Experimental Research on Pre-Stressed Concrete Composite Box Girders with Corrugated Steel Webs

摘要

The development and application of pre-stressed concrete composite box girders with corrugated steel webs were presented in this paper. A model (1:4) of pre-stressed concrete composite box girder with corrugated steel webs was made in order to investigate the mechanical properties of the composite box girders. Through the static loading tests,the experimental research on bending,shear and torsion of the pre-stressed concrete composite box girder with corrugated steel webs was performed. The deformation of the box girder,the strain of top and bottom concrete slabs,the corrugated steel webs and the diaphragms,bearing force,cracking load and failure load were obtained under the multi-step loading. Test results showed that compared with the common pre-stressed concrete box girders,the pre-stressed concrete composite box girders with corrugated steel webs have particular mechanical properties. Under loading,bending moment is approximately only resisted by top and bottom concrete slabs,and most of the shear force is sustained by the corrugated steel webs. Under symmetric loading,negative shear lag is observed on the top concrete slabs at mid-span. Within elastic range,longitudinal strain on top and bottom concrete slabs distribute linearly which accord with the assumption that the cross-section of beams keeps plane during loading. The bending process of box girders has three stages,which includes elastic stage,crack stage and failure stage. Additionally,Torsional stiffness of box girders was effectively improved by the setting of diaphragms.