TY - JOUR
T1 - Experimental assessment of the cyclic behaviour of concrete-to-concrete interfaces subjected to combined shear and bending moment
AU - Cavaco, Eduardo
AU - Almeida, Tiago
AU - Câmara, José
N1 - Publisher Copyright:
© 2022 ICE Publishing: All rights reserved.
PY - 2022/11
Y1 - 2022/11
N2 - Ductility of Reinforced Concrete (RC) members connections is of paramount importance on seismic regions, regarding energy dissipation. Recent research has suggested that the presence of concrete-to-concrete interfaces subjected to shear force and bending moments, can potentially reduce ductility of RC beams under monotonic loading, due to the occurrence of a shear slippage along the interfaces. In this paper, the cyclic behaviour of RC beams with concrete-to-concrete interfaces subjected to shear force and bending moment, is experimentally investigated by submitting specimens to a load protocol consisting into cycles of reverse imposed displacements, with growing amplitude. Concrete-to-concrete interfaces are located on the hogging region to recreate a practical situation of the precast construction where continuity between precast elements (columns, beams and slabs) is ensured by localized casting of joint connections in situ. Three types of casting interfaces were studied: (i) vertical and unreinforced; (ii) vertical and reinforced; and (iii) diagonal and unreinforced. In all the cases, no special treatment to increase the interfaces' roughness was carried out. The results obtained were compared to those of a reference specimen produced without casting interfaces. Results show that the presence of casting interfaces do not reduce the specimens' maximum strength but can reduce the percentage of cycles sustained after yielding, up to failure, in 9% to 15%. Ductility, measured in terms of the ratio between ultimate and yielding displacements, is reduced in 30%. Interface reinforcement and interface direction have negligible influence on the specimens' behaviour.
AB - Ductility of Reinforced Concrete (RC) members connections is of paramount importance on seismic regions, regarding energy dissipation. Recent research has suggested that the presence of concrete-to-concrete interfaces subjected to shear force and bending moments, can potentially reduce ductility of RC beams under monotonic loading, due to the occurrence of a shear slippage along the interfaces. In this paper, the cyclic behaviour of RC beams with concrete-to-concrete interfaces subjected to shear force and bending moment, is experimentally investigated by submitting specimens to a load protocol consisting into cycles of reverse imposed displacements, with growing amplitude. Concrete-to-concrete interfaces are located on the hogging region to recreate a practical situation of the precast construction where continuity between precast elements (columns, beams and slabs) is ensured by localized casting of joint connections in situ. Three types of casting interfaces were studied: (i) vertical and unreinforced; (ii) vertical and reinforced; and (iii) diagonal and unreinforced. In all the cases, no special treatment to increase the interfaces' roughness was carried out. The results obtained were compared to those of a reference specimen produced without casting interfaces. Results show that the presence of casting interfaces do not reduce the specimens' maximum strength but can reduce the percentage of cycles sustained after yielding, up to failure, in 9% to 15%. Ductility, measured in terms of the ratio between ultimate and yielding displacements, is reduced in 30%. Interface reinforcement and interface direction have negligible influence on the specimens' behaviour.
KW - Concrete-to-Concrete Interface
KW - Cyclic behavior
KW - Ductility
KW - Plastic hinge
KW - Precast Construction
KW - Shear-friction
UR - http://www.scopus.com/inward/record.url?scp=85127020932&partnerID=8YFLogxK
U2 - 10.1680/jmacr.21.00093
DO - 10.1680/jmacr.21.00093
M3 - Article
AN - SCOPUS:85127020932
SN - 0024-9831
VL - 74
SP - 1150
EP - 1164
JO - Magazine of Concrete Research
JF - Magazine of Concrete Research
IS - 22
ER -