Concrete block, block joint and block structure

Abstract

A concrete block having comparatively light weight and capable of being manufactured easily and used in various fields of application; a block joint for the concrete blocks, capable of carrying out the arrangement of the concrete blocks simply and retaining the arranged concrete blocks in good order; and a structure made by using the concrete blocks and the block joints. The joint ( 1, 2 ) has seats ( 1 b, 2 b ) which are formed by cutting off predetermined portions thereof and adapted to restrict positions in which the concrete blocks ( 3 ) are arranged horizontally and vertically so that horizontally adjacent and vertically adjacent concrete blocks have clearances therebetween, and which support corner portions of the concrete blocks ( 3 ) thereon, each of the concrete blocks ( 10 ) being formed in a cubic outer shape so that it has an outwardly opened hollow structure, by using a split core ( 12 ) which can be broken down and removed after the concrete has been hardened, thus obtaining a structure of which the interior of the concrete blocks ( 10 ) communicate with each other when a plurality of blocks ( 10 ) are horizontally and vertically arranged.

1 . A concrete block having a shape of cube having first, second and third pairs of opposed outer square surfaces, each outer square surface having a circular opening extending inwardly and cylindrically to form a hallow intercommunicating with the opposed outer square surface, thereby forming a quarter circle shaped haunch extending from each corner of the outer square surface to each corresponding corner of the opposed outer square surface, wherein the circular opening has the diameter of 56 to 82% of the side length of the outer square surface.  
     
     
         2 . A concrete block according to  claim 1  wherein the circular opening has the diameter of 60 to 80% of the side length of the outer square surface.  
     
     
         3 . A concrete block according to  claim 1  wherein the circular opening has the diameter of approximately 80% of the side length of the outer square surface  
     
     
         4 . A concrete block according to  claim 1  wherein all of the circular openings have substantially the same diameter.  
     
     
         5 . A concrete block according to  claim 1  wherein the center of each circular opening corresponds to the center of the outer square surface forming each of the circular opening.