Probably you would see more Iron. Concrete wasn't used too much in the 19th century in buildings, at least not like we saw in the 20th. But Iron frames did provide the major revolution in construction technologies providing for the skyscraper for example. There already were some interesting projects, mostly speculative, to advance the use of stone but non really caught on and I can't really see that changing. Though if you are interested take a look at some of the work of Viollet le Duc. Maybe just maybe you could see more of that if concrete and thus reinforced concrete is delayed significantly but its very unlikely. After a certain point its just easier to work with iron alone. Case in point, the Monadnock building which was the last load bearing building. Using stone meant that the walls were 6' thick at the base.
The main impact would be on infrastructural projects especially in things like dams, walls, pillars etc where concrete was more useful. Instead these would likely be made of stone, and perhaps have to be designed more conservatively. As a quick primer on building technologies concrete alone (ie not reinforced with steal), like stone, is great in compression but not in tension. Thus a concrete beam like a stone lintel would tend to sag and crack but a concrete pillar works great to support a load. Thus the great revolution in architecture in the 19th century was the use of iron which enabled longer bridges, taller buildings and lots of big glass windows and huge spans for massive factory roofs. All these things would still be possible with only minor difficulty with out concrete. By the time you get around to needing concrete (in its steel reinforced form) for really tall buildings and really long bridges and of course huge dams its nearing the end of the century and its likely someone would have figured out how to make it.