Summer delayed coagulation type high-performance structural adhesive and preparation method thereof

Abstract

The invention provides a summer delayed coagulation type high-performance structural adhesive and a preparation method thereof. The summer delayed coagulation type high-performance structural adhesivecomprises epoxy resin, silica powder, nano calcium carbonate, chopped carbon fibers, modified graphene, polyamide, aromatic amine and a silane coupling agent. The preparation method comprises the following steps: mixing and stirring epoxy resin, silica powder, nano calcium carbonate, chopped carbon fibers, modified graphene and a silane coupling agent to prepare a mixture A; mixing and stirring polyamide, aromatic amine, silica powder and chopped carbon fibers to obtain a mixture B; stirring the mixture A and the mixture B in the step 1 according to the mass ratio is 2:1, and putting the material into a closed container for vacuum-pumping and bubble-removing treatment to obtain the high-performance structural adhesive. The high-performance structural adhesive has the advantages of being high in bonding strength, good in weather resistance and durability, long in construction working life in a high-temperature environment, free of sagging, good in thixotropy, high in strength, environmentally friendly, convenient to construct and the like, has certain rigidity and toughness, has good market prospects and is suitable for popularization.

Description

technical field [0001] The invention relates to the technical field of bridge structural adhesives, in particular to a summer slow-setting high-performance structural adhesive and a preparation method thereof. Background technique [0002] In the process of bridge construction and use, the problems related to concrete cracks affecting the quality of the project are more prominent. Bridge concrete cracking can be said to be a "common disease" and "frequent disease", which poses a safety hazard to the operation of the expressway. If it is not repaired, it will cause internal steel reinforcement corrosion, reduce service life, and even lead to damage and collapse of the overall structure. According to the cause and development degree of cracks, the treatment methods mainly include structural reinforcement method and crack closure method. In these two methods to deal with cracks, structural adhesive is mainly used as the connection between the reinforcement material and the rein...

AI Technical Summary

Problems solved by technology

[0003] For structural adhesives used as a connecting agent between the reinforcement material and the reinforced structure, there are mainly the following problems: (1) The mechanical properties of structural adhesives are not high, especially the bonding performance

According to the actual engineering research, in the current strengthening methods such as pasting carbon fiber cloth, pasting carbon fiber plate, pasting prestressed carbon fiber plate and pasting steel plate, before the mechanical properties of the reinforced material are fully exerted, the reinforcement system is due to the failure of the structural adhesive. damage, resulting in a great waste of reinforcement material strength

(2) The weather resistance and durability of the structural adhesive are poor, and the construction performance is poor

High sensitivity to temperature, easy to crystallize at low temperature, easy to hang at high temperature, especially in summer high temperature environment (>30°C), the bridge concrete surface is exposed to the sun for a long time, the temperature can reach 50°C, the structural adhesive is prone to flow, resulting in construction Increased difficulty and easy waste of materials

(3) Insufficient application period for summer construction

It usually takes 60 minutes for structural adhesives to be prepared, glued, spliced ​​and applied. However, bridge concrete is mostly reinforced outdoors. In addition to the time of transportation, the service life is required to be longer. Currently, the gelation time of structural adhesives on the market is seriously affected by the ambient temperature. Under high temperature construction conditions in summer, the curing rate is fast (pot life <30min), resulting in insufficient operating time, which seriously wastes materials and affects construction progress

(4) The waterproof and anti-corrosion performance of the structural adhesive is weak, and it cannot provide effective protection for the steel bars inside the structure

Since the working environment of the structural adhesive is usually in the wild, it is greatly affected by external factors such as ultraviolet rays, rain and snow. The weak waterproof and anti-corrosion performance of the structural adhesive will cause the performance of the structural adhesive to degrade or even fail, and at least affect the durability of the reinforced structure and the reinforced system. security, and seriously threaten the security of the structure

(5) The structural adhesive is brittle and brittle after curing and lacks toughness

The current structural adhesives usually introduce rigid structures such as benzene rings, biphenyls and fused rings, which help to improve the rigidity of the resin skeleton, but the cured resin products are relatively brittle and have a high risk of brittle failure. If such adhesives are used on the surface of concrete structures Structural adhesives are used as interface agents, which can easily cause joint damage when subjected to strong stress, resulting in failure of reinforcement.

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