Nano-based early strength type compound polycarboxylate water reducer and preparation method thereof

Abstract

The invention provides a nano-based early strength type compound polycarboxylate water reducer. The nano-based early strength type compound polycarboxylate water reducer is prepared from following raw materials in percentage by mass through heating and complexing: 18%-25% of an early strength type polycarboxylic superplasticizer, 2%-5% of a nano-based early strength agent, 0.05%-0.1% of a workability regulator, 1%-3% of a reactive activator, 0.5%-1.5% of a complexing stabilizer, 0.04%-0.1% of a defoaming agent and the balance of water. The invention further provides a preparation method of the nano-based early strength type compound polycarboxylate water reducer. The preparation method is simple, low in raw material cost and widely sourced, the prepared nano-based early strength type compound polycarboxylate water reducer is good in stability, avoids layering, is free of chlorine or sulfate radicals, contains no formaldehyde and has high early strength, air content of concrete is low, water-reducing rate is high, workability and construction performance are good, and effects are remarkable.

Description

technical field [0001] The invention relates to the technical field of special concrete admixtures for pipe piles, in particular to a nano-based early-strength composite polycarboxylate water reducer and a preparation method thereof. Background technique [0002] The recent promotion of national key projects such as "Western Development" and "Belt and Road" has increased the amount of concrete used, and there are more and more requirements for it. One of the important directions is the application of concrete prefabricated components. Such components are not only widely used in projects such as intercity high-speed railways, cross-sea bridges, water supply and drainage, subsea tunnels, and subways, but also the construction of sponge cities, urban underground pipe corridors, and "prefabricated buildings" that the country is now vigorously promoting are all related to prefabricated buildings. components are closely related. Such concrete components require higher early stren...

AI Technical Summary

Problems solved by technology

But at present, to achieve this strength index, it is necessary to adopt steam curing and pressure steaming process. This operation process increases equipment investment and energy consumption. At the same time, the working cycle is longer and the operation process is complicated.

At present, the prefabricated component industry uses more naphthalene-based water reducers. Even if polycarboxylate water reducers are used, ordinary polycarboxylate water reducers are usually compounded with inorganic salts with early-strength properties to achieve early-strength effects. However, it is still difficult to get rid of the process of steaming and steaming

[0003] The patent document with the publication number CN104402288A discloses a calcium silicate hydrate gel solution early strength agent, and its raw material adopts calcium material, silicon material and gel dispersant, because the dispersant used in it is naphthalenesulfonic acid Salt-formaldehyde condensate has limited dispersing effect, so the prepared gel particle size is relatively thick, and the early strength effect is limited. At the same time, the dispersant contains formaldehyde and other substances that are harmful to the human body, and is affected by the rigid structure of naphthalene-based water reducers. The formed substance is not an intercalation substance, and the intercalated nanomaterial will have a better early strength effect

The patent documents with publication numbers CN105585286A and CN103724557A respectively disclose an early-strength polycarboxylate water reducer. The structure of the water reducer prepared by it has amino cations, but the preparation process is relatively complicated and the cost is relatively expensive.

In the patent documents whose publication numbers are CN106007452A and CN103373831A, sodium sulfate and thiocyanate are used as inorganic early-strength agents and polycarboxylate water-reducers to compound, so that they have early-strength effects, and the content of thiocyanate in cement There are strict restrictions. Thiocyanate has great side effects on the human body, and the use of sulfate as an early-strength material has a negative effect on the later durability of concrete.

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