Exploration of Structural Performance of Stiffened Steel-Concrete Composite Beams with Perforated Stiffening Rib Plates

A ribbed steel plate-concrete composite section (PSRP) was proposed to prevent or limit flexural cracking in the negative moment region normally with a spiky rise and rapid reversal. The proposed section was composed of concrete and steel plate with perforated stiffening rib plate to reduce the dependency of shear transfer on interfacial bond. The objective of this study was to obtain experimental and analytical data essential to investigate, and establish, a design method for the steel plate reinforced concrete against flexural cracking under the service load condition. This paper presents the results of a total of eight scale specimens prepared for the comparison test. Six specimens were reinforced using steel plate with perforated stiffening rib plates, one specimen was reinforced using conventional reinforcing bars and one specimen was reinforced using epoxy-bonded steel plate for comparison. All beam specimens were tested to failure. The test results indicated the steel plate with rib stiffeners can offer a pronounced improvement to the cracking resistance of the concrete. The cracking load for the PSRP specimen with stiffening rib plate is three times higher than the specimen reinforced with conventional steel, and two and half times higher than specimen reinforced with epoxy-bonded steel plate. The perforated stiffening rib plate appears to have not only increased interfacial bond area and but also provide a volumetric restraint and confinement to adjoining concrete that improves ist material uniformity, in comparison to the discrete and localized line bonding provided by the reinforcing bars. This improvement of the material uniformity may have led to a significant rise of tensile stress limit of the confined concrete.