0
Why it is need to use high strength concrete in prestressed concrete?
Wiki User
∙ 11y ago
to offer high resistance in tansion,shear and bond
Wiki User
∙ 11y ago
Add your answer:
Earn +20 pts
How is pre-stressed concrete made?
Pre-stressed concrete is made by using,high strength steel bars(tendons).normal concrete(>M25)sheaths for cable duct.anchors.jacks.
Why is high tensile steel wire used in prestressed concrete?
To mobilise the compressive strength of the full thickness of the slab. For an explanation see below. Concrete tends to be stronger in compression than tension. If you can imagine a large flat slab of concrete that is much wider than it is thick (for example a slab to be used in the construction of the floor of an upper level of a house), it will be supported at the corners or edges. This allows the centre of the slab to deform vertically downwards (by a very small amount). This deformation due to it's own self weight generates stresses in the slab. You now need to imagine that there was a straight line drawn along the centre of the edge of the slab from one end to the other. When the slab deforms this line will become a curve or arch. This is in fact what the slab is doing - performing as an arch. This means that the lower portion of the slab (below the line will have stretched and be under tension and the upper portion of the slab will have been compressed. Now in this case the failure strength of the arch is being controlled by the tensile strength of the slab which is much lower than it's compressive strength. As such when the concrete is being formed, high tensile strength steel wires are connected to anchor points in the factory and they are stretched or placed under a tensile stress. The concrete is than poured into a mould around the steel wire and allowed to set (or cure). The concrete than adheres to the steel cable. Once the concrete has fully hardened the stell wires are cut from the anchor points and the steel wires attempt to return to their original size, This stress is transferred to the concrete as compression by friction due to the bond between the c able and concrete. Now when the concrete slab is used as a floor it begins to deform under it's own weight, however the pre-stressed steel wires already under tension act to pull the entire slab including the base back into a compressive stress state meaning that the whole of the slabs compressive strength is mobilised rather than just the upper half and this effectively acts to make the slab stronger. There are a number of differing methods of making steel reinforce pre-stressed concrete and for further information, please see the related link.
Do vinyl fence posts need to be set in concrete?
yes they need to be set in concrete. depending on your fence, one bag of concrete per post should be enough.
How do you put concrete on concrete and make it stick?
you need to have a ''keyway''---that is a groove in the base concrete,can be cut in if concrete has set,if not set,oil a 2x4lightly(lightly) & imbed it into the base concrete flush.
Do you need a license to pour concrete?
Yes
How do check the mixdesign for concrete is correct or not?
for checking the mix design for concrete, we need to initially prepare the mix n take samples n do cube tests to find the compressive strength n find out if desired strength is obtained for 7 days & 28 days strength. if desired strength is not obtained v need to adjust the mix proportions. its actually a trial n error method.
Do you need concrete footings behind steel pool walls?
Absolutely! You need a "concrete collar" around the entire wall in addition to "concrete piers" at the end of the "A" brace. Only with this added strength can the walls withstand the hydostatic pressure when the water level is lowered, intentionally or unintentionally. Good luck with your pool.
How is pre-stressed concrete made?
Pre-stressed concrete is made by using,high strength steel bars(tendons).normal concrete(>M25)sheaths for cable duct.anchors.jacks.
What high school courses are needed in wrestling?
pe and strength because they need strength to wrestle other people... hope this helps.
What is curing why need to curing in buildings?
Curing in buildings is a process that is keeps freshly poured concrete from drying. It is kept at a certain temperature to keep it moist. Curing in buildings is important because it gives concrete what it needs to gain strength properly.
What must you do to get a job in construction?
You first need at least a high school diploma to get a job in construction. You then need a certificate in wielding, scaffolding, or concrete finishing.
Why is high tensile steel wire used in prestressed concrete?
To mobilise the compressive strength of the full thickness of the slab. For an explanation see below. Concrete tends to be stronger in compression than tension. If you can imagine a large flat slab of concrete that is much wider than it is thick (for example a slab to be used in the construction of the floor of an upper level of a house), it will be supported at the corners or edges. This allows the centre of the slab to deform vertically downwards (by a very small amount). This deformation due to it's own self weight generates stresses in the slab. You now need to imagine that there was a straight line drawn along the centre of the edge of the slab from one end to the other. When the slab deforms this line will become a curve or arch. This is in fact what the slab is doing - performing as an arch. This means that the lower portion of the slab (below the line will have stretched and be under tension and the upper portion of the slab will have been compressed. Now in this case the failure strength of the arch is being controlled by the tensile strength of the slab which is much lower than it's compressive strength. As such when the concrete is being formed, high tensile strength steel wires are connected to anchor points in the factory and they are stretched or placed under a tensile stress. The concrete is than poured into a mould around the steel wire and allowed to set (or cure). The concrete than adheres to the steel cable. Once the concrete has fully hardened the stell wires are cut from the anchor points and the steel wires attempt to return to their original size, This stress is transferred to the concrete as compression by friction due to the bond between the c able and concrete. Now when the concrete slab is used as a floor it begins to deform under it's own weight, however the pre-stressed steel wires already under tension act to pull the entire slab including the base back into a compressive stress state meaning that the whole of the slabs compressive strength is mobilised rather than just the upper half and this effectively acts to make the slab stronger. There are a number of differing methods of making steel reinforce pre-stressed concrete and for further information, please see the related link.
Who is better a construction worker or a math teacher?
Depends on whether you need to lay some concrete, or get a high score on the ACT.
need quote on installed concrete patio?
need quote on installed concrete patio
How can you use the word strength in a sentence?
He has great strength. you need alot of strength to lift that. need i go on?
What is the formula for calculating how much concrete you need?
What can you do with aluminium?
Most of the things you can do with steel, but you need to consider: Aluminum has about one-third the strength of steel when objects of equal weight and design are considered. But aluminum weighs one third of what steel does, and you can design complex engineered shapes to get you back the strength you lose if you need both low weight and high strength.
