Journal of Chemical and Pharmaceutical SciencesISSN: 0974-2115 A review on building industrialization Pradeep Kumar A*, Vinayak Dave Dept. of Civil Engineering, Saveetha school of Engineering, Saveetha University, Chennai *Corresponding author: E-Mail: [email protected] ABSTRACT This paper has set the building industrialization as the main line and studies the common building types (single/low-level/multi-level/high-level residential buildings) in different countries. In the following sections, comparative analysis has been done in selecting construction methods, durations and costs based on various structural systems (wood, steel, prefabricated structures). After this, the underlying causes of these differences should be revealed. The final step is going to be the exploration of the most suitable industrialization residential building types for each. The main part of the paper has been divided into two parts: One is the common building types of single/low-level industrialized housing systems; the other is the common types of multi-story/high-level housing systems. For lower level buildings, the wood and light steel structures are easier to implement the design goal of ‘design diversity, modern manufacturing factory and green’. Meanwhile, the construction period is far more shorter than traditional brick and situ concrete engineering. The wooden houses in different countries (North America Finland, Japan and China) has distinct geographical and cultural characteristics and the cold-formed light steel keel systems have been greatly developed in Europe, North America, Australia and Japan. In these countries, different structural systems result in the change of construction methods. In accordance with the multi and high level buildings, the precast concrete and prefabricated steel structures has been most widely developed and used in Europe, America and Japan. The design of nodes is emphasized compared to other aspects. KEY WORDS: Prefabricated structures, Precast concrete, insitu concrete engineering. 1. INTRODUCTION According to Yang X.Y. (2009), the so-called building industrialization adopts modern scientific and technological means, uses industrialized, automatic large-scale production mode instead of traditional scattered handicraft production mode and makes full use of high technology to build the most satisfactory houses with minimum labor, shortest time and the most reasonable price. The industrialization of residential construction simply means: building houses like making cars. There are three types of structures which are suitable for residential industrialization: wooden structures, steel structures and precast concrete structures. Steel structures include light gauge steel structures and heavy gauge steel structures. Based on Han (2008), idea, the housing industrialization developing process of United States, Japan and other developed countries in Western Europe has mainly gone through three stages. The first stage is the initial stage, which is the formation of industrialization. It mainly focuses on establishing the industrialized production mode. The second stage is the development stage of promoting industrialization and this stage stressed on the increase of the ratio between housing quality and price. The third stage is the maturity of industrialization development. At this stage, buildings are focused on lowering the material consumption and the burden to environment, and developing a recycling-oriented house at the same time. The regional distributions of the residential industrialization are as follow: North America pays more attention to the development of the wooden frame houses and secondly the light steel residential structures; In Finland, Sweden and other Europe countries, the low-layer light wooden frame houses have been vigorously promoting; The industrialized housing in Japan is manly in low-rise wooden frame house, following by the high-rise precast concrete and steel structures. In Australia, light steel structural houses are also the mainstream; among all types of industrialized housing systems, the prefabricated steel structures are developing more quickly. Comparisons of single and low storey buildings in different countries: This section investigates and compares the structural systems, the construction methods and the comprehensive economic benefit of normal single and low-layer wooden and steel constructions in countries all over the world. Comparison of building systems and construction methods of wooden constructions: So far, the development of modern wooden construction has been characterized with distinct regional culture characteristics and integrated the science, the technology and the art together. In addition to this, the wooden frame buildings have been approved as green building types of energy conservation, emission reduction and sustainable development. Light wooden frame houses in North America: Frameworks use standard dimension lumbers processed by log. All timbers used in the construction are subject to quality classification and drying treatment. Timber for plates is generally plywood or oriented strand board (OSB board). They are mainly used as the coverage of wall, floor and roof systems. Other wooden members include standard dimension lumber, integrated wood, laminated veneer lumber and light timber- truss. The construction of light wooden frame structures in North America is called as Platform Framing. And the

