Op-amp symmetrical triangular wave
The problem is that the triangle wave is saw toothed instead of
  symmetrical. Why is this? what mistake have i made in my circuit?


You have chosen values for R1 and R2 that are not identical. 

You are also assuming that the output of the LM324 can drive equally up to the positive supply as it can to 0V (I'm thinking of the comparator section of the circuit here). Read the data sheet and note the typical full scale output voltage levels that the LM324 can drive - it can drive down to the negative rail (earth in your example) but it won't get to within maybe a couple of volts of the positive rail.

This will delver a very asymmetrical charging current to the integrator.

Having said all of that, maybe it isn't that important if you are only using the asymmetrical triangle wave just for PWM creation.