1. Pre-construction Process Qualification

Prior to the commencement of rebar splicing operations, and periodically throughout the construction phase, a process qualification test must be conducted for each consignment of incoming materials. For this qualification inspection, a minimum of three test assemblies shall be prepared for each rebar diameter and grade specified in the project. The assembled coupling specimens, including the spliced rebar substrates, must be subjected to a uniaxial tensile test to verify that the connection achieves the required ultimate load capacity, with the failure mode thoroughly documented.

2. On-Site Acceptance Lot Inspection

Field inspection of the completed mechanical splices is carried out on the basis of acceptance lots. Joints fabricated from rebar of the same material grade, diameter, and heat number, and produced under identical construction conditions, shall be grouped into a single inspection lot. The standard lot size is defined as 500 pieces; however, any residual quantity totaling fewer than 500 pieces shall also be treated as an independent acceptance lot. For each lot, three specimens shall be randomly selected from the completed structure and subjected to a uniaxial tensile strength test to ensure compliance with the specified performance criteria.

3. Test Equipment and Configuration

Tensile strength evaluation constitutes one of the most critical parameters for assessing the structural integrity of rebar mechanical connectors. A servo-controlled universal testing machine (UTM), equipped with appropriate wedge or screw-type grips, is typically employed to fulfill this requirement. The testing apparatus must be properly calibrated and configured to apply a continuous, monotonically increasing tensile load at a controlled displacement rate, thereby accurately determining the ultimate tensile capacity and overall load-deformation behavior of the spliced joint until failure occurs.