Experimental Study On Principle Of Self-repairing Concrete With Thin-walledalumina Bubbles

Self-repairing concrete, belonging to the intelligent concrete, not only can minimize themaintenance cost and the labor intensity of the concrete structure effectively, but also can takeactive prevention to the concrete damage. In addition, it can prolong the service life ofconcrete structures. This paper starts the experimental research on self-repairing concrete withthe steel fiber reinforced concrete as the substrate, epoxy resin adhesive as the healing agentfor self-repairing concrete and alumina bubbles as the storage container.The self-repairing properties of concrete depend on the viscosity of epoxy resin andcuring agent and final strength. The viscosity of epoxy resin and curing agent decreased andtheir mobility increased with increasing the amount of acetone, which is conducive tointegration of epoxy resins and curing agents and cracks filled. however, when the usage ofacetone exceeds appropriate value, the curing time of the adhesive system will be extended ornot even cured. The results of tests show that resin, reactive diluent, curing agent and acetoneratio of1:0.3:1:0.2(mass ratio) is reasonable.Thin-walled alumina bubbles containing resin or curing agent were respectively preparedby vacuum process and the surfaces of balls sealed with a clay. Self-repairing concretespecimens were made by same mass of steel fiber reinforced concrete for the matrix andadded with different mass repair balls. The mechanical properties and self-repairing propertiesof the self-repairing concrete were investigated. The results show that the recovery rate offlexural strength increase and the flexural strength and compressive strength decrease with theincreasing amount of embedded alumina bubbles. Comprehensive consideration draw aconclusion that the optimal amount of steel fiber is1.5wt.%, and the optimal mixing amountof the repairing balls is9wt.%.