Perpustakaan Digital ITB

Many experimental to investigate behavior of concrete column composite has been carried out. Results show that concrete columns composite can be effective increasing in strength and ductility of concrete columns compared with normal concrete columns (unconfined concrete columns). This experiment was carried out of obtain a valid experimental test result and perform the failure behavior of concrete columns confined with PVC illustration, such as maximum load behavior, deformation load behavior, failure mode and failure criterion. Parameter used in this experiment were concrete strength of core (KO=sand, K1=10 MPa and K2=25 MPa) and slenderness ratio (L/D = 2,4,6 and 8). KO can resist axial load caused by compressive strength from PVC tubes as compared with unconfined sand condition. Maximum load of KO , Kl and K2 with slenderness ratio L/D > 2 was not different from specimen with slenderness ratio L/D = 2. Compressive strength of K1 increased significantly 146,6%, K2 increased significantly 59,3% as compared with compressive strength of core. when confined compressive concrete strength increased, percentage of increasing load capacity become decreased. As compressive concrete strength increased, the average of axial and lateral deformation as reach maximum load became lower. This caused by difference elasticity of modulus, dilatability behavior and more higher the strength of concrete. Because of the difference of compressive strength of core, stiffness of KO, K1, and K2 would be different. Failure mode of K1 and K2 shows shear failure mode, that caused by confinement effect (that caused multiaxial stress). Failure mode of KO Show as PVC-yield failure mode. According to experimental (test) data, Mohr-coulomb, Dracker-Prager and Ottosen failure mode are obtained appropriate for concrete confined with PVC cylinder tube.