Concrete building block

Description

1. Concrete building block

1.1 : Perspective

1.2 : Front

1.3 : Back

1.4 : Top

1.5 : Bottom

1.6 : Right

1.7 : Left

1.8 : Cross sectional

The broken lines do not form part of the claimed design; reproduction 1.8 is a cross sectional view cut horizontally at the center in a longitudinal direction of the product as shown by lines “A-A” in reproduction 1.2.

Claims

The ornamental design for a concrete building block, as shown and described.