ASTM A722-2018 pdf free download

ASTM A722-2018 pdf free download.Standard Specification for High-Strength Steel Bars for Prestressed Concrete
1. Scope
1.1 This specification covers Type I and Type II high- strength steel bars intended for use in prestressed concrete construction or in prestressed ground anchors. Type I bars have a plain surface. Type II bars have surface deformations. Bars are of a minimum tensile strength level of 150 000 psi [1035 MPa]. 1.2 A supplementary requirement (S1) is provided for use where bend tests of bars are required by the purchaser. The supplementary requirement applies only when specified in the purchase order. 1.3 The text of this specification references notes and footnotes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the specification. 1.4 This specification is applicable for orders in either inch-pound units (as Specification A722) or in SI units (as Specification A722M). 1.5 The values stated in either inch-pound or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the specification. 1.6 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
6. Tensile Requirements
6.1 Tension tests shall be conducted in accordance with Test Methods and Definitions A370. 6.2 Bars shall have a minimum tensile strength of 150 000 psi [1035 MPa]. 6.3 The minimum yield strength of Type I and Type II bars shall be 85 % and 80 %, respectively, of the minimum tensile strength of the bars. The yield strength shall be determined by either of the methods described in Test Methods and Defini- tions A370; however, in the extension under load method, the total strain shall be 0.7 %, and in the offset method the offset shall be 0.2 %. 6.4 The minimum elongation after rupture shall be 4.0 % in a gage length equal to 20 bar diameters, or 7.0 % in a gage length equal to 10 bar diameters.
7. Number of Tests
7.1 The number of tension test specimens shall be one from each 39 tons [36 tonnes] or fraction thereof, of each size of bar rolled from each heat but not less than two tension test specimens from each heat. 7.2 For Type II bars, one set of dimensional property tests including bar weight [mass], and spacing, height and projected area ofdeformations shall be made ofeach bar size rolled from each heat.
8. Retests
8.1 If any tensile property of any tension test specimen is less than that specified, and any part of the fracture is outside the middle third of the gage length, as indicated by scribe scratches marked on the test specimen before testing, a retest shall be permitted. 8.2 If the results of an original tension test specimen fail to meet specified requirements, two additional tests shall be made on specimens from the same heat and bar size, and if failure occurs in either of these tests, the bar size from that heat shall be rejected. 8.3 Ifany test specimen fails because ofmechanical reasons such as failure of testing equipment, it shall be discarded and another specimen taken. 8.4 Ifany test specimen develops flaws, it shall be discarded and another specimen of the same size bar from the same heat substituted.