish the use of time, increment the nature of work, and benefit rate by wiping out the wastage of materials. It finally, points in giving lodging to all classes of people, in this way enhancing the economy of India. Going through this study, it will explore & analyze some projects and case studies from many points of views, Geometrically, Architecturally, structurally, financially, and of course environmentally. The deployment of containers as building modules has grown in popularity over the past years due to their inherent strength, modular construction, and relatively low cost. Finally, conclusions are going to be drawn on the important worth of lean construction against the traditional practice with consideration for the future benefits within collaborative technological models.

Effect of different notch prefabrication methods and notch lengths on rock three-point bending test

Effect of different notch prefabrication methods and notch lengths on rock three-point bending test

Influence of initial defects on crack propagation of concrete under uniaxial compression

In order to evaluate the safety of concrete structures with the initial defect, the meso-scale mechanical characteristics needed to be studied. The uniaxial loading failure process of concrete containing expanded polystyrene (EPS) particles was studied by X-ray computed tomography (X-CT), acoustic emission (AE) and numerical simulation in this manuscript. The results show that cracks were observed preferentially at the corners and the defects close to the outside. The bearing capacity was seriously affected by splitting cracks. The location where open cracks often appear was the largest macroscopic defect in the horizontal projection. The method of prefabrication of defects was reasonable. A polygon aggregate modeling method was proposed considering statistical features. The established model can accurately describe the mechanical behavior, which verifies the consistency of meso-simulation and mechanical experiments. Several meso-scale models with cavities were provided. The size of the defect radius was positively correlated with the macro cracks and the damage degree of tension crack, but negatively correlated with the total damage parameter, the damage degree of mortar and ITZ, and the damage degree of shear crack. The size of the defect mainly plays a major role in the damage of the mortar.

Flexible Design: An Innovative Approach for Achieving Sustainability in Primary Public Schools in Egypt

Public schools in Egypt are considered a valuable asset that should be preserved and sustained, as they play a paramount role for the development of a sustainable community. Whereas, currently, the schools in Egypt are not sustainable from social, economic and environmental perspective as they are generally heavy, fixed and normally irreversible once construction has been completed. This is due to the traditional construction method used in the construction of schools which consumes time and generates a vast amount of waste. In addition, the changing demands of the occupants may confront the need for future expansion or complete changeover. With the increase in labour costs, lack of skilled labours for different trades, demand for faster construction, increased considerations for safety and environment and above all meeting these demands at an economic and reasonable price requires us to change the approach used in construction. Hence, these faults could be sufficed with the introduction of green prefabrication methods as a flexible design approach for achieving sustainability for primary public schools in Egypt. Therefore, this paper aims to formulate a matrix that correlates the flexible design criteria with suistainability in order to achieve suistainability in Primary Public schools in Egypt. A research methodology consists of literature review to investigate the topics of primary public schools, flexible design, Green prefabrication and sustainability.

Another way of living: The Prefabrication and modularity toward circularity in the architecture

The world requires housing capable of addressing the ecological challenge and social changes. Various architecture projects have used alternatives to solve these problems, like housing complexes to increase density, fast and low-cost constructions with prefabricated and modular methods and materials. The concrete will always be rooted in the culture of architecture, even the industry of construction can work with other materials and whose manufacture produces a considerable amount of CO2. Taking into account the different construction cycles and the evolution of uses and users, a change in architectural culture is required. This paper aims to shows that it is possible to achieve the concept of circularity in the built environment through the architectural design process. The research by design methodology was used to develop the recyclable typology named Slab focused on residential prefabrication methods, which will facilitate their disassembly and recycling. As a result, the design process and the models’ evolution of the Slab prototypes are presented in this paper. Prioritizing prefabrication and the modularity within the architectural design process has advantages, such highly effective reduce footprint areas, large-scale infrastructure for flexible use, and individual housing units with communal activities, besides, assure the building conditions for future disassembly and recycle.

Autonomous dry stone

On-site robotic construction not only has the potential to enable architectural assemblies that exceed the size and complexity practical with laboratory-based prefabrication methods, but also offers the opportunity to leverage context-specific, locally sourced materials that are inexpensive, abundant, and low in embodied energy. We introduce a process for constructing dry stone walls in situ, facilitated by a customized autonomous hydraulic excavator. Cabin-mounted LiDAR sensors provide for terrain mapping, stone localization and digitization, and a planning algorithm determines the placement position of each stone. As the properties of the materials are unknown at the beginning of construction, and because error propagation can hinder the efficacy of pre-planned assemblies with non-uniform components, the structure is planned on-the-fly: the desired position of each stone is computed immediately before it is placed, and any settling or unexpected deviations are accounted for. We present the first result of this geometric- and motion-planning process: a 3-m-tall wall composed of 40 stones with an average weight of 760 kg.