Effectiveness of high performance fiber-reinforced cement composites in slender coupling beams

This study aims at exploring the use of high performance fiber-reinforced cement composites (HPFRCCs) as an innovative method of improving the seismic performance of slender coupling beams. Also, the effect of diagonal reinforcement in slender coupling beams is evaluated in comparison to conventional reinforcement. Three 1/2-scale coupling beams having the length-to-depth ratio of 3.5 were tested under cyclic lateral loading up to about 10% drift. The key test variables were material type and reinforcement layout. For the material type, normal concrete and HPFRCC using PVA discrete fibers of 2% volumetric ratio were compared. The mix proportions of the HPFRCC were determined through detailed material tests. Two types of reinforcement layout were tested: conventional and diagonal layout. Furthermore, the strength and stiffness characteristics of reinforced concrete or HPFRCC coupling beams are examined by assembling a database of almost all coupling beam tests available in literature.