Shrinkage Performance of UHPC-NC Bonding Interface in Bridge Structure Repair
When applying ultra-high performance concrete(UHPC)to repair bridge components,in order to clarify the shrinkage deformation and stress distribution of the bonding interface between post poured UHPC and existing normal concrete(NC),shrinkage tests were conducted on UHPC-NC bonded specimens to measure the free shrinkage deformation of UHPC specimens and the constrained shrinkage deformation of UHPC-NC bonded specimens.A finite element analysis model was established to discuss the slip of the bonding interface,and the stress distribution and influencing factors in the interface and post poured UHPC were analyzed.The results indicate that the free shrinkage strain growth of UHPC follows an exponential development law.The interface of UHPC-NC bonded specimens exhibits slip,which can effectively reduce interfacial stress.The interface cracking stress increases with the decrease of repair layer thickness and the increase of repair bottom surface area.The maximum shear stress is caused by shrinkage at the end of the bonding interface.The interface stress shows a rapid increase followed by a gradual stabilization as the bonding age increases,and steel fibers in UHPC can reduce the interface stress.UHPC is an ideal bridge component repair material as it does not experience cracking due to shrinkage constraints when it is used for concrete repair.
NETL
NSTL
万方数据
