Concrete Construction Online Magazine: Dry Shakes & Sealants

Concrete Cares Promotes Breast Cancer Awareness

Wed, 19 Dec 2012 12:38:43 EST

A diverse group of concrete industry veterans are promoting pink concrete to raise cancer awareness.

SWRInstitute Announces Publication of Air Barrier Technical Bulletin

Fri, 16 Dec 2011 01:27:27 EST

The Sealant, Waterproofing & Restoration Institute released the latest addition to its Technical Bulletin Series about air barriers.

Evaluating Flatness and Levelness when Polishing Concrete

Fri, 16 Dec 2011 01:17:39 EST

Flatness and levelness are important factors for building owners.

Using Color Hardeners

Fri, 10 Dec 2010 06:04:03 EST

Concrete can be colored integrally or with color hardeners. Integral colors are added to concrete before placement. Color hardeners (also referred to as "dust-ons" and "dry-shakes") are broadcast as powders over the top of freshly struck concrete and are finished into the surface.

Efflorescence on Decorative Concrete

Fri, 10 Dec 2010 06:00:14 EST

The last thing you as a contractor or specifier want to hear when you complete a decorative, colored concrete installation (integral, dry-shake, stamped, textured, stenciled, or trowel finished) is that the owners are unhappy because the color wasn't what they ordered. Then you find yourself in the awkward position of telling them that the color is right, but efflorescence has lightened its appearance. Owners frequently respond to that news by stating they want the color they ordered before they will pay for the job. What to do?

When to Start Curing Decorative Concrete

Fri, 10 Dec 2010 05:57:30 EST

When is the proper time to start curing decorative concrete that's textured using mats or skins and colored with a dry-shake hardener and release agent? Some people say curing should begin immediately, but whenever we try to use impermeable coverings, such as plastic or waterproof paper, we get discoloration. And we can't apply a cure-and-seal product until the next day, after we've washed off the release agent.

Coloring flatwork after it's in place

Thu, 9 Dec 2010 04:24:05 EST

We wrote a job specification calling for application of a colored dry shake to 50,000 square feet of concrete floor. The contractor didn't read the specification and finished the concrete without applying the colored dry shake. Workers applied a membrane curing compound to the concrete. Is there any way to color the floor now so it doesn't have to be removed and replaced?

Coating a metallic dry-shake hardened floor surface

Tue, 21 Dec 2010 01:49:30 EST

We're a bleach manufacturer, and we've just acquired a facility with a floor that contains a metallic-aggregate surface hardener. We want to install a high-build epoxy coating on the floor to resist bleach spills. How should we prepare the floor for coating?

Preventing trowel burns on white floors

Thu, 9 Dec 2010 04:10:14 EST

We're building a floor that calls for a white dry-shake to make it light-reflective. The specs also call for a hard troweled finish. We're concerned about burning the white surface. Is a stainless steel or plastic trowel better than an ordinary steel trowel? What else can we do to prevent burn marks?

Floor joint repair

Tue, 21 Dec 2010 01:47:57 EST

We've been asked to repair deteriorated joints in a 2-year-old concrete floor. The floor is 8 inches thick and is placed on a 4-inch-thick crushed stone base. The 3000-psi concrete was treated with 2 pounds per square foot of a dry shake hardener. Keyed joints are spaced 50 feet apart and there are two layers of wire mesh in the floor. Here's the problem. The keyed joints have opened up as much as 3/8 to 7/16 inch. Then under hard-wheel dolly traffic, the top edge of the female side of the keyed joint has broken off. There's also spalling on both sides of the joint. To repair it, I'm proposing that we saw out a 3-foot strip of concrete centered on the joint. Then at each sawed face we'll drill holes to accept smooth dowel bars and epoxy one end of the dowel while leaving the other end free to move within the concrete. We'll place a low-slump repair concrete and saw a joint above both rows of dowels. The joint will be filled with a semirigid epoxy. Does this sound like a good approach?

Dry Shakes for Floors

Thu, 9 Dec 2010 02:54:54 EST

Why should you apply a dry shake to a slab on grade? The answer is that the surface quality obtained by the usual practices will not be adequate for every purpose. Frequently the top surface is likely to be of lower strength and have the least sound materials in the slab.