【正文】 r constituents: gravel, sand, water, and concrete has some type of reinforcement, typically steel, bined withconcrete to produce a stronger system than plain concrete. Concrete is strong in pression but weak in tension. Tensile forces cause concrete to crack and eventuallyfail in a brittle manner at stresses significantly lower than the pression strength ofconcrete. Steel, or another type of reinforcement material, can be used to pensate forthe weak tensile strength of concrete. This system is referred to as reinforced concrete. As reinforced concrete ages, a variety of detrimental effects can occur. These includespalling, flaking, or cracking of the concrete, and subsequent corrosion of the reinforcingsteel. These occurrences can significantly affect the strength of structural displaying these adverse affects may be rehabilitated using an appropriateretrofit method. Retrofitting is typically done for two reasons: rehabilitation or strengthening. As previously discussed, rehabilitation is fixing the structural deficiencies of a damaged structure or structural member. This may be necessary for aging members that no longerdisplay the strength of the original design. Strengthening increases the loadcarryingcapacity of a structural member (Ersoy et al. 1993). This may be necessary if thesupported load is altered through the life of the structural member, or if current designstandards have more stringent reinforcement requirements. Additionally, structuralmembers in seismic regions may need to be upgraded to current seismic requirements. Retrofitting can be applied to any structural members, including beams and methods are traditionally utilized for retrofitting. These include concretejacketing, steel jacketing, and FRP strengthening (Wipf et al. 1997). Reinforcement forconcrete jackets can be provided by rebar reinforcement or welded wire fabric (WWF).Additionally, a relatively new product, Prefabricated Cage System reinforcement (PCS),is suggested as a possible reinforcement alternative for concrete jacket retrofits. PCS Benefits PCS reinforcement has some unique properties. The longitudinal and lateral reinforcement for PCS are located the same distance from the center of the member crosssection. This provides increased flexural capacity, using the same amount of steelas a traditional rebar system, and results in more efficient use of the reinforcing monolithic action of PCS eliminates separation of longitudinal and transverseeinforcement. Additionally, PCS reinforcement is spread in a planar configurationwhich offers greater confinement than rebar reinforcement, as displayed in Figure of the PCS steel determines the dimensions of the reinforcement confining the concrete. PCS reinforcement offers several additional benefits. Dimensions of the reinforcementare determined by the designer to produce any desired amount of transverse andlongitudinal reinforcement. This allows a great deal of flexibility and efficiency in thedesign process, as reinforcement choices are not limited to available stock , PCS reinforcement can be fabricated offsite and immediately placed for concrete casting without additional fieldwork, such as tying, cutting, or bending ofreinforcement, which prolong construction time. Offsite fabrication also provides anincreased level of quality control for the reinforcement. In PCS production, dimensionsand spacing are far more accurate which minimizes opportunities for human error andeliminates acceptance of subpar detailing or inadequate construction. This, in turn,results in an increased factor of safety for construction projects Retrofit Methods As previously mentioned, mon retrof