Egyptian pre-stressed Concrete wires co. EPCW
Product
PRODUCT LIST
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PC wire stands for "Pre-Stressed Concrete Wire." It is a high-strength steel wire commonly used in the pre-stressing process of concrete elements. The pre-stressing technique involves applying a compressive force to the concrete, enhancing its load-bearing capacity and durability. PC wire plays a pivotal role in this process by providing the necessary tensile strength
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PC wire is typically made from high-carbon steel, ensuring the required strength for pre-stressing applications. The steel used in PC wire is alloyed with elements such as carbon, manganese, and silicon to achieve the desired mechanical properties.
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PC Wire is considered as the desirable steel material used in large-load, pressure and weather protection PC structures, such as PC pipe, PC sleeper, PC Pole and PC Pile.
According to the surface treatment, it is classified into plain PC wire, indented PC wire and spiral ribbed PC wire with the following characteristics:
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Material: high carbon steel
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Diameter: 4 mm - 10 mm.
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Surface: smooth.
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Tensile strength: 1470 MPa, 1570 MPa, 1670 MPa, 1770 MPa, 1860 MPa.
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Standards: BS 5896, ASTM A421, ASTM A468, EN10138-2, BSEN ISO15630-3, etc.
1 -Plain PC Wire
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Also called plain surface PC steel wire or smooth PC wire, features low relaxation and high tensile strength, ideal for concrete structures.
Low relaxation plain PC wire
Cold drawing PC Wire
2 -Indented PC Wire
Also called indented PC steel wire, PC indented wires is a kind of PC wire with surface indented
The surface shape of indented PC wire can be classified into round, oval and deformed. And the shape can be 2-sided, 3-sided and 4-sided.
And according to customers' special requirement, we can supply indented PC steel wires of different diameters, tensile strengths, and national standards.
3- Spiral ribbed PC wire
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Also called spiral PC wire and spiral ribbed PC steel wire, is one of the traditional products of PC wire
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Spiral ribs can obviously strengthen the combination between wire and concrete, thus increasing the performance of the PC construction structure and extending its service life.
4 -Highly straightened cut to length wire
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PC wire may be used to reinforce and pre-stress concrete sleepers, increasing their durability and load-bearing capacity.
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These wires are tensioned or pre-stressed to a certain level to induce compressive forces within the concrete. This process improves the load-bearing capacity of the sleepers.
Highly straightened cut to length PC Wires
Manufacturing Process
1- Pickling:
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All wire rod (raw material) must be de-scaled to remove the mill scale (iron oxides) present on the steel surface this descaling process can be done chemically or mechanically using shot blasting line
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After the oxide scale has been removed, the wire rod is then coated with a textured carrier coating that promotes lubricant adherence during the subsequent wire drawing process. The most commonly used carrier coating is Zinc Phosphate (ZnPO4) but other coatings are sometimes used (borax, lime,) etc.
2- Drawing:
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The wire rod is drawn through a series of normally 7 dies but might be up to 9 Carbide dies for smaller sizes, to achieve the desired mechanical properties. This is a cold-working process; therefore, the wire drawing practices are tightly controlled to prevent premature die wear or damage to the steel wire. In PC Wire drawing, the wire rod cross –sectional area is reduced up to 85% when comparing the finished wire area to the area of the original wire rod. The tensile strength of the wire rod is normally ~1050
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MPa. After the wire drawing process, the wire tensile strength is >1600 MPa; therefore, the tensile gained is >50% due to work hardening
3- Stabilization:
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After cold drawing with resultant stresses and to relieve these wire stresses, it is loaded into pay-off of the treatment line, The wire is subjected to a thermo-mechanical process in which the wire is continuously heated to ~380ºC +/- 25ºC while under tension at ~40 - 50% of the minimum ultimate tensile strength of the wire. This process acts to relieve the drawing stresses, permanently elongate the wire, increase the yield strength and reduce relaxation losses. The combination of factors gives the wire a very consistent modulus of elasticity
Production range and technical data
The dimensions and properties of the wires are put across table 1 to 8
Table 1 and Chemical composition
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Surface state:
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Plain (Smooth) or Indented
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Specification of Indentation
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Conformity with standards BS5896
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For example specified indentations dimensions in mm for indent type T1 (also known as triple indent) as below table
Surface state:
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Specification of Indentation
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Conformity with standards BS5896
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Table 4: ASTM A421 for Uncoated Stress-Relieved Steel Wire for Prestressed Concrete
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Table 5: BS 5896
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Note:
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The modulus of elasticity may be taken to be 205 GPa (KN/mm2).
