The Research On Interfacial Bond Quality Inspection Of New-to-old Concrete And The Prediction Model For The Pull Strength Of The Bonding Interface

The repair and strengthening of concrete structure has become an important engineering domain. The enlarging section method(the reinforcement and strengthening technique of integral type of new to old concrete)is widely applied in the repair and strengthening of concrete structure. The bonding quality of new to old concrete interface is the key to this kind reinforcement work. Therefore, the research on quality inspection on adherence of new to old concrete has profound significance. Proceed from inspection of construction quality, the core-drilling and pull-stripping test method was chosen as on-site test method and the pull strength of new to old concrete adherence was regard as evaluation index for new to old concrete interface bonding quality inspection. And based on these conditions, systematic experimental study on the relevant problems of the interface bonding quality was carried on and the prediction model for the pull strength of the bonding interface was set up combined the test results in this paper.Firstly, the quantization study on surface roughness of old concrete which is the key control point of bonding quality was carried on by roughness test. The relationship between roughness and tensile splitting strength of bonding interface was analyzed, and comprehensive test results and conclusions before, the range of 1.2~ 2mm was recommended as actual construction roughness range.Secondly, standard test of bonding interface tensile splitting strength and on-site simulated test of bonding interface pull-off strength were carried on after the roughness test study. Influence of several main factors to the bonding interface strength was researched, such as interface agent, age of bond, strength classes of concrete , etc.Several respects directly related to quality inspection were especially discussed in this paper. The relationship between diameter of core and pull strength of bonding interface was especially analyzed. And the recommended range of core diameter which is suitable for interface bonding quality inspection in-site test was put out. Conversion relation between bonding interface tensile splitting strength got under the standard maintenance system and bonding interface pull-off strength got under natural maintenance system was studied. And the conversion relation can offer the data support for corresponding method and criterion which are applied in actual project...