Experimental Study On Repair Properties Of Microcapsules Self-repairing Concrete Under Uniaxial Compression

Self-repairing technology of Concrete can intelligently perceive the microscopic-crack and damage inside the concrete structure and repair it in time.The durability and reliability of the concrete structure could be improved,further more the service life of the structure could be prolonged.The micro-capsule self-repair technology rely on its own unique advantage has became the mainstay of self-repair technology.In this paper,the strength and deformation characteristics of self-repair concrete specimens were studied on uniaxial compression test,and the microcapsule size and dosage as the effect factors of the strength and deformation of concrete were studied.The pore structure parameters of the microcapsule self-repaired concrete were got by mercury intrusion test.The influence rules and mechanism of microcapsule content and particle size on the pore structure of concrete were studied.Through the uniaxial compression test before and after the repair of damaged specimens,the strength and deformation recovery ability of the microcapsules’self-repairing concrete specimens was studied.The calculation of the correlation degree was used to obtain the diameter,dosage,damage degree and curing age of the repaired specimens.The influence of the effect has attempted to analyze the influence mechanism of each influencing factor on the repair effect.details as follows:(1)The effect of the microcapsule particle size and content on the initial strength and deformation of the concrete was obtained by stress-strain curve analysis.It was found that the content increased from 5%to 15%and the particle size was 121.66μm to 286.35μm.Compared with ordinary concrete,its strength has decreased by 3.16%to 17.87%,elastic modulus has decreased by 4.70%to 21.11%,and the peak strain of self-repaired specimens increased.Among them,the radial strain was most obvious,and the increment has increased,while dosage and particle size increased.Secondly,the self-repaired curing of the damaged specimens was studied.The self-repairing properties of ordinary concrete specimens and self-healing specimens were studied.Through stress-strain curve analysis,we found that ordinary concrete specimens and microcapsules self-repaired concrete specimens were preserved.After the strength and deformation have been repaired,but the self-healing microcapsule repair effect is far greater than ordinary concrete,this proved the superiority of microcapsule self-repair.(2)The initial pore structure parameters of the self-healing samples were obtained by mercury intrusion test.The test showed that the pore structure parameters(median pore size,porosity,and total pore volume)of the self-healing samples were all larger than those of ordinary samples,this menings that the microcapsules’s amount and the size affect the strength and deformation of the concrete by changing the pore structure of the concrete.(3)In this part,Self-repairing properties of ordinary concrete and Microcapsule Self-repairing Concrete were studied.Through stress-strain curve analysis,we found that ordinary concrete specimens and microcapsules self-repaired concrete specimens pass through After curing,the strength and deformation were repaired,but under the same conditions,the repair rate of Microcapsule Self-repaired specimens were 1.5 to3 times as ordinary concrete samples.This indicates that the microcapsule self-repair system has better repair effect to damage specimens.(4)Damage degree(40%σm,60%σm,80%σ_m),curing age(3d,7d,14d,28d),dosage(0%,5%,10%,15%),particle size(0μm,121.66μm,184.26μm,286.35μm)and the correlation degree of Microcapsule Self-repairing Concrete sample’s strength repair rate,the results show that:the main factors affecting the repair effect of particle size and blending amount.among them,the effect of particle size is the greatest,the effect of blending volume is relatively weak,and the degree of damage and the age of curing affect the reduction once.(5)Considering the effect of the microcapsule size and amount on the concrete’s initial mechanical properties and the repair properties,the analysis shows that:when the amount of microcapsule between 0%and 10%,the particle size of microcapsule between 184.26μm and 286.35μm,the repair rate were great and have little effect on initial mechanics of concrete.