METHOD STATEMENT TMT STEEL REINFORCEMENT · GRADES Fe500 / Fe550 / Fe600

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Arshavtar.in by Er. Kuljit Singh
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1. TMT REINFORCEMENT – SCOPE
1.1 Scope Of Work

Supply, cutting, bending, and fixing of Thermo-Mechanically Treated (TMT) steel bars for RCC structures including foundations, columns, beams, slabs, and walls for residential, commercial, and infrastructure projects.

1.2 Reference Standards

IS 1786:2008 (High strength deformed steel bars), IS 2502 (Code of practice for bending and fixing), and project structural drawings.

🧪 TMT GRADES – MECHANICAL PROPERTIES
Fe500, Fe550, Fe600 – typical values
GradeYield Strength (min) MPaTensile Strength (min) MPaElongation %Typical Applications
Fe50050054514.5General RCC – residential, commercial
Fe500D50056516High ductility – seismic zones
Fe55055058514Heavy structures, bridges
Fe550D55060016High rise, industrial
Fe60060066012Special structures, pre-stressed

* As per IS 1786 and manufacturer data. 'D' denotes higher ductility.

TMT manufacturing process: Quenching → Self-tempering → Atmospheric cooling. Produces hard outer martensite and soft inner ferrite-pearlite core for strength + ductility [citation:1][citation:4][citation:10].

📏 STANDARD DIAMETERS & UNIT WEIGHT
Diameter (mm)Cross-section area (mm²)Weight per meter (kg/m)Standard length (m)
6 mm28.30.22212 (or coil)
8 mm50.30.39512 (or coil)
10 mm78.50.61712
12 mm113.10.88812
16 mm201.11.5812
20 mm314.22.4712
25 mm490.93.8512
32 mm804.26.3112
40 mm1256.69.8612

Weight formula: d²/162 (kg/m). Standard length 12m, but cut & bend services available [citation:3].

📐 BAR BENDING SCHEDULE – CUTTING & BENDING
Hook & bend lengths
  • Hook length (for stirrups): 9d or 10d (usually 9d for 90° bend, 10d for 135° hook).
  • Bend deduction: 2d for 90°, 1d for 45° (approx).
  • Development length (Ld): As per IS 456 – for Fe500, Ld ≈ 47d (tension).
  • Lap length: 50d – 60d for tension, 45d for compression (depends on grade).
Typical cut length formulas
ElementCut length formula
Straight barSpan + development length (both ends)
Bent-up barSpan + 0.42H (each bent) + Ld
Rectangular stirrup2*(A+B) + 24d (hook length) – bend deductions
Chair bar (raft)Top + bottom + 2*height + bends

Refer IS 2502 for detailed bending diagrams.

Clear cover norms
  • Footing: 50 mm (bottom), 40 mm (side)
  • Column: 40 mm (for d>12mm), 25 mm (for d≤12mm)
  • Beam: 25 mm (for main bars)
  • Slab: 15-20 mm (depending on exposure)
  • Retaining wall: 30-50 mm (earth face)
🔧 FIELD PRACTICE – SPACING & LAPPING
ElementMain bar spacingDistribution bar spacingLap length (tension)
Slab (one-way)100–200 mm c/c150–250 mm c/c50d – 60d
Beamas per designstirrups @ 150–30050d (at flexure zone avoid)
Columnvertical barsties @ 150–30050d (staggered)
Footing100–200 mm100–200 mm50d (if needed)

Spacing as per structural drawings; minimum spacing 25mm or 1.5×agg size.

⏱️ LABOUR OUTPUT – REBAR FIXING (per 8 hours)
ElementSkilled bar bender + 2 helpersRemarks
Footing reinforcement150–250 kgsimple grids
Column / beam (simple)120–180 kgincludes stirrups tying
Slab reinforcement200–300 kgmesh work, faster
Complex / heavy cages80–120 kge.g. pile caps, heavy beams
Stirrups making (per labour)80–120 nos.for 8-10mm dia

Output depends on complexity, bar diameter, and site conditions.

🛡️ DURABILITY & WELDABILITY
Corrosion-resistant TMT

Cu-Cr alloy TMT (e.g. Cu-TMT) offers enhanced corrosion resistance for coastal/marine environments. Tests show similar weldability to tor steel, with adequate cold-cracking resistance [citation:7].

Weldability

Low carbon content in TMT ensures good weldability without loss of strength. Fe500D and Fe550D grades are preferred for welding [citation:1][citation:6]. Use proper preheating for larger diameters (>25mm) as per code.

TOOLBOX TALK RECORDS

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Er. Kuljit Singh · Arshavtar.in