Expansive agent, post-tensioned prestressed concrete channel grouting agent and grouting material

Abstract

The invention relates to an expanding agent, a post-tensioning prestressed concrete porelike grouting agent and a grouting material. The expanding agent comprises a nitrogen expanding agent, gypsum and magnesium oxide at a mass ratio of (0.3-0.6):30:(3-15). The post-tensioning prestressed concrete porelike grouting agent comprises the following components in parts by mass: 5-12 parts of water reducing agent, 0.3-0.7 parts of stabilizing agent, 18-60 parts of mineral admixture, 0-15 parts of early strength agent, and 35-50 parts of expanding agent. The invention further provides the post-tensioning prestressed concrete grouting material which comprises portland cement, water and the grouting agent, wherein the mass ratio of the grouting agent to the portland cement is (10-20):(80-90), and a range of the water-binder ratio is 0.26-0.28. In a grouting material slurry hardening process, a continuous and stable expanding effect is generated, so that the grouting material can be tightly bonded with prestressed reinforcements and structural concrete, and the effective transmission of a stress is ensured.

Description

technical field [0001] The invention relates to an expansion agent, a post-tensioning prestressed concrete channel grouting agent and a grouting material, belonging to the field of building materials. Background technique [0002] Prestressed concrete members have the characteristics of high rigidity, high strength, strong shear resistance and good fatigue resistance, which can effectively reduce the structural section size, reduce self-weight, prevent cracking and reduce deflection. be widely used. Prestressed concrete components need to reserve holes during processing to allow prestressed steel bars to pass through, and fill the holes with grout after prestressing the prestressed steel bars, so that the prestressed steel bars can be combined with the structural concrete. They can give full play to their strengths and obtain excellent mechanical and structural properties, but one of the prerequisites is that prestressed tendons must work together with structural concrete a...

AI Technical Summary

Problems solved by technology

Specifically, after Portland cement is hydrated, it is easy to produce chemical shrinkage and plastic shrinkage, which leads to a decrease in expansion stress and affects the expansion performance of the expansion agent; The expansion effect can only be produced by the chemical reaction of the product. When the strength of the hardened press grout slurry is low (or no effective strength stage is formed), the expansion agent expands and still cannot form a large expansion stress, so that the hardened press grout slurry When the strength of the hardened slurry is high, the hydration process of the cement has consumed a large amount of water and formed a large amount of hydration products. At this time, the expansion agent has lost its reaction. The necessary conditions and the space required to form expansion products such as ettringite

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