Architectural building block system

An architectural building block system comprising:

• (a) three side walls, each having an inside surface and an outside surface, said three side walls cooperate to form a triangular tube having three corners, said outside surface of each of said three side walls extending outwardly from an inner surface to an outer surface and said inside surface of each of said three walls is disposed substantially at right angle to each of said inner surface and said outer surface;
• and (b) three channel pairs, each configured to receive a rebar, each channel pair comprising a first channel disposed on one of said three side walls on said inner surface, wherein said first channel extending from said inside surface to said outside surface of said one of said three side walls, and a second channel disposed on said inner surface and a corner of said three corners that is opposingly disposed from said one of said three side walls and a common axis which each of said first channel and said second channel is co-axial with, said common axis is substantially parallel to said inner surface, wherein at least one said side wall is configured to be positionable so as to mate with a side wall of an adjacently disposed block to form two aligned channel pairs having end channels, each with a wall leaning inwardly towards one another such that a rebar is anchorable within said two aligned channel pairs, whereby curved structures may be constructed from a plurality of such blocks to form a dihedral angle between each set of two blocks.