ASTM A1061 Tensile Testing machine of Multi-Wire Steel Prestressing Strand tensile Breaking Elongation Stress Relaxation Steel Wire Test
ASTM A1061 Testing of Prestressing Steel Strands, Fatigue dynamic Testing machine, tensile testing equipment. ISO 15630-3, ASTM A416 and ASTM A1061 test standards offer guidelines for testing steel strands. Manufacturers of steel strands are required, through product standards, to test their products using both static and dynamic conditions.
ASTM A1061 tensile test for breaking elongation stress relaxation on steel wire deals with the standard types and grade requirements of seven-wire, uncoated steel strands for use in the construction of pre-tensioned and post-tensioned pre-stressed concrete. The two types of strand specified by the ASTM A1061 specification are low-relaxation and stress-relieved (normal relaxation). The base metal shall be made of carbon steel and shall undergo stranding and continuous thermal and mechanical treatment. Mechanical testing methods shall be performed alongside ASTM A1061 to determine the breaking strength, yield strength, elongation, and stress relaxation properties wherein the strand shall conform to the required mechanical attributes of the product. Final product requirements of ASTM A1061 shall be furnished on reels or in reelless packs for packaging and marked with two strong tags for identification. The requirements specified in ASTM A1061 shall also be applicable for pre-stressed ground anchor construction.
ASTM A1061 - Mechanical Testing - Dimensional Measurement - Corrosion Tests - Prestressing Steels - Concretes - Reinforcing Materials - Stress Corrosion - Reinforcing Steels - Prestressed Concrete - Construction Materials - Steels - Reinforced Concrete - Modulus of Elasticity - Wires - Bars (Materials) - Bend Testing - Stress Relieving - Fatigue Testing - Tensile Testing
Static Tensile test of steel strands:
In static tensile tests according to ISO 15630-3, ASTM A416, and ASTM A1061, the steel strand undergoes elongation until it fractures. Steel strands are composed of multiple wires twisted together, and they tend to untwist when subjected to tensile loads.
Throughout the tensile test, both the force applied to the specimen and its elongation are measured. Testing machines designed for high test loads are predominantly utilized because prestressing steel is a high-strength steel.
Dynamic Tests on Prestressing Steel Strands
In the high cycle fatigue test (for example, according to ISO 15630-3, XP A 35-045-2011, EN 10138-3:2009) on steel strands, the specimen must withstand two million test cycles at a maximum frequency of 20 Hz without fracturing.
specimen fractures near or in the grip, the test is considered invalid and needs to be repeated. Invalid tests are very costly, as the fatigue test lasts several days. Prestressing steel strands, being highly stiff, are particularly sensitive to notching.
