Comparison of types of concrete installations used in construction and their uses (pre-stressed concrete and pre-cast concrete)
System Admin
05/15/2022
Comparison of types of concrete installations used in construction and their uses (pre-stressed concrete and pre-cast concrete)
Pre-stress concrete (tensile) and precast concrete:
First: Pre-stressed concrete:
Pre-stress concrete is applied by pouring concrete in conjunction with rebar, which is usually in the form of an upper and lower arming network and a steel cable epidemic (strands). Once the concrete reaches its required strength, the cables are released. Steel cables interact with editing, transporting tensile stresses to concrete, making a stronger structural component.
This method is usually adopted in buildings that have multiple floors, i.e. vertical buildings (towers)
This is due to the short implementation period for the dumplings of each floor, and the possibility of starting on the next floor very shortly from 10 to seven days compared to the normal armed concrete, which requires 28 days so that we can start the work of the next floor, in addition to this method helps to reduce the amount of iron used in construction on the one hand and reduce concrete pillars on the other hand due to the possibility of working large seas between mayors and thus weight loss on the bases as well and is currently used Mainly in building vehicle traffic bridges.
Sometimes bridges are used only from pre-tensile concrete in villas, mosques and halls and merged with regular concrete roofs so that we can dispense with the mayors required to support these roofs.
It should be noted that pre-stress concrete is rarely used in whistling projects because the difference in duration is not feasible to think about using it, such as the building being two or three floors.
To explain how to implement pre-stress concrete ceilings with a severe conclusion:
First: The completion of the construction of the wood intensity of the floor that we started implementing.
Second: The metal cables are brought in the form of roll for the project.
Third: The length of the cables is cut according to the operational plans of the site
Fourth: The lower iron grid is activated and electricity extensions and the location of mechanical openings
Fifth: Tim bring the so-called daktat which is an iron tube in which the cables called
strands in this case
Sixth: The uniqueness of the decats along the basket in both directions according to the construction plans and the contractor sprays the places of cables using a red spray usually and placed on the so-called chairs, which is an iron pillar often 8 or 6 mm
To give the shape of the decat in the end the form of moments origin and attached to the chairs well and the most important here are the places of the upper azzoum (such as the middle of the bridges) where the highest heights of the decats are the areas of the upper invitation and then we use chairs stronger 10 mm
Seventh: Cables are also placed in the decats according to the charts, the one decat may have two or more cables
Eighth: The places of the so-called living endings, which are pulled from and the so-called dead ends, are confirmed and operate using a particular machine in the form of an onion or someone who calls it a rose.
Eighth: The living ends are connected to the so-called anchor, where the cables are assembled and set on the horizontal bricks around the roof slab, and sometimes inside the basket, a wood box is placed around it and protected by bolts during casting so that we can reach the cables and tighten them after casting.
9th: The cables are fixed with so-called widjat to preserve them
X: The upper iron and extra iron mesh are placed in the strengthening areas and the alloy is equipped for casting.
Eleven: Casting is done
Twelve: Cables are usually tightened the next day with a so-called initial tightening
Thirteen: After the concrete reaches 75% of its strength, which has been confirmed by the results of the examination of cubes that take the time of casting and the approval of the consultant, the final tension is done as required in the executive plans and is usually three quarters of its final strength worth approximately 148 kN and the excess of cables is cut and educated so that they are not accidentally tightened again and close the place of tension with approved materials
Finally: The rupee is poured into the shops using a concrete robe through tyups placed at both ends of the circuits before casting for this purpose
Back propping is currently worth it that when unscrewing the stents for the dumplings must put the so-called
Long enough to make sure the building is safe.
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