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Engineered cementitious composites (ECCs) are materials featuring strainhardening behavior with the formation of multiple cracks. When ECC is incorporated in structural applications such as beam, it is expected to significantly improve their mechanical performance. In this study, finite element analysis is performed to investigate the characteristics of the plastic hinge in reinforced ECC (RECC) beams. The plastic hinge lengths of RECC beams, involving rebar yielding zone, concrete crushing zone and curvature localization zone, are found to be much larger than those for reinforced concrete (RC) beams. Based on the above results, parametric studies on the plastic hinge lengths in RECC beams are conducted to study the influences of the tensile\compressive properties of ECC, yielding strength\hardening modulus\ultimate strain of tensile reinforcement, tensile\compressive reinforcement ratio and beam size. This theoretical study has shown that the existing empirical models for RC beams' plastic hinge length are not applicable to RECC beams which exhibit much longer plastic hinge length. A new empirical equation for predicting the plastic hinge lengths of RECC beams is thus proposed.

Engineered cementitious composite is an advanced composite material with strain-hardening and multiple cracking behavior. Substituting conventional concrete with engineered cementitious composite can significantly improve the seismic performance of reinforced concrete structures. This article presents the seismic behavior of a precast engineered cementitious composite/reinforced concrete composite frame and a precast reinforced concrete frame. In the precast engineered cementitious composite/reinforced concrete composite frame, engineered cementitious composite is used to replace concrete in the beam-to-column joints and the bottom columns. The shaking table test results on the two scaled frames are presented. The frame failure characteristics and dynamic properties, including the fundamental frequency, story displacement, inter-story drift, and story acceleration, are comprehensively studied. The test results indicate that the connection method adopted in the tested frames is applicable and reliable. Both of the frames have good seismic performance and can withstand earthquakes at the design seismic intensity. Using engineered cementitious composite in precast frames can greatly reduce damage. The precast engineered cementitious composite/reinforced concrete composite frame has better deformation capacity, better energy dissipation ability, and slower stiffness deterioration than the precast reinforced concrete frame.

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