Stepped closure for duct coupling

A reinforced concrete block assembly comprising:

• a concrete block having a body, wherein the body comprises a hollow space extending along the body;
• wherein the concrete block further comprises:
• a first side with a crenellation pattern, wherein the crenellation pattern comprises one or more merlons and embrasures, where the merlons extend outwardly from the first side;
• a second side opposite the first side, wherein the second side comprises openings aligned with the hollow space;
• and
• at least one duct disposed within the hollow space and extending through the openings on the second side, where the at least one duct configured to receive tendons;
• wherein the crenellation pattern is configured to mate with a corresponding crenellation pattern of a second concrete block assembly when arranged adjacent thereto, such that the merlons of the first concrete block assembly align with merlons of the second concrete block assembly, thereby forming an open space between the first and second concrete block assemblies.

A concrete block assembly comprising:

• a concrete block having a rectangular body, wherein the body comprises a hollow space extending along a longitudinal axis of the body, wherein the hollow space is configured to receive at least a duct;
• the concrete block further comprising:
• a first side with a crenellation pattern, the crenellation pattern comprising one or more merlons and one or more embrasures, wherein the merlons extend outwardly from the first side;
• a second side opposite the first side, wherein the second side comprises openings aligned with the hollow space;
• and
• wherein the crenellation pattern is configured to mate with a corresponding crenellation pattern of a second concrete block assembly.