Experimental study on flexural behavior of partially precast high-strength steel reinforced ultra-high performance concrete beam

Abstract

High-strength steel (HSS) and ultra-high performance concrete (UHPC) are materials that countries use to promote the development of green and energy-saving civil engineering construction. The objective of this study was to investigate the flexural performances of partially prefabricated and assembled HSS reinforced UHPC (PPHSRC) beams. To this end, six PPHSRC beams were produced and the static bending tests were conducted while considering the primary design parameters such as the thickness of the steel flange, the type of the steel section and the form of the laminate slab. Typical flexural failure mode and crack patterns were observed, and the flexural characteristics were evaluated based on the load–deflection behavior and ductility. The results showed that PPHSRC beams were well-composite and had good ductility. With the increase of the thickness of the steel flange, the ultimate bearing capacity of the PPHSRC beam increased remarkably, but the cracking bearing capacity was less affected. Compared with inverted T-steel, unequal flange I-steel was beneficial to the flexural capacity of the PPHSRC beam, though the effect was slight. The flexural capacities of PPHSRC beams with the keyways structure concrete laminated slab were much higher than those of PPHSRC beams with the reinforced trusses concrete laminated slab. Finally, a calculation method for flexural capacity based on the plastic theory was proposed. The calculation results were in good agreement with experimental results, confirming that the method can be applied to accurately predict the flexural capacity of the PPHSRC beam and provide a reference for further research.