Structural Crack — Idecad

Consider a 200 mm thick RC slab for an underground water tank with a crack width limit of 0.2 mm. A traditional engineer might use minimum reinforcement (Ø12@200 mm). However, ideCAD’s crack analysis for the quasi-permanent load combination (full water pressure + self-weight) calculates a differential strain of 0.0012. Given a 40 mm cover and Ø12 bars, the predicted crack width is 0.28 mm—exceeding the limit. The software instantly suggests two solutions:

IdeCAD compares the cost and constructability of both options, allowing the engineer to choose. After redesign, the software re-checks and confirms compliance. This iterative process, which might take hours manually, is reduced to seconds. idecad structural crack

In standard reinforced concrete design, "checking for cracks" means verifying that the width of cracks under service loads does not exceed the limits set by the design code (e.g., Turkish Standard TS 500 or Eurocode 2). Consider a 200 mm thick RC slab for

  • Slab Mats: For raft foundations and mat slabs, ideCAD performs rigorous crack checks based on the reinforcement layout provided.

    • IdeCAD’s toolset also aids in differentiating between acceptable cracks and structural failures. IdeCAD compares the cost and constructability of both

    The "Planned" Crack: Construction Joints In the 3D modeling environment, engineers can define construction joints. These are deliberate discontinuities where concrete pours are halted. In ideCAD, defining these zones is crucial for linear elements like retaining walls or long-span beams. The software understands that these joints transfer shear (often through shear keys or dowels) but may not transfer the same moment as a monolithic pour.

    The "Unplanned" Crack: Non-Linear Analysis For advanced users, ideCAD offers non-linear analysis options where the "crack" becomes a data point rather than just a parameter. By running pushover analysis (a non-linear static procedure), engineers can observe the formation of "plastic hinges." These are essentially zones where the steel has yielded and the concrete has crushed/cracked to the point of non-repair. ideCAD color-codes these zones (often from Blue/Immediate Occupancy to Red/Collapse Prevention), providing a visual map of where the structure will "break" safely.

    While powerful, ideCAD’s crack module does not replace engineering judgment. First, it assumes perfect bond between steel and concrete—real-world corrosion or poor compaction invalidates results. Second, thermal and shrinkage cracks (non-load-induced) are only indirectly considered via minimum reinforcement requirements; the software does not model thermal gradients. Third, for very thick sections (dams, mat foundations), the plane-sections-remain-plane assumption underpinning the strain calculation becomes inaccurate. In such cases, ideCAD’s output must be supplemented with specialized finite element models.