Experimental Investigation On Stone-arch Bridge Strengthened With Injecting High Performance Cement Composite Concrete

In our country, Stone arch bridge has a long history, and has advantages such asgraceful shape, cost cheap, drawing materials convient, skillful techniques etc. Thestone arch bridge has been widely used in early china and plays an important role inthe traffic construction and history of china. However, due to the reason of long yearsout of repaired, increasing traffic and natural disasters etc, most of the stone archbridges have diseases of cracking, damage etc, and exist some security risks.Strengthing the remaking bridges in danger is the best choice because demolition andreconstruction not only spend a lot of money but also cause some society questionsconsidering that the remaking bridges in danger have a large amout of quantity andbeen wildly used.High-performance cement composite concrete reinforcement technology is a newmethod and being widely used in the field of masonry and concrete structurereinforcement because it can effectively improve the compressive strength, flexuralcapacity, whole performance, and control structural cracks. High-performancecomposite concrete reinforcement technology has the advantages of convenientconstruction, good economic benefit, good durability with inorganic materialscompared with other bridge reinforcement technologys. High-performance cementcomposite reinforced concrete stone arch bridge has important social and engineeringsignificance because it can greatly reduce engineering without excavateing the upperfill.In order to investigate the reinforcement effect of stone arch bridge strengthenedwith injecting high performance cement composite concrete, an unreinforced stonearch bridge model and an reinforced stone arch bridge model were made in thestructure laboratory of Hunan Univerty. The reinforced model strengthened byinjecting60mm high-performance cement composite concrete when loading to70%ofultimate load because stone arch usually has a large dead load which isn’t removable.The effect of cracking model, failure mode and ultimate bearing capacity of stonearch bridge strengthened with injecting high performance cement composite concretewere investigated by comparing the results of the experimental.The experimental results show that the ultimate bearing capacity of theunreinforcement stone arch bridge model is800kN. The ultimate bearing capacity ofthe reinforcement stone arch bridge model is1000kN. There is25percent increase of the ultimate bearing capacity. Strengthening stone arch bridge by injectinghigh-performance cement composite concrete can effectively improve the failure load.The unreinforced stone arch bridge appeared quickly a crack in the failureposition when loading to95%of ultimate load, and failure was significantly brittlebecause it was so rapidly that there was no reaction time. The reinforced stone archbridge had obvious cracks in the failure position when loading to90%of failure load,which was the sigh of destruction before failure. The stone arch bridge’s property ofbrittle failure can been effectively improved with Strengthened by injectinghigh-performance cement composite concrete. Reinforcement layer bonded well witharch bridge model, no peeling and slip. Arch bridge model remained the whole afterthe destruction which showed that the integrity of arch bridge model was improved byreinforcement layer.The bearing capacity calculation method of arch bridge model was fitted on thebasis of the theoretical analysis and test results. The results of the calculationcoincide with the test results. The calculation method can be reference for thestrengthening engineering design.