Clear Spacing Between Beam Bars
Mediumdetailingbar-spacinggeometry
A beam is 300 mm wide. Clear cover from each side face to the outside of the 10 mm stirrup is 40 mm. Four 25 mm longitudinal bars lie in one row inside the stirrup with equal clear gaps. Ignore stirrup bend radii. What is the clear horizontal gap between adjacent bars?
- A25.0 mm
- B40.0 mm
- C48.3 mm
- D33.3 mm
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Answer: D. 33.3 mm
Equation: usable width = b − 2(cover) − 2(stirrup dia.); gaps = (usable width − bar diameters)/(number of bars − 1). Inputs: 300 − 2(40) − 2(10) = 200 mm; four bars occupy 100 mm. Substitution: s = (200 − 100)/3 = 33.3 mm (three gaps for four bars). Wrong: 25.0 mm divides by four gaps; 40.0 mm omits the stirrup thickness (300 − 80 − 100)/3; 48.3 mm measures the 40 mm cover to the bar center, which leaves bar centers 220 mm apart: 220/3 − 25.
mm
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