Endüstrileştirilmiş Bina Yapımında Açık Kapalı Üretim Ve Pazarlama Sistemlerinin Uygulama Sorunları

Abstract

Bugün Türkiye 'de nüfusun hızla artmasına, tarımın ekonomideki payının azalmasına, üretim ve hizmet sektörünün belli bölgelere yığılmasına paralel olarak nüfus hareketleri, işsizlik ve istihdam problemini büyük boyutlara ulaştırmıştır. Bunların sonucunda kentleşmenin neden olduğu sosyal ve ekonomik sorunlar, bütün dünyada olduğu gibi ülkemizde de daha rasyonel çözüm olanaklarının araştırılmasını ve uygun teknolojilerin seçimini gündeme getirmiştir. Türkiye 'deki yapı üretim probleminin çözümünde artık geleneksel sistemlerin ihtiyacı istenen nitelik ve nicelikte karşılayamıyacağı görülmektedir. Dolayısıyle diğer ülkelerde olduğu gibi endüstrileşmiş yapımda hızlı, ucuz yapı üretiminin teorik ve pratik olarak ele alınması gerekmektedir. Avrupa ülkelerinde endüstrileşmeye geçişte atılımın öncüleri üretici kesim olduğu için yapı, kapalı üretime dayanmıştır. Bu tür bir üretim ve pazarlama biçimi ise, standart yapının ortaya çıkmasına, standardize bir mimari çevrenin yaratılmasına neden olmuştur. Ancak yine de üretim dizileri gerçek bir endüstrinin gerektirdiği düzeyden daha aşağı kalmıştır. Böyle bir durumda çözüm, üretilen hazır parçaların mümkün olduğunca çok planlama çeşitliliğine ve değişik yapılarda kullanılabilme olasılığının sağlanmasına imkan veren bir yöntemin uygulanmasıdır. Bu çalışmada ana tema, endüstrileştirilmiş bina üretimindeki iki temel görüş olan kapalı - açık üretim ve pazarlama sistemlerinin ele alınmasıdır. Çalıfrna kapsamında yapımda endüstrileşmenin genel karakteristikleri, gelişimi, kapalı - açık üretim ve pazarlama sistemlerinin özellikleri incelenmiş, bu iki temel görüş çeşitli açılardan karşılaştırılarak olumlu ve olumsuz yönleri ortaya konmuştur.

