- 1 How does post-tensioned concrete work?
- 2 What is the purpose of post tensioning?
- 3 What is post-tensioned concrete slab?
- 4 What is the benefit of a post tension slab?
- 5 What happens if you hit a post tension cable?
- 6 Where is post tensioned concrete used?
- 7 Which is better post tension or rebar?
- 8 What does post-tensioning mean?
- 9 Which is better pre tensioning or post-tensioning?
- 10 Do post tension slabs have rebar?
- 11 Can I drill into a post tension slab?
- 12 Can a post tension slab be repaired?
- 13 How much does a post tension slab cost?
- 14 What are the advantages and disadvantages of prestressed concrete?
- 15 What year did post tension slabs start?
How does post-tensioned concrete work?
Post tensioning is a technique for reinforcing concrete. Post – tensioned concrete means that the concrete is poured and then the tension is applied-but it is still stressed before the loads are applied so it is still prestressed. For an excellent overview of PT, visit the Post – Tensioning Institute.
What is the purpose of post tensioning?
The function of post – tensioning is to place the concrete structure under compression in those regions where load causes tensile stress. Post – tensioning applies a compressive stress on the material, which offsets the tensile stress the concrete might face under loading.
What is post-tensioned concrete slab?
Post tension slab is a combination of conventional slab reinforcement and additional protruding high-strength steel tendons, which are consequently subjected to tension after the concrete has set. This hybridisation helps achieve the formation of a much thinner slab with a longer span devoid of any column-free spaces.
What is the benefit of a post tension slab?
Post – tensioning, which is a form of prestressing, has several advantages over standard reinforcing steel (rebars): It reduces or eliminates shrinkage cracking-therefore no joints, or fewer joints, are needed. Cracks that do form are held tightly together. It allows slabs and other structural members to be thinner.
What happens if you hit a post tension cable?
Cables typically run East to West or North to South. Do NOT cut into a post tensioned slab if there is a chance you will rupture a cable. People have been dismembered and killed when cables are cut and burst out of the concrete.
Where is post tensioned concrete used?
Post – tensioning now is used extensively in bridges, elevated slabs (parking structures and residential or commercial buildings), residential foundations, walls, and columns. Jim Rogers Bending and flexing creates high tensile forces that can cause the concrete floor slab to crack.
Which is better post tension or rebar?
Strength. Post – tensioned concrete is stronger and more flexible than conventional steel-reinforced concrete. According to the Concrete Network, post – tensioning helps reduce cracking from shrinkage as the concrete dries, and holds together any cracks that do form.
What does post-tensioning mean?
OVERVIEW. Post – tensioning is a method of reinforcing (strengthening) concrete or other materials with high-strength steel strands or bars, typically referred to as tendons.
Which is better pre tensioning or post-tensioning?
This method is developed due to the bonding between the concrete and steel tendons. This method is developed due to bearing. Pre – tensioning is preferred when the structural element is small and easy to transport. Post – tensioning is preferred when the structural element is heavy.
Do post tension slabs have rebar?
Post – tension slabs are created with concrete trenches around the perimeter of the house where the external walls will be placed. The top slab of concrete is thinner than with concrete & rebar.
Can I drill into a post tension slab?
PT slabs on ground can be placed and stamped just like with any other concrete slab. Surfaces can be stained or overlaid. The only concern is to always remember not to cut or drill into post – tensioned concrete slabs, since once a tendon has been cut, it is very difficult to repair.
Can a post tension slab be repaired?
Post tension ( PT ) tendon systems are primarily used for large slab construction projects. Since the early 1950’s, post tension tendons have been used in the design of concrete structures. For such critical structural element, the repair should only be completed using a certified, experienced repair contractor.
How much does a post tension slab cost?
The cost of the post – tensioned slab is $30.52 per square foot which is approximately the average cost of the four floor systems. At the interior supports, a substantial amount of reinforcement was required for ultimate strength.
What are the advantages and disadvantages of prestressed concrete?
It requires high strength concrete and high tensile strength steel wires. The main disadvantage is construction requires additional special equipment like jacks, anchorage, etc. It requires highly skilled workers under skilled supervision. Construction cost is little higher than RCC structures.
What year did post tension slabs start?
Unbonded post – tensioning (PT) mono-strand tendons have been used in the United States as a form of concrete reinforcement for buildings since the late 1950s (PTI 2006). The first Post – Tensioning Manual was published in 1972, and provided the fundamentals for PT design and construction.