ABSTRACT
Reinforced concrete is a composite material. A lattice or cage of steel bars is embedded in a matrix
of Portland cement concrete (see Figure 7.1). The specified compressive strength of the concrete typi-
cally ranges from 3,000 to 10,000 psi. The specified yield strength of the reinforcing steel is normally
60,000 psi. Reinforcement bar sizes range from 3 8
to 21 4
in. in diameter (see Table 7.1). The steel rein-
forcement bars are manufactured with lugs or protrusion to ensure a strong bond between the steel and
concrete for composite action. The placement location of the steel reinforcement within the concrete is
specified by the concrete cover, which is the clear distance between the surface of the concrete and the
reinforcement. Steel bars may be bent or hooked.
