Internal steel reinforcement

Corrosion of Cement-Based Pipes Nearly 17% of US transmission water lines are built from concrete and asbestos concrete materials. Internal steel reinforcement wires and bars (rebar) steel mesh and steel plates are used to provide tensile... 

Debonding of the EBFR in conjunction with the internal steel reinforcement in an elastic or yielding state is the most common failure mode. Further failure modes of the members that can be observed are concrete... 

The end anchorage debonding failure mode is expected for short beams, if the cracks are near to the supports and if the end of the strip is not near to the support. Furthermore, if only a small internal steel reinforcement cross-section exists, the strip must carry a larger portion of the tensile force, which also increases the danger of end anchorage failure. 

For the cross-section analysis, different bond properties must be considered by using the bond coefficients k = 0.7 and Kt = 0.9 for the internal reinforcement steel bars and the externally bonded strips, respectively. For compatibility relationships in the cross-section analysis, the mean values of the strains, s, in the internal steel reinforcement and ft in the EBFR can be used however, for the equilibrium relationships, the maximum values of the strains for the internal reinforcement steel bars and the externally bonded strips. 

The fundamental idea behind the SLS verification is to limit the strain in the EBFR to ensure that the internal steel reinforcement does not yield at serviceability. The strains in the internal reinforcement, and in the EBFR, Ei, can be calculated using cross-section analysis identical to that used for the ultimate hmit state and should be limited to... 

The safety concept for the ultimate limit state is to guarantee the yielding of internal steel reinforcement so that the strengthened member will fail in a ductile manner. With a view to assuring safety, a minimum strain capability has been intfo-duced for FRP laminates and steel reinforcements as shown below ... 

The existing design codes assume that the FRP effective strain remains constant whether the RC beam has transverse steel or not. However, Chaallal et al. (2002), Pellegrino and Modena (2002) and Bousselham and Chaallal (2004) have shown that the contribution of the FRP composites to the shear resistance (i.e. the effective strain) of the beam decreases as the internal steel-reinforcement ratio increases. 

S. R. Yeomans, M. P. Novak, "Further studies of the comparative properties and behaviour of galvanized and epoxy coated steel reinforcement , International Lead Zinc Research Organization (ILZRO) project ZE-341, Progress report... 

The use of cathodic protection for the protection of the internal surfaces of process equipment in the chemical process and in the pulp and paper industries, the protection of water boxes and condenser tube sheets in the electric power industry [53], and the protection of steel reinforcing bars in concrete in highway bridges and parking garages, clearly reveal that this technique is used in a broad variety of appHcations. 

Lempton, R. D. Jr., and Schemberger, D. 1996. Improving the Performance of Fusion-Bonded Epoxy Coated Steel Reinforcing Bars, CORROSION 96, Paper No. 323, NACE International, Conferences... 

E.A. Baker, K.L. Money, C.B. Sanborn, Marine corrosion behavior of bare and metalhc-coated steel reinforcing rods in concrete, in D.E. Tony, S.W. Dean Jr. (Eds.), Chloride Corrosion of Steel in Concrete ASTM, STP629, ASTM International, Philadelphia, PA, 1977, pp. 30-50. 

Kessler, R.J., Powers, R.G. and Lasa, L.R. (1995). Update on Sacrificial Anode Cathodic Protection of Steel Reinforced Concrete Structures in Seawater. Corrosion 95, Paper 516, NACE International, Houston, TX. 

The ULS shear resistance of a member can be calculated using eqn 4.29. It is recommended that the concrete contribution (Fr c = 0) is neglected. The contribution of the internal steel stirrups, Fr, can be calculated using the truss model (assuming a shear reinforcement inclination of 90°) such that ... 

Figure 5-4. Conceptual scheme of a composite containment for a PWR (internal steel shell and external structure in reinforced concrete from J. EibI, reproduced courtesy of Forschungszentrum, Karlsruhe, Germany).

This appendix considers one of the more extreme solutions against severe accidents (see Chapter 5) which consists of a steel-reinforced concrete cage built around a PWR vessel with the purpose of absorbing, by plastic deformation, the energy released by a steam explosion (internal or external to the vessel) and which causes its rupture and the violent projection of its pieces into the surrounding space. 

In the particular case of the apphcation of glass-fibre reinforced vinylester composites as internal reinforcement for concrete bridge deck slabs, the results showed their superior fatigue performance and longer fatigue life when compared with the steel-reinforced ones (El-Ragaby et al., 2007). 

Sutton, J. and Lewis, K. G The Detection of Internal Corrosion in Steel-Reinforced Aluminum Overhead Power Line Conductors," Proceedings, UK Corrosion 86, Vol. 1, 1986, Birmingham, UK, pp. 345-359. 

MacDonald, D. B., Sherman, M. R., Pfeifer D. W. and Y. P. Virmani (1995) Stainless steel reinforcing as corrosion protection. Concrete International, May 1995. 

The protective enclosure of the reactor compartment of a land-based nuclear cogeneration plant is double, consisting of an internal steel protective enclosure and a containment made of reinforced concrete without pre-stressing (Fig. VII-4). 

Chloride-induced rebar corrosion tends to be a localized corrosion process, with the original passive surface being destroyed locally under the influence of chloride ions. Apart from the internal stresses created by the formation of corrosion products leading to cracking and spalling of the concrete cover, chloride attack ultimately reduces the cross section and significantly compromises the load-carrying capability of steel-reinforced concrete. 

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