High-volume phosphogypsum composite stable roadbed material and preparation method thereof

Abstract

The invention discloses a high-volume phosphogypsum composite stable roadbed material and a preparation method thereof, and belongs to the technical field of highway construction materials. The roadbed material comprises the following components by weight percentage: 90-95% of phosphogypsum, 1-6% of a curing agent, 1.5-4% of a curing accelerator and 2-4% of water; the curing agent comprises Portland cement, superfine steel slag powder and blast furnace slag powder; the curing accelerator comprises water glass and a cationic styrene-acrylic emulsion. Through the synergistic effect of all the components of the curing accelerator, soluble P and F in the phosphogypsum can be effectively cured, early hydrolysis is promoted, the gelling activity of the phosphogypsum with the Portland cement andthe like is enhanced, an electronegative product generated in the modification process can be chemically bonded with cationic styrene-acrylic emulsion, the binding power between the raw materials is enhanced, and the mechanical strength of the material is improved; and secondly, under the bridging action of the electronegative product, the cationic styrene-acrylic emulsion can be firmly coated onthe surface of the phosphogypsum and the like to prevent the phosphogypsum from being dissolved in water, thereby enhancing the water stability.

Description

technical field [0001] The invention relates to the technical field of road construction materials, in particular to a large-volume phosphogypsum composite stable roadbed material and a preparation method thereof. Background technique [0002] With the rapid development of the phosphate fertilizer industry, according to incomplete statistics, the country currently produces about 30 million tons of industrial by-product phosphogypsum every year, and this figure is growing at a rate of 15% every year. How to effectively deal with a large amount of stockpiled phosphogypsum has become an urgent problem in our country and even in the world. The use of phosphogypsum in road construction can not only consume a large amount of phosphogypsum, but also reduce the cost of road construction and relieve environmental pressure. The application of phosphogypsum in highway construction mainly includes being used as roadbed filler and modified fly ash-stabilized pavement base material. How...

AI Technical Summary

Problems solved by technology

However, the above-mentioned phosphogypsum highway base material contains phosphogypsum. After the phosphogypsum is ground, it will release a large amount of soluble P and F, which can easily interact with the surrounding calcium ions to form calcium phosphate, calcium fluoride and other hydroxyapatite. The insoluble matter of the structure is deposited on the surface of the phosphogypsum particles, causing the hydration to be hindered, causing severe retardation, and the prolongation of the setting time will lead to a slightly lower early strength of the concrete, so it takes a longer time to reach a higher strength

In addition, Chinese Patent No. CN201210121568.X discloses a road subgrade filler and its preparation method, which is prepared from lime, fly ash, phosphogypsum and stabilizer raw materials; each raw material in lime, fly ash and phosphogypsum The percentage by weight is: 4-15% of lime, 30-50% of fly ash, 35-60% of phosphogypsum, and the sum of the weight percentages of each raw material is 100%; the stabilizer is water glass or NaAlO 2 , the amount of water glass added is 2-6% of the total mass of lime, fly ash and phosphogypsum, NaAlO 2 The added amount of lime, fly ash and phosphogypsum is 0.5-2% of the total mass; it also has the problem of low early strength, and the formed road matrix is ​​too rigid, which is easily affected by temperature and humidity and cracks, resulting in crack resistance Poor performance and poor water stability, can not be immersed in water for a long time, otherwise it will cause serious strength loss

In addition, the content of phosphogypsum in the above patents is low and the economic benefits are poor. Therefore, it is still of great significance to develop a phosphogypsum stable roadbed material with a higher content of phosphogypsum and higher strength.

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