ASTM A955

ASTM A955 – Standard Specification for Deformed and Plain Stainless Steel Bars for Concrete Reinforcement

Description:

Abstract

This specification covers deformed and plain austenitic and duplex (austenitic/duplex) stainless steel bars for concrete reinforcement proposed to be used in applications requiring corrosion resistance, controlled tensile properties or controlled magnetic permeability. For each specimen, one tension test, one bend test, if required, and one set of dimensional property tests shall be made. If the results of the test fail to meet the specified minimum requirements, a retest shall be permitted on two random specimens for each original tension specimen failure from the lot. If a specimen fails a bend test due to reasons other than mechanical or flaws, a retest shall be permitted on two random specimens from the same lot.

Scope

1.1 This specification covers deformed and plain stainless steel bars for concrete reinforcement in cut lengths and coils used in applications requiring resistance to corrosion, restrictive mechanical properties, or controlled magnetic permeability. This specification has a minimum actual tensile strength to actual yield strength ratio (Table 3). The standard sizes and dimensions of deformed bars and their numerical designation shall be those listed in Table 1.

1.1.1 A supplementary requirement (S1) is provided for use where a controlled magnetic permeability product is required by the purchaser. Supplementary Requirement S1 applies only when specified in the purchase order.

1.1.2 A supplementary controlled mechanical properties requirement (S2) is provided for use where a restricted yield strength range and a higher actual tensile to actual yield strength ratio is required by the purchaser. Supplementary Requirement S2 applies only when specified in the purchase order.

1.2 The chemical composition of the stainless steel alloy shall be selected for suitability to the application involved by agreement between the manufacturer and the purchaser. This is an important consideration in achieving the desired corrosion resistance or controlled magnetic permeability, or both, because these properties are not provided by all stainless steels.

1.3 Corrosion Resistance requirements are contained in Section 11 and Annex A1 and the test procedures options are Annex A2 (Rapid Macrocell Test) or Annex A3 (Cracked Beam Test).

1.4 The requirements for introduction of new alloys into a mandatory chemical composition requirements table in this specification are given in Annex A5.

1.5 Requirements for the relative deformation area of three-sided deformed bars are contained in Annex A4.

1.6 Bars are of three minimum yield strength levels, namely, 60 000 psi [420 MPa], 75 000 psi [520 MPa], and 80 000 psi [550 MPa], designated as Grade 60 [420], Grade 75 [520], or Grade 80 [550], respectively.

1.7 Plain bars in sizes up to and including 2 in. [50.8 mm] in diameter in coils or cut lengths are furnished in accordance with this specification in Grade 60 [420], Grade 75 [520], and Grade 80 [550], respectively. Mechanical testing, when required, shall be to the nearest nominal deformed bar size. Requirements providing for deformations and marking shall not be applicable to plain bars.

1.8 When stainless steel is to be welded, use a procedure suitable for the chemical composition and intended use or service.

NOTE 1: Welding of stainless steel reinforcement would occur after shipment from the manufacturer. Structural welding should be performed in accordance with the latest edition of AWS D1.6/D1.6M, any other internationally accepted stainless steel welding code, or a procedure suggested by the material manufacturer. AWS D1.6/D1.6M describes the proper selection of the filler metals, temperature control, as well as, performance, procedure qualification and inspection requirements.

1.9 This specification is applicable for orders in either inch-pound units (as Specification A955) or in SI units (as Specification A955M).

1.10 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.

1.11 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 nonconformance with the specification.