Duty cycle of 555 timer
The circuit is theoretically correct, the faults are probably due to the assembly.
(Is R2 likely to be connected to the Discharge pin?) R1 is not required for proper operation at all. The frequency depends on R4 and the duty cycle is always 50%.


EDIT:
NE555 at 3V. You built it well and measured accurately. :)
The NE555 need a minimum operating voltage of 5V.

NE555 at 5V: