Time-dependant reliability is analyzed for the flexural cracking of prestressed concrete bridges under service limit state. The limit state function and random variables are derived from Chinese highway bridge design ...Time-dependant reliability is analyzed for the flexural cracking of prestressed concrete bridges under service limit state. The limit state function and random variables are derived from Chinese highway bridge design specifications. For deterioration of structural performances, chloride-induced reinforcement corrosion is emphasized. Through integrating first order reliability method （FORM） and time discretized approach, the time-variant reliability is evaluated. For illustrative propose, the reliability of a typical simply supported prestressed concrete beam is exemplified.展开更多
In this study,we conducted experimental tests on two specimens of reinforced concrete beams using a three-point bending test to optimize the flexure and stiffness designs.The first specimen is a reinforced concrete be...In this study,we conducted experimental tests on two specimens of reinforced concrete beams using a three-point bending test to optimize the flexure and stiffness designs.The first specimen is a reinforced concrete beam with an ordinary reinforcement,and the second specimen has an invented reinforcement system that consists of an ordinary reinforcement in addition to three additional bracings using steel bars and steel plates.The results of the flexure test were collected and analyzed,and the flexural strength,the rate of damage during bending,and the stiffness were determined.Finite element modeling was applied for both specimens using the LS-DYNA program,and the simulation results of the flexure test for the same outputs were determined.The results of the experimental tests showed that the flexural strength of the invented reinforcement system was significantly enhanced by 15.5%compared to the ordinary system.Moreover,the flexural cracks decreased to a significant extent,manifesting extremely small and narrow cracks in the flexure spread along the bottom face of the concrete.In addition,the maximum deflection for the invented reinforced concrete beam decreased to 1/3 compared to that of an ordinary reinforced concrete beam.The results were verified through numerical simulations,which demonstrated excellent similarities between the flexural failure and the stiffness of the beam.The invented reinforcement system exhibited a high capability in boosting the flexure design and stiffness.展开更多
文摘Time-dependant reliability is analyzed for the flexural cracking of prestressed concrete bridges under service limit state. The limit state function and random variables are derived from Chinese highway bridge design specifications. For deterioration of structural performances, chloride-induced reinforcement corrosion is emphasized. Through integrating first order reliability method （FORM） and time discretized approach, the time-variant reliability is evaluated. For illustrative propose, the reliability of a typical simply supported prestressed concrete beam is exemplified.
基金This study was conducted with the financial support from the project GACR 17-23578S“Damage Assessment Identification for Reinforced Concrete Subjected to Extreme Loading”provided by the Czech Science FoundationFurthermore,we acknowledge the cooperation of the civil engineering department of Tishk International University-Sulaimani in the Kurdistan Region of Iraq,who granted us official permission to conduct the experimental tests on the two specimens at their concrete laboratory.
文摘In this study,we conducted experimental tests on two specimens of reinforced concrete beams using a three-point bending test to optimize the flexure and stiffness designs.The first specimen is a reinforced concrete beam with an ordinary reinforcement,and the second specimen has an invented reinforcement system that consists of an ordinary reinforcement in addition to three additional bracings using steel bars and steel plates.The results of the flexure test were collected and analyzed,and the flexural strength,the rate of damage during bending,and the stiffness were determined.Finite element modeling was applied for both specimens using the LS-DYNA program,and the simulation results of the flexure test for the same outputs were determined.The results of the experimental tests showed that the flexural strength of the invented reinforcement system was significantly enhanced by 15.5%compared to the ordinary system.Moreover,the flexural cracks decreased to a significant extent,manifesting extremely small and narrow cracks in the flexure spread along the bottom face of the concrete.In addition,the maximum deflection for the invented reinforced concrete beam decreased to 1/3 compared to that of an ordinary reinforced concrete beam.The results were verified through numerical simulations,which demonstrated excellent similarities between the flexural failure and the stiffness of the beam.The invented reinforcement system exhibited a high capability in boosting the flexure design and stiffness.
