Prefabricated Construction Systems Research Articles

Modular construction as a promising alternative for the construction of affordable and quality housing

This study seeks to explore the fundamental characteristics of modular construction, which covers the details of design and construction processes, from production through to assembly. Its objective is to evaluate essential parameters, such as project timelines and costs, associated with this construction method, in comparison with traditional construction systems. This analysis is prompted by labour shortages and the lack of affordable housing in Portugal. Modular construction prioritises the adoption of prefabricated construction systems, with potential benefits including cost and time savings, contributing to the provision of quality, economically viable, and accessible housing. This study provides valuable insights to tackle housing challenges in the Portuguese context, highlighting modular construction as a promising and sustainable alternative within the engineering domain.

Behavioral Assessment and Evaluation of Innovative Hollow Glue-Laminated Timber Elements.

Due to the growing need to preserve our planet and reduce carbon emissions during construction, the use of the only carbon-absorbing material, timber, is increasingly being imposed. In addition to the requirement of reducing emissions, there is a necessity for the shortest possible construction time and the minimum use of construction machinery, which has led to the development of prefabricated construction systems. This paper deals with the innovative, hollow, glue-laminated timber elements which are intended for modular construction. Comparing this new system with existing modular systems, the main features and behavior of the constitutive elements, i.e., the hollow, glue-laminated timber elements, are presented. Experimental and numerical analysis of the mechanical performance of the timber elements was carried out and a comparative analysis of the behavior of two different types of hollow timber elements was conducted. The finite element method was used to predict the behavior of this innovative structural system. The results are compared with the analytical procedure to provide a background for the development of standardized methods for the design of timber structures.

Thermal performance of a novel lightweight emergency construction system in different climates

Prefabricated, lightweight construction systems, thanks to their quicker construction processes, cheapness, higher portability, and adaptability, are increasingly proposed all around the world as emergency architectures (after natural disasters, pandemics, etc.), and as affordable housing solutions in countries with increasing housing demand. Due to their low thermal inertia, however, these buildings are often characterized by poor thermal performance in hot climates due to indoor overheating. The possible application of passive cooling measures is often investigated to improve their thermal performance. Among others, cool materials present some advantages in terms of ease of application and costs. However, few studies investigated the impact of this passive strategy on the thermal performance of emergency buildings. For this reason, this work evaluates the impact of cooling materials on the thermal performance of a novel lightweight prefabricated construction system (HOMEDONE) based on the assembly of reinforced-EPS panels. First, a numerical model of an experimental mock-up was created and calibrated on experimental data. Then, the thermal performance of a typical temporary housing solution was numerically evaluated under different climatic locations. Finally, the effectiveness of cooling finishing materials is investigated. The potential of cooling materials in reducing the energy demand for the studied construction system is then highlighted.

What is the potential for prefabricated buildings to decrease costs and contribute to meeting EU environmental targets?

The European Union (EU-27) targets buildings' decarbonization by 2050, and prefabrication presents an opportunity to reduce buildings and construction sector impacts. A stock-based approach was developed to measure the influence of wide adoption of building prefabrication in the EU-27 building stock from 2020 to 2050. Impacts and costs of five typologies using conventional or prefabricated construction systems were assessed for three cities – Lisbon, Berlin, and Stockholm – and three insulation levels. Results were calculated at the building and country levels and then combined at the stock level. Global warming (GW) varies between 5kgCO2eq/m2 for prefabricated light steel framing (prefab_LSF) medium- or a high-rise in France and 85kgCO2eq/m2 for the conventional concrete single-family (SF) in Poland. Life cycle costs vary between around 900€/m2 for multi-family buildings in prefabricated LSF in Bulgaria and over 11 000€/m2 for an SF in conventional concrete in Luxembourg. Prefabrication can further decrease building stock burdens up to 6% and reduce building stock costs up to 10%. The developed building stock model has proven to be a fast and reliable tool to forecast the market dynamics when introducing a technological innovation, such as prefabrication. Prefabrication can contribute to achieving the EU-27 targets and reduce construction costs, increasing the construction sector's productivity and sustainability.

