Table 7-8. Types of Concrete Armor Units 



* The units have been tested, some extensively, at the 

 Waterways Experiment Station (WES). 



t Cubes and rectangular blocks are known to have been used 

 in masonry type breakwaters since early Roman times, and 

 in rubble-mound breakwaters during the last two centuries. 

 The cube was tested at WES as early as 1943. 



X Solid tetrahedrons are known to have been used in hydraulic 

 works for many years. This unit was tested at WES in 1959. 



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