Summary of Test
ASTM A1061 is a testing standard that describes the mechanical testing procedure for testing multi-wire steel strand. Strands are made out of two or more steel wires wound together in a helical form. The mechanical properties of the strand are determined by a test in which fracture of the specimen occurs in the free span between the grips of the testing machine.
Gripping the strand wire and measuring its elongation can be challenging. ADMET wedge grips with serrated v-jaws are often used for A1061 multi-wire steel strand testing. The yield strength and elongation measurements can be done using the same extensometer or two separate extensometers. For yield strength measurements, the required extensometer is Class B-1 Epsilon Model 3542 extensometer. For elongation measurements, a Class D extensometer is sufficient as long as the gauge length is 24 in (600 mm).
Prior to conducting ASTM A1061, it is important to read the entire specification in the relevant ASTM publication.
Recommended Equipment
Testing Procedure
- Measure and record the specimen dimensions necessary to determine the cross sectional area at its smallest point. MTESTQuattro will calculate the original cross sectional area and use it for all engineering stress calculations.
- Mark the gauge length with a center punch, scribe marks or draw with ink. The distance between the gauge marks after the specimen is broken is used to determine the percent elongation at break.
- Yield Strength – Zero the testing machine without the specimen inserted in the grips. Install the specimen in the grips and apply an initial load of 10% of the required minimum breaking strength to the specimen. Adjust the extensometer to a reading of 0.1% of gauge length. Increase the load until the extensometer indicates 1% extension and record the load for this extension as the yield strength.The class B1 extensometer can then be removed.
- Elongation – Zero the testing machine without the specimen inserted in the grips. Apply a load of 10% of the required minimum breaking strength to the specimen. Attach a Class D extensometer having a minimum gauge length of 24 in (600 mm) to measure elongation and zero the device. Increase the load until the extensometer indicates an elongation value greater than or equal to the minimum specified elongation value. It is not necessary to determine the total percent elongation at maximum force.
- Run the test until specimen fracture to measure the breaking strength.
Note: The speed of testing is determined in one of three manners: a) free running, unloaded crosshead speed (inches/minute; b) free running, loaded crosshead speed (inches/minute) c) stress rate (psi/minute or mpa/minute); or d) strain rate (inch/inch/minute axial strain). Any convenient speed of testing may be used up to one half the specified yield point and down to 1/10 the specified maximum rates for determining yield strength and tensile strength
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Questions about running ASTM A1061 on your system?
