BIM for Rebar Modeling: Why Revit is better for Rebar?

BIM Revit rebar modeling by United-BIM

CAD goes far beyond handmade paper drawings to support the development of the Architecture, engineering, and construction (AEC) industries, enabling them to create more complex and accurate designs.

Today, AEC businesses continue to face new challenges, including monetary constraints, deliver projects faster and more accurately. As a result, AEC industries are adopting their technology to BIM which is proven to deliver more benefits over CAD.

With the advent of BIM, many new features have been added to the BIM-related software for improving the efficiency and capabilities of rebar detailing & design.

Revit for rebar design and detailing allows you to model, document, track and control any structure design, making it easy to coordinate and manage.

Structural Business Challenges when using CAD

Some of the challenges include:

  1. As the complexity of the project increases, there is a lack of design information, leading to inaccurate estimates.
  2. Detailers and drafters need an efficient way to collaborate with the design team.
  3. Lack of Jobsite coordination creates waste and inefficiencies.
  4. Fabricators are required to use technology that gains more insights into how to fabricate and install building components and systems.

Benefits of BIM for Rebar Modeling

BIM-centric solution for concrete and rebar differs drastically depending on someone’s role on a project.

  • Engineers and designers wish to gain more engineering insights while making the design intent of structures, coordinating with the help of analysis tools and local building requirements.
  • Fabricators wish to maximize the productions and delivery efficiency of structural components while minimizing the turnaround time on detailing and field coordination.
  • Contractors wish to optimize planning and to determine accurate quantity estimating in the early stage of the project to avoid rebar clashes on sites and clash coordination with other trades.

What are the benefits of using a Revit-based strategy? What value does it provide to Revit users?

BIM-centric concrete solutions help Revit users in four main areas:

  1. This methodology consolidates the flexibility of 2D documentation with the significant level of exactness of 3D modeling of steel reinforcement and concrete accessories, with minimum efforts to produce both.
  2. It allows structural detailing and designing with clash prevention, keeping in mind reducing clashes during the pre-construction and construction phase of the project.
  3. It allows the transition from design intent to the detailed model while respecting 2D and 3D perspectives, following local building codes.
  4. A model created in Revit can provide quality information for bidding and procurement and allow access to it in a collaborative environment for accurate quantity estimation.

Design Focused Workflow for Rebar Modeling in Revit

Design Focused Workflow for Rebar Modeling in Revit

Key Revit Features for Rebar Modeling

1. Parametric Modeling

Every building element/component in Revit is a part of the Revit families includes walls, ceilings, beams, columns, and rebar. Revit families are parametric, and they inserted into the Revit creates a parametric Revit model.

Parametric Revit family have parameters like height, length, depth, etc., and a change in a parameter of a Revit family will subsequently adjust the parameter of other relevant Revit families.

For example, Stirrups dimensions depend on the concrete element section size. If the size of the section is changing, stirrups will be updated automatically following the element’s dimensions. (as well as shop drawings and rebar bending schedules)

2. Quick and Precise Rebar Placement

There are many methods for adding rebar into concrete elements.
a) Sketch Rebar
Using this approach, Revit automatically recognizes the shape code and assigns it to the newly created rebar instance.

b) Use the library of Rebar Shapes
Another way is to utilize the library of shapes stacked into the project by setting the positioning plane, arrangement direction, and rebar properties.

3. Rebar Sets

Rebar sets are used to speed up the process of adding rebar by providing quantities of identical bars, accurate schedules that display varying lengths.
a) Layouts

  • Fixed number
  • Maximum spacing
  • Number with spacing
  • Minimum clear spacing

b) Types

  • Regular set
  • Varying rebar set

4. Tools for Planner Elements

a) Area reinforcement
b) Path reinforcement
c) Fabric area reinforcement

Area Reinforcement can be used to create large amounts of reinforcement in up to four layers in walls and floors.
The Path Reinforcement tool can be used to create shape-driven reinforcement distributed along a path, in walls and floors.

5. Free Form Rebars

a) Rebar distribution along with multiple face segments
b) Create sets with planar bars, distributed along with complex structural elements
c) Bars can be perpendicular to an edge or parallel to a selected face
d) Constrained to the framework and adjust to its changes

6. Rebar Constraints & Rebar Cover

In Revit, every concrete element has concrete cover settings defined.
a) Full control over rebar placement
b) Parametric association between bars
c) Two-way constrains
d) Constrains to any rebar or host in the project

7. Rebar Couplers

a) Define rebar connection requirements
b) Comprehensive and detailed model
c) Symbolic representation for rebar accessories
d) Coupler numbering
e) High fidelity of rebar modeling for fabrication

Rebar Couplers are family-based and completely adaptable, and each colleague can utilize them as indicated by their requirements. Rebar Couplers interface with the rebar they associate to, facilitating change management.

  • Structural engineers can use schematic connectors to define requirements.
  • Detailers can utilize them to produce shop drawings.
  • Manufacturers can go into full detail, precisely modeling and representing reinforcement connectors to create installation instructions.

8. Numbering and Partitioning

a) Numbering automation and customization
b) Pouring sequencing

  • Construction sequence and phasing
  • Host element types
  • Precast fabrication needs
  • Location with a host
  • Location in the model

Revit has Rebar Numbering that enables identical reinforcement elements to be matched for schedules and tags.
Partitioning for reinforcement identification serves several organizational purposes, depending upon building design or how it will be constructed.

9. Rebar Annotations

a) Single rebar annotation
b) Rebar set annotation
c) Multi-rebar annotation

These annotations can be used to tag each bar in rebar sets with detailed fabrication and construction information.

10. Presentation and Rebar Sets

These enable the creation of legible reinforcement documentation and provide the ability to create better correct detail shop drawings for reinforcement.

11. Rebar Bending Schedules

a) Grouping, sorting, filtering rebar
b) Grouping rebar by host
c) Rebar shapes included

They are an imperative way to display model information and are essential when documenting your project.

Conclusions

Today, owners desire their design and construction to be quick, collaborative and seamlessly coordinated. Using BIM technology and Revit 3D modeling for rebar detailing & designing can be beneficial for every structural stakeholder. They can model, coordinate, document, track, and manage the design and changes accurately.

Don’t wait to move to BIM, the time is right NOW.