Stop concatenate adding decimal places back

Excel experts, hi!

How do I stop concatenate adding decimal places back?

Concatenate is referencing a simple cell containing a number formulated elsewhere and adding ":1" to the end (to give a ratio reading)

=CONCATENATE(AF32,":1")

The referenced cell AF32 is set to 0 decimal places, the cell containing the concatenate is set to 0 decimal places. Without concatenate, AF32 references (in any cell) as it should with no decimals, so why does concatenate add the rogue decimal places back in??? Excel tsk!!!! tsk!!!!!