New-old concrete composite system usually exists in concrete repairing structure.In the present work,series of experiments were carried out to investigate permeability and ion diffusion properties of new-old concrete ...New-old concrete composite system usually exists in concrete repairing structure.In the present work,series of experiments were carried out to investigate permeability and ion diffusion properties of new-old concrete composite by measuring 6-hour coulomb charge and chloride diffusivity.The interrelation among transport properties of new-old composites,new,and old concretes was also discussed.Results indicate that the permeability and chloride diffusivity of new-old concrete composite system closely interrelate to the corresponding new concrete and old concrete.The interfacial transition zone between new concrete and old concrete greatly influences the transport property of new-old concrete system.Compared with the corresponding new concrete and old concrete lower permeability and diffusivity values for the new-old concrete composites can be achieved by choosing suitable new concrete.It is possible to design the tailor-made new-old concrete composite system for repair given the transport property.展开更多
Using composite cubic specimens of new-old concrete,the bond splitting tensile strength and failure mechanism for the interface of new-old concrete in saturating state were explored when exposed to freeze-thaw cycling...Using composite cubic specimens of new-old concrete,the bond splitting tensile strength and failure mechanism for the interface of new-old concrete in saturating state were explored when exposed to freeze-thaw cycling. Specimens were experienced for 0,25,50,75,100 and 125 freezing cycles. The roughness and adhesion agent including cement paste,cement mortar and cement paste with 10 percent of UEA expanding agent were also investigated. The test results indicate that the bond splitting tensile strength decreases with increased numbers of freezing-and-thawing cycles. The roughness and adhesion agent have different effects on the bond strength.展开更多
基金Project(2013CB036201)supported by the National Basic Research Program of ChinaProject(51178467)supported by National Natural Science Foundation of ChinaProject(NCET-10-0839)supported by Program for New Century Excellent Talents in University,China
文摘New-old concrete composite system usually exists in concrete repairing structure.In the present work,series of experiments were carried out to investigate permeability and ion diffusion properties of new-old concrete composite by measuring 6-hour coulomb charge and chloride diffusivity.The interrelation among transport properties of new-old composites,new,and old concretes was also discussed.Results indicate that the permeability and chloride diffusivity of new-old concrete composite system closely interrelate to the corresponding new concrete and old concrete.The interfacial transition zone between new concrete and old concrete greatly influences the transport property of new-old concrete system.Compared with the corresponding new concrete and old concrete lower permeability and diffusivity values for the new-old concrete composites can be achieved by choosing suitable new concrete.It is possible to design the tailor-made new-old concrete composite system for repair given the transport property.
基金the National Natural Science Foundation of China(Grant No.59778045).
文摘Using composite cubic specimens of new-old concrete,the bond splitting tensile strength and failure mechanism for the interface of new-old concrete in saturating state were explored when exposed to freeze-thaw cycling. Specimens were experienced for 0,25,50,75,100 and 125 freezing cycles. The roughness and adhesion agent including cement paste,cement mortar and cement paste with 10 percent of UEA expanding agent were also investigated. The test results indicate that the bond splitting tensile strength decreases with increased numbers of freezing-and-thawing cycles. The roughness and adhesion agent have different effects on the bond strength.
