CN115196936A

CN115196936A - Gypsum-based indoor terrace self-leveling concrete prepared from phosphogypsum active powder and preparation method and application thereof

Info

Publication number: CN115196936A
Application number: CN202210851519.5A
Authority: CN
Inventors: 何松涛; 陈忠华; 宋维相; 李泽钢; 徐虎; 徐韦洪; 朱国飞; 卢云; 郗权; 刘洪波; 郑方龙; 张燕; 王琴; 何海; 项军; 龙森林; 王静峰; 刘功高; 李志刚; 郭子民
Original assignee: Guizhou Phosphate Green Environmental Protection Industry Co ltd
Current assignee: Guizhou Phosphate Green Environmental Protection Industry Co ltd
Priority date: 2022-07-19
Filing date: 2022-07-19
Publication date: 2022-10-18

Abstract

The invention discloses gypsum-based indoor terrace self-leveling concrete prepared from phosphogypsum active powder, which is prepared by mixing compound phosphogypsum active powder, an additive, sandstone and water according to the following weight part ratio: 300 to 580 parts of compound phosphogypsum active powder, 5 to 14 parts of additive and 1500 to 1900 parts of sandstone; the compound phosphogypsum active powder is prepared by mixing phase gypsum and alpha-type high-strength gypsum according to 1:1-1:3 or phosphorus building gypsum and alpha-type high-strength gypsum according to 1:1-1:4. The compounded phosphogypsum active powder is used as a main raw material, the prepared self-leveling concrete has strong fluidity, does not need to be spread and vibrated in the construction process, can reach the compactness required by construction by the self fluidity, has the effects of early strength, self-leveling, self-compaction, no shrinkage and micro-expansion, low cost and environmental protection, and can achieve the aims of saving energy, reducing carbon and reducing cost.

Description

Gypsum-based indoor terrace self-leveling concrete prepared from phosphogypsum active powder and preparation method and application thereof

Technical Field

The invention belongs to the technical field of building concrete materials, and particularly relates to gypsum-based indoor terrace self-leveling concrete prepared from phosphogypsum active powder, and a preparation method and application thereof.

Background

Concrete (Concrete) refers to the generic term for engineered composites where aggregate is consolidated into a whole by cementitious materials. Concrete generally refers to cement as a cementing material, and granular materials such as sand, stone and the like as aggregates (aggregates); the cement concrete is also called as common concrete and is obtained by mixing the cement concrete with water (which can contain additives and admixture) according to a certain proportion and uniformly stirring. The concrete has the characteristics of rich raw materials, low price and simple production process, so that the consumption of the concrete is increased more and more. Meanwhile, the concrete also has the characteristics of high compressive strength, good durability, wide strength grade range and the like. These characteristics make it very widely used, not only in various civil engineering, but also in shipbuilding, machinery, ocean development, geothermal engineering, etc., and concrete is also an important material.

Self-leveling concrete can quickly, economically and effectively obtain a level, firm or decorative ground, generally consists of cement, mineral powder, fine aggregate, coarse aggregate, an expanding agent, an additive and water, does not need manual paving and vibrating leveling, and automatically flows to form a level surface by virtue of the high fluidity of slurry. The self-leveling concrete has high fluidity, high cohesiveness, high water-retaining property and micro-expansibility, can ensure that the concrete can flow automatically and be compactly molded, can ensure that the concrete does not generate segregation phenomenon in the flowing and parking processes, and can ensure that the surface of the concrete does not have bleeding and does not shrink in the hardening process.

The main component of the phosphogypsum is dihydrate gypsum (CaSO) ₄ ·2H ₂ O), the particle diameter is generally 5-50 μm, the content of crystal water is 20% -25%, the particle is a solid byproduct generated in the wet-process phosphoric acid production process, the particle is a waste for preparing phosphate fertilizer, and 4-5 tons of phosphogypsum can be generated when 1 ton of phosphorus pentoxide is produced. The composition of the phosphogypsum is complex, besides calcium sulfate, incompletely decomposed phosphorite, residual phosphoric acid, fluoride, acid insoluble substances, organic matters and the like exist, and the existence of fluorine and the organic matters has the greatest influence on the resource utilization of the phosphogypsum. The annual discharge amount of phosphogypsum in China exceeds 7500 million tons, the resource utilization rate is less than 50 percent, the random discharge and accumulation of the phosphogypsum not only occupies land resources, but also seriously destroys the ecological environment, and impurities such as phosphorus, fluorine and the like in the phosphogypsum can enter soil along with the washing of rainwater, thereby polluting the soil and underground water. The phosphogypsum can be used as a building material, and opens up a road for the comprehensive application of the phosphogypsum.

Comprehensive utilization of phosphogypsum is very common, the resource utilization approach of the phosphogypsum at present is mainly used for producing various products such as building gypsum powder, gypsum mortar, building wallboard and batten, cement retarder, cement, silicon-calcium-potassium-magnesium fertilizer and the like, and the market coverage area of the products is limited due to the lower added value of the products and the limitation of the transportation radius, so that the recycling amount of the phosphogypsum is limited. Along with the continuous improvement of various requirements of China and the construction industry on construction, quality, environmental protection, heat preservation, sound insulation and the like of buildings, the traditional building materials also face great opportunities and challenges, particularly, the traditional floor leveling concrete material and the construction process thereof are relatively backward, the construction process difficulty is high, the leveling is difficult, the strength of a finished product after construction is low, hollowing and cracking are easy to occur, the moisture resistance is poor, a series of problems that bubbles, raised yellow sand, honeycomb pitted surface and the like are easy to form on the surface and are difficult to effectively solve are solved, and the resource consumption of the traditional concrete product on the natural yellow sand is huge. Therefore, a concrete material having the characteristics of self-leveling, self-compaction, strong hardness and the like and a construction process thereof are urgently needed, the material quality is ensured, the requirements of safety and environmental protection are met, the economic benefit is improved, the use of natural resources and the utilization of waste resources can be greatly reduced, and the energy conservation and the environmental protection are realized.

