PVC leak-free joints without glue
You could probably use Flex Couplings like these:  



To connect a pipe to an elbow, you'd have to find a coupling
which fits both the outside diameter of the pipe, as well as the outside diameter of the elbow.
Something like this one might be flexible enough to both stretch over the elbow and still clamp tightly onto the pipe:

https://www.plasticpipeshop.co.uk/75-89mm-EPDM-Adaptor_p_6140.html
or otherwise possibly one of the reducing versions which have a different size on each side.