Concatenating a field without special characters

I'm struggling to find a solution to CONCATENATE two fields, a date & time field and a text field, but I want to eliminate the special characters such as / and :

For example:

Field1 = ABCD

Field2 = 10/04/2016 01:29 PM

I can combined these fields as "ABCD10/04/2016 01:29 PM", however my goal is to get "ABCD100420160129PM"

Any suggestions would be great.