Super plasticizer of polyether for rapid hardening concrete

Abstract

The present invention relates to one kind of super plasticizer of polyether for rapid hardening concrete. The super plasticizer is prepared through the first free radical copolymerization of monomer A in 84-94 wt%, monomer B in 5-15 wt% and monomer C in 1-3 wt% in water-base medium; and the subsequent neutralization reaction of the copolymer and alkoxyl organic amine to regulate the pH value of the copolymer to 6.0-7.5. The super plasticizer has excellent dispersing performance and reinforcing effect, especially obvious early reinforcing effect, and is favorable to raise construction speed and raising the durability of concrete.

Description

technical field [0001] The invention relates to a polyether super-early-strength concrete superplasticizer, which can significantly improve the early strength of concrete without delaying the setting time of cement, and belongs to the technical field of concrete admixtures. Background technique [0002] Compared with traditional polycondensation-type admixtures such as naphthalene and melamine, polycarboxylic acid admixtures have become a worldwide research focus and development focus due to their advantages such as low dosage, good dispersion, and large degree of freedom in molecular structure. It is called the third generation superplasticizer. According to reports, Japanese graft copolymer admixtures have accounted for more than 80% of the total number of high-performance admixture products. Due to the rise of large-scale infrastructure such as nuclear power, water conservancy, bridges, and tunnels in China, especially the planning of the national railway passenger dedica...

AI Technical Summary

Problems solved by technology

Chloride accelerators are the earliest inorganic salt accelerators, which can improve the early strength of concrete, but seriously affect the later strength of concrete, and because they contain Cl - , it is easy to cause depassivation and corrosion of steel bars, and its application is restricted

Sulfate early strength agents are likely to lead to poor performance in the later stage, and "hoarfrost" is easy to precipitate on the surface of the concrete, which affects the appearance, and increases the alkali content in the concrete, which will accelerate the alkali-aggregate reaction

Although alcohol amine accelerators have little effect on the later performance of concrete and have no chloride ions, their addition is difficult to control, which can easily cause serious retardation of concrete and decrease in concrete strength, and its high price has affected its popularity in the concrete industry. Applications

U.S. Patent US4444593 has announced the composite early strength agent of sodium carbonate and ferric sulfate, and Japanese patent JP6005050 has announced the composition of sodium carbonate and aluminum sulfate, and its common feature is: after they are mixed into concrete, improve early strength (1 day Within) the strength at the same time, but the 28-day strength is reduced, so that the impermeability is reduced, which is not conducive to the improvement of durability

[0004] In summary, it is unsatisfactory to use traditional inorganic salts or organic early strength agents to improve the early strength of concrete.

[0005] lower concrete strength

However, the early strength effect of polycarboxylate admixtures currently on the market is not completely satisfactory, especially the development of strength in low temperature environments is slow.

However, when compounding traditional inorganic salts or organic early strength agents into high-efficiency superplasticizers, not only is it easy to delaminate, the storage stability will deteriorate, and the dispersion performance of the superplasticizer will be reduced.

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