Yield Strength, Ultimate Strength & %
Elongation Of Rebar
Objective: To get Yield Strength, Ultimate Strength, Mass/Meter & % Elongation of Rebar
Test Method: IS 1608: Part 1: 2022, IS 1786:2008 (RY: 2018)
Apparatus:
1) Universal Testing Machine- 1200 KN capacity- With Software
2) Weighing balance- 15 kg Cap, LC-0.5g
3) Vernier Caliper-300mm, LC-0.01 mm
4) Extensometer LC=0.001 mm
5) Measuring Tape: 3m, LC-1mm
5) Diamond Cutter
Procedure:
- Clean the surface of Rebar by means of brush.
- Prepare Sample by cutting edge of rebar not less than 0.5 Meter with the help of Diamond cutter.
- Calculate Weight/ Meter, C/S Area (A) & Gauge length-G0 (5.65vA) area as per procedure
- Mark Gauge length on Rebar with the help of Vernier.
- Clamp the sample in UTM.
- Start Software of UTM, enter necessary data Like Sample ID, Bar Dia, W/meter in software.
- Attach extensometer with rebar at center.
- Apply tensile load with rate 6-60 N/mm2.sec
- Load becomes static for a moment this will give Yield Load-Yl(kN).
- Remove extensometer after yield point.
- Continue loading - At moment when load becomes maximum it gives Ultimate Load-Ul (kN).
- Continue Loading till bar break.
- Get 0.2 %Yield Stress, Ultimate stress directly from software.
- Connect two pieces of rebar & measure final gauge length (G1)
Calculation:
- Yield Stress-N/mm2 = Yl/A
- Ultimate Stress-N/mm2 = Ul/A
- % Elongation: (G1-G0) *100/G0
Where -
Yl- Yield Load
Ul- Ultimate Load
G0- Original Gauge Length
G1- Final Gauge Length
