Method of making concrete structures of prefabricated blocks

A method of making a concrete structure in the form of a rigid, three-dimensional lattice of concrete bars interconnected at nodes, said method comprising:

• prefabricating blocks having a node and a plurality of arms radiating from the node, forming at least one longitudinal socket having an opening in a free end of each arm, forming at least one transverse passage in each arm communicating with the socket for inserting mortar into the socket and for removing air therefrom, and connecting the prefabricated blocks by:
• aligning an arm of one block with an arm of another block;
• inserting a common reinforcing member in the aligned sockets;
• moving the aligned arms together axially to define a junction zone at the ends of the aligned arms;
• surrounding the junction zone of the two aligned arms with a sealing sleeve;
• and
• injecting mortar through the transverse passages into the sockets of the said aligned arms to fill the sockets.