This is a vague question.
Pipe thickness?
Type of brazing alloy?
Length of brazing?
Type of copper alloy?
The code or spec it needs to meet?
All of these questions and more will dictate the strength of the pipe. Usually, the brazed area need to be calculated and designed such that it will be stronger than the bare pipe. Therefore, when a brazed pipe is tested till burst, it should burst along the bare pipe and never in the brazed area.