The gypsum-based self-flowing concrete is a novel concrete building material prepared by elaborately preparing and uniformly mixing gypsum materials, special aggregates and various building chemical additives in a factory, has good fluidity and stability, is a floor material capable of automatically leveling the floor, does not need to be leveled by external force, has high early strength, high construction speed and low labor intensity, and is an important development direction of the floor construction of modern buildings. At present, there are some publications on the preparation of gypsum-based self-leveling concrete materials using phosphogypsum:

1. patent application CN201910540915.4 discloses a phosphogypsum heat-preservation self-leveling material and a preparation method thereof, and the raw materials comprise: modifying phosphogypsum; the modified phosphogypsum is the mixture of phosphogypsum and zeolite powder. The modified phosphogypsum is obtained by mixing phosphogypsum and zeolite powder and neutralizing acid in the phosphogypsum by zeolite. In addition, the self-leveling material can also comprise sand, cement, heavy calcium carbonate, rubber powder, a water reducing agent, a water retaining agent, a retarder and a defoaming agent. The preparation method of the self-leveling mortar is simple, can be directly used for preparing the heat-preservation self-leveling mortar, has good mortar flow leveling property and short time for people to get on, and can replace a composite heat preservation layer, a pea concrete layer and a leveling layer when being applied to a floor heating system, thereby simplifying the installation process and the cost of the existing floor heating system.

2. Patent application CN201910674995.2 discloses a novel water-resistant gypsum-based self-leveling material, which comprises the following raw materials in parts by weight: 300 to 500 portions of semi-hydrated gypsum, 100 to 150 portions of calcium hydroxide, 30 to 45 portions of soluble carbonate, 100 to 200 portions of active silica-alumina powder, 250 to 450 portions of dry sand, 10 to 20 portions of instant soluble water glass and 2.5 to 38.5 portions of concrete additive. According to the method, calcium hydroxide powder is added into a gypsum base material, soluble carbon salt is doped to provide carbonate for the carbonization of the calcium hydroxide, the calcium hydroxide is promoted to be quickly carbonized to generate calcium carbonate crystals insoluble in water, so that the water resistance of the gypsum base material is quickly improved, a part of strong base is generated while the calcium carbonate crystals are generated, and the strong base and water glass are compounded to effectively promote the polymerization reaction of active silicon-aluminum powder to generate high-strength reticular silicon-aluminum tetrahedrons, also called geopolymeric cement, so that the later-stage water resistance and the strength of the gypsum base material are continuously improved.

3. Patent application CN202210100638.7 discloses a high-strength thick-layer silica sol self-leveling concrete, which comprises the following formula raw materials in proportion: 250-350 kg of double-fast cement, 600-800 kg of desulfurized building gypsum, 0.3-0.7 kg of cellulose, 2-8 kg of sodium silicate, 5-15 kg of silica fume, 2-8 kg of silica sol, 2-8 kg of water reducing agent, 0.2-0.6 kg of flatting agent, 1-3 kg of retarder, 800-1200 kg of river sand, 800-1200 kg of melon seed pieces and 1-5 kg of iron black.

However, in the prior art, the self-leveling concrete is usually prepared by taking phosphogypsum as a filler, taking cement, fly ash or other active materials as a cementing material and adding an additive, so that the formed concrete can generate larger expansion in the later period to cause cracks; the concrete prepared by directly using the calcined phosphogypsum has low softening coefficient, poor moisture resistance, poorer construction performance than cement concrete and high cost although the strength is achieved without modification treatment. Moreover, most of the existing self-leveling concrete only adopts one modified phosphogypsum, the prepared self-leveling concrete has poor fluidity, needs to be paved and vibrated during construction, cannot reach the compactness required by construction by the self fluidity, and improves the construction difficulty.

Disclosure of Invention

The invention provides gypsum-based indoor terrace self-leveling concrete prepared from phosphogypsum active powder and a preparation method and application thereof to solve the technical problems. The compounded phosphogypsum active powder is adopted as a main raw material, the prepared self-leveling concrete has strong fluidity, does not need to be paved and vibrated in the construction process, can reach the compactness required by construction by the self fluidity, reduces the construction difficulty and lightens the labor intensity of workers.

In order to achieve the above purpose, the invention adopts the following technical scheme:

the gypsum-based indoor floor self-leveling concrete prepared from the phosphogypsum active powder is prepared from compound phosphogypsum active powder, an additive, gravel and water, wherein the compound phosphogypsum active powder, the additive and the gravel are mixed according to the following weight parts: 300 to 580 parts of compound phosphogypsum active powder, 5 to 14 parts of additive and 1500 to 1900 parts of sandstone; the compound phosphogypsum active powder is prepared by mixing phase gypsum and alpha-type high-strength gypsum according to 1:1-1:3 or phosphorus building gypsum and alpha-type high-strength gypsum according to 1:1-1:4.

