Many of the parking structures where silica-fume concrete is used tend to be
over-finished. By this we mean that the concrete receives more finishing
than is necessary for the application. The more steps that are involved in
the finishing process, the longer the concrete will be exposed to the
potential for plastic shrinkage.
Silica-fume concrete usually does not bleed. While this is a good feature
as far as strength and durability are concerned, it does increase the
potential for plastic shrinkage. The "one-pass" finishing process was
developed to take advantage of the lack of bleeding in silica-fume concrete
and to get the concrete finished as quickly as possible.
One of the problems associated with implementing the one-pass technique may
be resistance from the owner or architect, who may want to specify more
finishing than is needed in a parking structure. A broomed finish is
usually satisfactory for such applications. The trial placement is a good
time to get the owner or architect's approval for the finish that will be
applied during the project.
The Silica Fume Association
38860 Sierra Lane, Lovettsville, VA 20180
Tel: 540.257.4224 Fax: 540.822.9456