GOST 12004-81 PDF

Full title and description

GOST 12004-81 — "Сталь арматурная. Методы испытания на растяжение" (Reinforcing-bar steel. Tensile test methods). The standard specifies procedures for tensile testing of reinforcing steel (wire, bars and strands) of round and deformed profiles intended for ordinary and prestressed reinforced concrete structures.

Abstract

GOST 12004-81 defines sample preparation, test conditions and measurement procedures to determine mechanical characteristics of reinforcing steel in tensile tests — including ultimate tensile strength, yield (physical and conditional), elongation (total and after fracture), uniform elongation, reduction of area and initial modulus of elasticity. It establishes test temperature conditions and applicable nominal diameters for which the methods apply.

General information

• Status: Effective / in force (limitation of effectiveness was lifted by protocol of 17 May 1994).
• Publication date: Introduced 1981, publication/entry into force date 1 July 1983 (designation GOST 12004-81).
• Publisher: Approved by Gosstandart (State Committee for Standards of the USSR); developed by the Ministry of Metallurgy of the USSR.
• ICS / categories: ICS 77.140.15 (Steel for reinforcement of concrete) — metallurgy / test methods classification.
• Edition / version: Original designation GOST 12004-81 (with subsequent amendments noted in 1985 and 1990).
• Number of pages: Approximately 10 pages in the published PDF/design version.

Scope

Applies to tensile test methods for reinforcing steel of nominal diameters from about 3.0 mm up to 80 mm (wire, bars and reinforcing strands), for round and deformed profiles used in ordinary and prestressed reinforced concrete. Tests are performed under specified ambient test temperature conditions (nominal 20 °C with allowable deviations indicated in the standard) and are used to determine the mechanical properties listed in the abstract.

Key topics and requirements

• Definitions and sampling requirements for test specimens (wire, single bars, strand segments).
• Conditions and temperature for tensile testing (nominal test temperature and allowable range).
• Test procedure: machine type, gripping, strain measurement and extensometry recommendations.
• Measured properties and calculation methods: ultimate tensile strength, (physical) yield, conditional yield/limit, total elongation, elongation after fracture, uniform elongation, reduction of area, initial modulus of elasticity.
• Reporting format and required test records, plus normative references to measuring instruments and related GOSTs.

Typical use and users

Used by metallurgical manufacturers, quality control and testing laboratories, construction material certifiers, design and engineering offices concerned with reinforced concrete, and regulatory authorities. The standard provides a common, repeatable test method for verifying mechanical properties of reinforcement during production control, incoming inspection and certification.

Related standards

Replaces GOST 12004-66. Normative and related references include GOST 1497 (general tension test methods for metals), GOST 5781-82 (specifications for hot-rolled reinforcing steel), GOST 10884-94 (thermomechanically hardened reinforcement) and later national and industry standards that reference or build on these tensile test methods; ISO standards for reinforcement (for example ISO/EN series on steel for the reinforcement of concrete) are comparable international documents.

Keywords

rebar, reinforcing steel, tensile test, tensile strength, yield strength, elongation, modulus of elasticity, GOST, test methods, metallurgical testing.

FAQ

Q: What is this standard?

A: GOST 12004-81 is the national (USSR-origin) standard that specifies tensile test methods for reinforcing steel (wire, bars and strands) used in reinforced concrete, providing procedures to measure tensile and deformation characteristics.

Q: What does it cover?

A: It covers specimen preparation, test conditions (including nominal test temperature), testing procedure (machinery, grips, strain measurement), and calculation/reporting of results such as ultimate tensile strength, yield (physical and conditional), elongation measures and modulus of elasticity for nominal diameters ~3–80 mm.

Q: Who typically uses it?

A: Metallurgical producers of reinforcement, independent and in-house testing laboratories, certification bodies, construction engineers and standards/regulatory organizations use it to ensure consistent, repeatable tensile property measurements of reinforcement.

Q: Is it current or superseded?

A: GOST 12004-81 is listed as effective (its limitation of effectiveness was lifted in 1994). However, in practice it is used alongside later national and industry standards and amendments; users should check whether a specific project or regulatory domain requires more recent or amended documents.

Q: Is it part of a series?

A: It is part of the metallurgy/test methods family of standards and is linked to other reinforcement and testing GOSTs (for example GOST 1497, GOST 5781 and GOST 10884). It replaces the earlier GOST 12004-66 and is referenced by later standards covering reinforcement products and testing.

Q: What are the key keywords?

A: Reinforcing-bar steel; tensile test; tensile strength; yield limit; elongation; rebar testing; metallurgy; GOST 12004-81.