Sectional Analysis of Reinforced Engineered Cementitious Composite Columns Subjected to Combined Lateral Load and Axial Compression

Abstract

The ultra-high tensile ductility of ECC provides an alternative way to enhance the ductility of structural members by using high-ductile matrix material instead of simply increasing reinforcements. However, the application of ECC members is still limited due to the relatively short research time and the lack of design specifications. Being equivalent to eccentric compressive members, a sectional analysis of RECC columns subjected to combined lateral load and axial compression are proposed in this paper. Based on the design theory of load capacity of eccentric compression columns and the unique constitutive model of ECC, the calculation equations for the sectional load capacity of RECC columns are derived. The analytical prediction of the load capacity of RECC column is evaluated in comparison with that of experiments that confirm the capacity of the proposed calculation method to capture the behavior of the RECC column accurately. The strength-interaction diagrams showing the axial force-moment (N-M) interaction curves are then constructed for analysis using the proposed calculation equations. A parametric study is also carried out by using the proposed calculation equations, demonstrating the effects of ultimate tensile strain of ECC, compressive and tensile strength of ECC, yield strength of steel bar, and reinforcement ratio on the N-M interaction curves of RECC columns. The investigations exhibited in this paper are expected to provide insight into the design principles of RECC columns.