What is Post-Tensioning?
It is a special production process designed for increasing the tensile load capacity of the concrete. The desired compressive force in the concrete is obtained by stretching the high-strength steel strands, which pass through the galvanized steel pipes in the concrete, and by locking them in that way. The process of strengthening the ropes in the post-tensioning is made after pouring the concrete, not before it. It differs from other prestressed systems in this respect.
How Is The Post-Tensioning Application Made?
Mostly galvanized steel pipes (protecting cover) in the predetermined amounts and sizes are placed in the reinforcement that is prepared in conformity with the project. Afterwards, concrete is poured and prestressed concrete beams (steel strands) are spread on these corrugated ducts. Pressure values to be loaded on concrete, which is calculated in the Project, is transferred to concrete by means of hydraulic tensioning jacks. Reactions of steel strands to the tension load during this transfer (elongations) are noted, and compared with the project values. After tension (loading) process is completed, grout injection is made into the corrugated ducts.
What Are The Advantages of Post-Tensioning System?
Production time of structures, which are manufactured with the post-tensioning system, is shorter compared to other methods. Gaps both in bridges and buildings, hotels, storages, silo and similar structures are bigger compared to classical methods. Amount of concrete and reinforcement decreases, structure gets lighter and becomes much more economical in the post-tensioning applications. This lightening also affects the seismicity behaviors of the structure positively.
In What Type Of Structures Can Post-Tensioning Be Applied?
Post-Tensioning may be used in large areas such as Bridges, High-Rise Buildings, Hotels, Silo, Industrial Store Houses and Working Areas, Pools, Water Tanks, and Chemical Storage Tanks, and in all structures where impermeability is important.