Further, the compound phosphogypsum active powder is mixed-phase gypsum calcined at 230-500 ℃, the phase composition of the compound phosphogypsum active powder is that the anhydrous content of the third gypsum is less than or equal to 5 percent, the composition of the compound phosphogypsum active powder is that the anhydrous content of the second gypsum is more than or equal to 20 percent, the content of the beta-type semi-hydrated gypsum is more than or equal to 60 percent, the content of the dihydrate gypsum is less than or equal to 5 percent, the initial setting time is more than or equal to 10min, the final setting time is less than or equal to 120min, the bending and compression strength of 2h reaches more than 2.5MPa and 6.0MPa respectively, and the bending and compression strength of 28d reaches more than 4.0MPa and 15.0MPa respectively; the special medicament is prepared by compounding a trapping agent, an inhibitor and an activator, and specifically comprises the following raw materials in parts by weight: 80-90 parts of trapping agent, 10-20 parts of inhibitor and 2-10 parts of activating agent; the trapping agent is composed of an inorganic acid regulator, a modified fatty acid collecting agent and an ethioamine ester auxiliary agent, and specifically comprises the following raw materials in parts by weight: 60-80 parts of inorganic acid regulator, 20-40 parts of modified fatty acid and 5-10 parts of ethioamine ester auxiliary agent; the inhibitor is prepared by compounding humic acid, calcium hydroxide, sulfonated phenol tar and an L-type organic inhibitor, and specifically comprises the following raw materials in parts by weight: 40-70 parts of humic acid, 10-20 parts of calcium hydroxide, 5-20 parts of sulfonated phenol tar and 2-6 parts of L-shaped organic inhibitor; the activating agent is composed of water glass, aluminum sulfate, ammonium salt, oxalic acid and organic silicon, and specifically comprises the following raw materials in parts by weight: 60-80 parts of water glass, 10-25 parts of aluminum sulfate, 5-20 parts of ammonium salt, 10-20 parts of oxalic acid and 3-7 parts of organic silicon.

Furthermore, the mixed phase gypsum is gypsum calcined at 230-500 ℃, the phase composition of the mixed phase gypsum is anhydrous III type (AIII) gypsum with the content less than or equal to 5%, anhydrous II type (AII) gypsum with the content more than or equal to 20%, beta type semi-hydrated gypsum with the content (HH) more than or equal to 60%, dihydrate gypsum with the content less than or equal to 5%, the initial setting time of the mixed phase gypsum is more than or equal to 10min, the final setting time is less than or equal to 120min, the bending and compression strength of 2h respectively reaches more than 2.5MPa and 6.0MPa, and the bending and compression strength of 28d respectively reaches more than 4.0MPa and 15.0 MPa.

Furthermore, the alpha-type high-strength gypsum is alpha-type high-strength gypsum produced by crystallization at the temperature of 120-150 ℃ and the pressure of 0.13-0.50 MPa, and comprises the components of alpha-type semi-hydrated gypsum (HH) content of more than or equal to 70 percent, dihydrate gypsum (DH) content of less than or equal to 5 percent, initial setting time of more than or equal to 10min, final setting time of less than or equal to 40min, bending strength of 2h of more than 4.5MPa, and drying compressive strength of more than 40.0 MPa.

Furthermore, the phosphorous building gypsum is produced at the low temperature of 110-170 ℃, and comprises the components of beta-type semi-hydrated gypsum (HH) more than or equal to 80 percent, dihydrate gypsum (DH) less than or equal to 5 percent and anhydrous tri (AIII) less than or equal to 8 percent, wherein the initial setting time is more than or equal to 3min, the final setting time is less than or equal to 9min, and the bending and compression strengths of 2h reach more than 3.0MPa and 6.

Furthermore, the sand rate of the sand stone is controlled between 35 percent and 45 percent, the water-cement ratio is designed to be 0.30 to 0.40, namely the water accounts for 30 to 40 percent of the compound phosphogypsum active powder; the sand stone is prepared by shaping and screening according to a certain gradation, the sand stone has uniform size and complete particle type, the content of needle-shaped particles in the shaped sand stone is reduced, the content of cubic particles is more than or equal to 98 percent, the content of stone powder is less than or equal to 0.5 percent, the content of broken stone with particle size distribution of more than 31.5mm is 0, the content of 30 percent in the particle size distribution of 19.0-31.5 mm, and the content of 70 percent in the particle size distribution of 9.5-19.0 mm; the sand and stone mud content is less than or equal to 1.0 percent; the sand stone contains more than or equal to 90 percent of cubic sand particles, less than or equal to 2.0 percent of stone powder, less than or equal to 1.4 percent of mud, and the fineness modulus is between 2.1 and 3.2.

Further, the additive is composed of the following raw materials in parts by weight: 3 to 12 parts of water reducing agent, 2 to 7 parts of retarder, 3 to 6 parts of lubricant, 3 to 10 parts of waterproof agent, 1 to 3 parts of pumping aid and 1 to 5 parts of modification reinforcing agent.

Further, the water reducing agent is polycarboxylate ethers or other materials suitable for phosphorous building gypsum; the retarder is protein, inorganic salt or multifunctional other materials suitable for the phosphorous building gypsum; the lubricant is magnesium aluminum sulfate; the waterproof agent is paraffin, modified organic silicon or other materials which are used in ardealite products and can improve the fluidity and the waterproof performance; the pumping agent is modified calcium lignosulfonate or other specially-made organic high polymer materials capable of improving the activity dispersibility and the flowability of the phosphogypsum; the modified reinforcing agent is cement, lime calcium, silicon steel element, aluminum hydroxide, calcium aluminate, aluminum metasilicate, calcium oxalate or other materials capable of enhancing the strength and hardness of the phosphogypsum active powder.

