A prestressed channel grouting agent with self-healing function

Abstract

The invention discloses a prestressed duct grouting agent with a self-repairing function. the grouting agent is composed of the following raw materials, by weight, 5-20% of a high-efficiency water reducer, 0.2-1.0% of a retarder, 0.01-0.2% of a thixotropic agent, 5-20% of a plastic swelling component, 40-70% of a middle- to late-stage swelling component, 5-10% of silica fume , 4-6% of a calcium ion compensation agent, 5-20% of an inorganic salt crystalline precipitating agent, 5-20% of an active catalyst, and 0.05-0.3% of a re-dispersible latex powder. According to the prepared grouting agent, functional components such as a dispersant, a retarder, a thixotropic agent, a capillary crystalline component material, a bonding modifier and the like are compounded based on a slight expansion function. By multifunctional compounding, rheological property of a grouting material is improved and regulated, and volume stability of a paste and mechanical property of a hardened paste are raised. The self-repairing capability of the grouting material is further enhanced, and a permanent self-repairing function of the grouting material is achieved.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a prestressed channel grouting agent with self-repairing function, which is specially used for channel grouting construction of various post-tensioned prestressed concrete beams. Background technique [0002] Post-tensioned prestressed concrete beams are widely used in long-span slab girder structures such as road and railway bridges and high-rise buildings due to their reliable durability. In the beam structure, the grout for the tunnel bears the important task of protecting the prestressed steel bars from harmful ion erosion, and making the prestressed steel bars and the surrounding concrete work together as a whole. Therefore, the performance of tunnel press grout is directly related to the durability of post-tensioned prestressed concrete beams. [0003] In recent years, structural damage events have occurred frequently due to various defects of grouti...

AI Technical Summary

Problems solved by technology

Although some add plastic expansion components, there are various problems. For example, some add aluminum powder, which makes the foam expansion uncontrollable; although some add organic plastic expansion components, most organic foaming agents All can be foamed at a higher temperature, and it is difficult to foam at normal temperature, so a composite catalytic foaming aid is needed to reduce the foaming temperature. In the present invention, the biuret catalytic foaming aid is added to reduce The foaming temperature of the organic blowing agent

[0005] Since the strength development of the grout after hardening of the grouting material always lags behind the strength development of the prestressed concrete beam matrix, the stress difference between the two makes the hardened grout easy to crack, although the expansion function component has a self-healing function on the cracks , but its self-healing function is limited, that is, the self-healing function will be lost as the reaction of the expansion component is consumed. The overall structural durability of stressed concrete beams is greatly improved

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