Prefabricated versus conventional construction: Comparing life-cycle impacts of alternative structural materials

Prefabrication can have advantages in terms of materials and time efficiency, but the overall environmental and cost trade‐offs between the two construction methods are unclear and influenced by the choice of the structural material. A life cycle assessment was carried out to compare two constructive systems (prefabrication and conventional) and different structural materials for a single-family house. Impacts, waste, costs, and production time were assessed for two prefabricated construction systems – lightweight steel frame (LSF) and wooden frame (WF) – and two conventional construction systems – reinforced concrete (RC1) with a single layer concrete block or with a double-layer brick external wall (RC2). Results showed that WF has the lowest impacts followed by LSF, and that embodied impacts can represent more than half of total impacts. Prefabricated houses have up to 65% less embodied impacts, and end-of-life impacts of prefabricated LSF are lower due to recycling; thus, unveiling the importance of embodied and end-of-life phases. Prefabrication can decrease impacts, materials consumption, and waste generation, pushing forward circularity within the construction sector.

AN ECO-SUSTAINABLE PARAMETRIC DESIGN PROCESS OF BIO-BASED POLYMERS TEMPORARY STRUCTURES

The primary common goal of any resource processing intervention is environmental sustainability. It seeks practical collaboration in construction technology and innovation, whether intentionally used to increase eco-friendly energy savings or implicitly used to reduce the impact of construction projects on the global environment. Biopolymers are a promising field for growth because they combine high technological potential with environmental sustainability. A viable alternative to conventional, costly, and complicated construction systems is the employment of technologies that exploit environmental sustainability concepts to create temporary modular structures that maximize manufacturing times and costs. The paper presents an innovative process for designing temporary structures for social, cultural, and exhibition use. The present paper aims at the following objectives: (i) to illustrate a parametric approach to the design of spaces for such proposes; (ii) to study a prefabricated construction system consisting of interlocking elements to be dry assembled; (iii) to propose the use of new bio-based material. The building system originated based on these research instances targets the requirements of: adaptability, flexibility, and reversibility of spaces; prefabrication, lightness, and speed of installation and assembly; environmental sustainability and recyclability of components employed. In particular, the modules that make up the final product, characterized by vaults, are conceived as small shelters for reading and social activities.

CONSTRUCTION-TECHNICAL SPECIFICS OF A PREFABRICATED WOOD CONSTRUCTION SYSTEM

Wood as a raw material and material in the construction of wooden buildings has an irreplaceable position in terms of the complex of mechanical, thermal-technical, aesthetic, utility, technological properties and the impact on the environment. In many countries of our region, it is a strategic, yet renewable raw material, which brings considerable profits to national economies, especially where it is comprehensively processed in products with high added value. Today's wood-based construction methods are very diverse and can be individually adapted and combined. Current wooden buildings intended for housing can in principle be divided according to the character and nature of vertical load-bearing structures into massive, skeletal and elementally constructed elements composed of individual elements. From the point of view of the efficiency of the construction process, an effective solution is especially construction systems that use elements of automation and prefabrication of structural elements of the construction site. The production process of prefabricated components is diverse depending on the specific manufacturer of the individual components. Pre-prepared structural elements and parts of structures more or less finalized are then transported to the construction site where they are assembled into the final form. In connection with prefabricated construction systems for the construction of wood-based structures, it is necessary to analyze their production process where it is possible to identify significant reserves and propose improvements to streamline the production process. From this point of view, in this paper we focused on the analysis of the production processes of a prefabricated wood-based construction system.

Model validation of factors limiting the use of prefabricated construction systems in Turkey

PurposePrefabricated construction technology enables relatively faster and easier construction of building structures at a lower project cost, providing improved quality control with minimal material waste. Despite the advantages of prefabricated construction systems, they are not extensively used in Turkey because of specific yet largely undefined challenges. Therefore, the purpose of this study aims to determine the factors currently affecting the extensive use of prefabricated construction systems in Turkey.Design/methodology/approachThe reasons for such systems not being used extensively in Turkey were examined using responses to a questionnaire distributed amongst architects working at design firms, prefabricated-building manufacturers and contractors. The obtained survey data were statistically analysed using the SPSS 22 and LISREL 8.7 software to rank the severity of the identified challenges and determine the most critical factors.FindingsEight critical factors groups affecting the use of prefabricated construction systems and their associated factors were identified according the responses provided by the participants. Potential solutions and recommendations were proposed based on these factor groups that are expected facilitate the implementation of prefabricated construction systems in Turkey.Originality/valueLittle previous research has provided insight into the specific factors limiting the use of prefabricated construction systems. This study accordingly approaches the subject considering all phases of prefabricated construction systems and presents a structural model of the factors obtained by a confirmatory factor analysis for application to expand the use of prefabricated construction systems.

