talk to the guys at the redwing store,
i have a pair of irish setters, (712's i think) that i bought in 87 or 88, and worked in them for about 5 years straight, they sold me some silicone stuff for the tops, and i used redwing oil (?)(looked like CLP) to keep the uppers pliable
they are currently my outdoor cold weather whatever boots, look like shit but are still waterproof (up to about 6-7inches deep)
i used to be a butcher (as in meat cutter/journeymnan meat cutter)
blood and the cleaning chemicals we used are tough on leather
not sure if that will help with concrete, but the shop i deal with would rebuild almost any part of the boot,
HTH