Modular block and modular structural elements constructed therefrom

Claim 1

A horizontally extending modular structural element constructed from a plurality of modular blocks, the element comprising: a plurality of modular blocks, each block having a generally hollow T-shaped cross-section, the block comprising a base section having opposite ends and comprising two oppositely extending colinear legs terminating respectively at said opposite ends and defining a flat generally horizontal top surface extending between said opposite ends; a stem section having outer sides spaced inwardly from said opposite ends and extending downwardly from the center of the bottom of the base section, the stem section having a compound configuration comprising a first portion having inner sides and upper sections of said outer sides tapering downwardly and inwardly from the base section, the stem section having a second portion below the first portion having generally vertical parallel lower sections of said outer sides; an axial hole defined at least in part by the inner sides extending through the first portion of the stem section; and, at least three axial passages for receiving tension members, the three passages being arranged in a triangular pattern around the axial hole, a side of this triangular pattern being parallel to the flat top surface of the block; the plurality of blocks being arranged in a line parallel to the three passages and of uniform cross section, the line of blocks having first and second ends with their axial passages aligned to define three triangularly oriented compound passages through the blocks extending from the first end to the second end for receiving tension members; a tension member extending through each compound passage in the blocks; and means for engaging the tension member to the block at each end of the line, the tension member exerting a compressive force on the blocks, holding the blocks together and putting the blocks under a compressive pre-stress.