Code Related Data

Codes with strength reduction factors

• ACI318-08
• ACI318-11
• ACI318-14 |
• AS3600

Codes with partial safety factors on materials

• EN1992-1-1 2004 +A1:2014
• EN1992-2 2005
• Hong Kong Buildings 2013
• Hong Kong Structural Design Manual for Highways and Railways 2013
• Indian concrete road bridge IRC:112 2011
• Indian concrete rail bridge IRS 1997
• Indian building IS456

Current tabular codes

• PR China GB 50010 2002

Codes with resistance factor on materials

• CSA A23.3-04
• CSA A23.3-14
• CSA S6-14

Superseeded codes with partial safety factors on materials

• BS8110 1997 & Concrete Society TR49
• BS8110 1997 (Rev 2005) & Concrete Society TR49
• BS5400 Part 4 & Concrete Society TR49
• Hong Kong Buildings 2004
• Hong Kong Buildings 2004 AMD1 2007
• Hong Kong Highways 2006

American Codes

These codes use strength reduction factors.

	ACI318-08	ACI318-11	ACI318-14
Concrete strength
Steel strength
Strength reduction factor for axial compression*	f = 0.65 [9.3.2.2]	f = 0.65 [9.3.2.2]	f = 0.65 [21.2.2]
Strength reduction factor for axial tension*	f = 0.9 [9.3.2.1]	f = 0.9 [9.3.2.1]	f = 0.9 [21.2.2]
Uncracked concrete design strength for rectangular stress block	0.85  [10.2.7.1]	0.85  [10.2.7.1]	0.85  [22.2.2.4.1]
Cracked concrete design strength (equal to twice the upper limit on shear strength)	(5/3)   (   in MPa) 20     (   in psi) [11.2.1.1 & 11.4.7.9]	1.66    (   in MPa) 20     (    in psi) [11.2.1.1 & 11.4.7.9 11.9.3]	1.66   (   in MPa) 20       (    in psi) [11.5.4.3]
Concrete tensile design strength (used only to determine whether section cracked)	(1/3)   (   in MPa) 4       (   in psi) [11.3.3.2]	0.33    (   in MPa) 4       (   in psi) [11.3.3.2]	0.33   (   in MPa) 4      (   in psi) [22.5.8.3.3]
Compressive plateau concrete strain	0.002 [assumed]	0.002 [assumed]	0.002 [assumed]
Maximum axial compressive concrete strain	0.003 [10.2.3]	0.003 [10.2.3]	0.003 [22.2.2.1]
Maximum flexural compressive concrete strain	0.003 [10.2.3]	0.003 [10.2.3]	0.003 [22.2.2.1]
Proportion of depth to neutral axis over which constant stress acts	0.85-0.05( ‑30)/7 (   in MPa) 0.85- 0.05( /1000‑4) (   in psi) but within limits 0.65 to 0.85 [10.2.7.3]	0.85-0.05( ‑28)/7 (   in MPa) 0.85- 0.05( /1000‑4) (   in psi) but within limits 0.65 to 0.85 [10.2.7.3]	0.85-0.05( ‑28)/7 (   in MPa) 0.85- 0.05( /1000‑4) (   in psi) but within limits 0.65 to 0.85 [22.2.2.4.3]
Maximum value of ratio of depth to neutral axis to effective depth in flexural situations	[10.3.5]	[10.3.5]	[7.3.3.1 & 8.3.3.1]
Elastic modulus of steel	200 GPa [8.5.2]	200 GPa [8.5.2]	200 GPa [20.2.2.2]
Design strength of reinforcement in tension	[10.2.4]	[10.2.4]	[20.2.2.1]
Design strength of reinforcement in compression	[10.2.4]	[10.2.4]	[20.2.2.1]
Maximum linear steel stress	[10.2.4]	[10.2.4]	[20.2.2.1]
Yield strain in tension	/ [10.2.4]	/ [10.2.4]	/ [20.2.2.1]
Yield strain in compression	/ [10.2.4]	/ [10.2.4]	/ [20.2.2.1]
Design strain limit	[0.01] assumed	[0.01] assumed	[0.01] assumed
Maximum concrete strength	-	-	-
Maximum steel strength	-	-	-
Minimum eccentricity	0.10 h [R10.3.6 & R10.3.7]	0.10 h [R10.3.6 & R10.3.7]	0.10 h [R22.4.2.1]
Minimum area compression reinforcement	-	-	-
maximum permitted angle between applied and resulting principal stress	-	-	-

*Applied forces and moments are divided by the strength reduction factor to obtain design values for use within RCSlab. The appropriate vales are determined as follows:

k_uc = ε_cu/(ε_cu + f_yd/E_s)

k_ut = ε_cu/(ε_cu + 0.005)

M_c = φ_ck_ucβf_cdc × (1 - k_ucβ/2) × (h/2 + z_min)² - N × z_min

M_t = φ_tk_utβf_cdc × (1 - k_utβ/2) × (h/2 + z_min)² - N × z_min

If

If

Otherwise:

Australian Codes

This code uses strength reduction factors.

