ILX Concrete sizes and details beams, columns, slabs, walls, and footings using strength design and strain-compatibility analysis. It builds real P-M interaction surfaces, checks shear and detailing, and documents every step in a calculation report your reviewer can follow.
Concrete design lives in dozens of one-off spreadsheets: a beam sheet here, a column interaction macro there, a footing workbook that nobody fully trusts. ILX Concrete consolidates that work into a single, consistent tool that applies the strength design method uniformly across member types — so the same material model, strength-reduction factors, and detailing rules apply whether you are checking a beam or a biaxially loaded column.
Every member type uses strain-compatibility analysis at its core. For flexure that means locating the neutral axis and integrating the concrete stress block against the steel layers; for columns it means constructing the full interaction surface rather than relying on simplified approximations. The output is a transparent calculation that shows the section, the reinforcement, the governing condition, and the demand-to-capacity result.
Rectangular and T-beams in flexure and shear, with stirrup design, minimum and maximum steel, and crack-control checks.
Rectangular and circular columns checked against a full P-M interaction surface, including biaxial bending and slenderness.
Strip design for flexure, shear, temperature and shrinkage steel, and deflection control.
Flat plates and slabs with two-way and punching-shear checks around columns and edges.
Bearing and shear walls under combined axial and in-plane and out-of-plane demands.
Isolated footings for bearing, one-way and two-way shear, flexure, and dowel development.
Multi-column footings with soil-pressure distribution and reinforcement design.
Development length, hooks, and lap-splice checks integrated into each member result.
Plotted P-M (and P-M-M) surfaces with the factored demand points overlaid for instant verification.
| Domain | Basis | What it governs |
|---|---|---|
| Concrete design | ACI 318 — Building Code Requirements for Structural Concrete | Flexure, axial-flexure interaction, shear and torsion, walls, footings |
| Detailing | ACI 318 development and splice provisions | Development length, hooks, lap splices, spacing, and cover |
| Serviceability | ACI 318 deflection and crack-control provisions | Minimum thickness, deflection limits, distribution of reinforcement |
| Loads | ASCE 7 — Minimum Design Loads | Factored load combinations for strength design |
| Adoption | International Building Code (IBC) | Reference standard adoption and design parameters |
| Materials | Specified concrete and reinforcement grades | Compressive strength, steel yield strength, and modulus |
Standards are referenced by their issuing organizations for interoperability. ILX Studio is an independent software developer and is not affiliated with, nor endorsed by, any standards body.
1. Define the section. Set dimensions, concrete and steel strengths, cover, and bar layout.
2. Apply demands. Enter factored forces directly or bring reactions in from your analysis model.
3. Analyze. The member is solved by strain compatibility; columns produce a full interaction surface.
4. Detail. Reinforcement, shear steel, and development are checked against code detailing limits.
5. Document. Produce a calc sheet with interaction plots, ready for ILX PDF assembly.
Design follows ACI 318, Building Code Requirements for Structural Concrete, using the strength design method, with factored load combinations from ASCE 7 and the IBC.
Yes. Columns are evaluated against a full three-dimensional axial-moment interaction surface built from strain compatibility, so biaxial bending is checked directly rather than through a simplified reciprocal-load approximation.
It covers spread, combined, and strap footings, one-way and two-way slabs including punching shear, and structural walls, in addition to beams and columns.
Both. Each member result includes minimum and maximum reinforcement, spacing, cover, development length, hooks, and lap splices alongside the strength checks.
Every result shows the governing condition, inputs, and capacity with the relevant code basis. The engineer of record reviews and seals the calculation; the software supports the work rather than replacing professional judgment.
ILX Concrete is a member-level reinforced-concrete structural design tool for Windows. It designs and details individual concrete members to ACI 318-19 with code-cited, seal-integrity-gated calculation reports.
ILX Concrete enforces a principle most incumbent software does not: a design that fails cannot be sealed. The PE-seal block on every report is only activated when every limit-state check passes and at least one check actually ran. A failing design shows REQUIRES REDESIGN; an unchecked design shows NOT CHECKED. There is no way to accidentally seal a failing report.
