Calculadora de Separación de Varilla Gratis
Calcula el espaciado óptimo de varillas de refuerzo. Ingresa las dimensiones de la losa o muro.
Min concrete cover from edge to first bar
Number of Bars
30
Number of Bars vs Span Length
Fórmula
How to Calculate Rebar Spacing
Formula
Usable Span = Total Span - 2 × Edge Cover
Number of Bars = floor(Usable Span / Spacing) + 1
Actual Spacing = Usable Span / (Number of Spaces) × 12
Edge cover is the minimum distance from the edge of the concrete to the nearest rebar. Typical cover is 3 inches for cast-against-ground concrete and 1.5 inches for formed surfaces.
Ejemplo Resuelto
Rebar across a 30 ft span at 12-inch spacing with 3-inch edge cover.
- 01Cover in feet = 3 / 12 = 0.25 ft
- 02Usable span = 30 - 2 × 0.25 = 29.5 ft
- 03Spacing in feet = 12 / 12 = 1.0 ft
- 04Number of bars = floor(29.5 / 1.0) + 1 = 30 bars
- 05Actual spacing = 29.5 / 29 × 12 = 12.21 inches
Preguntas Frecuentes
What is the minimum concrete cover for rebar?
3 inches for concrete cast directly against earth. 2 inches for formed concrete exposed to weather. 1.5 inches for formed concrete not exposed to weather.
What is the maximum rebar spacing?
ACI code limits rebar spacing to 18 inches or 3 times the slab thickness, whichever is less. For temperature/shrinkage steel, maximum spacing is 18 inches or 5 times the thickness.
How do I mark rebar spacing on forms?
Measure and mark the cover distance from each edge, then mark at the calculated spacing intervals. Snap a chalk line to guide placement.
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