Standard Specification for Reinforced Autoclaved Aerated Concrete Elements - PDF

ASTM C1452 Shear Fixture – Universal Grip Data Sheet (PDF)

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ASTM C1452 and Weld Shear Testing of Reinforcement

Status: ASTM C1452 (Reinforced Autoclaved Aerated Concrete Elements) was withdrawn in 2013. Reinforced AAC panels and lintels are now covered by ASTM C1694, with the AAC material itself in C1693. These elements are reinforced with welded steel wire mats, and the welds that hold the cross wires must carry shear so the mat can anchor the bars in the AAC. This fixture tests that weld shear strength.

Today the weld shear test for welded wire reinforcement is defined in ASTM A1064/A1064M, which replaced A185 and A497 for welded wire. The same fixture also suits welded rebar mats, wire mesh and other cross-welded wire products.

How the Weld Shear Test Works

• The larger (longitudinal) wire hangs vertically through a notched anvil, with its lower end gripped in the bottom jaws of the tensile machine

• The cross (transverse) wire rests on the anvil on both sides of the notch and is held close to the vertical wire so it cannot rotate

• Free-rolling rollers keep the vertical wire straight as it is pulled down

• The machine pulls the longitudinal wire until the weld shears off the cross wire

• The fixture hangs from a ball-and-socket joint so it self-aligns with the load line

Specimen and Test Requirements

• Cut a cross from the mat: the transverse wire extends about 25 mm (1 in) past each side of the longitudinal wire, and the longitudinal wire is long enough to reach the grips

• Use the smallest anvil notch that clears the longitudinal wire; the original jig took wire up to 15.9 mm (5/8 in)

• Test four welds chosen at random from the specimen

• Loading rate no more than 689 MPa/min (100,000 psi/min) on the wire

Confirm requirements against your copy of A1064 or the project specification.

Acceptance and Calculation

Minimum average weld shear force = 241 MPa × nominal area of the larger wire (mm²)

In inch-pound units: 35,000 psi × nominal area of the larger wire (in²). The requirement applies where the smaller wire is at least 40% of the larger wire's area (for example W10 with W4, or W20 with W8).

Example: W10 × W4 mesh. The larger wire, W10, has a nominal area of 0.10 in² (64.5 mm²). Minimum average weld shear = 35,000 × 0.10 = 3,500 lbf (15.6 kN). If the four welds average 4,100 lbf, the mesh passes.

If the average of four welds fails, test all the welds across the specimen; the material passes if that average meets the minimum.

Equipment

• Universal testing machine with 50 kN or more capacity and wedge grips for the wire

• Weld shear fixture with interchangeable anvil notches and free-rolling guide rollers

• Ball-and-socket hanger for self-alignment

• For AAC elements themselves: compression platens and a bend fixture for panel and lintel tests

• Environmental chamber for temperature testing

Related Standards

• ASTM C1694 – reinforced AAC elements (current)

• ASTM C1693 – autoclaved aerated concrete material

• ASTM A1064/A1064M – carbon-steel wire and welded wire reinforcement (weld shear test)

• ASTM A185 and A497 – former welded wire fabric specifications (replaced by A1064)

• ASTM A370 – mechanical testing of steel products

ASTM C1452 Weld Shear FAQ

Is ASTM C1452 still active?

No. C1452 was withdrawn in 2013. Reinforced AAC elements are now covered by ASTM C1694, and weld shear of the welded wire reinforcement is tested per ASTM A1064.

What is the minimum weld shear strength for welded wire reinforcement?

The average of four welds must be at least 35,000 psi × the nominal area of the larger wire (241 MPa × area in mm²), where the smaller wire is at least 40% of the larger wire's area.

How is a weld shear test set up?

The larger wire hangs vertically through a notched anvil and is gripped at the bottom; the cross wire bears on the anvil. Pulling the vertical wire shears the weld off the cross wire.

How many welds are tested?

Four welds chosen at random. If their average fails, all the welds across the specimen are tested and the average of those decides acceptance.