Reinforcing bars application

FIG U RE 5.9 Displacement of finite elements of model at design tension stress in reinforced bar. (Reprinted from O. Figovsky, V. Karchevsky, and D. Beilin, Application of Polymeric Coatings for Concrete Structures, Scientific Israel Technological Advantages 5, nos. 1-2 (2003) 84-92. With permission.)... 

Exterior durable powders are generally used in either architectural applications like aluminium window frames, facades, or general applications like inside and outside coating of steel pipelines, coating of concrete reinforcing bars, gate, lamp posts, etc. [114]. 

Vinylester resins differ from polyesters in that the unsaturation is located at the end of the molecule and not along the chain. They exhibit a much better resistance to hydrolysis and are stable in aqueous environments. They are thus preferred to unsaturated polyesters for specific applications requiring alkali resistance, and are commonly used in the composition of FRP reinforcing bars... 

During the last decade, there have been continuous improvements in the selection of constitutive materials, in the manufacturing processes and the field implementation of polymer composites for civil engineering applications. The use of FRP materials as externally bonded reinforcement is now an attractive solution to increase the lifespan of existing concrete infrastructures, while their use as internal reinforcing bars or as structural members is intended to prevent corrosion problems and increase the overall durability of new constructions exposed to severe environments. Nevertheless, key issues regarding the long-term durability of FRPs for infrastructure applications have been only partially addressed, and there remain considerable needs for research and development in this field ... 

Steel fibres continue to have a wide range of apphcations in civil engineering materials. There are some structural applications where they have been used in concrete without any conventional reinforcing bars. These have been short span, elevated slabs, for example a parking garage at Heathrow Airport... 

As an example, reinforced concrete slabs are prepared for an experiment to compare effectiveness of arc-sprayed zinc and titanium anodes. All the slabs will be put under impressed current cathodic protection, and exposed to controlled applications of chloride to the concrete to promote corrosion of the reinforcing bar. Slabs are assigned randomly to be coated with either arc-sprayed zinc or titanium. In this case, randomization is a desirable precaution to control small inconsistencies due to mixing of the concrete, the chemical composition of the concrete, or the distribution of aggregate in the concrete. 

The current application of cathodic protection to steel reinforcing bars in concrete structures is illustrated in Fig. 10.32. 

Because of these differences, there are certain applications in which fibre reinforcement is better than conventional reinforcing bars. These include ... 

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