simplification selection plages discontinues

Dim Plage As Range, i As Long
    Set Plage = Range("B12:K50")
    For i = 1 To 52
        Set Plage = Application.Union(Plage, Range("B" & 12 + i * 57 & ":K" & 50 + i * 57))
    Next i
    Plage.Select

Set zone = Range("B12:K50")
For i = 1 To 52
    Set zone = Application.Union(Range("B" & (i * 57) + 12 & ":K" & (i * 57) + 50), zone)
Next i

Dim pl As Range
Set pl = Range("B12:K50")
For x = 69 To 2976 Step 57
    Set pl = Application.Union(pl, Range(Cells(x, 2), Cells(x + 38, 10)))
Next x

Sub test()
Dim i As Integer, c As Range
Set c = Range("B12:K50")
For i = 69 To 2976 Step 57
    Set c = Union(c, Cells(i, 2).Resize(39, 10))
Next i
End Sub