precast concrete paver blocks are provided with interlocking edge joints so that abutting edges of adjacent paver blocks align when the blocks are installed and are maintained in alignment . at each joint , each block includes a tapered projection and a recess . when edges of two blocks are moved to abut each other , the tapered joint projection on each block enters the joint recess on the other block . the taper on the projections move the blocks to align the block surfaces . the edges of the blocks are angled or relieved below the joints to ensure a tight fit at the top of the paver blocks .