The  First closure technique

The first technique for tightly closing the suggested coupler over the reinforcing bars ends is comprised of the two sleeve halves and an outer cylindrical pipe having specific length and an internal diameter slightly less than the outer diameter of the two sleeve halves, the coupling is performed by entering the reinforcing bars ends male deformations into the two sleeve halves female grooves then intruding outer cylindrical pipe over assembled two reinforcing bars and sleeve halves achieving pressure sufficient to prevent the two connected reinforcing bars from splitting.