Aci 544.2r-89 ((exclusive)) Jun 2026

Despite these criticisms, the 1989 report was revolutionary for its time. It forced the concrete industry to think beyond first-crack strength.

| Property | ACI 544.2R-89 | Modern Standard (e.g., ASTM C1609 / EN 14651) | |----------|----------------|------------------------------------------------| | Flexural test | Four-point bending, toughness indices I5, I10, I20 | Four-point bending, residual strength f150, f300, f600 | | Impact | Drop-weight (blows to failure) | Not recommended for design; replaced by instrumented pendulum | | Compression | Standard cylinders | Same, but with note on ductility observation | | Acceptance criteria | None provided | EN 14845, Model Code 2010 provide classes (e.g., 1a, 2e) | | Application notes | General research use | Specific to slabs, shotcrete, precast, seismic | aci 544.2r-89

From this curve, the report defines: