Cyclic Behavior of Steel-Rubcrete-Steel Sandwich Beams

In this study, four steel-concrete-steel (SCS) sandwich beams were tested experimentally under incrementally increasing cyclic loading. Each beam had a length of 1000 mm, and upper and lower steel plates with 3 mm thickness sandwiched the concrete core which had a cross section of 150 mm × 150 mm. Two of the beams were constructed out of Rubcrete with welded and bolted shear connectors, the other two beams were constructed with welded shear connectors and either conventional concrete or lightweight expanded clay aggregate (LECA) concrete. The performance of the SCS sandwich beams performance including damage pattern, failure mode, and load-displacement response were compared. The results showed that while Rubcrete was able to provide similar concrete cracking behaviour and strength to that of conventional concrete, LECA concrete degraded the strength properties of SCS. Using bolted shear connectors instead of welded ones caused high number of cracks that resulted in a reduced ductility and deflection capacity of the beam before failure.