Masonry Magazine May 2003 Page. 20
Brick, Block and Stone
offer designs in smooth-face and split-face textures," says Alan Ferguson, director of marketing at AZAR. "Over 500 home basements use AZAR Dry-Stack instead of poured/cast in place concrete. The new AZAR Brick can be laid as fast as one can stack-on a brick ledge or angle-and wraps easily around the corner of a structure. It uses tiebacks that are easily installed in the bricks where required, usually on 16 inch centers."
Even with a new system, changes take place. Ferguson continues, "AZAR, in an exclusive agreement with Pavestone Company, has set the stage for extensive use of dry-stack systems for above-grade building construction. It can be used for projects ranging from a simple masonry mailbox to masonry walls/fencing. But more importantly, Pavestone and the other AZAR independent producers will provide mason contractors all over the country a way to stay competitive in the face of other masonry alternatives."
He also says that in discussions with masonry contractors it has been evident that they need new ways to construct with block and brick. "AZAR Dry-Stack allows masonry projects to be built up to 10 times faster than conventional mortared systems.
THE ART OF COLORING MORTAR
New brick and block textures and colors require a change in how masons treat mortar. Owners want everything to match. Here's how.
By Rich Solomon
President, Solomon Colors, Springfield. III.
Designers have used mortar color for years to complement the wide range of colors found in clay brick, colored block and stone. Since mortar joints make up 18 to 20 percent of the wall surface, the mortar color shade is very instrumental in complementing the overall design and appearance of the structure. However, most people are not aware of the normal variations in regular uncolored mortar. When color is added to the equation, heightened expectations are generally the norm.
The first step toward achieving a consistent mortar color is using the same ingredients and procedures throughout the job. The appearance of the mortar color joint is directly impacted by many factors other than the addition of iron oxide pigments to the mix. Variations in cement, sand, water-to-cement ratio, rate of hydration, environmental conditions, tooling of the mortar joints, and cleaning procedures can change the appearance of the colored mortar. The following criteria should be considered when using mortar color on your next project.
Cement Shade
Masonry and Portland cement are produced with different manufacturing processes offering a variety of shades from light gray to dark gray color tones. The cement color shade will have a direct and pronounced effect on the mortar color. Adding color to light gray cements will produce brighter and cleaner color shades. Conversely, utilizing dark gray cement will limit your ability to produce light color shades such as buff or pink. If a light pastel color is specified, more than likely white cement will be used to obtain the desired mortar color.
In the past few years there have been tight cement production levels with increased demand for cement, which in turn has created a shift toward darker shades of cement. To maintain uniformity throughout the job, visual Inspections of each cement delivery should be compared against future shipments. In addition, stay with the same cement manufacturer for the duration of the job. The use of the lightest shade of gray Portland or masonry cement will enhance the vibrancy of the finished mortar color.
Mortar Mix Design
The ASTM C270 Specification for Mortar Unit Masonry includes Prepared Masonry (ASTM C91) Type N, S and M Masonry Cement and Type O, N, S and M Portland Cement (ASTM C150) - Lime (ASTM C207) Mortars plus Sand (ASTM C144) used in each mix design. As with the shade of cement affecting the mortar color, the type O, N, S and M strength mortars and sand shade will also influence the colored mortar shade. The cement to lime ratio will determine the lightness of the mortar. The more cement in the mix, the darker the mortar. Thus, type M strength mortar will be the darkest, type S second darkest, type N third darkest, and type O lightest with the highest concentration of lime. With more Type S mortars being specified, the ability to produce lighter colored mortar joints such as buffs, tans and pink shades are becoming more difficult without utilizing white cement or a light gray Portland cement.
As with cement, the shade of sand will change the shade of colored mortar. Clean light colored sand will allow a brighter more Intense color; conversely, darker sand will mute the color shade. Sand with a more fine particle size will also mute the color shade due to the increased surface area the pigment is required to coat with colored particles.
Color Pigments
A stable, high quality pigment should be utilized to assure a long lasting mortar color shade. Color pigments with a proven history of longevity in masonry are made from natural and synthetic iron oxides (red black and yellow), Cobalt (blue), titanium oxide (white), and Chromium oxide (green). Blends of the red, black and yellow natural and synthetic iron oxides will produce buffs, browns, tans, coppers, oranges, chocolates and other colors needed to complement the vast colors found in