Since nobody is answering you I will try my best to help you out.
First of all, there are a number of factors as to how long, will they hatch, are they fertilized.
#1 good water conditions help out a lot with egg layers
#2 If you see the eggs starting to mold,cave in,turn a yucky color only being a day or so old. Then that usually tells you that they are not fertilized.
I honestly couldn't tell you how long they would take to hatch, temp and water conditions along with what kind of barb it is would be a factor.
I personally have only bred angel fish so I know nothing about the barbs in person.
Hope this helps
8)
P.S. if you know the name of your Barb, simply type it in a search engine example.. "Breeding Cherry Barbs" etc.