An article of manufacture for building concrete structures from precast
blocks and the process for making the structural system. The block
comprises one or more annular tire wall stack units embedded in
reinforced concrete. Prestressing and/or post-tensioning structural
reinforcing techniques are used with assembled building blocks. The
blocks are made by placing used tire stacks in a form that centralizes
the stacks so that reinforced concrete can be placed around them while
maintaining a hollow core through the stacks. Horizontal interlocking
between blocks uses reinforcing bars and/or a tongue and groove
configuration, and/or post-tension wire strand placed in a recess or
post-tension tubes formed in the blocks and mortared in-place during
construction. Vertical interlocking between blocks uses a
tongue-and-groove interlock, shiplap splicing, and reinforcing bars.
Post-tension wire strand, pipe, or H-piles are placed in and through the
stacks and mortared in-place during construction.