Further, the water reducing agent is modified polycarboxylate ether, the retarder is a protein material, the lubricant is magnesium aluminum sulfate, the waterproof agent is modified organic silicone oil, the pumping agent is modified calcium lignosulfonate, and the modification reinforcing agent is a meta-aluminum silicate material.

Further, the preparation method of the gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder comprises the steps of putting the compounded phosphogypsum active powder and the additive into a stirrer in proportion and stirring uniformly, then putting the sandstone and water into the stirrer in proportion and stirring uniformly, and measuring the slump and the extensibility of the concrete to be qualified to obtain the gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder.

Further, the gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder is qualified when the slump is more than 250mm and the extensibility is more than 650 mm.

Further, the gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder and prepared by the preparation method is applied to indoor terrace construction.

The phosphogypsum is calcined, modified and the like to form phosphogypsum active powder with certain gelling property, the phosphogypsum active powder is prepared with reshaped sandstone according to a certain proportion and supplemented with additives such as a water reducing agent, a retarder, a lubricating waterproof agent, a pumping agent, a modification reinforcing agent and the like, and after water is added according to a certain proportion and processed by adopting a traditional concrete stirring process, the phosphogypsum active powder can be pumped or manually unloaded to a required construction operation surface by a pump truck without spreading and vibration and reaches the compactness required by construction by virtue of self fluidity.

The construction method of the gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder comprises the following steps:

(1) Indoor terrace basic unit is handled: paving a gravel cushion on the ground according to the design requirement;

(2) The preparation of gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder comprises the following steps: putting the phosphogypsum and the additive into a stirrer in proportion and stirring uniformly, then putting the sandstone and water into the stirrer in proportion and continuously stirring uniformly to obtain gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder;

(3) And (3) determination: taking a gypsum-based indoor terrace self-leveling concrete sample prepared from the phosphogypsum active powder in the step (2) and measuring the slump and the expansibility of the sample;

(4) The gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder and qualified by determination is unloaded to a required construction working surface by pumping or manpower, the compactness required by construction is achieved by the self-fluidity, and the self-leveling concrete is naturally cured for 14 days at normal temperature without spreading and vibration.

Further, in the step (2), the mixing and stirring time of the phosphogypsum and the additive is 2-3 min, and the mixing and stirring time of adding the sandstone and the water is 1-2 min.

Further, in the step (1), the thickness of the gravel cushion layer is 10-15 cm.

A construction surface structure of gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder and prepared by the construction method comprises a gravel cushion layer and a gypsum-based indoor self-leveling concrete layer which are sequentially paved on an indoor ground base layer from bottom to top; the broken stone cushion layer is graded broken stone blocks, and the paving thickness is 10-15 cm; the gypsum-based indoor self-leveling concrete layer is a gypsum-based indoor terrace self-leveling layer prepared from phosphogypsum active powder and paved with self-leveling concrete.

After the phosphogypsum is added with a special medicament for washing and flotation, the chemical composition of the phosphogypsum is superior to the requirement of a first-grade product in GB/T23456; then drying, calcining at low temperature or high temperature, and grinding to obtain phosphogypsum active powder with 2h flexural strength and 6.0MPa (GB/T9776) respectively, wherein the later strength of the material can be continuously increased, and the 28d compressive strength can be more than 10.0 MPa.

The sandstone is shaped, sharp surfaces of common sandstone are ground by a sandstone shaping machine, and the sandstone with uniform size and complete grain type is formed by screening, the shaped sandstone reduces the content of needle-shaped particles, reduces the content of irregular polygon, improves the sphericity of broken stone particles, has the cube content of 98 percent, contains less stone powder, has no fine grains or segregation of coarse and fine particles, and has adjustable fineness modulus or gradation; the gypsum-based indoor floor self-leveling concrete prepared from the phosphogypsum active powder can effectively improve the fluidity of the concrete.

The ardealite and the shaped sandstone are prepared, are uniformly mixed with additives, are added with water and are processed by adopting the traditional concrete stirring process, and are pumped or manually unloaded to a required construction operation surface by a pump truck without spreading and vibration, and the compactness required by construction is achieved by the self-fluidity.

Due to the adoption of the technical scheme, the invention has the following beneficial effects:

the gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder has strong flowability, and is capable of automatically leveling without vibration during construction, the slump of the terrace after construction is more than 250mm, the expansibility is more than 650mm, the 1d compressive strength can reach more than 10.0MPa, and the 14d natural curing can meet the requirement of design strength, so that the gypsum-based indoor terrace self-leveling concrete has the effects of early strength (14 d not only reaches the required design strength), self-leveling, self-compaction, no shrinkage (micro-expansion, and the 14d expansion rate can reach 0.5 ten thousandth), no need of curing (under natural construction conditions, no need of water spraying, film covering and other manual curing), low cost (lower than traditional cement concrete), environmental protection (energy conservation and carbon reduction), and can achieve the aims of energy conservation, carbon reduction and cost reduction.

Detailed Description

The following is a detailed description of the embodiments of the present invention, but the present invention is not limited to these embodiments, and any modifications or substitutions in the basic spirit of the embodiments are included in the scope of the present invention as claimed in the claims.

Example 1

The gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder is prepared from compound phosphogypsum active powder, an additive, sandstone and water, wherein the compound phosphogypsum active powder, the additive and the sandstone are mixed according to the following weight parts: 300 parts of compound phosphogypsum active powder, 10 parts of additive and 1700 parts of sandstone; the compound phosphogypsum active powder is prepared from mixed-phase gypsum and alpha-type high-strength gypsum according to 1:1.

