Factors affecting the cost of precast concrete industrial buildings

As a result of human needs and implacaple seekings, technology improves day by day with an inceasing acceleration. Prefabrication technology is the result of this seeking in construction industry. Pre-manifacturing structural elements are the best way to built a construction with high quality and the fastest way at the same time. Precast concrete have so many area of usage. These are housings, industrial buildings, multi-storey car parkings, shopping centers and bridge girders. In Republic of Turkey, the most common usage of precast concrete members are in the pre-stressed bridge beams and industrual buildings. This master thesis has been made with the aim of determining the factors affecting the cost of prefabricated industrial structures and structural studies have been carried out for structures with different heights, width and floors in locations with different earthquake zones and soil classifications. In order to determine the fine construction works costing the structures, researches were carried out including the roof panel procurement, transportation and labor prices made for market prices, facade panels, procurement, transportation, cranes and labor costs. In the first section of this master thesis, the definition of prefabrication, the advantages and disadvantages of prefabricated reinforced concrete structures and the materials used are mentioned. Prefabrication is an industrial construction thecnology. Structural members of a prefact constructions are manifactured in production areas, wait until setting, took from specific steel templates and then put into stock sites. After the foundation of construction is ready, memners can be transported and montage can be made with the cranes. Prefabrication has so many advantages. Firstly, prefabrication is a very fast way to build a construction. While making of foundation process continues, precast members of the constuction could be manifactured and this gains inventors time. Secondly, because of prefabrication is industrial technology, there is no chance to make mistakes. Thirdly, especially in Turkey, with the low raw material costs, precast concrete structures are cheaper then steel structures. Fourthly and lastly, concrete has much more fire resistance when it compared to steel and this makes it more prefable then steel especially in textile facilities. Prefabrication has disadvantages too. With the necesserity of high span, precast concrete loses it's advantahe due to weight when it compared to steel. In the second chapter of this master thesis, prefabricated reinforced concrete bearing elements, which are bar elements, superficial elements and connection elements are introduced. Columns and beams can be shown as bar elementsslab panels and wall panels can be shown as surface members, and the necessary in situ elements which are bonding beams and bars are connection elements. In the third chapter of this master thesis, precast structural systems composed of structural prefabricate members which are emphasized in the second chapter are reviewed in the third chapter. Precast structural systems are precast frame systems, panel systems, cell-box systems and mix systems. In the fourth chapter, it is aimed to determine the factors effecting the cost of the prefabricated reinforced concrete industrial structures a total of 26 different structural designs were made. 16 of them in four different earthquake regions of Turkey, with different anticipated allowable bearing values and with four different soil classifications of DBYYHY. 5 of them with different column heights, 1 of them with different roof spans, 3 of them with different snow load areas. 1 partial multi-storey structure is also modelled to determine the storey necessarity. Member calculations of all structural models were presented and at the same time the design criteria were mentioned. The connection of precast frame and precast panel structures are calculated based on TS 9967. In addition to describing what prefabrication is, there are also types of structural systems and design criteria included in chapter four. In the fifth chapter, for the purpose of determining the cost of the finishing construction works. Roof sandwich panels with different filling materials and sheet metal thicknesses price research is made which includes market and transportation prices and labor prices, crane billets and wall sandwich panels with different filling material and sheet metal thicknesses price research is made which includes market and transportation prices and labor prices, crane billets, using different quality materials, has been researched and presented. Field concrete market research is also made for two different types with all components. In the sixth chapter, the results obtained from this study and the evaluatins were summerized. It is sayable that variation in earthquake zones and soil classifications affects the column and foundation specifications. However there is no change in beams. Only the connection of beams change according to earthquake zones. Snow load directly affects the sizes and numbers of beams. It is sayable that snow load does not change column sizes, but numbers and diameters of steel bars in it slightly changes. There is also slight differences in foundations snow loads cause. Different height causes the changes in columns sizes and foumdations. It ıs also seen that different roof spans slightly affect the construction cost. For thin construction works which have non-structural design elements, it is aimed to obtain calculated unit prices and to get ideas for constructions in variable dimensions. For the constructions which has different areas from the one in this master thesis, unit prices will be helpful to predict approximate construction cost.