Have a block paving driveway on my property (came with the house).
Seems to be just sand between the blocks, though now it is more sand
and weeds.
Can I brush out the sand, and use weedkiller then use a dry mix of sand
and cement to "seal" the gaps between the blocks ?

Also, I have some slabs in the patio - is it recommended to fill the
gaps between these with a dry mix of sand and cement ?

TIA