	AS3600
Concrete strength
Steel strength
Strength reduction factor for axial compression*	f = 0.6 [Table 2.2.2]
Strength reduction factor for axial tension*	f = 0.8     (N bars) f = 0.64   (L bars) [Table 2.2.2]
Uncracked concrete design strength for rectangular stress block	Where  = 1.00-0.003  but within limits 0.67 to 0.85 [10.6.2.5(b)]
Cracked concrete design strength (equal to twice the upper limit on shear strength)	0.4  [11.6.2]
Concrete tensile design strength (used only to determine whether section cracked)	0.36 [3.1.1.3]
Compressive plateau concrete strain	0.002 [assumed]
Maximum axial compressive concrete strain	0.0025 [10.6.2.2(b)]
Maximum flexural compressive concrete strain	0.003 [8.1.2.(d)]
Proportion of depth to neutral axis over which constant stress acts	1.05-0.007  but within limits 0.67 to 0.85 [10.6.2.5(b)]
Maximum value of ratio of depth to neutral axis to effective depth in flexural situations	0.36 [8.1.5]
Elastic modulus of steel	200 GPa [3.2.2(a)]
Design strength of reinforcement in tension	[3.2.1]
Design strength of reinforcement in compression	[3.2.1]
Maximum linear steel stress	[3.2.1]
Yield strain in tension	/ [3.2.1]
Yield strain in compression	/ [3.2.1]
Design strain limit	Class N 0.05 Class L 0.015 [3.2.1]
Maximum concrete strength	-
Maximum steel strength	£ 500 MPa [3.2.1]
Minimum eccentricity	0.05 h [10.1.2]
Minimum area compression reinforcement	0.01 (0.5% each face) [10.7.1 (a)]
Maximum permitted angle between applied and resulting principal stress	-

*Applied forces and moments are divided by the strength reduction factor to obtain design values for use within RCSlab. The appropriate vales are determined as follows:

k_uc = (1.19 - φ_c) × 12/13

k_ut = (1.19 - φ_t) × 12/13

k_ub = ε_cu/(ε_cu + f_yd/E_s)

M_c = φ_ck_ucβf_cdc × (1 - k_ucβ/2) × (h/2 + z_min)² - min(0, N) × z_min

M_t = φ_tk_utβf_cdc × (1 - k_utβ/2) × (h/2 + z_min)² - min(0, N) × z_min

N_b = [φ_ck_ubβf_cdc × (1 - k_ubβ/2) × (h/2 + z_min)² - M] / z_min

If

If

Otherwise:

If

If

Otherwise:

Eurocode

These codes use partial safety factors on materials.

	EN1992-1-1 2004 +A1:2014	EN1992-2 2005
Concrete strength
Steel strength
Partial safety factor on concrete	= 1.5 [2.4.2.4(1)]	= 1.5 [2.4.2.4(1)]
Partial safety factor on steel	= 1.15 [2.4.2.4(1)]	= 1.15 [2.4.2.4(1)]
Uncracked concrete design strength for rectangular stress block	50 MPa                               / > 50 MPa            (1 ‑ (-50)/200) / is an NDP* [3.1.7(3)]	50 MPa                 / > 50 MPa           (1 ‑ (-50)/200)  / is an NDP* [3.1.7(3)]
Cracked concrete design strength (equal to twice the upper limit on shear strength)	0.6(1‑/250) / [6.2.2(6)]	0.312(1‑/250) / [6.109 (103)iii]   (see also ϕΔ)
Concrete tensile design strength (used only to determine whether section cracked)	50 MPa    0.21 2/3/ > 50 MPa 1.48 ln[1.8+ /10] / is an NDP*   [Table 3.1]	50 MPa    0.21 2/3/ > 50 MPa 1.48 ln[1.8+ /10] / is an NDP*  [Table 3.1]
Compressive plateau concrete strain	50 MPa 0.00175   > 50 MPa 0.00175+ 0.00055 [(‑50)/40]   [Table 3.1]	50 MPa 0.00175   > 50 MPa 0.00175+ 0.00055 [(‑50)/40]   [Table 3.1]
Maximum axial compressive concrete strain	50 MPa 0.00175   > 50 MPa 0.00175+ 0.00055 [(‑50)/40]   [Table 3.1]	50 MPa 0.00175   > 50 MPa 0.00175+ 0.00055 [(‑50)/40]   [Table 3.1]
Maximum flexural compressive concrete strain	50 MPa 0.0035   > 50 MPa 0.0026+0.035 [(90‑)/ 100]4   [Table 3.1]	50 MPa 0.0035   > 50 MPa 0.0026+0.035 [(90‑)/ 100]4   [Table 3.1]
Proportion of depth to neutral axis over which constant stress acts	50 MPa        0.8   > 50 MPa                   0.8-(‑50)/400   [3.1.7(3)]	50 MPa        0.8   > 50 MPa                   0.8-(‑50)/400   [3.1.7(3)]
Maximum value of ratio of depth to neutral axis to effective depth in flexural situations	50 MPa              (1- )/ > 50 MPa              (1- )/ ,  ,    and     are NDPs*     [5.5(4)]	50 MPa               (1- )/ > 50 MPa             (1- )/ ,  ,    and     are NDPs*     [5.5(104)]
Elastic modulus of steel	200 GPa [3.2.7(4)]	200 GPa [3.2.7(4)]
Design strength of reinforcement in tension	/ [3.2.7(2)]	/ [3.2.7(2)]
Design strength of reinforcement in compression	/ [3.2.7(2)]	/ [3.2.7(2)]
Maximum linear steel stress	/ [3.2.7(2)]	/ [3.2.7(2)]
Yield strain in tension	/( ) [3.2.7(2)]	/( ) [3.2.7(2)]
Yield strain in compression	/( ) [3.2.7(2)]	/( ) [3.2.7(2)]
Design strain limit	NDP* []	NDP* [