TÜRKİYE’DE BETONARME PREFABRİKASYON

In parallel with the socio-economic and technological developments, rational solutions were sought in construction systems and prefabricated construction systems emerged finally industrialization. Developments in prefabricated construction systems have increased the need for regulations, standard and technical specifications related to this subject, and encouraged many experimental and theoretical types of research. While reinforced concrete prefabricated systems are at high levels in developed countries, our country is well below these levels. The ratio of prefabricated production to the number of people is 0,38 m3/person in European countries and 0,02 m3/person in our country. This study summarized the situation in Turkey and world reinforced concrete prefabrication; evaluations were made in Turkey for the use of prefabrication. Also, the effects of economic growth and construction volume on prefabricated construction systems were analyzed through sector reports. In the study the prefabrication of the structures produced in Turkey generally focus on building infrastructure and industry, but it is seen that the largest share of the production of housing should be spread.

Analysis of Prefabricated Systems in the Construction of Family Houses

At the moment the human is trying to make the construction as efficient as possible, accelerate and facilitate the introduction of different types of innovations. Therefore, to the fore a new concept of prefabrication, which we call modern methods of construction MMC is coming. In this article, 3 prefabricated construction systems were chosen for the analysis of the construction of the family house. It is a system of Europanel SIP technology, CLT panels and ceramic panels. These are systems of euro panels' technology SIP, CLT panels and ceramic panels. The choice of construction systems has taken into account that all three systems fall under the MMC philosophy. Subsequently, selected parameters of individual structural systems were analysed, such as wall thickness, ceiling thickness, bulk density, compressive strength of walls, heat transfer coefficient, reaction to fire, fire resistance, usable area and price on a particular family house project.

Assessing the productivity of prefabricated and in-situ construction systems using hybrid multi-criteria decision making method

There is little interest in prefabrication in the construction industries of developing countries, despite all its advantages. The main challenge goes back to the low level of knowledge and wrong believes about the productivity of prefabrication construction systems in comparison with conventional ones. The purpose of this study is to provide a comprehensive and systemic decision-making tool to assess the productivity of construction systems of residential buildings. First, the determinants of productivity are identified using the Delphi method. Then, the Decision making trial and evaluation laboratory (DEMATEL) method is used to determine the level of influence of various criteria. Thereafter, the Analytic Network Process (ANP) method is utilized to determine the importance weight of criteria and finally, the ranking is done by the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method. Our analysis indicated that the management and planning criterion is the most influential criteria, and the cost is the most impressionable criterion in terms of productivity. Also, the case study results demonstrated that the prefabricated concrete buildings are the most productive ones, compared to the other two construction systems of prefabricated, and in-situ concrete. In the lack of possibility of complete prefabricated method, the combination of in-situ and prefabricated concrete construction system can be applied as a productive method in building the structure and façade. Finally, the results confirmed that the proposed decision-making process could assist the investors to select the most appropriate prefabricated construction system to achieve the highest level of productivity.

Environmental Benefits of Timber-Concrete Prefabricated Construction System for Apartment Buildings – a Simplified Comparative LCA Study

The aim of a research project TiCo (Timber Concrete) is to create a standardized flexible construction system for multifamily apartment buildings for central European climatic conditions with low environmental impact. It exploits advantages of advanced prefabrication and favourable material properties of its main elements. Prefabricated structural system was designed using concrete frame with thin columns and lightweight ceilings with reinforcing core. Façades and interior partition walls were designed from prefabricated timber frame panels. The paper presents a simplified comparative LCA study of the designed TiCo building system and conventional building solutions. The compared variants had the same key parameters – load bearing capacity and heat transfer coefficients of building’s envelope. The analyses include load-bearing structures, façade, partition walls, foundations and roof. The others like HVAC systems, floors, doors, windows or tin work were not included. A simplified comparative LCA is based on procedure described in method SBToolCZ, which evaluates the quality of buildings in terms of sustainability. The assessment covered embodied environmental impacts of the construction system structures with their replacement based of their service lives. Prefabricated concrete frame structure with timber envelope was found environmentally friendlier compared to conventional solutions. The combination of the concrete load-bearing structure and lightweight timber frame panels that benefits from favourable characteristics of both materials for the given purpose appropriately used in the construction appeared to be an efficient way of minimizing building’s environmental impact.

