Bionic self-repairing concrete and preparation method thereof

Abstract

The invention discloses bionic self-repairing concrete and a preparation method thereof. The bionic self-repairing concrete is characterized by being prepared from the following raw materials in partsby weight: 240 to 360 parts of cement, 180 to 250 parts of active admixture, 1300 to 1600 parts of aggregate, 60 to 90 parts of mesoporous bioactive glass composite microspheres, 20 to 30 parts of calcium peroxide microspheres, 20 to 30 parts of carbon nanotubes, 8 to 16 parts of polycarboxylate water reducing agent and 190 to 220 parts of water. The bionic self-repairing concrete provided by theinvention has a rapid self-repairing capability, can continuously and automatically repair micro-cracks or micro-damages of different deep layers in the concrete, promotes the continuous increase ofthe matrix strength after crack repairing, and improves the strength and durability of the concrete. The self-repairing concrete has the advantages of being wide in repairing range, rapid in repairingand lasting in repairing.

Description

technical field [0001] The invention relates to the technical field of building materials, in particular to a bionic self-repairing concrete and a preparation method thereof. Background technique [0002] The inherent defect of high brittleness of concrete materials seriously affects its crack resistance. Microscopic damage such as micro-cracks of the matrix often occurs in actual engineering, and such micro-cracks are usually invisible, let alone repaired. If these damaged parts cannot be repaired in time, it will not only affect the strength and durability of the concrete material, affect the normal performance of the structure and shorten the service life, but also may cause macroscopic cracks and brittle fractures, resulting in serious catastrophic accidents. The repair form of traditional concrete materials is mainly regular maintenance and after-event maintenance. This negative and passive maintenance method is not only expensive, but also ineffective, and it cannot m...

AI Technical Summary

Problems solved by technology

However, the practical application of microbial self-healing concrete still faces many problems, mainly including the following points: 1) Most of the concrete is in a high-alkaline and harsh environment, and the microorganisms are directly mixed into the concrete, and the premature death of the microorganisms fails to exert the repairing effect

2) In the tiny cracks deep in the concrete, the permeability of oxygen and water is not good, and it is difficult for microorganisms to activate in the environment of lack of oxygen and water, and the repair effect cannot be exerted

4) After microbial activation, the metabolic function is restored, and carbon dioxide is produced by respiration. In a humid environment, carbon dioxide reacts with calcium ions in cement-based materials to form calcium carbonate, which is used to fill cracks. Calcium ions, which will lead to a decrease in the stability of the concrete structure

5) Use microcapsules to load microorganisms for repair. Once the microcapsules break and release the microorganisms, they will leave holes in the concrete and reduce the strength of the concrete. Moreover, most of the existing microcapsules are high molecular polymers, which are difficult to degrade in the natural environment of concrete. , whose residues can negatively affect the cementitious matrix

The invention adopts the method of separately immobilizing bacteria, substrates and nutrients, which not only limits the diffusion of bacteria, substrates and products, but cannot guarantee the rapid and sufficient reaction between bacteria and substances, and the mixing of carrier A and carrier B The carrier is directly blended into the concrete as a light aggregate, replacing part of the amount of aggregate, especially the use of coarse aggregate, which will cause greater strength damage to the concrete, although the strength after repair has a certain degree of strength compared to that without treatment. recovery, but it is far from making up for the strength loss caused by the incorporation of the carrier, which limits the application of such cement-based materials in engineering practice

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