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FRP lacks ductility so its application as reinforcement of new structures in seis-mic areas is not common. Seismic actions can produce a large capacity and ductil-ity demand. Although large capacity is readily available in FRP reinforced con-crete elements, ductility capacity is often lacking. A large amount of building stock consists of low to mid-rise buildings with a significant number of walls. In such structures, most of the capacity is usually provided by walls. This means that the behaviour of the whole structure depends on the behaviour of the walls, more specifically on their load bearing and lateral drift capacity. For squat walls, there is usually an excess of load bearing capacity but for more slender walls, some amount of ductility is required. This ductility is provided by bending of an element, so drift capacity depends on curvature capacity. In this paper, curvature ductility of FRPRC walls with different reinforcement configurations is theoreti-cally and numerically analysed. There is a large number of different FRP rebar products available on the market, each with different strength and ultimate strain. Using only one type of rebar in a wall can provide some amount of ductility, depending on the diameter and spac-ing of bars. However, combining different products can lead to a significant change in the overall behaviour of an element. This paper provides a quick, pre-liminary analysis of FRPRC slender walls to provide a basis for developing more comprehensive research and guide future experimental efforts.

Serviceability limit states are very important in the design of reinforced concrete elements but they are complex to calculate. Simplified serviceability calculations are provided in EN 1992-1-1 (2013) for steel reinforced elements. The crack widths are assumed to be acceptable if the bar diameters or bar spacings are not too large, while deflections are acceptable if the slenderness is not too large. In recent decades, FRP bars have become an adequate replacement for steel bars, especially in aggressive environments. The calculation procedures for FRP-reinforced concrete elements (FRPRC) were developed from calculation methods for steel reinforced elements. The first part of this paper demonstrates the procedures and parametric investigation for calculating the maximum bar diameter and bar spacing for the purpose of controlling the crack width, focusing on calculations for the maximum bar diameter for which cracks widths are acceptable. The second part of the paper demonstrates the procedures and parametric calculations for the slenderness limits for concrete elements reinforced with FRP bars in order to satisfy the usual deflection limits. Due to the different modulus of elasticity values of FRP and steel, the tables used for steel cannot be used for concrete beams reinforced with FRP bars. Therefore, new tables and diagrams are proposed in the paper. The new tables and diagrams for the maximum allowable bar diameters for the different modulus of elasticity values of FRP can be useful for the rapid control of the crack width in FRPRC elements. They are conservative compared to the exact calculations because some assumptions taken in the calculations are different to those taken in the exact calculation procedure for the crack width. The results of parametric calculations for the slenderness limits for FRPRC elements are provided in the form of a diagram for different concrete classes. Satisfying the slenderness from these curves will result in a smaller deflection than that allowed for each parameter related to that class of concrete.