FRP Design using structural mechanics models

Abstract

The application and expansion of FRP reinforced concrete has been hindered and obstructed through the misconception and misunderstanding that empirically derived rules developed for steel reinforced concrete in cracked regions can be used either directly or as a guidance for FRP reinforced concrete. This assumption is incorrect because the empirical rules developed for steel reinforced concrete in cracked regions, as with all empirical rules, should only be used within the bounds of the testing regimes from which they were developed, which for steel reinforced concrete is normal strength concrete with high ductile steel that has very good bond. As these bounds do not apply to FRP reinforced concrete, the steel RC empirical rules for cracked concrete are of little or no help for FRP RC. In fact, they are often misleading and as such prevent the widespread use of FRP reinforcement. It will be shown and illustrated in this presentation that generic mechanics based rules can be developed at all load conditions for RC beams that applies to both steel and FRP reinforcement. And, furthermore, that these generic mechanics based design rules allay many of the misconceptions inferred by the empirically based RC design rules such as that moment redistribution cannot occur with brittle FRP reinforced concrete which is simply not the case. © Tsinghua University Press, Beijing and Springer-Verlag Berlin Heidelberg 2011.