Technical Bulletin

DRY-BLOCK® System – TB-01D

8 January 19

DRY-BLOCK® is a system specially designed to provide concrete masonry structures with outstanding water-repellent characteristics. The DRY-BLOCK® System consists of two separate admixtures. DRY-BLOCK® Block Admixture is mixed throughout the concrete during manufacture of the concrete masonry units and DRY-BLOCK Mortar Admixture is added to the mortar. To complement DRY-BLOCK admixtures, a VOC compliant water-based, clear penetrating sealer, can be field applied to provide maximum protection to the masonry wall.

DRY-BLOCK® Block and Mortar Admixtures are chemically different and are NOT interchangeable. The differences between concrete block and mortar are extensive and a well-engineered admixture system will address the requirements of each wall component separately by providing a unique formulation for each.

On one hand, concrete block is manufactured with low-slump concrete using relatively low cement to aggregate ratios, a wide variety of aggregates, a relatively small amount of water and special curing conditions. DRY-BLOCK® Block Admixture is formulated for use in concrete masonry units and provides the block producer with a single, easy to use product that imparts water-repellency. DRY-BLOCK® Block Admixture also provides other useful benefits to manufactured low-slump concrete, like improved compressive strength and absorption properties, as well as improved “machinability” or ease of manufacturing units.

Mortar, on the other hand, is produced to a more fluid consistency with higher cement to aggregate ratios, a finer aggregate, greater amounts of water and curing under open air conditions. Taking these characteristics into account, DRY-BLOCK® Mortar Admixture is formulated to provide water-repellency and workability to the mortar. It is specifically formulated to work with concrete masonry units containing DRY-BLOCK® Block Admixture. This combination provides a wall system with water-repellent properties able to meet and exceed the most stringent industry standards.

When a DRY-BLOCK® water-repellent wall system is desired, both the block and mortar admixtures must be used. Elimination of either component will compromise the integrity of the water-repellent properties of the masonry structure and is not allowed by the DRY-BLOCK® specification.

DRY-BLOCK® Block and Mortar admixtures have successfully performed as a standalone system for years. But, if a “belt and suspenders” system is desired, then field apply a VOC compliant water-based, clear, penetrating water-repellent sealer to the exterior of the wall.

DRY-BLOCK® is a system engineered to impart superior water-repellent properties to concrete masonry assemblies. Each admixture is designed to provide the necessary properties to both the block and mortar so that the resultant wall offers a high level of performance. DRY-BLOCK® Admixtures have achieved more than 30 years of success in creating superior masonry structures.

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