JCHPS Special Issue 6: November 2016 www.jchps.com Page 243 Journal of Chemical and Pharmaceutical SciencesISSN: 0974-2115 construction process is mainly divided into five stages: foundation construction, wall framework, floor pavement, roof assembly and the internal and external decoration. The construction methods in each stage have been introduced in detail. For wooden structures, the preventive measures are imperative. It is highlighted by the author that moisture, termite and fire preventions are crucial to ensure the safety and health of the structures. Finnish wooden buildings: The traditional log structure and the modern light wood structures are the two main forms of wooden structures in Finland. Logs make houses have excellent insulation properties and a strong artistic expression of interior decoration. The developed industrialization of Finnish construction is mainly reflected in the material pre- cutting and the manufacturing process of various building components. Finnish building system implements standardization by fully complying with strict standardized modular system. So it can realize producing in factory and assembling on site. The long term development of Finnish wooden structures is closely related to the rich forest resources nationally. Japanese low-rise wooden houses: There two common modes of Japanese modern wood structures: the shaft set engineering mode and the frame wall construction method. The first one is the most prevalent structural type for Japanese residential buildings because the room layout is relatively free. In order to reduce the respond of earthquake, several approaches have been considered in the seismic design of Japanese wooden buildings: special shock absorbers that is a kind of shear resistance member is recommended to install between the studs; add metal shock absorber which can strengthen the vulnerable parts of the nodes; seismic isolation devices could also decrease the overall shaking caused by earthquakes. The SE construction method derived from English ‘Safety Engineering’ integrates wood components and steel fittings together to form a complex structural member with great engineering performance in real cases. In this method, the installation of steel connectors is operated on the foundation corner and the wood members. Then they are joined together. Chinese low-rise timber structures: The post and lintel structures and the column and tie structures are the two main types of Chinese traditional wooden structures. The first type of structures uses tenon and mortise as the connection and hand-made beams or columns. The characteristics of these structural types are the loading bearing structures and the enclosing structures are clearly divided. Wall only play a role of spacing division. As comparison, the column and tie structures have a relatively small spacing between columns and the columns directly bear the weight of purlins. Longitudinally connection columns by ties that insert the column heads. The general construction pattern is as following: brick foundation, timber frame, 240brick wall, timber roof truss and grey tiles. This old building type cannot satisfy the requirement of seismic resistance in Chinese structural engineering codes. However, in recently years, new model of light timber residential buildings have gradually spread in major consumption cities. But the number is still quite small. Economic analysis of single and low layer wooden house: Because the wooden frame structures have a higher degree of industrialization, the construction period is much shorter than other types of structures. By considering the concept of ‘full life-cycle costs’, this index of wooden residential houses is only higher than traditional structures 3.5%-11.4%, which is acceptable to people who intend to acquiring much more comfortable life. Comparison of light steel building systems and construction methods in different countries: Light steel structural systems can be broadly divided into two categories: the light keel structures and light steel frame structures. Light steel structures in British: In accordance with the different sizes of the prefabricated unit, the systems can be divided into ‘stick’ structures, ’panel’ structures and ’modular’ structures. During the construction process of each method, labour and large lifting machinery costs are saved on site. More specific works such as roof insulation treatment can be finished in short construction duration. Lightweight steel housing in Australia: The load bearing structures adopts the cold formed light steel and high strength, corrosion resisting steel coils. Retaining walls mostly adopt the fiber cement board. And the roof systems use water proof glass tiles, membranes, stringers and fireproof plasterboards. It is completed by software in the whole process of structural member production. Japanese light steel residential construction: A new type of Japanese system is formed which consists of steel frame and thin shear wall. The characteristic of this structural form is that the load-bearing framework is composed of lightweight steel columns and H-shaped steel beams. The construction steps is divided into columns mounting, H-shaped beams and roof installing. At last, the retaining wall is constructed. Economic benefits analysis of light steel housing construction: From case study, it is informed that the construction costs of civil part of low-rise lightweight keel construction is higher than brick-concrete structure by 27.1% and higher than reinforced concrete frame structure by 11.4%. The main reason for this is the higher price of steel. But by overall consideration, we cannot