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The specified characteristic value of the 0.1% proof force is calculated as 88% of the specified characteristic value of the maximum force, except Y1860C which is 89%
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Table 6-1: ASTM A648 for concrete pipe Stress relieved steel wire
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Min. Tensile Strength based on nominal wire diameter
Table 6-2: Chemical requirements for Classes II and III ASTM A648
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Table 7: EN 10138-2 for Stress relieved steel wire
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The modulus of elasticity may be taken to be 205 Gpa (KN/mmᶟ)
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Note: The specified characteristic value of the 0.1% Proof force is calculated
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For grade y1570C, with diameter over 8 mm as 87%of the specified value of the maximum force for Y1860C is 89% and for other grades and diameters is 88%
Table 8: EN 10138-2 for Stress relieved steel wire – For highly straightened cut to length wires
Follow Table 8: EN 10138-2 for Stress relieved steel wire – For highly straightened cut to length wires
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Ruptures in "arrow-head" are prohibited. In case of dispute the percentage reduction of area shall be determined and the value shall be ≥ 25 % for plain wire and ≥ 20 % for indented wire.
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b The requirement for 70 % Fma is mandatory. A requirement for a value of 80 % Fma may be agreed between purchaser and manufacturer for specific applications.
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c Class R2 shall only be used for highly straightened cut to length wires with maximum bow height of 4 mm/length.
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d When regulatory requirements for stress corrosion exist the additional test solution B for initial type testing defined in EN ISO 15630-3 shall be used as defined in prEN 10138-1.
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e Where there are no regulatory requirements, the products may be assigned as Class C0
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For type T2, the minimum number of reverse bends shall be two
Applications of PC Wires
Applications of PC Wires
Installation:
PC steel Wire is installed within the concrete components of construction. It is placed in a specific configuration, tensioned, and then anchored to ensure that it remains under tension, helping the concrete resist the forces that act upon.
Advantages of PC Steel wires:
Improved Durability:
PC steel wires significantly extends the lifespan of Concrete pipe, poles, piles, slabs, hollow slabs and railway sleepers by reducing the risk of cracking and deterioration.
Greater Load-Bearing Capacity:
The pre-stressing effect increases the load-bearing capacity
Enhanced Structural Performance:
PC steel wires reinforces effect, making it more resilient to various stresses, including those caused by weather, pressure and seismic activity.
PC Wires applied and used in the following constructional pre-stressed concrete:
1- Pre-stressed concrete pipe with PC Wires
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Low relaxation plain PC wire
2- Pre-stressed Spun Concrete Poles with PC Wires
Concrete poles
Spun Pole Mould with longitudinal pre-stressed wires
3- Pre-stressed Spun Piles with PC Wires
Concrete piles
Precast Reinforced Concrete piles are commonly in square sections ranging from 250 mm to about 450 mm with a maximum section length of up to about 20 m, other pile sections may include hexagonal, Circular, Triangular and H shapes
4- Prestressed Concrete Slabs & Hollow Core Slabs with PC Wires
Concrete slabs and hollow core slabs
5- Production of Railway Sleeper with PC Wires
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PC wire may be used to reinforce and pre-stress concrete sleepers, increasing their durability and load-bearing capacity. The application of PC wire in concrete sleepers helps prevent cracking, improve structural integrity, and extend the lifespan of the sleepers, thereby enhancing the safety and efficiency of railway tracks. Pre-stressed concrete (PC) wire are commonly used in the construction of railway sleepers to reinforce and strengthen them.
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Here are some key points about PC wire for railway sleepers:
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Material: PC wires are usually made from high-strength steel, often with a carbon content designed to withstand the demands of the railway environment.
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Pre-stressing: These wires are tensioned or pre-stressed to a certain level to induce compressive forces within the concrete. This process improves the load-bearing capacity of the sleepers.
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Diameter: The diameter of PC wires can vary depending on the design specifications and the load requirements of the railway line. Common diameters include 5mm, 7mm, 8 mm and 9.4 mm.
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Strength: PC wires are known for their high tensile strength, which is essential for maintaining the structural integrity of railway sleepers over time.
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Manufacturing Standards: PC wires for railway sleepers should meet specific manufacturing standards and guidelines to ensure they are suitable for the intended purpose and meet safety requirements.
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Durability: Railway sleepers are subjected to a lot of stress, so the durability of PC wires is crucial in ensuring the long-term integrity of the track.
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Installation: Proper installation of PC wires is essential to ensure they are correctly pre-stressed and embedded within the concrete sleeper.
Rail Seat Section of Different Types of Pre-stressed Concrete Sleepers
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Precast Reinforced Concrete piles are commonly in square sections ranging from 250 mm to about 450 mm with a maximum section length of up to about 20 m, other pile sections may include hexagonal, Circular, Triangular and H shapes