Flexural Response of CFST Beams with Incorporated DCLs

Concrete Filled Steel Tubes (CFSTs) have been studied and used for a long time since it confines the concrete inside which significantly increases its mechanical properties. Most current studies focus on the axial behaviour of CFST. Furthermore, there are few experiments that incorporate recycled and waste materials in the concrete mix of CFST beams. This study aims to evaluate the flexural response of CFST beams that incorporate Demolished Concrete Lumps (DCLs) in a unique arrangement to minimize their effect on different mechanical properties. Seven circular CFST specimen were casted and tested under bending using the four-point bending test, where the Universal Testing Machine (UTM) was utilized. Different DCL sizes and occupied areas are considered in this study. The CFST beams are evaluated by plotting moment vs. deflection and moment vs. microstrain curves, and the specimens are then compared by assessing the capacity, ductility, and stiffness.