XP A 35-045 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.  

XP A 35-045 - 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.