Published in Masonry Chronicles, Summer July 1, 2009.
Copyright © 2009 Concrete Masonry Association of California and Nevada.
Concrete, which is a product containing Portland cement, is the second most used building material (after water) worldwide. Masonry grout is similar to concrete except that grout has a high water content and smaller size aggregates. The excess water is immediately absorbed into the masonry units during placement, which lowers the water/cement ratio and allows for a normal hydration process. During the process of making Portland cement, more than 1/5 ton of carbon dioxide is produced for every ton of cement with 60% of the carbon dioxide production due to a chemical reaction. There is currently no viable remedy to reduce the carbon dioxide emission due to this chemical process. To limit carbon dioxide emission from Portland cement production, cement use in concrete products can be reduced (e.g. concrete and grout) . However, the reduction in Portland cement content must not compromise strength or building processes (time).