Automated Concrete Slab Design to Eurocode 2 [WEBINAR RECORDING 2020]

Posted on June 5th, 2020 in Webinars

Summary

This source provides an in-depth demonstration of MasterSeries structural analysis software, specifically focusing on the automated design of concrete slabs to Eurocode 2. The presenter illustrates a streamlined workflow, beginning with importing architectural models from Revit, which includes elements like shear walls, columns, and openings. The core of the demonstration revolves around defining slab geometry, applying various loading patterns (including live and alternate loads to capture maximum moments), and specifying codified concrete material properties while accounting for cracked sections for more accurate deflection calculations. The software then performs a finite element analysis, generating results for bending moments, deflections, and initial steel area assessments. Finally, the video highlights the advanced features for detailed reinforcement design, including bottom and top steel, peak reinforcement zones, and an innovative punching shear check that considers column types, openings, and different reinforcement arrangements, ultimately allowing for direct export of detailed rebar drawings to AutoCAD.

Key Concepts

• Slab Design
• Reinforcement
• Loading Pattern
• Punching Shear
• AutoCad Exports

Description

MasterSeries 2020 offers a comprehensive solution for Automated Concrete Slab Design to Eurocode 2, utilizing a new system that replaces older flat slab programs. The software allows for full finite element (FE) analysis and design, integrating with other MasterSeries modules and external programs like Revit.

Here's a summary of its key features and workflow:

• Revit Integration and Model Setup

    ◦ The process can begin by importing a Revit model, including sheer walls, columns, openings, and even mismatched columns across levels, via a link manager.

    ◦ Users can choose to import slab elements and walls to create a new MasterSeries model.

    ◦ Alternatively, slabs can be created from scratch within MasterSeries by defining borders, adding openings, and specifying material properties.

• Slab Definition and Material Properties

    ◦ Slab surfaces are easily created by defining their main borders and openings.

    ◦ Codified materials like C28/35 concrete can be assigned, along with a specified thickness (e.g., 200mm).

    ◦ For more realistic deflection predictions, the system allows the use of a cracked short-term load factor for serviceability loading cases, modifying Young's modulus as per BRE concrete society guide recommendations.

• Loading and Pattern Loading

    ◦ Users can apply basic dead loads and additional live loads.

    ◦ A crucial feature is the ability to define alternate loading patterns to generate maximum sagging moments and deflections. This involves setting up "load groups" for different panels to create max-min-max-min patterns in both perpendicular directions.

    ◦ This results in a comprehensive set of loading cases (e.g., 12 cases), covering all spans loaded, alternate patterns in one direction, and then in the other, including serviceability checks.

• Analysis and Initial Assessment

    ◦ After setup, a static analysis is performed using the finite element method, with options for default mesh size and even horizontal notional loads for ultimate limit state.

    ◦ Analysis results can be graphed, showing bending moments, widest displacements (ultimate and serviceability, considering cracked creep loading), and initial estimates for required steel areas (top/bottom, X and Y directions). This provides a "rough area of Steel Eurocode" assessment.

• Concrete Slab Design (New Facility)

    ◦ The software then moves into a dedicated concrete slab design program, which can handle flat slabs with or without beams.

    ◦ Basic Reinforcement: Users can add basic reinforcement (e.g., T10s at 200mm spacing) across the entire slab. The software checks unity values to identify areas where the basic reinforcement is insufficient (e.g., sagging failures).

    ◦ Peak Zones for Hogging Steel: For areas requiring additional reinforcement, especially over supports for hogging moments, "peak zones" can be added.

        ▪ These zones can be auto-sized for both their area and the required steel (e.g., T16s at 200mm).

        ▪ Defaults for peak zones include resolution (e.g., 250mm for 1250mm, 1500mm, 1750mm, 2m strips), and limiting rebar options.

        ▪ The system includes warnings, such as "strip averaging" issues, recommending an effective depth limit for averaging.

        ▪ Peak zones can be adjusted for angle (e.g., -30 degrees) and extended graphically.

    ◦ Strip Method: For supports like walls, a strip method can be used to define additional reinforcement (e.g., extra T10s perpendicular to the wall). Strips can be drawn and modified graphically to cover specific areas.

    ◦ Rationalization: Reinforcement zones can be rationalized to standardized sizes and spacings for practical construction on site.

• Punching Shear Design

    ◦ The software performs punching shear checks at columns and even corners and edges of walls, which are often overlooked but can have high shearing stresses.

    ◦ It identifies locations where punching shear reinforcement is required and suggests options like radial layered bars (mimicking shear rails), equally spaced bars, grid arrangements, or cruciform patterns.

    ◦ The system is "very clever" at understanding openings close to columns and modifying the column design and perimeter checks accordingly.

    ◦ Calculations can use either the Eurocode method or the FE surfaces method, typically yielding similar reinforcement requirements.

    ◦ For piled slabs, punching shear is handled by assuming a column underneath each pile location or by creating localized drops (e.g., 500mm drop, 100mm extra thickness) in the slab to resist punching shear without extra reinforcement.

• Output and Export

    ◦ Once the design is complete, detailed rebar information can be generated.

    ◦ This can be exported to AutoCAD (DXF/DWG format) at a specified scale (e.g., 1:100), providing views of bottom steel in different directions and top steel, including detailing for middle and outer strips, ready for detailers.

MasterSeries provides free trials and guided learning to help users become proficient with the software.