Mechanical behavior of concrete filled glass fiber reinforced polymer-steel tube under cyclic loading

The mechanical behavior of concrete-filled glass fiber reinforced polymer(GFRP)-steel tube structures under combined seismic loading is investigated in this study. Four same-sized specimens with different GFRP layout modes were tested by a quasi-static test system. Finite element analysis(FEA) was also undertaken and the results were presented. Results of the numerical simulation compared well with those from experimental tests. Parametric analysis was conducted by using the FE models to evaluate the effects of GFRP thickness, axial compression rate, and cross sectional steel ratio. The experimental and numerical results show that the technique of GFRP strengthening is effective in improving the seismic performance of traditional concrete-filled steel tubes, with variations related to different GFRP layout modes.

Bond Mechanical Properties of Glass Fiber Reinforced Polymer Anti-Floating Anchor in Concrete Baseplate

Combined with fiber Bragg grating(FBG)sensing technology,four glass fiber reinforced polymer(GFRP)anti-floating anchors and four steel anti-floating anchors were tested for on-site destructive failure to investigate the anchoring performance and the bonding characteristics between GFRP anti-floating anchor and concrete floor.The test results show that bending GFRP anchor will be broken at the common boundary between vertical anchorage section and bending section during the pullout process,and the spring-back load provided by the rupture contributes to a decrease of bearing capacity and an inflection point on the load-slip curve.The loaddisplacement curve of the straight anchor GFRP anti-floating anchor is smoother and has better predictability than the same type of steel anchor.Additionally,different forms of GFRP anti-floating bolt have different bondslip constitutive relations.By introducing the sliding-slip correction factor of bending bolt,constitutive models describing the rising-section of sliding-slip relation of bending and straight-anchored GFRP anti-floating bolt are established respectively.The model can fit the test results rightly.

Experimental Study of the Shear Capacity of Glass Fiber Reinforced Polymer Reinforced Concrete Beam with Circular Cross Section

In order to research the shear behavior of glass fiber reinforced polymer (GFRP) reinforced concrete beam with circular cross section, based on the test results of 36 concrete beams subjected to four-point loading up to failure, the shear capacity and mechanical properties of deformation were analyzed comparatively between GFRP reinforced concrete (GFRP-RC) beams and steel reinforced concrete (steel-RC) beams. Furthermore, influencing factors of shear capacity of GFRP-RC beam with circular cross section were also investigated. The test results indicate that the failure modes of GFRP-RC and steel-RC beams are the same, but the crack patterns are slightly different. And, the shear capacity of GFRP-RC beam firstly increases with the reduction of shear span ratio, and then decreases. In addition, it was found that the influencing coefficient of GFRP on concrete increases with shear span ratio reducing.