Further, the compound phosphogypsum active powder is mixed-phase gypsum calcined at 230-500 ℃, the phase composition of the compound phosphogypsum active powder is that the anhydrous content of the third gypsum is less than or equal to 5 percent, the composition of the compound phosphogypsum active powder is that the anhydrous content of the second gypsum is more than or equal to 20 percent, the content of the beta-type semi-hydrated gypsum is more than or equal to 60 percent, the content of the dihydrate gypsum is less than or equal to 5 percent, the initial setting time is more than or equal to 10min, the final setting time is less than or equal to 120min, the bending and compression strength of 2h reaches more than 2.5MPa and 6.0MPa respectively, and the bending and compression strength of 28d reaches more than 4.0MPa and 15.0MPa respectively; the special medicament is prepared by compounding a trapping agent, an inhibitor and an activator, and specifically comprises the following raw materials in parts by weight: 80 parts of trapping agent, 10 parts of inhibitor and 2 parts of activating agent; the trapping agent is composed of an inorganic acid regulator, a modified fatty acid collecting agent and an ethioamine ester auxiliary agent, and specifically comprises the following raw materials in parts by weight: 60 parts of inorganic acid regulator, 20 parts of modified fatty acid and 5 parts of ethionamide auxiliary agent; the inhibitor is prepared by compounding humic acid, calcium hydroxide, sulfonated phenol tar and an L-type organic inhibitor, and specifically comprises the following raw materials in parts by weight: 40 parts of humic acid, 10 parts of calcium hydroxide, 5 parts of sulfonated phenol tar and 6 parts of L-shaped organic inhibitor; the activating agent is composed of water glass, aluminum sulfate, ammonium salt, oxalic acid and organic silicon, and specifically comprises the following raw materials in parts by weight: 80 parts of water glass, 25 parts of aluminum sulfate, 20 parts of ammonium salt, 20 parts of oxalic acid and 7 parts of organic silicon.

Furthermore, the mixed phase gypsum is gypsum calcined at 230-500 ℃, the phase composition of the mixed phase gypsum is that the content of anhydrous III type (AIII) gypsum is less than or equal to 5%, the content of anhydrous II type (AII) gypsum is more than or equal to 20%, the content of beta type semi-hydrated gypsum (HH) is more than or equal to 60%, the content of dihydrate gypsum (DH) is less than or equal to 5%, the initial setting time of the mixed phase gypsum is more than or equal to 10min, the final setting time is less than or equal to 120min, the 2h flexural and compressive strengths respectively reach more than 2.5MPa and 6.0MPa, and the 28d flexural and compressive strengths respectively reach more than 4.0MPa and 15.0 MPa; the alpha-type high-strength gypsum is produced by crystal transformation at the temperature of 120-150 ℃ and the pressure of 0.13-0.50 MPa, and comprises the components of alpha-type semi-hydrated gypsum (HH) content of more than or equal to 70 percent, dihydrate gypsum (DH) content of less than or equal to 5 percent, initial setting time of more than or equal to 10min, final setting time of less than or equal to 40min, bending strength of 2h reaches more than 4.5MPa, and drying compressive strength is more than 40.0 MPa; the phosphorous building gypsum is produced at the low temperature of 110-170 ℃, and comprises the components of beta-type semi-hydrated gypsum (HH) content of more than or equal to 80 percent, dihydrate gypsum (DH) content of less than or equal to 5 percent, anhydrous tri (AIII) content of less than or equal to 8 percent, initial setting time of more than or equal to 3min, final setting time of less than or equal to 9min, and bending and compression strengths of 2h respectively reaching more than 3.0MPa and 6.

Furthermore, the sand rate of the sand stone is controlled between 35 and 45 percent, the water-glue ratio is designed to be 0.30 to 0.40, namely the water accounts for 30 to 40 percent of the compound phosphogypsum active powder; the sand stone is prepared by shaping and screening according to a certain gradation, the sand stone has uniform size and complete particle type, the content of needle-shaped particles in the shaped sand stone is reduced, the content of cubic particles is more than or equal to 98 percent, the content of stone powder is less than or equal to 0.5 percent, the content of broken stone with particle size distribution of more than 31.5mm is 0, the content of 30 percent in the particle size distribution of 19.0-31.5 mm, and the content of 70 percent in the particle size distribution of 9.5-19.0 mm; the content of sand and stone is less than or equal to 1.0 percent; the content of cubic sand particles in the sand stone is more than or equal to 90 percent, the content of stone powder is less than or equal to 2.0 percent, the mud content is less than or equal to 1.4 percent, and the fineness modulus is between 2.1 and 3.2; the additive is prepared from the following raw materials in parts by weight: 12 parts of water reducing agent, 2 parts of retarder, 3 parts of lubricant, 10 parts of waterproofing agent, 1 part of pumping aid and 1 part of modification reinforcing agent; the water reducing agent is modified polycarboxylate ether, the retarder is a protein material, the lubricant is magnesium aluminum sulfate, the waterproof agent is modified organic silicone oil, the pumping agent is modified calcium lignosulfonate, and the modification reinforcing agent is a meta-aluminum silicate material.

The preparation method of the gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder comprises the steps of putting the compounded phosphogypsum active powder and an additive into a stirrer in proportion, uniformly stirring, putting sandstone and water into the stirrer in proportion, continuously uniformly stirring, and measuring the slump and the extensibility of the concrete to be qualified to obtain the gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder; the slump of the gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder is more than 250mm, and the expansibility is more than 650mm, so that the gypsum-based indoor terrace self-leveling concrete is qualified.

The gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder and prepared by the preparation method is applied to indoor terrace construction.

Example 2

The gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder is prepared from compound phosphogypsum active powder, an additive, sandstone and water, wherein the compound phosphogypsum active powder, the additive and the sandstone are mixed according to the following weight parts: 400 parts of compound phosphogypsum active powder, 8 parts of additive and 1600 parts of sandstone; the compound phosphogypsum active powder is prepared from mixed-phase gypsum and alpha-type high-strength gypsum according to 1:3.

Further, the compound phosphogypsum active powder is mixed-phase gypsum calcined at 230-500 ℃, the phase composition of the compound phosphogypsum active powder is that the anhydrous content of the third gypsum is less than or equal to 5 percent, the composition of the compound phosphogypsum active powder is that the anhydrous content of the second gypsum is more than or equal to 20 percent, the content of the beta-type semi-hydrated gypsum is more than or equal to 60 percent, the content of the dihydrate gypsum is less than or equal to 5 percent, the initial setting time is more than or equal to 10min, the final setting time is less than or equal to 120min, the bending and compression strength of 2h reaches more than 2.5MPa and 6.0MPa respectively, and the bending and compression strength of 28d reaches more than 4.0MPa and 15.0MPa respectively; the special medicament is prepared by compounding a trapping agent, an inhibitor and an activator, and specifically comprises the following raw materials in parts by weight: 90 parts of trapping agent, 20 parts of inhibitor and 10 parts of activator; the trapping agent is composed of an inorganic acid regulator, a modified fatty acid collecting agent and an ethioamine ester auxiliary agent, and specifically comprises the following raw materials in parts by weight: 60 parts of inorganic acid regulator, 20 parts of modified fatty acid and 10 parts of ethionamide auxiliary; the inhibitor is prepared by compounding humic acid, calcium hydroxide, sulfonated phenol tar and an L-type organic inhibitor, and specifically comprises the following raw materials in parts by weight: 70 parts of humic acid, 10 parts of calcium hydroxide, 5 parts of sulfonated phenol tar and 2 parts of L-shaped organic inhibitor; the activating agent is composed of water glass, aluminum sulfate, ammonium salt, oxalic acid and organic silicon, and specifically comprises the following raw materials in parts by weight: 80 parts of water glass, 25 parts of aluminum sulfate, 5 parts of ammonium salt, 10 parts of oxalic acid and 3 parts of organic silicon.

Furthermore, the mixed phase gypsum is gypsum calcined at 230-500 ℃, the phase composition of the mixed phase gypsum is that the content of anhydrous III type (AIII) gypsum is less than or equal to 5%, the content of anhydrous II type (AII) gypsum is more than or equal to 20%, the content of beta type semi-hydrated gypsum (HH) is more than or equal to 60%, the content of dihydrate gypsum (DH) is less than or equal to 5%, the initial setting time of the mixed phase gypsum is more than or equal to 10min, the final setting time is less than or equal to 120min, the 2h flexural and compressive strengths respectively reach more than 2.5MPa and 6.0MPa, and the 28d flexural and compressive strengths respectively reach more than 4.0MPa and 15.0 MPa; the alpha-type high-strength gypsum is the alpha-type high-strength gypsum produced by crystallization at the temperature of 120-150 ℃ and the pressure of 0.13-0.50 MPa, and comprises the components of alpha-type semi-hydrated gypsum (HH) content of more than or equal to 70 percent, dihydrate gypsum (DH) content of less than or equal to 5 percent, initial setting time of more than or equal to 10min, final setting time of less than or equal to 40min, bending strength of 2h reaches more than 4.5MPa, and drying compressive strength is more than 40.0 MPa; the phosphorous building gypsum is produced at the low temperature of 110-170 ℃, and comprises the components of beta-type semi-hydrated gypsum (HH) content of more than or equal to 80 percent, dihydrate gypsum (DH) content of less than or equal to 5 percent, anhydrous tri (AIII) content of less than or equal to 8 percent, initial setting time of more than or equal to 3min, final setting time of less than or equal to 9min, and bending and compression strengths of 2h respectively reaching more than 3.0MPa and 6.

Furthermore, the sand rate of the sand stone is controlled between 35 and 45 percent, the water-glue ratio is designed to be 0.30 to 0.40, namely the water accounts for 30 to 40 percent of the compound phosphogypsum active powder; the sand stone is prepared by shaping and screening according to a certain gradation, the sand stone has uniform size and complete particle type, the content of needle-shaped particles in the shaped sand stone is reduced, the content of cubic particles is more than or equal to 98 percent, the content of stone powder is less than or equal to 0.5 percent, the content of broken stone with particle size distribution of more than 31.5mm is 0, the content of 30 percent in the particle size distribution of 19.0-31.5 mm, and the content of 70 percent in the particle size distribution of 9.5-19.0 mm; the content of sand and stone is less than or equal to 1.0 percent; the content of cubic sand particles in the sand stone is more than or equal to 90 percent, the content of stone powder is less than or equal to 2.0 percent, the mud content is less than or equal to 1.4 percent, and the fineness modulus is between 2.1 and 3.2; the additive is composed of the following raw materials in parts by weight: 12 parts of water reducing agent, 7 parts of retarder, 3 parts of lubricant, 3 parts of waterproofing agent, 3 parts of pumping aid and 5 parts of modification reinforcing agent; the water reducing agent is polycarboxylic acid ether or other materials suitable for phosphorus building gypsum; the retarder is protein, inorganic salt or multifunctional other materials suitable for the phosphorous building gypsum; the lubricant is magnesium aluminum sulfate; the waterproof agent is paraffin, modified organic silicon or other materials which are used in ardealite products and can improve the fluidity and the waterproof performance; the pumping agent is modified calcium lignosulfonate or other specially-made organic high polymer materials capable of improving the activity dispersibility and the flowability of the phosphogypsum; the modified reinforcing agent is cement, lime calcium, silicon steel element, aluminum hydroxide, calcium aluminate, aluminum metasilicate, calcium oxalate or other materials capable of enhancing the strength and hardness of the phosphogypsum active powder.

