Ground-face block is a concrete masonry unit that is mechanically abraded on one or more sides to expose the natural beauty of the aggregate and provide textural interest. It is used for exterior or interior walls or for contrasting accents. Producers can achieve aesthetic variety by using different aggregate colors and block shapes, scoring, and edge chamfering. Ground-face block are easier to install than some other architectural block due to their reduced weight and precisely ground surfaces.
Because the grinding process adds to the cost of producing ground-face block, manufacturers are concerned with minimizing grinding costs to be more competitive. Recently, several block producers have significantly lowered production costs, while improving product quality, using a new diamond-grinding process. Developed by Di-Coat Corp., Novi, Mich., the grinding equipment consists of a steel drum electroplated with a random layer of manufactured diamond crystals. As the block move underneath the drum on a belt, the drum rotates, abrading their surfaces.
This system is advantageous for a number of reasons: other systems pull aggregate out of the surface or leave inconsistencies in the block finish--the diamond crystals cut through aggregate, creating a perfect surface. Diamond grinding also reduces costs by significantly increasing cutting speed and extending tool life. Sandpaper needs frequent adjustment and replacement, whereas diamond tools can grind more than 50,000 block before adjustment or replacement are required.