The Research On Jetting High Performance Cement Composite Concrete To Strengthening Stone Arch Bridge On Stiffness Performance

The stone arch bridge is a structure which is beautiful.easily obtained and with high bearing capacity.It plays a very important role in the field of bridge construction.However,with the progress of the time,and the development of transportation,there are a variety of inevitable problems has been happened to those stone arch bridges that built in the early times due to their low-grade design standards,and the natural disasters.The bridge collapse accident happened in recent years has make us realize the importance and urgency of the strengthening of old bridges.It is a difficult problem for scholar researchers and engineers to find a safe.economy way to strengthening those old stone arch bridges.Faced with the reality that a lot of stone arch bridge was lack of security in the process of operation,we proposed a way of jetting High Performance Cement Composite Concrete to strengthening old stone arch bridges based on the mature technology of shotcreting concrete,and we try to make some researches to study how this strengthening methods will influence the stiffness performance of stone arch bridges.Firstly,in order to investigate capacity mechanism.failure mode and capacity elevated degree of the stone-arch bridge,2 groups of compressive specimens of stone masonry strengthened by injection high-performance cement composite concrete and 1 group of contrastive specimens were made for the axial compression test.The strengthening effects of the thickness of concrete on the strengthened stone masonry were analyzed.The experiment results show that the cracking capacity of strengthened stone masonry can be greatly improved by 103.1%?119.8%,andthe ultimate capacity can also be improved by 21.2%?36.4%.Secondly,we designed a shrink-scale model experiment based on the secondary loading characteristics of stone arch bridge,the result shows that this method can effectively improve the stiffness performance of stone arch bridges.And we introduce stiffness indicators to evaluate the strengthening effect,the results show that the method can met the indicators very well.In this thesis,we provide a number of issues should be pay attention to under the construction process and can be a reference for the strengthening design.