Seismic Performance of RC Beam-Column Connections with Continuous Rectangular Spiral Transverse Reinforcements for Low Ductility Classes

Table 3

Connection design formulas for ductility classes low in Eurocode.

DCL
Beam	Longitudinal Bars (L)
	Critical Region Length
		0.04
	Transverse bars (w)
	Outside Critical Regions
	Spacing ≤	0.75 d
	≥
	In Critical Regions
	Spacing ≤	—
	≥	6 mm
	Column	Longitudinal Bars (L)
Critical Region Length		—
		4%
Bars per side		2
Spacing between restrained bars		—
Transverse bars (w)
Outside Critical Regions
≥
Spacing ≤
In Critical Regions
≥
Spacing ≤	—

where is characteristic compressive cylinder strength of concrete at 28 days, is design value of concrete compressive strength, is mean value of axial tensile strength of concrete, is characteristic yield strength of reinforcement, is design yield strength of reinforcement, is design yield of shear reinforcement, d is effective depth of section, is longitudinal bar diameter, is diameter of hoop, is cross-sectional depth of beam, is cross-sectional depth of column in the direction of interest, is design value of steel strain at yield, is curvature ductility factor, is shear reinforcement ratio, is compression steel ratio in beams, and is width (minimum dimension) of confined concrete core (to centreline of hoops).