| Cracks and local damage may occur in the course of concrete usage.The traditional way of ex post repair has been unable to meet the requirements of modern society.Self repairing technology can solve the technical problems which are difficult to solve by traditional methods,and have long-term significance for ensuring the safety and durability of the project.At present,researches on the selection and the mutual matching of concrete matrix,repair containers and repair adhesive,effects of repair containers on concrete strength and repairing effect still remain in the stage of exploration and experiment.In this paper,the mechanism and experiment of self repairing are studied,which aims to lay a theoretical foundation for popularizing the technology of concrete self repairing.Based on the composite material theory,a mechanical analysis model of interaction between glass tube and component in concrete is established.Considering the factor of glass tube orientation and length,the stress distribution formula of irregular distribution glass tube is deduced by introducing the effective coefficient of irregular distribution of glass tube.Based on the basic principle of elastic fracture mechanics,the theory of fiber spacing is introduced,the expression of glass tube spacing is deduced and the influence of short glass volume rate,diameter,length and distribution mode on short distance of glass is analyzed.According to the mechanism of self repairing concrete,the properties of self repairing adhesive,such as viscosity,flow property,tensile bond strength and flexural bond strength,were tested.According to the test results,modified epoxy resin adhesive was chosen as the repairing adhesive.According to the previous research results from the quartz glass sleeving as repair containers,a self repairing contrast test of concrete cracks without repairing system and two different quantities and layout methods is carried out,and the influence of the number and arrangement of hollow glass tubes on the repair effect of concrete cracks is analyzed.Three groups of self repairing concrete specimens under normal maintenance conditions after curing to maturity were tested for the repair effect.The self repairing effect was tested by the bending strength,the outflow of adhesive in the self repairing container,the way of the adhesive surface of the concrete and the flexural strength after two bonding. |
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