Title: Cyclic Behavior of Rubberized Beam-Column Joints Reinforced with Synthetic Fibers
Author(s): Basem H. AbdelAleem and Assem A. A. Hassan
Publication: Materials Journal
Appears on pages(s): 105-118
Keywords: beam-column joints; coarse aggregate size; cracking; ductility; energy dissipation; failure; loading; macro-synthetic fibers; micro-synthetic fibers; reinforcement; structural element
This investigation aims to study the effect of different types and volumes of synthetic fibers (SFs) on the cyclic behavior of rubberized beam-column joints. Different self-consolidating rubberized concrete (SCRC) mixtures with different percentages of crumb rubber (CR) and SFs were tested. The main parameters were the percentage of CR (0, 15, and 25% by volume of sand), coarse aggregate size (10 and 20 mm [0.39 and 0.79 in.]), concrete type (SCRC and vibrated rubberized concrete), type of SF (microsynthetic fibers [MISFs] and macro-synthetic fibers [MASFs]), length of SFs (19, 27, 38, 50, and 54 mm [0.75, 1.06, 1.5, 1.97, and 2.13 in.]), and volume of SFs in the mixture (0, 0.2, and 1%). The structural performance of the tested beam-column joints was assessed based on load-deflection response, initial stiffness, load-carrying capacity, first cracking load, cracking behavior, failure mode, rate of stiffness degradation, displacement ductility, brittleness index, and energy dissipation. The results indicated that using MISFs slightly improved the structural performance of beam-column joints, while using MASFs had a significant effect on enhancing the load-carrying capacity, ductility, stiffness, and energy dissipation of tested joints. The highest improvement in the cyclic performance of beam-column joints was noticed when 38 mm (1.5 in.) MASFs were used. The results also showed that adding a high percentage of SFs (1%) to joints with a high percentage of CR (25%) compensated for the reduced load-carrying capacity caused by the high percentage of CR and helped to develop the joint with significant improvements in ductility, cracking behavior, brittleness index, first crack load, and energy dissipation.