According to the preparation method of the gypsum-based indoor floor self-leveling concrete prepared from the phosphogypsum active powder, the compounded phosphogypsum active powder and the additive are proportionally put into a stirrer to be uniformly stirred, then, gravel and water are proportionally put into the stirrer to be continuously and uniformly stirred, and after the slump and the extensibility of the gravel are measured to be qualified, the gypsum-based indoor floor self-leveling concrete prepared from the phosphogypsum active powder is obtained; the slump of the gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder is more than 250mm, and the expansibility is more than 650mm, so that the gypsum-based indoor terrace self-leveling concrete is qualified.

Example 3

The gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder is prepared from compound phosphogypsum active powder, an additive, sandstone and water, wherein the compound phosphogypsum active powder, the additive and the sandstone are mixed according to the following weight parts: 580 parts of compound phosphogypsum active powder, 14 parts of additive and 1500 parts of sandstone; the compound phosphogypsum active powder is prepared from phosphorus building gypsum and alpha-type high-strength gypsum according to 1:1.

Further, the compound phosphogypsum active powder is mixed-phase gypsum calcined at 230-500 ℃, the phase composition of the compound phosphogypsum active powder is that the anhydrous content of the third gypsum is less than or equal to 5 percent, the composition of the compound phosphogypsum active powder is that the anhydrous content of the second gypsum is more than or equal to 20 percent, the content of the beta-type semi-hydrated gypsum is more than or equal to 60 percent, the content of the dihydrate gypsum is less than or equal to 5 percent, the initial setting time is more than or equal to 10min, the final setting time is less than or equal to 120min, the bending and compression strength of 2h reaches more than 2.5MPa and 6.0MPa respectively, and the bending and compression strength of 28d reaches more than 4.0MPa and 15.0MPa respectively; the special medicament is prepared by compounding a trapping agent, an inhibitor and an activating agent, and specifically comprises the following raw materials in parts by weight: 85 parts of trapping agent, 15 parts of inhibitor and 6 parts of activating agent; the trapping agent is composed of an inorganic acid regulator, a modified fatty acid collecting agent and an ethioamine ester auxiliary agent, and specifically comprises the following raw materials in parts by weight: 70 parts of inorganic acid regulator, 30 parts of modified fatty acid and 7 parts of ethioamine assistant; the inhibitor is prepared by compounding humic acid, calcium hydroxide, sulfonated phenol tar and an L-type organic inhibitor, and specifically comprises the following raw materials in parts by weight: 50 parts of humic acid, 13 parts of calcium hydroxide, 10 parts of sulfonated phenol tar and 3 parts of L-shaped organic inhibitor; the activating agent is composed of water glass, aluminum sulfate, ammonium salt, oxalic acid and organic silicon, and specifically comprises the following raw materials in parts by weight: 65 parts of water glass, 15 parts of aluminum sulfate, 10 parts of ammonium salt, 13 parts of oxalic acid and 6 parts of organic silicon.

Furthermore, the sand rate of the sand stone is controlled between 35 and 45 percent, the water-glue ratio is designed to be 0.30 to 0.40, namely the water accounts for 30 to 40 percent of the compound phosphogypsum active powder; the sand stone is prepared by shaping and screening according to a certain gradation, the size of the sand stone is uniform, the grain type of the sand stone is complete, the content of needle-shaped particles in the shaped sand stone is reduced, the content of cubic particles is more than or equal to 98 percent, the content of stone powder is less than or equal to 0.5 percent, the content of broken stone with grain size distribution of more than 31.5mm is 0, the content of broken stone with grain size distribution of 19.0-31.5 mm is 30 percent, and the content of broken stone with grain size distribution of 9.5-19.0 mm is 70 percent; the content of sand and stone is less than or equal to 1.0 percent; the content of cubic sand particles in the sand stone is more than or equal to 90 percent, the content of stone powder is less than or equal to 2.0 percent, the mud content is less than or equal to 1.4 percent, and the fineness modulus is between 2.1 and 3.2; the additive is prepared from the following raw materials in parts by weight: 10 parts of water reducing agent, 6 parts of retarder, 5 parts of lubricant, 5 parts of waterproofing agent, 1 part of pumping aid and 2 parts of modification reinforcing agent; the water reducing agent is polycarboxylate ethers or other materials suitable for the phosphorus building gypsum; the retarder is protein, inorganic salt or multifunctional other materials suitable for the phosphorous building gypsum; the lubricant is magnesium aluminum sulfate; the waterproof agent is paraffin, modified organic silicon or other materials which are used in ardealite products and can improve the fluidity and the waterproof performance; the pumping agent is modified calcium lignosulfonate or other specially-made organic high polymer materials capable of improving the activity dispersibility and the flowability of the phosphogypsum; the modified reinforcing agent is cement, lime calcium, silicon steel element, aluminum hydroxide, calcium aluminate, aluminum metasilicate, calcium oxalate or other materials capable of enhancing the strength and hardness of the phosphogypsum active powder.

