In this study,a fully precast steel—ultrahigh performance concrete(UHPC)lightweight composite bridge(LWCB)was proposed based on Mapu Bridge,aiming at accelerating construction in bridge engineering.Cast-in-place join...In this study,a fully precast steel—ultrahigh performance concrete(UHPC)lightweight composite bridge(LWCB)was proposed based on Mapu Bridge,aiming at accelerating construction in bridge engineering.Cast-in-place joints are generally the controlling factor of segmental structures.Therefore,an innovative girder-to-girder joint that is suitable for LWCB was developed.A specimen consisting of two prefabricated steel—UHPC composite girder parts and one post-cast joint part was fabricated to determine if the joint can effectively transfer load between girders.The flexural behavior of the specimen under a negative bending moment was explored.Finite element analyses of Mapu Bridge showed that the nominal stress of critical sections could meet the required stress,indicating that the design is reasonable.The fatigue performance of the UHPC deck was assessed based on past research,and results revealed that the fatigue performance could meet the design requirements.Based on the test results,a crack width prediction method for the joint interface,a simplified calculation method for the design moment,and a deflection calculation method for the steel—UHPC composite girder in consideration of the UHPC tensile stiffness effect were presented.Good agreements were achieved between the predicted values and test results.展开更多
基金The authors gratefully acknowledge the following support:National Key R&D Program(No.2018YFC0705400)National Natural Science Foundation of China(Grant No.51778223)+1 种基金Major Program of Science and Technology of Hunan Province(No.2017SK1010)The authors also express their sincere appreciation to the reviewers of this paper for their constructive comments and suggestions.
文摘In this study,a fully precast steel—ultrahigh performance concrete(UHPC)lightweight composite bridge(LWCB)was proposed based on Mapu Bridge,aiming at accelerating construction in bridge engineering.Cast-in-place joints are generally the controlling factor of segmental structures.Therefore,an innovative girder-to-girder joint that is suitable for LWCB was developed.A specimen consisting of two prefabricated steel—UHPC composite girder parts and one post-cast joint part was fabricated to determine if the joint can effectively transfer load between girders.The flexural behavior of the specimen under a negative bending moment was explored.Finite element analyses of Mapu Bridge showed that the nominal stress of critical sections could meet the required stress,indicating that the design is reasonable.The fatigue performance of the UHPC deck was assessed based on past research,and results revealed that the fatigue performance could meet the design requirements.Based on the test results,a crack width prediction method for the joint interface,a simplified calculation method for the design moment,and a deflection calculation method for the steel—UHPC composite girder in consideration of the UHPC tensile stiffness effect were presented.Good agreements were achieved between the predicted values and test results.
