Main Differences Between GB 50367-2013 And ACI 440.2R-17?

What Are The Main Differences Between GB 50367-2013 And ACI 440.2R-17?

GB 50367-2013, "Code for Design of Reinforced Concrete Structures" (China), and ACI 440.2R-17 (USA) are generally similar in their design concepts, calculation methods, and construction requirements for carbon fiber (CFRP) reinforced concrete structures. However, there are some key differences. The following is a comparison of the two:

1. Design method and safety factor

Item	GB	ACI
Design Method	Based on Limit State Design, Partial Factor Method (similar to Eurocode)	Based on Strength Reduction Factor Method (LRFD, US specification system)
Material Partial Factor	CFRP Material Property Partial Factor (γ_f = 1.1-1.4)	Environmental Reduction Factor (C_E = 0.65-0.95)
Concrete Strength Requirements	Reinforced concrete strength ≥ 15 MPa (C15)	Reinforced concrete strength ≥ 21 MPa (3000 psi)

2. Material properties and parameters

Item	GB	ACI
CFRP Ultimate Strain	Flexural Reinforcement: ≤0.01 (Test verification required)	Flexural Reinforcement: ≤0.006 (to control debonding failure)
Shear Reinforcement Intrinsic Strain	U-Wrap: ≤0.002; Full Wrap: ≤0.004	Effective Strain ≤0.004 (considering reduction factor)
Bond Strength Calculation	Using an interfacial bond formula based on concrete strength	Empirical model based on FRP stiffness and concrete strength

3.Structural Requirements

Item	GB	ACI
End Anchorage	U-hoops or mechanical anchors are clearly required, with anchor lengths ≥ 200mm.	End anchorage is recommended, but no minimum length is specified.
Time Between Multiple Layers	≤ 30 minutes between each layer (epoxy resin).	Depends on the resin curing time (usually ≤ 1 hour).
Fire Protection	Fireproofing coating is required (e.g., cement mortar ≥ 25mm).	Protection measures are recommended, but the specific thickness is determined by fire protection regulations.

4. Loads and combinations

Item	GB	ACI
Load Combinations	According to GB 50009	According to ASCE 7
Dynamic Load Reduction	CFRP Strength Reduction Factor 0.5 under Fatigue Load	Fatigue Reduction Factor 0.55 (Based on Testing)

5. Construction and Acceptance

Item	GB	ACI
Hollowing Detection Standards	Single hollow area ≤ 100 cm², total area ≤ 5%	Hollowing area ≤ 1% and maximum diameter ≤ 50 mm
On-site Testing Requirements	A positive tensile bond strength test (≥ 2.5 MPa) is required.	Not mandatory, but sampling testing is recommended.