This is defined as "as-cast" concrete where appearance is less critical or takes second place to cost. Usages are normally for parking garages, utilitarian buildings, retaining walls, etc.. While good appearance is still desirable, little time or money will be spent improving the pour.
Recommended Form Materials for Smooth Finish: The low "cost per pour" factor of all Olympic Panel® panels, plus the savings from easy stripping and maintenance, provide very acceptable as-cast concrete at a cost to fit any budget. Specify MultiPour® HDO or Classic HDO™ for high re-use in this area. With a fewer number of reuses, specify B-Matte® 333 for a softer appearing finish.
This is concrete not normally exposed to public view (foundations, etc.). Surface defects may be tolerated so long as they do not impair the performance of the concrete structure.
Recommended Form Materials for Rough Finish: BB Plyform could be used but cost conscious builders are finding that they can actually save money by using Olympic Panel® overlaid plywood panels. Easy stripping, low cleanup and maintenance costs, and high re-use add up to a considerable reduction in labor and material costs over the lifetime of a job. Check with your Olympic Panel® supplier for the panel best suited to your needs.
There are many degrees of abrasive blasting ranging from "Brush Blasting," which results in a sandpaper-like texture through "Light Blasting," which exposes most of the fine aggregate, to "Heavy Blasting" which erodes the surface to the point where heavy aggregate projects beyond the mortar. Form requirements are as stringent as for as-cast concrete. Boat patches, improperly aligned or taped joints, and form surface imperfections can cause defects through the blasted finish. Attention should also be paid to the thickness tolerance standards of specified form materials to avoid offset joints.
Scaling produces a subtle texture similar to sandblasting. While more expensive, it's easier to correct defects and is a cleaner method.
Bushhammering provides a method of disguising minor surface defects. Both scaling and bushhammering produce quite effective finishes with conventional concrete mixes. Tooling is usually done when scaling or bushhammering. The texturing tool is moved to produce a prescribed pattern that may or may not be repeated as panels of texture.
Recommended Form Materials for Mechanically Textured Finishes: To minimize any defect capable of transferring into the cast concrete or characteristics conducive to surface discoloration, overlaid form panels should be specified. Forms should strip easily so that no concrete clings and pulls away from the cast face. Depending upon the re-uses and surface finish expected from the forms, use MultiPour® HDO, Classic™ 100/30 or B-Matte® 333.
These are usually heavily textured "acoustical type" coatings sprayed on ceilings and, more rarely, walls. The thickness and texture of the coating tends to cover most minor mechanical flaws in the concrete.
Sprayed-on exterior coatings are often used to protect the concrete from weathering and to help achieve a monolithic appearance. These coatings are dense, weather resistant, and are applied in relatively thin coats. They cover surface discolorations but do not effectively mask mechanical defects in the pour.
Recommended Form Materials for Coated Concrete: Form materials must present a uniform surface and must strip cleanly, leaving a cast face that will encourage bonding. "Matte" surfaces such as those achieved by casting against B-Matte® 333, accept and adhere to coatings without sandblasting or other preparation. MultiPour® HDO or Classic HDO™ may also be used in combination with a chemically reactive release agent to provide a bonding surface. The release agent must be compatible with the coating.