VBA does not have an idea which " is the end of the string defining formula. Try:
Range("AA2:AA" & Range("A" & Rows.Count).End(3)(1).Row).Formula = _
    "=CONCATENATE(A1,""-"",R1,""-"",S1,""-"",T1,""-"",G1)"
note that I used formula not formulaR1C1 - not tested but could give other than expected result with R1