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How to Check and Accept Prestressed Concrete Wires and Strands?

time2022/02/09

This article specifically shares the standards and methods for the acceptance of prestressed concrete steel wires and strands for your study and reference.
 the material characteristics and the quality control factors of raw materials of prestressed concrete steel wires

The acceptance process of prestressed concrete steel wire and prestressed concrete steel strands has some similarities, but the inspection standards for the two are different. Then the following is the specific inspection method of prestressed concrete steel wire and prestressed concrete steel strand.

Prestressed concrete steel wire acceptance

1. Visual inspection

The appearance quality of the steel wires for prestressed concrete should be checked on a plate by plate. There should be no oil stains, scales, cracks, or mechanical damage on the surface of the steel wire, but floating rust and tempering colors are allowed on the surface. The zinc layer of galvanized steel wire should be smooth and uniform without cracks. For wire diameter inspection, select 10% discs, but not less than 6 discs.

2. Mechanical performance test

The mechanical properties of prestressed concrete steel wire should be sampled and tested. Each acceptance batch should be composed of prestressed concrete steel wires of the same brand, same specification, and the same production process system, and the weight should not be greater than 60t.

After the steel wire has passed the visual inspection, 10% reels (not less than 6 reels) of steel wires are randomly selected from the same batch. Cut two specimens at any position on each plate, one for the tensile test (tensile strength and elongation), and one for the repeated bending test.

If a certain test result does not meet the requirements of the GB 5223-2002 standard, the steel wire coil is a non-conforming product; and a double number of test pieces are taken from the same batch of untested steel wire coils for re-inspection, such as If there is still one test result that is unqualified, the batch of steel wires shall be judged as unqualified products, or the qualified products shall be inspected one by one.

If the design documents have specified requirements for fatigue performance, employability, etc., sampling tests should be carried out again.

Prestressed concrete steel strand acceptance

1. Visual inspection

The appearance quality of the steel strand wire for prestressed concrete should be inspected one by one. The lay length of the steel strand should be uniform, not loose after being cut, and its surface must not have oil stains, rust spots, or mechanical damage, but floating rust and tempering are allowed.

The coating surface of galvanized or epoxy-coated steel stranded wire, unbonded steel stranded wire, etc. should be uniform, smooth, free of cracks, and no obvious folding. The grease weight and sheath thickness of the unbonded prestressing tendons shall be 60t as a batch, and 3 test pieces shall be taken for inspection. The test results should meet the quality requirements of unbonded prestressed tendons.

2. Mechanical performance test

The mechanical properties of prestressed concrete steel strands should be sampled for inspection. Each acceptance batch should be composed of steel strands of the same brand, same specification, and the same production process system, and the weight should not be greater than 60t. After the steel strands have passed the visual inspection, 3 reels of steel strands shall be randomly selected from the same batch.

A test piece is intercepted from the position and subjected to a tensile test. If a certain test result does not meet the requirements of the GB/T 5224-2003 standard, the unqualified disk shall be discarded. Take twice the number of test pieces from the prestressed concrete steel strands that have never been tested for re-inspection. If there is still one unqualified item, the batch of prestressed concrete steel strands shall be judged as unqualified products.

For the fatigue performance and deflection tensile performance specified in the design documents, sampling tests should be carried out again.

If you want to know more about prestressed concrete wires and strands after reading the above, please continue to pay attention to our news.

CHUNPENG is a professional manufacturer of prestressed concrete products. We have many years of experience and a strict quality inspection system. We uphold a responsible attitude towards users and take full control of all aspects of product manufacturing and export. At the same time, we will also provide a one-stop-shopping service according to the diverse needs of users. If you want to buy our prestressed concrete strands and steel wires, please contact us immediately!