Transverse Reinforcement

Transverse reinforcement is either reported as a required amount, or the user can input it and the program will check that is is sufficient. Inputting the reinforcement also gives a more detailed summary sketch and ledge shear capacity (where Vn is required).

Required Transverse Reinforcement

The program reports required area’s of steel in three different tables, the shear table, torsion table, and combined shear / torsion table. The shear and torsion table report only values for pure shear / torsion respectively. That means that in the torsion table, all Av requirements are not being shown (this is even true for the slender spandrel method where Av is added in to the inner and outer face requirements).

Shear

The shear table reports three different steel areas, all provided as an area per foot. They are the computed minimum transverse area (which may or may not need to be accounted for), the shear steel requirement for Vs (which is the amount of steel needed so that the nominal shear capacity is equal to the shear force), and the required steel (which is the maximum of the area required for Vs and the minimum steel if minimum steel is required). This table is also where the maximum allowable spacing for transverse reinforcement is displayed.

Torsion

Three different torsion tables exist, one for the ACI Method, for for Zia Hsu, and one for Slender Spandrel. Although each table is unique they all display the same three steel areas. They display the transverse requirement on the outer face, the transverse requirement on the inner face, and the longitudinal steel requirement. The transverse requirement are both for pure torsion and do not take shear requirements into account (as previously stated). If the torsion method contains a minimum transverse requirement it will also be displayed here.

Combined Shear and Torsion

In additional to the pure shear and pure torsion tables, their is also a combined shear and torsion table. This table provides the user with the total transverse requirement on both the inside and outside face of the member. In addition to providing these total, it also provides the minimum area which both face needs to provide.

Provided Transverse Reinforcement

When the user tells Eriksson Beam that transverse reinforcement will be input into the program the user will have to define both the shear reinforcement and the torsion reinforcement. Transverse reinforcement can be inserted as either mesh, or mild bars. Mild bars come in a variety of shapes and end conditions summarized below:

Provided Area

The area an individual entry provides depends on the number of legs, and if the entry is included for shear or torsion. If the entry is included in shear, it is assumed that the number of legs times the bar area is provided for Av. If the entry is included for torsion, it is assumed that half of the bar area times the number of legs is provided on both the inner and outer face unless the number of legs is 1. For that case, all the reinforcement is placed on the nearest face.

Stirrup Shapes

The shape of the bar does not change the capacity directly but instead provides a more accurate summary sketch and selects the default number of legs for that shape.