Advanced Materials Research Vols. 163-167

Abstract: Based on twelve push-out specimens with different holes filling different materials,the paper compared and analyzed the capacity and the corresponding slip value of the stud shear connector.Meanwhile, tests were also conducted on three composite steel-FDPCP(Full-Depth Precast Concrete Panel) beams with different holes shape and degree of shear connection to investigate the characteistics of load-displacement,load-deflection,load-strain of the total cross section and monolithic action of the entire cross section in the paper. The results show that, as to the two different kinds of holes shape ,the strength of the stud shear connectors of square push-out specimens was huger than that of circular specimens with the same condition; the strength of stud shear connectors in steel-concrete composite structure was decided by the strength of concrete surrounding the shear in the holes, with increasing concrete strength, the strength of stud shear connectors improved greatly; the composite steel-FDPCP beams failed in bending,plane section was maintained in composite beams throughout the testing process.the composite steel-FDPCP beams have some merits :good bearing capacity, good anti-bend capability, fast pile-driving pace and perfect work behaviors as a whole;the ultimate flexural capacity of the composite steel-FDPCP beams with a full shear connection is close to that of a partial shear connection. The outputs of this study are very useful for further understanding of the characteristics of the composite steel-FDPCP beams,it is also expected that the results presented in this paper should be valuable for the design of the composite steel-FDPCP beams.

Abstract: According to the forced load-bearing characteristics of the prestressed concrete girder bridge with corrugated steel webs, the cross-section internal forces and stress redistribution of box-girder were studied under the influence of concrete creep. And the internal force redistribution formula on concrete creep was derived through the establishment of the compatibility equation of bending deformation; the stress redistribution formulas of the top slab and the bottom slab of box-girder at any time were also derived, through the establishment of the compatibility equation of the axial displacement and angular deformation of the top slab and the bottom slab of box-girder under the influence of concrete creep at any time. These show that the creep stress is only related to the box height and it’s the geometric properties of top slab and bottom slab concrete section, but not to the steel web’s size.

Abstract: Polystyrene (PS)/Poly(S-co-MA)/expanded graphite(EG)(PS/PSMA/EG) nanocomposites were prepared by melt blending, using a variety of PSMA/EG.. The electrical and mechanical properties of the PS/PSMA/EG were measured. Mechanical property measurements of composites indicated higher impact strength and lower tensile strength with increasing concentration of PSMA/EG. Exfoliated graphite has seen a significant reduction for composites in electrical resistivity.

Abstract: As composite materials have advantages of high strength-to-weight ratio and superior corrosion resistance properties, it is used in emergencies in the construction of mobile bridges as the preferred material. However, In contrast to traditional steel or aluminum to the movement of the bridge as the main material, the original bridge forms need to be improved in order to reach the full of FRP material properties. In this paper, to study the domestic light-weight mobile FRP Bridge, the finite element method is used to analysis the mechanical properties of bridge.

Abstract: To verify the rationality of calculation method on unified theory of concrete - filled steel tube short columns under axial force, Experimental Study on mechanical properties of the 12 concrete -filled steel tube short columns with 7 different sections under axial force is preformed. Failure process and Failure mode of them are observed, load-displacement curves are obtained, and the influence for confinement coefficient ξ to the mechanical properties of short columns under axial load is analyzed. Based on load-displacement curves, ultimate bearing capacities of them are given. By comparison for ultimate bearing capacity obtained by testing and the bearing capacity according to unified theory, the results show both are in good agreement. Calculation method on unified theory of concrete - filled steel tube is fit for calculating ultimate bearing capacity of short columns under axial force with different sections, and the results are safe and reliable.

Abstract: Diagrid tube structure system has advantages on constructing high-rise buildings due to its great stiffness, however, its seismic performance analysis are limited. 10 CFST diagrid tube-concrete core tube structures are analyzed by Mode-Pushover method using Perform-3D program. The plasticity developing process and components yield order are summarized. The force distribution between diagrid and core tubes is researched and the force redistribution reason is explained from the change of diagrid tube forces. The structure lateral stiffness degradation is discussed based on the developing process of diagrid and core tubes lateral stiffness. The influences of main lateral stiffness related factors on the structure plasticity developing process, force distribution and stiffness change of the tubes are discussed at last.

Abstract: In order to study the behavior of connectors used in steel-concrete composite beam subjected to single cyclic loading, three groups of studs were tested with new specimen and new method, stud’s diameter is different among each group(Φ16,Φ19,Φ22). Stud’s fatigue behavior subjected to single cyclic loading various with the diameter.

Abstract: Concrete is used in tower, and steel is used in anchor zone. It can make full use of the two materials’ nature. It can not only satisfy the tower’s stressed aptitude, but also can reduce the cost of construction. In this paper, the full size model has been designed and constructed. The test investigation of the statical performance have been proceeded. The results show that the neotype anchor system can make full use of the materials’ nature and is in good working order. The anchor system with enough bearing capacity satisfies the operating requiements of the cable-stayed bridge.

Abstract: Experimental study has been carried out on the seismic performance of SRC-RC transfer columns. The effect of extension length of shape steel has been analyzed. Degeneration of bearing capacity becomes much more obvious when extension length of shape steel increases and failure patterns change from shear failure to bond failure. Displacement ductility changes with increase of the extension length of shape steel, enhancing at first and then reducing, reaching peak value when extension length of shape steel gets close to three-fifths of column height. But extension length of shape steel has little effect on the bearing capacity of transfer column. Although double stirrups are arranged at the location of shape steel discontinuous, strain of stirrup at this position is still much higher than anywhere else.

Abstract: The main span is the steel truss and the side spans are the composite truss in Minpu Bridge. A 1:2.5 model is made to study the mechanical behavior of the joint segment of steel truss and composite truss. Both a model test and a numerical finite element analysis(FEA) method have been conducted. The results show that the joint segment remains in a linear elastic state under the condition. The maximum stress in the structure is less than the material allowable strength. The FEA results are in very good agreement with those of model test. This study shows that the force transformation of the joint segment is reliable and the composition details are rational. It is also expected that the results presented in this paper would be useful as references for the further research and the design of composite truss bridge and joint segment.