Parking Structures: Recommended Practice for Design and Construction

Parking Structures: Recommended Practice for Design and Construction

Parking structures have become important elements in today’s urban and suburban
environments. Owners have realized that parking services represent the first and last
impression a visitor receives of the facility, and that can be a pivotal factor when con-
sumers decide where to do business. Even more, owners and designers both are
acknowledging that parking structures must be designed specifically for the types of
visitors that structure will serve, based on the facilities they support and the flow of
daily traffic.
The need to create a parking structure that precisely fits the needs of the users can-
not be stressed enough. Unless the facility is user-friendly, projecting a safe, secure,

and easy to use environment, parkers will find other options. These needs have

become too vital to their peace of mind to be left unmet by the owner and designer.
As a result, creating the best parking structure for the site, users, and budget requires
a careful balance of all elements and a logical plan from start to finish. From the ini-
tial conception basics are decided until the parking structure opens, a host of choic-
es must be made that will affect the final design and cost of the project—which ulti-

mately will impact its value to the customer.

“High-performance concrete” has been part of the day-to-day operation in the pro-
duction of precast prestressed concrete since the first elements were cast. High

cement content and low water/cement ratios result in high early-strength and high
ultimate-strength concrete with low permeability thereby providing resistance to
chloride ion penetration.

The dramatic and overpowering effect of the water/cement ratio on the chloride per-
meability of concrete (see 1.1) requires that the potential advantages of “high perfor-
mance” concrete, such as low water/cement-ratio, heat-cured concretes or those con-
taining admixtures such as silica fume, be examined for comparison using realistic

water/cement values for project applications.
One such comparison would be of a conventional cast-in-place concrete parking

structure for which no specialty contractors or materials would be required. The con-
crete used in this hypothetical structure would be 0.46 w/c burlap-cured or 0.46 w/c

burlap-cured concrete with 5.0 or 7.5 percent silica fume. A 0.37 w/c heat-cured con-
crete would be used in the precast prestressed deck, which has been shown by recent

studies to be superior to the conventional system.
Today’s precast prestressed parking structures supply the standard of excellence
against which other parking structures are measured. A major contributor to that

excellence is the inherent ability of the structure to “breathe” due to the use of con-
nections between components. This design technique, used in all precast construc-
tion, allows the parking structure to relieve pressure from the ordinary expansion and

contraction that otherwise would cause cracking in the structural members.


Share this

Related Posts

Next Post »