Experimental Study On Bonding Mechanical Performance Of New And Carbonated Concrete

It needs to clean the carbonated concrete layer firstly when do the traditional new-to-old concrete construction,and the clearing work of the carbonated concrete is very time-consuming,which affects the progress of repairing work seriously.If there is a method that pouring the new concrete directly on the carbonated concrete without removing the carbonated layer,which can save a large amount of manpower and material resources.Then it needs to study the bonding problems between the carbonated and new concrete,the main work in the paper is as follows:(1)Preparation of the high anti-permeability repairing concrete.It designs eight kinds of concrete proportion plan.After testing the mechanics and durability performance and then selecting one to be the new repairing concrete , which is of the right strength,high anti-permeability and high anti-carbonation.(2)Preparation of the anti-carbonation interface agent.It designs thirty-six kinds of inorganic interface agent and seven kinds of organic interface agent proportion plan.Coating the agent on the concrete surface and testing the anti-carbonation performance and then selecting five high anti-carbonation interface agent which applied to the bonding of new and carbonated concrete.(3)Testing the bonding split tensile strength of new and carbonated concrete.It designs five kinds of new and carbonated bonding and four kinds of whole concomitant plan.It gets the bonding split strength growth law of new and carbonated concrete through the test during 90 d,analyses the enhancing reason of bond split tensile strength affected by concrete carbonation,systematically invests the variation of split tensile strength affected by the cement agent,silicon ash agent,water-reducing agent,shrinkage-reducing agent and expansion agent through the test of 7 d,28 d,60 d,90 d,and expounds from the mechanism.(4)Testing the bonding bend strength of new and carbonated concrete.It designs five kinds of new and carbonated bonding and four kinds of whole concomitant plan.It analyses the enhancing reason of bond bend strength affected by concrete carbonation,systematically invests the variation of bend strength affected by the cement agent,silicon ash agent,water-reducing agent,shrinkage-reducing agent and expansion agent through the test of 28 d,and expounds from the mechanism.(5)Testing the bonding incline shear strength of new and carbonated concrete.It designs five kinds of new and carbonated bonding and one kind of whole concomitant plan.It analyses the enhancing reason of bond incline shear strength affected by concrete carbonation ,systematically invests the variation of incline shear strength affected by the cement agent,silicon ash agent,water-reducing agent,shrinkage-reducing agent and expansion agent through the test of 28 d,and expounds from the mechanism.