Chapter 6 Concrete 109
Concrete Properties
Material properties determine how mate-
rials should be used. Often more than one prop-
erty is considered before a material is selected.
The main properties engineers look for in
concrete are strength, watertightness, durability,
and workability.
•
Strength—Concrete must be able to carry
heavy loads and must not wear away,
Figure 6-4.
•
Watertightness—High-quality concrete
resists water absorption. However, all
concrete will absorb some moisture.
Excessive absorption together with freezing
temperatures can damage concrete.
•
Durability—Concrete must provide long
life and minimal upkeep on construction
projects such as interstate highways and
runways.
•
Workability—Workable concrete flows
in and around steel reinforcing rods and
into the corners of forms, Figure 6-5.
Concrete that is not workable causes gaps
around rods and holes in corners of forms,
weakening the concrete and creating a poor
appearance.
Figure 6-4. A concrete bridge must support heavy loads.
Figure 6-3. Steel reinforcing bars are used in the
columns and floor of this concrete foundation.
(Bob Dale)