Beams · Slabs · Columns (uniaxial and biaxial) · Shear walls · Basement/retaining walls · Spread footings · Combined footings · Mat foundations · Pile caps · Corbels · Dapped ends · Coupling beams · Continuous beams (2D FEA)
Full application screenshot with the ribbon at the top, a column design input panel on the left, and the interactive cross-section viewport showing the reinforcement layout.
img/concrete_main_interface.png — screenshot coming soon
| Requirement | Minimum | Recommended |
|---|---|---|
| OS | Windows 10 (64-bit) | Windows 11 |
| CPU | 4-core | 8-core |
| RAM | 8 GB | 16 GB |
| Storage | 500 MB free | 2 GB |
| Display | 1920 × 1080 | 2560 × 1440 |
ILX-Concrete-Setup.exe from the ILX Studio website..ilxd project file association are registered automatically.ILX Concrete uses the unified license.ilxstudio.com portal. Your seat is verified at startup and periodically via a background heartbeat. Sign out via File → Account → Sign Out to transfer your seat to another machine.
Click New Project on the Start page (Ctrl+N). A project (.ilxd file) holds multiple member designs — think of it as a calculation package for one structure or design task. Add your first member from the ribbon: Home → New Member → [type].
Ctrl+S — saves all members and their results in the project file. Results are embedded so reopening a project shows the last computed state immediately.
| Tab | Contents |
|---|---|
| Home | New member, open/save, project settings |
| Design | Material, geometry, reinforcement inputs for the active member |
| Loads | Applied forces, moments, and load combinations |
| Analysis | Run design, run FEA, optimize reinforcement |
| Report | Generate PDF, preview, share |
| Manage | Project members list, batch, settings |
The right side shows the Results Summary after a design run: a table of limit states, demand/capacity ratios (DCR), pass/fail status, and the governing ACI clause. A visual status bar shows overall status — green (all pass), yellow (warnings), red (one or more failures).
Rectangular, T-beam, or L-beam cross sections. Checks: flexure (positive and negative), shear (§22.5), torsion (§22.7), deflection (§24.2), development length (§25.4), and crack width (§24.3).
Rectangular or circular cross sections. Full P-M interaction diagram, biaxial bending (3D P-Mx-My envelope), tie spacing and spiral pitch design, slenderness and moment magnification (§6.6–6.7), seismic capacity design (SDC C and above).
Column design results panel showing the biaxial interaction diagram with the applied load point inside the capacity envelope, alongside pass/fail check rows with ACI clause citations.
img/concrete_column_results.png — screenshot coming soon
In-plane shear/flexure (ACI §11), boundary element check (§18.10.6); spread/combined/mat footings; retaining wall overturning, sliding, bearing stability with stem design integrated.
Strut-and-tie corbels (ACI §16.5); pile cap configurations (2- through 9-pile); continuous beam 2D FEA for moment/shear envelopes.
| Parameter | Typical Range | Notes |
|---|---|---|
| f′c | 3,000 – 12,000 psi | Lightweight concrete flag available |
| fy | 40,000 – 80,000 psi | Grade 40, 60, 80, 100 presets |
| Es | 29,000 ksi | Fixed per ACI §20.2.2 |
| λ (lightweight factor) | 0.75 – 1.0 | ACI §19.2.4 |
Loads can be entered as factored (Pu, Mu, Vu, Tu) or unfactored (D, L, S, W, E components) — the app generates ACI/ASCE 7 load combinations and envelopes them. The Load Diagram panel lets you draw distributed and point loads graphically along the span.
Manual: specify bar size and count/spacing directly. Auto-optimize: click Optimize and ILX Concrete finds the lightest reinforcement layout that passes all checks, subject to detailing minima and your bar size preferences.
Any change to inputs clears the results and marks the member as Unanalyzed (yellow dot in the member list). Previous results are never shown alongside stale inputs — this prevents accidentally issuing an outdated passing result.
Every limit state check includes: check name, demand (Mu, Vu, etc.), capacity (φMn, φVn, etc.), DCR (demand/capacity ≤ 1.0 to pass), status (✓ PASS / × FAIL / ⚠ WARNING), and ACI clause (e.g. ACI 318-19 §22.5.5.1).
The P-M interaction diagram plots capacity (the envelope) and demand (the applied load point). The design passes when the demand point falls inside the envelope at all considered load combinations. For biaxial columns, the 3D P-Mx-My surface is shown as a contour plot with demand points overlaid.
Results panel for a beam design showing a clean check table with ACI clause numbers, green pass marks for flexure and shear, and a red fail mark for torsion with a “Redesign Required” banner.
img/concrete_beam_results.png — screenshot coming soon
Report → Generate PDF includes: project header, summary of all input parameters, all limit-state checks with the full hand-calc derivation (substituted values, intermediate results, code equation reference), reinforcement schedule and bar diagram, and the PE-seal block.
The PE-seal block activates only when: (1) at least one limit-state check was executed, and (2) every executed check shows PASS. REQUIRES REDESIGN appears if any check fails. NOT CHECKED appears if no check was run. This behavior cannot be overridden from the UI.
