First you need to check for any plumbing leakage around if non then Try to clean the cracks to get all loose material out then try injecting liquid mortar between the bulk Until you feel that the void is filled. Finally use thermal bricks on top of baseboard to protect the old base. Good luck.
Try always to took in the small details of anything around try to reason the small techniques and understand the how to. The more details you get get into your mind the more creative you will be in combining different cases to get the optimized solution you are looking for. Good luck.
there are cases for the joint condition, if you dont wish to transfer moment from beam to column (shear walls and frame elements take moment and seismic load) , depending on the structural system desired.
then you should release moment at beams and columns.