#criteria for judge rebar joint

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Criteria for Judging the Grade of Rebar Joints

We can judgment standard of rebar joints with the following regulations:

01 Grade I Joint

There are two criteria for judging Grade I Joints:

1) The actual tensile strength of the reinforcing bar connection must be greater than the standard strength of the reinforcing bar material and it should fracture at the reinforcing bar.

2) If the connecting piece does not break the reinforcing bar, the actual tensile strength of the reinforcing bar connection must be greater than 1.1 times the standard tensile strength of the material, reaching at least 594Mpa to be considered qualified. The standard tensile strength value for HRB400 reinforcing bar is 540Mpa.

02 Grade II Joint

The criteria for judging Grade II Joints is that as long as the actual tensile strength value of the reinforcing bar connection exceeds the standard tensile strength value of 540Mpa, regardless of where the connecting piece breaks, it can be considered qualified.

03 Grade III Joint

The criteria for judging Grade III Joints is that as long as the actual tensile strength value of the reinforcing bar connection meets or exceeds 1.25 times the standard yield strength value of the reinforcing bar, which means the actual tensile strength value of the connection reaches above 500Mpa, it is considered qualified. The standard yield strength value for the reinforcing bar is 400Mpa (using HRB400 reinforcing bar as an example here).

Changsha DLADTO Rebar Splice Co., Ltd as a division of ADTO Group. We are a professional rebar joints producer, we have been in this field for a long time with customers for all over the world. You can trust us and take the article when you be required to judge the grade of rebar joints.

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Performance Requirements of Grouting Rebar Coupler

Performance requirements of grouting rebar coupler are as follows:

1. Vertical rebar connections at the joints of prefabricated columns and prefabricated shear walls. Semi-grouting rebar coupler or fully grouted rebar coupler can be used.

2. Vertical rebar connections at the joints after pouring the lower part of the prefabricated overlay beam. Fully grouted rebar coupler should be used.

Since the rebar couplers of prefabricated components must be arranged at the same section, it is clearly stipulated in the “Technical Specification for Assembled Concrete Structures” JGJ1-2014 that the longitudinal rebar connections using sleeve grouting should meet the performance requirements of Grade I joints in the current national industry standard “Technical Specification for Mechanical Connections of Reinforcement Bars” JGJ107.

Whether the joints meet the performance requirements of Grade I joints is determined by the joint type test specified in JGJ107. The content includes three tests: uniaxial tension, high stress cyclic tension-compression, and large deformation cyclic tension-compression. The deformation performance and tensile strength of the joints are tested. Only the joints that meet the performance criteria for Grade I joints in all these tests can be judged as Grade I joints. The grouting sleeve connections of different specifications of rebars should be subjected to type tests separately.

Changsha DLADTO Rebar Splice Co., Ltd as a division of ADTO Group. We are a professional rebar coupler producer, we have been in this field for a long time with customers for all over the world. Welcome to contact us for any inquiry.

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Grade Judging Standard of Rebar Connector

Class I Rebar Connector

There are two criteria for determining the level I joint:

1) The actual tensile strength of the reinforcing rebar connector must be greater than the standard strength of the reinforcing bar base material, and it must be broken from the reinforcing bar.

2) If the connecting piece damages but didn't broken the steel bar, the actual tensile strength value of the rebar connector must be bigger than 1.1 times the standard tensile strength value of the parent material, and it can be judged as qualified when reach or over 594Mpa. The standard tensile strength value of HRB400 steel bar is 540Mpa.

Class II Rebar Connector

Judgment standard for grade II rebar connector: No matter which place of the rebar connector is broken, as long as the actual tensile strength value of the steel bar connector exceeds the standard tensile strength value of the steel base material by 540Mpa, it can be judged as qualified.

Class III Rebar Connector

Judgment standard for grade III rebar connector: No matter which place of the steel bar connectors is broken, as long as the actual tensile strength standard value of the steel bar connectors is greater than or equal to 1.25 times the standard value of the steel yield strength, that is, the actual tensile strength value of the steel bar connectors reaches 500Mpa, thye are can be judged as qualified.

Changsha DLADTO Rebar Splice Co., Ltd is a professional rebar coupler producer, we have been in this field for a long time with customers for all over the world. If you have any inquiry, welcome to contact us.