I have a brick porch with limestone steps and aluminum railing. I have two issues. First off, the railing is set quite solid, no wiggle at all but the holes that were drilled for the posts are not filled flush to the top with the anchoring material. I remember the guys used very strange stuff that looked just like pizza dough to set the posts then they flushed it with a hose and washed off the steps and too much out of the holes. Anyway, I want to top off these holes to keep water from puddling and freezing. The fill depth ranges from 1/2"-3/8". The other issue, as you can see in the photo, is a corner of the bottom step is cracked across the hole but it looks like the crack stops short of the last 1 1/2" of the step. It is not loose (yet). I was considering using Fast Plug hydraulic cement mixed with latex acrylic liquid since I have both on hand. My concern is that hydraulic cement is supposed to expand but will it expand so much as to bust the corner off the step? Will the admix interfere with the chemistry of the cement? Should I use a different solution altogether? I also want to fill that crack. What can I inject in there?" at widest point). What can I inject in that?

 

Use some mortar to fill the hole. You'll probably have to make the cracks a little wider & deeper to get anything in there. I would use the same mortar.

 

Mortar may work for filling the railing post holes, but I don't think it will do much for the cracks. Not enough adhesive capability to stick things together. And trying to widen and deepen the cracks first will only break off the corner concrete chunk(s) completely, making things worse than when you started.

Best bet for the cracks would be going with epoxy injection, by first setting a few injection ports using a fast-setting sealing gel, then pumping low viscosity epoxy into each port (at low pressure, to keep from blowing off the corners). Seal each port after pumping with a golf tee, then grind everything "pretty" after the epoxy takes a set.

 

Yeah, it's really a narrow crack and I don't want to do anything to widen it other than remove that one chip. I was thinking epoxy, BridgeMan but I don't know if it's available locally, I never really looked. I know I can get it online.
Thanks for the responses

 

Visit a local mason's supply store to see what they have available for concrete crack repairs. Most I've dealt with in the past have several name brand products that can be used by a DIYer, including relatively inexpensive dual-cartridge injection guns and mixing nozzles. Too bad you're not closer (to Oregon), as I have a gun and a few nozzles you could use for free. Tried to sell them at a garage sale, with no luck.

 

the crack fill is a little out of my league but some type of epoxy ejection is the right way. not at all sure of just what method, material or prep is required.

As for filling the holes. I would use a sealant and not mortar. I would suspect that this was the intent from the start and that would explain why the existing mortar was left below the top of the core. Try Sonneborn NP-1 sealant to fill the holes and try to sculpt a crown to the sealant to pitch the water away from the post.