ignore that the foundation costs of light steel keel structure can be relatively reduced due to reduction of self-weight of the structure itself. Moreover, industrialized steel housing has a shorter construction duration JCHPS Special Issue 6: November 2016 www.jchps.com Page 244 Journal of Chemical and Pharmaceutical SciencesISSN: 0974-2115 which means the developers will recover investment rapidly. In the aspect of environmental effects, 90% drying operation will obviously reduce the dust and air pollution in the construction. Comparisons of multistory and high-rise buildings in different countries: With consideration of possible renewal and transformation of buildings during their whole life cycle, the international SI residential system has been proposed. SI(S-skeleton and I-infill) combines industrialized production and supplement to ensure the durability and shock resistance of skeleton structure and the variability of indoor decoration and equipment. Comparison of precast concrete structure systems and construction methods in different countries: Comparing with the conventional situ concrete construction, the on-site wet work is significantly reduced and the construction process is much simplified. Due to the inevitable splice on site, the design methods and construction methods of nodes are different. The technology is mainly focused on the point that utilizing node connections to reach the same or even better overall performance with the situ concrete structures. Precast concrete structures in the North America: The related standards are perfect and comprehensive. The prefabricated walls and the precast structural components in North America are large-scale and pre-stressed that will optimize the structural reinforcement and connection. Recently, PCI has published books related to seismic design will guide the public with great prestige. Precast concrete structures in Europe: Due to demand for housing, Europe develops precast concrete structures at an early age. According to Yang (2009), France is the place where started ‘the first generation of industrialized buildings’ .The C5 software has replaced labour in the late 1990s. Japanese precast concrete structures: ‘Tilt up’ method is the symbol of industry production. As time goes on, more and more higher prefabricated concrete buildings has been built by government. Basically, Japan has divided the precast concrete structures in to four kinds: precast shearing wall structures, precast frame structures, precast frame-shearing wall structures and the prefabricated keel structures. The construction method of each structural form has been included into the thesis. Chinese precast concrete structures: The precast concrete buildings and the precast concrete hollow floor buildings are two kinds of major industrialized building types whose application rate is about 70%. Enter the year of 2000, a number of large real estate enterprises in China has actively introduced mature precast concrete technology and develop theories that are more suitable to Chinese own conditions. Comparison of prefabricated steel structure systems and construction methods among countries: Steel structure possesses the characteristic of lightweight, high strength, perfect earthquake resistance and environment protecting. As for the steel structures, the key factor of its overall performance lies in the structural lateral force resisting performance. The United States: The staggered truss structure system is developed by Massachusetts Institute of Technology is a kind of more economical system with superiority on building layout. It is studied by Zhao H.Z. (2006) that the staggered truss system is composed of columns, trusses and floors. The truss is the same height as the story and its length is equal to the width of the house. Japan: In the early 1970s, Japan invented dwellings in combination of H section steel and concrete, which is called HPC construction method. The Japanese construction methods of prefabricated steel structures are mainly from Japanese large-scale building estate enterprises such as the frame structure system, the framework-bracing system and the prefabricated unit system. China: Case analysis: Changsha Yuanda Group-inclined bracing structure systems. 2. CONCLUSIONS The wooden structures and light steel structures are the most common structural types for single ad lower residential buildings in all countries. The wood frame houses in all counties have distinct geographical and cultural characteristics, which are related to the local traditions, technologies and economic conditions. Another important aspect for the light steel structures is that the cold-formed steel keel systems have been greatly developed in Europe, North America and Australia because of its simple construction, seismic excellence and graceful appearance. For the multi- level and high-rise residential houses, the precast concrete and prefabricated steel structures are more appropriate selections. The key point is the node design. REFERENCES Han JQ, Research of Industrialization of Steel-structure Residential Housing, Wuhan University of Technology, Wuhan, China, 2008, 8. Yang XY, The Research on System and Design Method of Industrialized Housing Based on PCa Technology, Dalian University of Technology, Dalian, China, 2009, 8. Zhao HZ, Experimental Study on the Structure System and Joint for Multi-storey Steel Residential Building, Inner Mongolia University of Technology, Inner Mongolia, China, 2006, 19. JCHPS Special Issue 6: November 2016 www.jchps.com Page 245