Column Design: RCC P-M Chart

Column Design checks reinforced concrete columns the way engineers do: with a strain-compatibility P–M interaction diagram built for your exact section, bars and design code. Enter the column and its loads and the utilisation, every code check, the steel the loads need and the full working update as you type. FOUR DESIGN CODES • IS 456:2000 — parabola-rectangle at 0.446 fck, Fig. 23 steel, 3D/7 pivot, cl. 39.6 biaxial, cl. 39.7 slender columns • ACI 318-19 — Whitney block with β1, φ from εt (tied or spiral), 0.80φP0 cap, moment magnifier, Bresler reciprocal load • EN 1992-1-1 (Eurocode 2) — αcc option (1.0 or UK 0.85), Table 3.1 high-strength concrete, nominal curvature, 5.8.9 biaxial • AS 3600:2018 — α2 and γ block, straight line to the squash load, Table 2.2.2 φ (Amendment 2), moment magnifier, 10.6.4 biaxial INTERACTION DIAGRAMS • Nominal and design P–M curves about either axis, from pure tension to squash load • Balanced point, decompression and pure bending marked • Drag along the curve to read P, M, φ and the neutral axis depth • See the compression zone and strain diagram for any point DESIGN CHECKS • Rectangular or circular sections with any number of bars • Minimum eccentricity, slenderness and second-order moments for braced columns • Biaxial bending by exact load contour and by the code's simplified method • Reinforcement limits and the least steel that passes, with a bar suggestion DESIGN CHARTS • SP-16 style non-dimensional charts: p/fck curves for IS 456, steel ratio curves for ACI, EC2 and AS 3600 • Bars on two faces, four sides or in a circle; d'/D from 0.05 to 0.20; every common steel grade • Touch the chart to read the steel needed for any load MADE FOR iPHONE • Five themes — Pearl, Midnight, Blueprint, Sandstone and Royal Gold — plus Auto • Landscape layout with the chart beside the controls • Share the design: the full working plus a picture of the section • A theory guide to interaction diagrams and each code's rules PRIVATE BY DESIGN No account, no ads, no tracking and no internet connection needed. Column Design is a checking and learning tool; a qualified engineer must verify every design.