Wednesday, April 6, 2011

classification of exposed concrete and repair of formwork

Exposed concrete is very often the subject of a disharmony between architectural expectations and budget for contractor. To make building manageable and not go to court every time a house is built, standards have been erected for most everything that surrounds us on a construction site.
Of course the classification of surface quality of exposed concrete is one of these standards. The german standards for exposed concrete are some of the most ridgid classifications in the industry.
The requirements for exposed concrete are divided into the following four classes.
SB 1: low requirements, for basements or industrial use. no special requirements towards formwork. Low costs.
SB2: medium requirements to surface and design. formwork needs to be in good shape, although scratches, ripplings and repair marks are allowed. usually higher costs than SB1.
SB3: high requirements on surface and design. Used for exposed office walls etc.. High formwork requirements: no ripplings, no concrete residue, small scratches and repair marks allowed. High costs.
SB4: highest requirements. Concrete surface for "Dining rooms". Formwork can have small repair marks if architect agrees. Usually formwork is used only once for this kind of concrete.

(the emplica formwork repair system can be used for SB1 through SB3 and, if Architect agrees, even for SB4 formwork, discussion is necessary)

Additionally, all classes have a lot of sub-classes regarding texture, colour and porosity of the surface.

More information on exposed concrete can be found here:
http://www.sichtbeton-forum.de/sichtbeton_klassen.php (german)

the american concrete institute has a large database with documents to concrete...http://www.concrete.org/general/home.asp

No comments:

Post a Comment