Preparation method of phosphogypsum roadbed material based on high temperature activation and hydraulic hardness improvement

Abstract

The invention proposes a method for preparing a phosphogypsum roadbed material based on high-temperature activation and improved hydraulicity, which relates to the field of roadbed materials. In the present invention, phosphogypsum with a free moisture content of 7%-20% is firstly calcined at high temperature into a high-temperature product, and then the waterproofing agent slurry obtained by mixing silane coupling agent, polyvinyl alcohol and hot water is prepared, and finally the prepared high-temperature The product, waterproofing agent slurry and Portland cement are mixed according to the mass percentage of 85%-93%: 3.5%-5%: 3%-10%, and the phosphogypsum roadbed material is obtained by stirring evenly; , C 3 The mass fraction of mineral A in Portland cement is 2%-5%, and mineral admixtures containing aluminosilicate must not be mixed in Portland cement. The prepared phosphogypsum roadbed material has good strength, water stability and volume stability, and has simple preparation process, low production cost and wide source of raw materials.

Description

technical field [0001] The patent of the present invention relates to the field of roadbed materials, in particular to a method for preparing a phosphogypsum roadbed material based on high-temperature activation and hydraulic enhancement. Background technique [0002] Subgrade materials refer to road construction materials that are located below the base layer of the pavement, bear the vehicle load transmitted from the pavement during the application process, and resist the erosion of various environmental factors (freeze-thaw, drying, aqueous solution penetration, etc.). Roadbed materials should have good strength, water stability and durability. Traditional roadbed materials include natural resources such as pebbles, crushed stones, gravel and clay. With the construction of large-scale transportation facilities in my country, natural resources such as sand and gravel are close to depletion, and the use of clay will destroy vegetation and planting land. Therefore, from the ...

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Problems solved by technology

However, the existing studies only use phosphogypsum as an inert material, and do not utilize and develop the cementation strength of phosphogypsum itself. At the same time, there is a lack of investigation on the long-term volume stability of phosphogypsum roadbed materials, because from the mechanism, The slow hydration reaction between phosphogypsum and the calcium aluminate component in the cementitious material will generate ettringite, a hydration product with swelling capacity, which will cause expansion and damage of roadbed materials during service, endangering engineering quality and traffic safety

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