A completed PDF report page showing the PE-seal block activated at the bottom, with the ILX Concrete header, project info, and the first calculation section with ACI clause citations.
img/concrete_report_seal.png — screenshot coming soon
ILX Concrete includes a batch mode for parametric studies and load tables. The same calculation engine as the GUI — outputs are identical.
Create a CSV with one row per member. Column headers map to input parameters (see File → Batch → Download Template CSV for the correct headers). Run:
python -m ilxconcrete batch --input columns.csv --output results\
Each row produces a JSON results file and an optional PDF report (--reports flag). A summary CSV with pass/fail per member is also generated. The batch runner exits with code 0 if all members pass, non-zero if any fail — suitable for CI/scripted workflows.
For continuous beams and slabs, ILX Concrete uses a 2D frame FEA engine to compute moment and shear diagrams before applying ACI limit states.
Load input panel for a continuous beam with a graphical span diagram showing distributed loads, point loads, and support conditions, alongside the resulting moment envelope diagram.
img/concrete_continuous_beam_loads.png — screenshot coming soon
| Input | Description |
|---|---|
| Basic wind speed V | From ASCE 7 Figure 26.5-1A/B/C |
| Exposure category | B, C, or D |
| Building height | Eave/ridge/mean roof height |
| Enclosure classification | Enclosed, partially enclosed, open |
| Risk category | I, II, III, IV |
ILX Concrete computes MWFRS and C&C pressures per ASCE 7-22 Chapters 26–30 and applies them as lateral loads on wall and retaining wall members.
Select SDC (Seismic Design Category A–F), SDS / SD1 spectral accelerations, and system type. Seismic detailing requirements (ACI 318-19 Chapter 18) are automatically triggered based on SDC and called out in the report.
| Setting | Location | Options / Notes |
|---|---|---|
| Theme | File → Options → Display → Theme | Dark / Light / High-Contrast |
| Units | File → Options → Units | US Customary / SI |
| Default materials | File → Options → Defaults → Materials | Pre-populate new members with your most-used f′c and fy |
| Report branding | File → Options → Report | Firm name, PE name, logo (PNG ≤ 200 × 200 px) |
| Autosave | Default: every 5 minutes | %LOCALAPPDATA%\ILX Studio\Concrete\Autosave\ |
The design was modified after the last run. Re-run the design (F5) — results must be current for the seal block to activate.
The section geometry is too small for the applied loads, or bar spacing constraints cannot be satisfied. Try increasing the section size or relaxing bar size preferences in Optimization Settings.
For mat foundations or heavily loaded slabs, try increasing the soil spring stiffness or reducing the plate element size. Contact support if the issue persists.
Delete %LOCALAPPDATA%\ILX Studio\Concrete\Cache\ and restart. If the issue continues, re-run the installer to repair. Crash logs: %LOCALAPPDATA%\ILX Studio\Concrete\Logs\.
| Convention | Meaning |
|---|---|
| Bold text | Button, ribbon tab, menu item, panel name, or UI label |
Monospace | Command, file extension, keyboard shortcut, path, or literal value |
| ✓ / ✗ / ⚠ | Pass, fail, and warning status indicators |
Store active projects in a version-controlled folder. Use clear filenames with project number, discipline, revision, and date. Keep exported PDFs separate from editable native project files (.ilxd).
ILX Concrete provides code-based design assistance, but the responsible engineer must verify all assumptions, inputs, load combinations, member idealizations, detailing requirements, and final reports. A passing software result does not guarantee constructability or suitability for every project condition.
Dark, Light, and High-Contrast themes. Increase UI text scale in File → Options → Display.
Crash logs at %LOCALAPPDATA%\ILX Studio\Concrete\Logs\. Contact support@ilxstudio.com with product version, Windows version, project file (if permitted), and steps to reproduce.
| Term | Meaning |
|---|---|
| DCR | Demand-to-Capacity Ratio; values above 1.0 indicate failure for strength checks. |
| SDC | Seismic Design Category (A–F) — governs seismic detailing requirements. |
| LTD | Long-term deflection — includes creep effects per ACI §24.2. |
| LRFD | Load and Resistance Factor Design (φ factors per ACI 318-19). |
| Version | Date | Notes |
|---|---|---|
| 1.0 | 2026 | Initial manual draft. |
| 1.1 | 2026 | Expanded professional-use guidance, QA, accessibility, and glossary content. |
Request a demo and we will run a beam, a biaxial column, and a footing from input to calc sheet.
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