Design Methodology

The LinkStud PSR design methodology to EC2 design standard has been fully tested and is approved by CARES.

The design methodology follows the four-step process summarised below. For full descriptions, equations, and drawings, please refer to the LinkStud PSR Design Manual to EC2 that is available to download below.

Step 1 - Punching shear at the loaded area face

The first step is to check if (vEd 0) - the design value of the shear stress at the loaded area face (column or pile) - can be resisted by (vRd.max) - the concrete punching shear resistance.

Calculation of the design value of the shear stress must take account of the loaded area shape, the distance to the nearest edge, the value of direct shear force, any bending moments (if present) and the effective depth of the slab.

The concrete punching shear resistance at the loaded area face depends on compressive concrete strength and factors. In case of failure at the loaded area face the input data must be changed.

Step 2 - Punching shear at the basic control perimeter without reinforcement

This step is to determine if punching shear reinforcement is required.

According to EC2, if (vEd 1) - the design value punching shear stress at the basic control perimeter (2d from the loaded area face) - is greater than (vRd.c) - the concrete punching shear resistance - punching shear reinforcement is required.

If it is not, no further action is required.

Step 3 - Punching shear at the basic control perimeter with reinforcement

If punching shear reinforcement is required, the uout perimeter must be located, beyond which the concrete can resist shear stress itself.

The area inside the uout perimeter must be in-filled with punching shear reinforcement calculated as per the basic control perimeter taking into account the detailing rules described in Step 4.

Step 4 - Shear reinforcement detailing rules.

The first stud should be placed within 0.35d to 0.5d from the loaded area face,

The last stud should be placed at a distance not greater than 1.5d within the uout perimeter.

There should be a minimum of two perimeters of reinforcement.

The radial spacing of the shear reinforcement should not exceed 0.75d.

The tangential spacing of the shear reinforcement should not exceed 1.5d within the basic control perimeter and 2d outside the basic control perimeter.

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Approved to CARES ISO 9001, CARES Technical to EC2 and compatibility with BS8110 Structure Design