BIM-oriented data mining for thermal performance of prefabricated buildings

The use of energy efficiency procedures is a typical practice in building construction process that creates a huge amount of data regarding the building. This is particularly valid in structures which include complex collaborations, for example, ventilation, sunlight-based increases, inner additions, and warm mass. This paper proposes a new approach for automating building construction when improving their energy efficiency, aiming to foresee comfort levels based on Heating, Ventilating, Air Conditioning (HVAC), constructive systems performance, environmental conditions, and occupant behavior. More specifically, it presents a research work about thermal performance of prefabricated construction systems developed by an Argentine enterprise called Astori, using two Knowledge Discovery in Databases (KDD) processes to extract knowledge. In this context, Building Information Modeling (BIM) will give data to support the calculation to outline goal levels of a sustainable building performance concerning classification systems. The data were collected from a project in Uruguay referring to the construction systems and the energy efficiency of the building. The data mining tool SPMF was used to test the performance of classification and its use in prediction. Particularly, FP-Growth Algorithm and Clustering methodologies were used to analyze a combination of ambient conditions, in order to compare them using Revit© software. The results generated by these methods can be generalized for a set of buildings, according to the objective to be achieved concerning the thermal building performance.

Prefabrication as Large-scale Efficient Strategy for the Energy Retrofit of the Housing Stock: An Italian Case Study

In this work a multi-story residential building located in Cinisello Balsamo, near Milan, was considered as case study for the application of two new prefabricated building systems for the energy retrofit. The first one, developed within EASEE, a European project funded by 7th Framework Program, consists in a preassembled insulated panel for the retrofit of facades, based on two TRC thin precast layers rigidly connected to an EPS core. The panels can be easily applied on the external side of existing facades without the use of scaffoldings, providing an additional efficient insulation as well a new external cladding. The second one consists in a preassembled timber panel for existing pitched roofs. The process includes the substitution of the existing roof with modular integrated panels with a high content of recycled materials that can be easily fixed on the existing structures (timber frames, concrete, masonry, etc.). The combination of the two prefabricated construction systems, applied on the case study, allowed the reduction of the building energy demand by 82%.

The influence of prefabricated construction systems on Belgrade's architecture

In the second half of the 20th century Belgrade was being developed and expanded at a fast pace. Many residential areas that grew at the time were built using prefabricated industrialised systems. Prefabricated construction technologies were developed as a result of multiple influential factors such as the socio-economic situation, cultural, scientific and technical development, and housing policies. The paper presents several widely used prefabricated construction systems (IMS, Rad-Balansi, Jugomont, Trudbenik, Komgrap), points to a few characteristic examples of residential buildings, complexes, blocks or neighbourhoods dating from different decades of the second half of the 20th century, and identifies as yet unmapped examples of Belgrade's residential architecture using the historical method of research. The paper initiates further and more thorough research both into residential architecture in Belgrade and into the technology of prefabrication in the context of the technical and architectural achievements of the 20th century. The goal of the research is to gain a more thorough knowledge of the examples of residential architecture which are representative of a particular period or a type of housing. The paper draws attention to the architectural works which have not hitherto been studied or published but which deserve the attention of the professional and general public. Its particular contribution is in defining the ways in which prefabricated industrialised systems influenced architectural design, and in proposing a typology of floor layouts occurring in residential buildings constructed using these systems.

From Digital to Physical: Advancing Industrialized Construction through Digital Prototyping Processes

Recent development in digital design strategies and fabrication tools has offered the Architecture, Engineering, and Construction (AEC) industry the opportunity to rethink the prefabricated building industry. Different methodologies have been proposed with the aim of formulating an efficient link between design and fabrication processes, based on devising effective data workflows to overcome complexities associated with conventional production models. This paper demonstrates recent developments in implementing a Digital Prototyping model toward establishing a comprehensive strategy for design and fabrication of a family of building components. The proposed model is specifically designed and implemented to realize a prefabricated construction system, BONE Structure®, with the aim of enabling high precision in design and fabrication, in addition to supporting pre-defined assembly on jobsites. This paper represents a phase from an ongoing research endeavor toward infusing the design and production processes with digital logic, aiming for high flexibility and customization in building design, specifically the housing realm.

Behavior of C-Shaped Beam to Square Hollow Section Column Connection in Modular Frame

모듈러 건축은 사전에 설계 검토된 건물 요소를 공장에서 모듈로 제작하여 현장으로 운송 조립하는 프리패브 건축 시스템이다. 모듈러 건축물의 구조 형식은 공법, 재료, 부재 구성 등에 따라 다양하게 구분될 수 있지만 사용되는 모듈의 구조 형식은 크게 벽식과 가구식으로 나눌 수 있다. 벽식 모듈은 모듈의 입면을 패널을 이용하여 구성하여 수직하중과 수평하중을 전달시키는 방식이다. 가구식 모듈은 기둥과 보를 이용하여 모듈을 구성하고, 용도에 맞춰 입면을 마감하거나 개방시켜 놓는 방식이다. 이 두 가지 모듈 방식은 국내에도 사용된 바 있으나 최근 가구식 모듈이 보편화되고 있다. 가구식 모듈의 기둥 부재로 각형강관이 일반적으로 사용되고 있으며, 보 부재로 C형강 또는 H형강이 사용되고 있다. 각형강관이 기둥 부재로 사용된 가구식 모듈간 접합을 위해 각형강관 기둥 단부에 고력볼트를 채우기 위해 액세스 홀을 가공하는 경우가 있다. 액세스 홀은 볼트체결을 위해 사람의 손이나 공구가 폐쇄형 단면인 각형강관 내부에 접근하기 위한 개구부로 액세스 홀은 기둥-보 접합부의 거동에 영향을 미치는 패널존을 약화시킬 가능성이 높다. 이 연구에서는 가구식 모듈의 기둥-보 접합부 거동에 영향을 미치는 액세스 홀, 기둥 두께, 다이아프램을 변수로 5개의 실험체를 제작하여 실험을 실시하였고 그 결과를 분석하여 제시하였다. Modular building is a prefabricated construction system for building where factory-produced pre-engineered modular units are delivered to site and assembled as substantial elements of a building. There are two basic kinds of modular structures. One is a load-bearing wall structure designed to transfer the load through longitudinal walls. The other is a frame structure composed of columns and beams. For frame structure, square hollow section is often used as a column member and channel as a beam member in modular unit. Lower and upper modules are fasten with bolts via a pre-installed access hole in the SHS column. However, the access holes can weaken the panel zone that would affect the behavior of beam to column connection. The 5 specimens of beam to column connections with parameters of access hole, column thickness and diaphragm were made and this paper describes the test results.

Tu-P7:39 Vasclar inflammation and atherosclerosis development in a mouse model of alzheimer's disease on a ApoE KO background

In this work a multi-story residential building located in Cinisello Balsamo, near Milan, was considered as case study for the application of two new prefabricated building systems for the energy retrofit. The first one, developed within EASEE, a European project funded by 7th Framework Program, consists in a preassembled insulated panel for the retrofit of facades, based on two TRC thin precast layers rigidly connected to an EPS core. The panels can be easily applied on the external side of existing facades without the use of scaffoldings, providing an additional efficient insulation as well a new external cladding. The second one consists in a preassembled timber panel for existing pitched roofs. The process includes the substitution of the existing roof with modular integrated panels with a high content of recycled materials that can be easily fixed on the existing structures (timber frames, concrete, masonry, etc.). The combination of the two prefabricated construction systems, applied on the case study, allowed the reduction of the building energy demand by 82%.

Greenhouse gas balances in building construction: wood versus concrete from life-cycle and forest land-use perspectives

Prefabrication can have advantages in terms of materials and time efficiency, but the overall environmental and cost trade‐offs between the two construction methods are unclear and influenced by the choice of the structural material. A life cycle assessment was carried out to compare two constructive systems (prefabrication and conventional) and different structural materials for a single-family house. Impacts, waste, costs, and production time were assessed for two prefabricated construction systems – lightweight steel frame (LSF) and wooden frame (WF) – and two conventional construction systems – reinforced concrete (RC1) with a single layer concrete block or with a double-layer brick external wall (RC2). Results showed that WF has the lowest impacts followed by LSF, and that embodied impacts can represent more than half of total impacts. Prefabricated houses have up to 65% less embodied impacts, and end-of-life impacts of prefabricated LSF are lower due to recycling; thus, unveiling the importance of embodied and end-of-life phases. Prefabrication can decrease impacts, materials consumption, and waste generation, pushing forward circularity within the construction sector.

Inappropriate technology? Experiences of social housing in Britain

During the 1960's and early 1970's heavy prefabricated construction systems were employed on a large scale to attempt to solve the acute shortage of public housing in Britain. Subsequently a high percentage of these multi-storey blocks experienced severe problems: some because of serious technical faults, whilst others for largely social reasons. The problems worsened and during the 1980's large numbers of these blocks were demolished barely 20 years after their construction. This paper assesses the effects of technological choice in housing, discusses the interrelationship between technology design and social factors, and explores the explanations and implications of these failures.