It all started when...
The ASTM C90 standard changed from requiring 2.25 in/ft minimum equivalent web thickness to requiring 6.5 in2/ft2 normalized web area in standard concrete masonry units. What followed was a 6 year design genesis that has resulted in a full line of concrete masonry units that are a patented redesign of an A-shaped, open ended CMU. The design of the original ProBlock along with the logo, marketing literature, and even the website has matured along with the engineering behind it.
ProBlock is a patented concrete masonry unit developed and marketed by Johnson Concrete Company. It is the final result of close collaboration between Johnson Concrete's engineers and production team, block masons and architects. That collaboration yielded the idea to redesign the standard "knock-out" or "A" block to be more efficient to manufacture by the producers and put in place by the masons.
