Rebar sleeve connections for 25 mm diameter bars are primarily governed by two Chinese standards: the Technical Specification for Mechanical Connections of Rebars (JGJ 107‑2016) and the Sleeves for Mechanical Connections of Rebars (JG/T 163‑2013).

Applicable Standards

Technical Specification (JGJ 107‑2016) – This serves as the general basis for the design, construction, and quality control of mechanical rebar splices. It defines the performance grade classification and acceptance criteria for connections.

Product Standard (JG/T 163‑2013) – This is the dedicated specification for sleeve products. It covers rebar diameters from 12 mm to 50 mm, thereby including the 25 mm size.

Technical Requirements

Joint Performance Grade – For critical structures such as bridges and earthquake‑resistant buildings, Class I joints shall be used for load‑bearing rebar connections. These joints must develop a tensile strength not less than 1.10 times the characteristic yield strength (or specified value) of the rebar.

Sleeve Material – Sleeves are typically manufactured from high‑quality No. 45 carbon structural steel. Each sleeve shall bear clear, permanent stamped markings (e.g., manufacturer, specification, and batch number) to ensure full traceability.

Connection Method – New regulations issued by the Ministry of Housing and Urban‑Rural Development, effective August 2025, explicitly prohibit electroslag pressure welding for reinforcing bars with a diameter of 20 mm or greater. Moreover, they mandate mechanical connections for all reinforcing bars with a diameter of 25 mm.