Chemical Analysis — Pre-Stressed Wire Strand(IS 14268:2022)
Chemical composition testing of seven-wire low-relaxation prestressing strand per IS 14268:2022 — verifying carbon, manganese, sulphur and phosphorus against the specification's high-carbon steel requirements.
What is Prestressed Wire Strand Chemical Analysis?
Seven-wire low-relaxation prestressing strand to IS 14268:2022 is drawn from high-carbon steel wire rod and used in pre-tensioned and post-tensioned concrete elements — bridges, PT slabs, and precast girders. The high-carbon chemistry that gives the strand its tensile strength also makes composition control critical: sulphur and phosphorus must be tightly limited to avoid brittleness and stress-corrosion susceptibility under sustained tension.
Global Lab verifies strand composition using OES per IS 228 methods, reporting carbon, manganese, sulphur, phosphorus and silicon against IS 14268:2022 requirements — confirming the strand's base chemistry supports the low-relaxation, high-tensile performance the application depends on.
Chemical Analysis — Pre-Stressed Wire Strand — Site Images
How the Chemical Analysis — Pre-Stressed Wire Strand is Conducted
- 1
Sample Selection
A representative strand length is sampled and an individual wire separated for chemical analysis, matching the declared grade and relaxation class. - 2
Surface Preparation
The wire cross-section is ground flat and clean to remove surface scale before spectral analysis. - 3
OES Spark Analysis
Optical Emission Spectroscopy determines carbon, manganese, sulphur, phosphorus and silicon, calibrated against certified reference material. - 4
Compliance Check
Measured composition is checked against IS 14268:2022 limits, with particular attention to sulphur and phosphorus given their effect on stress-corrosion susceptibility under sustained tension. - 5
Reporting
Full elemental composition is compiled into a NABL-accredited report confirming compliance, issued via Autovity QLMS.
Applicable Test Standards
| Standard | Title | Scope | Type |
|---|---|---|---|
| IS 14268:2022 | Uncoated Stress Relieved Low Relaxation Seven-Wire (Ply) Strand for Prestressed Concrete — Specification | Chemical Composition & Mechanical Requirements | Indian Standard |
| IS 228 (Various Parts) | Methods for Chemical Analysis of Steels | Elemental Analysis Methods | Indian Standard |