August 8, 2015

How do you add Shear Caps to columns?

Per the ACI, you can add a Shear Cap to your column to increase the shear strength of the slab. In RISAFloor ES two-way slabs, adding a shear cap will thicken the plates around the column automatically. The Shear Cap will affect the Punching Shear and the One-Way shear calculations.

As you draw the columns in RISAFloorES, there is an option to include a Shear Cap. The thickness is measured from below the bottom of the slab. The Depth and Width are based on the column definition and local axis.

It is common to model without Shear Caps and only add Shear Caps as they are needed. You can add Shear Caps to the columns at any time from the Windows menu- Modify – Columns. This allows you to create a Shear Cap on an existing model and shift the Shear Cap eccentrically.

You can also modify the Shear Cap in information is stored in the Columns spreadsheet. The eccentricity is defined based on the column local axis. The picture below shows a Shear Cap that is shifted eccentrically by 12 inches in the ey and ez directions.

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Tags: RISAFloor ES, Concrete, New

November 21, 2022 | ADAPT-Builder, ADAPT, Slab, New, Punching Shear, Popular

Consideration of Drop Caps and Drop Panels for Punching Shear Design

ADAPT-Builder v22 now includes the ability to model a Drop Cap and a Drop Panel at the same support. The Punching Shear check considers both Drop Caps and Drop Panels when creating critical sections for the Two-Way Shear Design. Whether modeling a Drop Cap, a Drop Panel, or a Drop Cap within a Drop Panel, the critical sections will be considered at the support, at the Drop Cap, and at the Drop Panel, when performing a punching shearcheck. To place a Drop Cap and a Drop Panel at the same support, first place the Drop Cap and define the properties. Then, to model the Drop Panel, select the Drop Panel icon, and before placing the Drop Panel, change the Type in the Properties Grid from Drop Cap to Drop Panel. Once the drop panels and drop caps are modeled, you can perform a Two-Way (Punching) Shear Check as well as view Two-Way (Punching) Shear Check Results. For more information about this feature and the use of drop caps and drop panels within slabs in ADAPT-Builder, please visit our Help file by clicking the link below: ADAPT-Builder Help File…

January 1, 2021 | ADAPT-Builder, ADAPT, New, Punching Shear

Consideration of Openings for Punching Shear of Two-Way Slabs in…

Punching shear of two-way reinforced concrete and post-tensioned slabs is a critical design consideration. The presence of openings near a support can complicate the calculation of shear capacity at the location. ADAPT-Builder v20 now includes enhancements in how openings are treated near columns and walls that are checked for punching shear in the software. In previous versions of ADAPT-Builder, an opening in the vicinity of a column was treated the same as slab edge regardless of its size. For example, when a small opening is close to a column, the whole side of a column is disregarded from the punching shear check, which is conservative in many cases. For ADAPT-Builder 2020 the check for punching shear has been improved in the detection and handling of openings as per ACI code requirements. This new method for handling of openings is enabled when an ACI code version is selected. Two new input parameters are shown in the Punching Shear input dialogue. These include: Radius of detection – This setting is used to determine at what distance from the face of support will openings be detected and deducted from the critical sections that fall within the opening. The input is based on a…

January 1, 2021 | ADAPT-Builder, ADAPT, Concrete, New

User Defined Modulus of Rupture in ADAPT-Builder

For reinforced concrete and post-tensioned concrete beams and slabs, deflection control at serviceability conditions is a critical check for code compliance and satisfactory design. The ability to check if a member is cracked and has exceeded the cracking moment or threshold modulus at short- and long-term stages is a critical part of the design process. ADAPT-Builder now gives users more control over the rupture modulus that is used when determining a member’s cracking moment. The option for the user to override the program default and user define the modulus of rupture for cracked deflection of reinforced concrete and post-tensioned slabs and beams is now included in the Criteria > Concrete input dialogue. The definition of a concrete material includes a new section for modulus of rupture. The user-defined value for fr is used in two areas of the program: When calculating the cracking moment, Mcr for calculation of Ieff when cracked deflection calculations are considered in the software. In ACI 318, strength reinforcement for bonded prestressed systems should exceed 1.2Mcr. If this option is selected from Criteria > Analysis/Design Options the program calculates the cracking moments, Mcr based on the defined modulus of rupture assigned to the concrete in question…