Interlaboratory Study of Standard Methods for Testing Multiwire Steel Prestressing Strand

Abstract

■ Proposed changes to ASTM A1061-16 are presented with the aim of providing clarity to the standard, reducing the frequency of improper test procedures, and improving the test precision. Multiwire steel prestressing strand is widely used in precast and post-tensioned concrete construction. Although the mechanical properties of strand products are relatively invariant across production runs, it is necessary for producers and some end users, such as state departments of transportation, to document whether a given sample of strand complies with applicable specifications. Samples of strand are therefore frequently tested in tension in accordance with ASTM A1061, Standard Test Methods for Testing Multi-Wire Steel Prestressing Strand. Problems occasionally arise when producers and end users obtain different results from tests of samples from the same strand. These problems can be difficult to resolve because the precision of the ASTM A1061 methods has not been previously quantified.