Structural Applications of Polymers in Building Construction

Structural applications are snch that they reqnire proper mechanical performance (strength, stiffness, vibration damping ability) in the material, which may or may not bear the load in the strnctnre. Strnctnral components shonld withstand live loads (such as people, wind, etc.), as well as the dead loads (the weight of the strnctnre), which can be (a) load- bearing walls, (b) colnmns and beams, and (c) bracing in frame construction, or shear walls . 

For primary structural applications, which are load bearing firstly the strength of the material should be able to support at least in-plane loads, with proper stiffnesses (if bending and shear forces are involved), and mechanical property requirements are 

Rebars are polymer fibre reinforced-concrete composites, and they are used as primary structures. It is estimated that replacement of steel reinforcing bars by non-corrosive polymer fibres, i.e., by Kevlar or carbon fibres (which gives rise to Kevlar or C-composite bars) for concrete structures produces structures with one-quarter the weight and twice the tensile strength of the steel bar. It is known that, corrosion of steel reinforcement from carbonation or chloride attack can lead to loss of the structural integrity of concrete structures, and such a danger is non-existent for rebars. Thermal expansion coefficient (TEC) values of these fibres are closer to concrete than that of steel, which provides an another advantage and they have the same surface deformation patterns as the steel bars. In addition, they can provide more economy than epoxy-coated steel bars. 

Nevertheless, FRP fibres are better candidates for the pre-stressing and post-tensioning tendons in concrete strnctnres than steel [7], and more than 15 % of glass fibres produced are already being used by the building and construction industry [8, 9]. 

The secondary structural materials are materials that if the structure fails can only cause local damage that can be repaired, such as secondary wall panels for a steel framed building in a modular construction. These panels, which are aesthetically pleasing, are light to handle and are low in maintenance, are SWP with FRP or rigid metallic skins on the face and have a polymeric foam core, usually of EPS or PU. The load on these panels is mainly the pressure induced by wind. 

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