| Under strongly corrosive environments,such as marine environments,reinforced concrete structures suffer durability issues and premature damage due to the corrosion of steel bars.Given the advantages of high strength and excellent corrosion resistance of fiber reinforced polymer(FRP)bars,replacing traditional steel bars with FRP ones can fully solve the steel corrosion issue.In this thesis,the punching shear behavior of GFRP reinforced concrete(RC)slabs is studied experimentally.A total of 12 GFRP RC slabs under a concentrated load were designed and cast.The variable parameters are the effective plate thickness,the stub size,the concrete strength,and the longitudinal reinforcement ratio.The test results show that when the effective thickness of slabs increases by 23%～57%,the ultimate bearing capacity of the specimen increases by 51%～116%.When the stub size increases by 16.7%,the ultimate bearing capacity of the specimen increases by about 10%.When the concrete strength of specimens increases by 17%～46%,the ultimate bearing capacity of specimens increases by 11%～34%.The ultimate bearing capacity of specimens is increased by about 5%～7% when the longitudinal reinforcement ratio is increased by 44%～47%.Based on a group of experimental data collected from the literature and combining with self-conducted experimental results,the existing code-based models and commonly-used models in the literature are assessed quantitively.It can be seen from the analysis that the ACI440 punching shear model for FRP-RC slabs is based on the ACI318 punching shear model of RC slabs.The ACI440 model does not consider the size effect,the shape of the stub and other factors.As a consequence,the accuracy of the prediction results of the model is the lowest among the models assessed.Among all the code-based models,the CSA model takes the most comprehensive factors into consideration and provides the best prediction.In addition,both of the JSCE model and BS5400 model’s predicted results agree well with the experimental results.Among the existing punching-shear models,El-Gamal et al.’s model provides the best prediction.Moreover,the model takes the influence of the boundary condition of slabs into consideration.Nguyen-Minh’s model,which is a fracture mechanics-based model,is the only model that takes both the shear span ratio of and the dowel effect of the FRP bars and the punching span ratio into account.However,the accuracy of the model needs to be improved further. |
