Exposed aggregate on a vertical cement surface?

If you are wanting a rough look to them why not rock the pillars? Not all that hard to do even for first time DIYer's. Pillars are not hard to rock either a little chicken wire holding the rock on while it the cement dries putting in a few anchors while you patch the existing and being patient an not trying to go over 3 or 4 feet vertically in a day is all you really need to know.

After your pillars are stabilized, you can put any kind of finish on them you wish. All you need is some concrete mortar mix and some water. After slathering the pillars with wet mortar, you can apply any kind of substance you want as long as it isn't too heavy. I have even put stone or rocks on metal surfaces starting at the bottom of the piece and working your way up. You can incorporate marbles, metal pieces, anything that you can stick onto the mortar surface. I have spent the last 20 years mortaring rocks, and pieces of stone, metal etc. on concrete block walls. It is sooo creative and so much fun - messy too I might add. You can seal it when you are through if you want or leave it plain - I don't like shiny rocks. Be sure to wet any concrete surface before you start - old concrete will soak up the water added to mortar and will dry your project out and make it unstable. I am probably the only female stone mason in the state, it is a satisfying job to see it finished - all you need is imagination to create something quite your own. E-mail me for tips and complete information to get started.