I have had a new concrete car port also stamped it was too hot when they poured the concrete 45degrees I live in Spain,it set too quickly. The builders now want to pour new concrete over the old and re stamp,will this work?
It could work; and it could not work out; I speculate that the builder will want to do the new layer only a couple of inches, 6 - 7 cm, thick and if so it is a recipe to a likely problem not too far into the future. It would be best to break up the existing and place new concrete. Over 80 F, 26 C, you need to know what you are doing and adjust your mix, at 45 C, 112 F, you could easily have problems, it is more difficult to work with for the finish and it is more likely to have shrinkage problems and not develop full strength.