Application of post tensions in high rise building construction in sri lanka

Abstract

The world is changing; the economy is changing; and Architectural practice is changing. Therefore, there is a definite trend towards the irregular shapes with large spans in buildings due to the fact that there is now more emphasis on providing large uninterrupted floor space which can result in higher rental returns. Today the building industry is taking the next step in concrete technologies by introducing post-tension systems to slab construction with the use of system formwork and high strength concrete. Post-tensioned concrete has proven to be a preferred method of construction for commercial and office buildings, residential apartments, high-rise condominiums, parking structures, and mixed-use facilities such as hotels and entertainments. The main benefits over conventionally reinforced concrete being its ability to span greater distances without resorting to thick slabs and beams (and the consequent loss of head height), reduce deflection and cracking, Reduction in overall building mass, which is important in zones of high seismicity and superior performance of diaphragm action at building irregularities. There are also some associated labour and time savings. The objective of this paper is to introduce the post tension slab system to Sri Lankan construction industry. This study will discuss the benefits of having post tension in building industry, challengers encounter in PT designs and quality controlling process during construction