Introduction Today, the problems such as population growth and serious shortage of housing, share of limited resources, inadequate food and healty provision, pollution and appalling waste etc. show that should search we rational solutions and appropriate technologies because of the big imbalancy between world 's supply and demand. In this subject, the building industries also have important responsibilities for shelter and consequently health and share in many of the resources. These responsibilities can be caracterised the role of housing in human life and human society. Housing has tremendous social and economic impact on the total living environment of the world. It has direct and immediate influance on health, education, economy, environment, political and social life of any society. Today, in every country, studies concentrate what appropriate technologies are. Obuviously, in these researches, speed and the lower costs needs are two important criteria. With their slowness and inefficiency problems, conventional or traditional building systems do not seem to be able to cope with colossal shortage of housing. Therefore, generally the main solution area is searching industrialized building methods which mean systematizing pace of construction and which can be used for producing the buildings required relatively in a short time and economically. Similarly, as in many developing countries building - especially housing - in Tukey is a major economic and social problem. And it is necessary to search advanced technological methods - naturally, it means industrialized building technologies - both theoretically and practically. Closed - Open production and marketing systems There are a number of prerequisites for the healthy development of industrialized building, as assessed from the experience of developed countries, among which the following are the most important: IX - There should be a sufficient demand for housing over a reasonable period in and around a particular area to justify the capital investment to set up factories in that area for this purpose. - Building regulations and codes should not discourage industrialized building throughout the country. Existing regulations may have to be revised to permit and encourage industrialized building for housing and other purposes. - A high level of standardization is necessary for specifying not only dimensional requirements but also functional requirements in the form of performance standards, so that the manufacturer can have the necessary freedom in the design and manufacture of the components, and the user can have acertain amount of variety and choice among the available components to fulfill the given functional requirements. - Some initial incentive by government agencies to encourage industrialized housing in the form of preferential land allotment and loan assistance schemes would enable industrialized housing to increase significantly. The assistance of government agencies in pooling the demand for housing and arranging financial resources for this development would also encourage industrialization. - It has to be assured that industrialized buildings for housing are as satisfactory, and meet functional / user requirements as efficiently, as traditional buildings. There has been an uninformed feeling among the users that industrialized building is a form of cheap building as opposed to traditional quality building and this feeling can be removed only by incorporating desired quality elements in industrialized building. This can be achieved by including the desired quality levels in the performance standards. Industrialisation in building requires applications of mechanization, rationalisation, standardisation and prefabrication rules to whole building and its. When, the rules of industrialization applicate to building production and process, it can be mentioned that there are two main categories:. Closed production and marketing systems,. Open production and marketing systems. Closed systems are those where sets of components for particular buildings are manufactured for sale into a particular market of an extent known before the production comences. In that approach, standardised buildings are produced from standardised components, i.e. components are used as unique sets and interchangeability between them is only at a local level within the system. All decisions making role limited to a possible choice between a limited number of alternatives. Thus, the user has generally no significant control over the nature of the process or the from of its products. In the matter of production, the elements are fabricated in exact number of need only assembling is required. So one disadvantage of the system is that it is rigit and the number of elements produces in series is small. Open systems are that where components adaptable for any building are manufactured for the market where builders, designers or users many choose what they need among a wide range of possibilities. In other words, in this systems, components are producted freely, i.e. as not a part of an unique set. Obviously, the flexibility of market depends on the openness of the system at all level of production. Therefore, to achieve the compatibility of the various components found in the market the designer, the realiser and the productor should be close cooperation. These features of open systems can provide some advantages. Especially, if demand is changeable and if there are relatively small projects, the systems can be much more preferable. Open systems of industrialized building are based upon interchangeably of manufactured components. It is difficult to define "component" precisely, as this term may be used to describe anything from an uncomplicated product like a nail to a sophisticated sub-system like a box prefabricate. However, in the present context of industrialized building, components may be assumed to be discrete units which are both large and complex. Component can be desribe in that way also: The component is a building element, which is produced independently apart from a special project in a factory and which units with the building itself without getting any shaping process or any modification on site. In open systems the components should have following specifications: - It is a finished product, therefore it doesn't need any shaping process on site. - The component, compared with the general function of the building, has a neutral function. So it has a great composition flexibility. - The composition variety of the components is proportional to their own variety and flexibility in their assembling. - The component can be produced easily in mass production. - From the expression "a component is designed and produced independently apart from a special project," it is assumed that there is an independency between the production and usage of the component. The interchangeability is dependent upon: - The development of standards for dimensions and tolerances, - The development of performance standards based on functional requirements, - Jointing compatibility and conventions for jointing. XI Interchangeability of building components is secured only when components of ddifferent manufacture can be assembled in desired combination. To this end a set of common conventions for joint design in neccessary, or more precisely for the geometry of co-ordinating surfaces or edges of the components and for clearance between them. With regard to closed or semi-closed systems, such conventions will be necessary only when future interchangeability is considered. Standardization of joints and jointing procedures will also assist in the periodic replacement of components at different stages, as the user requires change and new products are introduced in the country, so as to upgrade continuously the quality of building. Standardization of jointing and jointing procedures is also expected to contribute effectively to variety reduction both in traditional and industrialized buildings. After these general information about two systems, it can be helpful looking to the ideas behind of the systems. The origins of the those two systems can be traced to two approaches to standardization in building. The first termed model approach is to standardise the whole building to start with as is done with TV sets, motor cars etc. all the building components and their methods of erection at site also being standardized. Every project has a certain number of building to be erected, from which they are required can be computed accurately.The only limitation to this approach is that the variety of houses limited to one or a few standard designs, which contributes to monotony in architectural development. This approach has led to the closed systems of industrialized building. The second approach, termed components approach which form the open systems, is based on the principle of standardizing building components, but leaving freedom of choice in the design of the whole building. Here, the aim is to supply the unification combinations of the components at maximum number by considering the economic advantages of the mass production, so that various user and customer needs should be satisfied. Components which are standart, interchangeable, and interuseable are produced by various producers and can be used in many different buildings. In other words, basic principle is the standardisation of the building components but the supply of maximum freedom to designer in choosing componenets and consequently in assembling is taken as fundamental. The components ( of open systems ) are designed carefully to meet the necessary functional requirements and to provide in a large number of types of building. Between the dimensions of mass produced components and other components, the dimensional coordination is supplied. xn These all features of two systems are also related with the role of designers. The role of the designer, in open systems, is different compared with the role in closed systems. The designer is more free in designing his building in open systems than in closed systems. He is not a part of the companies which own the system or the technology but accomplishes his job independently apart from them and therefore is able to create more architectural variousness. With the use of the open systems and with the wide spread of the desing possibiliy with components which are produced by indepent, separate producers and can be found in the marked, a great number of designers will be mixed up with the subject instead of limited number. Therefore, in national and even in international scale, a common building language will from and confusion of expessions will be abolished. To realise the dwellig construction with building components common rules of reconciliation should be determined, which are to be obeyed by the sections which take part in all processes of the production. As principle, the rules must supply the compability of the production the components with each other which come from different sources and from the building. Just later, all the common rules of reconciliation were developed and began to work, the components can be used in building. Main studies concerning the common rules of reconciliation are as follows: - ACC systems in France. - NEN 2883 rules in Holland. - BES systems in Finland, PLS 80 system being developed. - BPS rules in Demark. - KEP system in Japan. Conclusions In this study the results obtained about the position and importance of open systems in the dwelling problem are as follows: - When we consider short and long term national housing needs, it seems impossible to provide requirements of Turkey with conventional or traditional systems. So, we should incline industrialised building. - There is not only lack of supply but also a quality problems. It also points out industrialised building with their quality control possibilities. - So, here main solution area is open systems because of the its advantages:. Open systems have no threshold number in production, that is to say the amount of total m2 makes no limits, it can be used in the contraction of every kind of building. XIII . The prefabricated components which are mass produced with a certain quality and low- cost, can be basis of the contractor applications which from a great percentage of the dwelling construction whit the traditional / conventional systems in Turkey and that is because the components are suitable for transport concerning their sizes and weights because they only make the usage of simple machines necessary on site, because the joining of the elements requires a short time and few labour.. Open systems applications makes the development of traditional systems possible and thus it prevents a sudden setting out from present technics.. And, with their features open systems components can be produced and marketed to directly user of squatter or all individual enterprisers. Industrialized building has a bright future. Only a few standards in building, as for example, those relating to modular co-ordination and performance standards, have been developed to meet the requirements for industrialized building, and it is seen that only the fringle of the problem has been touched as yet. A considerable volume of work relating to standards has to be completed speedily to enable the faster introduction of industrialized building throughout the world, but this work necessarily has to await the results of building research and technological developments in many related topics. In general the appropriate solution should be decided cosidering short and long term policy. Here, it seems that open systems suit to Turkey's conditions. But we should develop scientific and economical infrastructure for industrialised systems. Directions of that kind of study should cover open systems as in many countries and also it will be necessary to determine a reconciliation base.