Steel wires or strands reinforcement used for the production of reinforced prestressed concrete elements must have a high tensile strength. They can be single wires or 2-3 or 7 wire strands.
Type Single Wire
Nominal Diameter (mm)
Cross section (mm²)
Mass
(g/m)
Strength (Mpa)
Total load at 1% typical (KN)
Total load at 1% typical (KN)
4
4
12.6
98.1
1860
20.6
23,4
5
5
19.6
153.3
1860
32.1
36.5
7
7
38.5
300.7
1770
60
68,1
Type Multi Wire
Nominal Diameter (mm)
Cross section (mm²)
Mass
(g/m)
Strength (Mpa)
Total load at 2% typical (KN)
Total load at 1% typical (KN)
2x2.25
4.50
7.95
62,5
1860
13.2
14,7
3x2.25
4.90
11.90
94
1860
19.8
22.1
3x3
6.50
21.20
167
1860
35.48
39,4
Type Strands
Nominal Diameter (mm)
Cross section (mm²)
Mass
(g/m)
Strength (Mpa)
Total load at 2% typical (KN)
Total load at 1% typical (KN)
7,9
38
300
1860
65.1
72.5
9.3
52
408
1860
86.8
96.7
12.9
100
785
1860
167
186
15.2
139
1090
1860
233
269
15.8
150
1180
1860
250
279
The most commonly used wire for flooring elements is the steel strand type because it has the highest adherence coefficient to concrete.
The maximum strength of the strands is between 140-190 kg/mm2.
The tension applied to the wires before concrete casting is approximately 60-70% of the breaking point of the wires.
Wire is packaged in rolls of up to 3000 Kg with the following dimensions:
Type
Bobbin weight
(kg)
External dia. (mm)
Internal dia. (mm)
Width:
(mm)
Single Wire
700-1300
2000-2100
1600
300-400
Multi Wire
1800-2200
1400
750
700
Strands
3000
1450
900
750
The size of the coils can be customized according to customer requirements and upon request, be packed with Kraft paper for shipment by sea.
For building safety it is necessary for the steel reinforcements to be:
1) completely free of any defects either made during manufacture, transportation or pre-tensioning;
2) of a strength neither too brittle nor too ductile;
3) fully protected from rust and corrosion both before and after the laying down.