SRDs (Shear Reinforcement of Dual anchorage) are easily applied headed shear reinforcements for concrete structures. Since their development in 2007, our performance tests have proven that their geometrical design provides excellent results. Now we can supply the SRD system at a very reasonable price.

The components of an SRD are the Anchor Heads (Upper and Lower), the Stem (vertical leg), Strips (two horizontal bars) and specially designed Spacers. Their respective roles are as follows:

• Upper and Lower Heads: the role of the heads is to provide anchorage to
transfer tensile loads to the stem. An SRD provides more than 10 times the anchorage area of the cross-sectional area of the stem.

• Stem: welded to the upper and lower heads, it carries tension between the two up until shear failure occurs in the concrete. The holes in the stem increases the adhesive force of the concrete structure, while directing concrete yields to the relatively safe vicinity of the holes.

• Strip: the strips connect each stem, by spot welding or bolting, to arrange them in the designed spacing. They also create a space between the heads and the strips for flexural rebar. The SRDs are connected to each other with rebar wired to the strips

• SRD Spacer: the spacers clip on to the heads to insure uniform thickness of the concrete cover and to make the SRD set self-standing.
  Design codes vary from country to country, but their principles are all based on the same theories.
For example, the flow chart below illustrates the design process for calculating the punching shear of flat plates.

SRDs can be designed to meet various building codes from all around the world, including ACI, BS, DIN, KBC and etc.

In the case of Dong-bu Steel, a partner in Korea, we apply the KBC (Korea Building Code-Structural) and use SRDesign V1.0 for flat plate design.

You can quickly easily design SRD systems using SRDesign V1.0. It uses the latest code and is user friendly.

SRD Notation is simple and intuitive.
A 13mm stirrup shear reinforcement is written as HD13, and the SRD equivalent is written as SRD13. For example: