As per your description ,you underwent open reduction with internal fixation. 115 degree flexion is not too bad this stage.but all depend upon what they did during surgery.
which part of ur forarm bones(radius and ulna) fractured and how they fixed it.
likewise there r many things to be assessed like endfeel of rang etc.
your physio can assess these things and could tell u whether u achieve normal rang of motion or not.
If we have proper information we will give you gud sugessions.
feel free to ask any further question
gud luck