Post Tensioned Roof

Post tensioning of foundations transfer beams and plates post tensioned masonry and the combination of precast elements with cast in place concrete by means of post tensioning offer other interesting opportunities.

Post tensioned roof.

After only 10 years of service the roof of a 15 million gallon reservoir in greeley colorado was near collapse. A post tensioning tendon is made up of one. Post tensioning is a method of prestressing in which the tendons are tensioned after the concrete has hardened and the prestressing force is primarily transferred to the concrete through the end anchorages. Ducts thin sheet metal pipes with claw coupling or welded overlapped seam supplied in lengths of 5 and 6 m.

To produce an r value of 24 the 7 inch thick concrete roof was cast in place over a 3 inch thick layer of expanded polystyrene. Tendons the basic element of a post tensioning system is called a tendon. Instead of being stressed to the normal 140 to 150 psi the school roof was post tensioned to 280 to 300 psi. Post tensioned slabs use high strength tensioned steel strands to compress the slabs keeping the majority of the concrete in compression.

The reservoir was originally designed and built as a partially buried tank with an exposed post tensioned concrete roof. The polystyrene was prefabricated in panels with 5 8 inch thick gypsum wallboard glued to the underside. Post tensioning is a method of reinforcing strengthening concrete or other materials with high strength steel strands or bars typically referred to as tendo beton design concrete design concrete structure steel structure suspended ceiling systems civil engineering design building foundation reinforced concrete architecture details. This gives a very efficient structure which minimises material usages and decreases the economic span range when compared to reinforced concrete.