Method for inhibiting decomposition of sodium gluconate in naphthalene-based superplasticizer for large and medium-sized hydropower engineering

Abstract

The invention relates to a method for inhibiting decomposition of sodium gluconate in a naphthalene-based superplasticizer for large and medium-sized hydropower engineering. A naphthalene-based superplasticizer solution comprises a component A, a component B and a component C, the component A is an inorganic base or a strong base and weak acid salt or a combination thereof, the component B is naphthalene-based superplasticizer powder, the component C is concrete mixing water, and the pH value of the naphthalene-based superplasticizer solution is 8.0-12.0. The preparation method is simple in preparation process, low in raw material price, simple and convenient in addition mode, good in economy, high in practicability and high in operability, and the production cost of the naphthalene-basedsuperplasticizer and the operation cost of a mixing system are hardly increased. The economical efficiency is good, the practicability is high, and the operability is high. The doped inorganic base and strong base and weak acid salt compounds are non-toxic and harmless, the unit dosage is relatively low, the durability such as corrosion, freezing resistance and seepage resistance of concrete reinforcing steel bars is not influenced while the concrete setting time is prolonged and the workability of a mixture is improved, and the method has a wide popularization and application prospect in large and medium-sized hydropower engineering.

Description

technical field [0001] The invention relates to the field of concrete admixtures, in particular to a method for inhibiting the decomposition of sodium gluconate in naphthalene-based high-efficiency water reducers used in large and medium-sized hydropower projects. Background technique [0002] Naphthalene-based water reducer is a chemically synthesized non-air-entraining high-efficiency water reducer. Its chemical name is naphthalenesulfonate formaldehyde condensate. Its consumption accounts for about 70% of the total consumption of water reducers in my country, and it is the largest production volume at present. , The most widely used water reducing agent varieties. Naphthalene-based high-efficiency water-reducing agent has the characteristics of high water-reducing rate (15-20%), relatively good adaptability to cement, can be used in combination with other admixtures, and relatively low price. It can be used to prepare normal, fluid, Cast-in-place concrete and prefabricate...

AI Technical Summary

Problems solved by technology

But its application in concrete will cause the following problems: (1) Casson (3C 4 h 4 ClNOS+C 4 h 5 The content of chlorine element in NOS) is relatively high (mass fraction 19%), and the chloride ions produced by degradation after adding to concrete will have an adverse effect on the corrosion of steel bars in reinforced concrete

(2) Hazardous substances contained in Kason (such as heavy metal lead ions, about 30ppm) will damage human health and pollute the natural environment

(3) Kathon is mainly used in the field of daily chemical industry. At present, there is no systematic research on the influence of Kathon on the mechanical properties and long-term durability of concrete, and there is a lack of theoretical basis for its application in concrete.

(4) The addition of Kathon as a preservative component will increase the production cost of the water reducer

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