Acceptance Criteria AC133 is referenced in ACI 318-08 within both (IBC) International Building Code 2009 and (IRC) International Residential Code 2009 under the (ICC) International Code Council.

Acceptance Criteria AC133 defines the process to uniformly evaluate mechanical connector systems of steel reinforcing bars used in building and construction. As ASTM A370 is referenced within AC133 for evaluation of the reinforcing bar alone, the test piece for AC133 consists of the assembly of the coupler and two sections of steel reinforcing bar.

The advanced cyclic profile of the test is completed in four distinct stages in either extension, or stress control with beginning and endpoints of each stage based upon yield values of the rebar. The test piece is exercised in tension and compression "through-zero", and extensometry is used to accurately measure strain throughout the test.

The challenges of testing to this standard are:

• High-capacity cyclic testing of rebar
• Advanced test profile
• Secure gripping of rebar
• Accurate strain measurement

Instron Solution:

• High capacity cyclic testing of rebar - 2000 kN capacity KPX style test system
• Advanced test profile - Bluehill testing software with Test Profiler capability to accurately control the 4-stage test profile required by AC133
• Secure gripping of rebar - use of Durasync Side-Acting Grips with through zero hardware is critical to successfully meeting the rigors of this high-capacity cyclic test
• Accurate strain measurement - E-Series Strain Gauge Extensometer (W-6280-200)