Example 4

The gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder is prepared from compound phosphogypsum active powder, an additive, sandstone and water, wherein the compound phosphogypsum active powder, the additive and the sandstone are mixed according to the following weight parts: 550 parts of compound phosphogypsum active powder, 12 parts of additive and 1600 parts of sandstone; the compound phosphogypsum active powder is prepared from phosphorus building gypsum and alpha-type high-strength gypsum according to 1:4.

Further, the compound phosphogypsum active powder is mixed-phase gypsum calcined at 230-500 ℃, the phase composition of the compound phosphogypsum active powder is that the anhydrous content of the third gypsum is less than or equal to 5 percent, the composition of the compound phosphogypsum active powder is that the anhydrous content of the second gypsum is more than or equal to 20 percent, the content of the beta-type semi-hydrated gypsum is more than or equal to 60 percent, the content of the dihydrate gypsum is less than or equal to 5 percent, the initial setting time is more than or equal to 10min, the final setting time is less than or equal to 120min, the bending and compression strength of 2h reaches more than 2.5MPa and 6.0MPa respectively, and the bending and compression strength of 28d reaches more than 4.0MPa and 15.0MPa respectively; the special medicament is prepared by compounding a trapping agent, an inhibitor and an activator, and specifically comprises the following raw materials in parts by weight: 88 parts of trapping agent, 18 parts of inhibitor and 8 parts of activating agent; the trapping agent is composed of an inorganic acid regulator, a modified fatty acid collecting agent and an ethioamine ester auxiliary agent, and specifically comprises the following raw materials in parts by weight: 75 parts of inorganic acid regulator, 35 parts of modified fatty acid and 9 parts of ethionamide auxiliary; the inhibitor is prepared by compounding humic acid, calcium hydroxide, sulfonated phenol tar and an L-type organic inhibitor, and specifically comprises the following raw materials in parts by weight: 60 parts of humic acid, 18 parts of calcium hydroxide, 15 parts of sulfonated phenol tar and 5 parts of L-shaped organic inhibitor; the activating agent is composed of water glass, aluminum sulfate, ammonium salt, oxalic acid and organic silicon, and specifically comprises the following raw materials in parts by weight: 75 parts of water glass, 20 parts of aluminum sulfate, 15 parts of ammonium salt, 18 parts of oxalic acid and 6 parts of organic silicon.

Furthermore, the sand rate of the sand stone is controlled between 35 and 45 percent, the water-glue ratio is designed to be 0.30 to 0.40, namely the water accounts for 30 to 40 percent of the compound phosphogypsum active powder; the sand stone is prepared by shaping and screening according to a certain gradation, the size of the sand stone is uniform, the grain type of the sand stone is complete, the content of needle-shaped particles in the shaped sand stone is reduced, the content of cubic particles is more than or equal to 98 percent, the content of stone powder is less than or equal to 0.5 percent, the content of broken stone with grain size distribution of more than 31.5mm is 0, the content of broken stone with grain size distribution of 19.0-31.5 mm is 30 percent, and the content of broken stone with grain size distribution of 9.5-19.0 mm is 70 percent; the content of sand and stone is less than or equal to 1.0 percent; the content of cubic sand particles in the sand stone is more than or equal to 90 percent, the content of stone powder is less than or equal to 2.0 percent, the mud content is less than or equal to 1.4 percent, and the fineness modulus is between 2.1 and 3.2; the additive is prepared from the following raw materials in parts by weight: 10 parts of water reducing agent, 6 parts of retarder, 5 parts of lubricant, 8 parts of waterproofing agent, 2 parts of pumping aid and 4 parts of modification reinforcing agent; the water reducing agent is polycarboxylic acid ether or other materials suitable for phosphorus building gypsum; the retarder is protein, inorganic salt or multifunctional other materials suitable for the phosphorous building gypsum; the lubricant is magnesium aluminum sulfate; the waterproof agent is paraffin, modified organic silicon or other materials which are used in ardealite products and can improve the fluidity and the waterproof performance; the pumping agent is modified calcium lignosulfonate or other specially-made organic high polymer materials capable of improving the activity dispersibility and the flowability of the phosphogypsum; the modified reinforcing agent is cement, lime calcium, silicon steel element, aluminum hydroxide, calcium aluminate, aluminum metasilicate salt, calcium oxalate or other materials capable of reinforcing the strength and hardness of the phosphogypsum active powder.

The gypsum-based indoor floor self-leveling concrete prepared from the phosphogypsum active powder and prepared by the preparation method is applied to indoor floor construction.

Example 5

The gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder is prepared from compound phosphogypsum active powder, an additive, sandstone and water, wherein the compound phosphogypsum active powder, the additive and the sandstone are mixed according to the following weight parts: 450 parts of compounded phosphogypsum active powder, 10 parts of additive and 1800 parts of sandstone; the compound phosphogypsum active powder is prepared from phosphorus building gypsum and alpha-type high-strength gypsum according to 1:3.

Further, the compound phosphogypsum active powder is mixed-phase gypsum calcined at 230-500 ℃, the phase composition of the compound phosphogypsum active powder is that the anhydrous content of the third gypsum is less than or equal to 5 percent, the composition of the compound phosphogypsum active powder is that the anhydrous content of the second gypsum is more than or equal to 20 percent, the content of the beta-type semi-hydrated gypsum is more than or equal to 60 percent, the content of the dihydrate gypsum is less than or equal to 5 percent, the initial setting time is more than or equal to 10min, the final setting time is less than or equal to 120min, the bending and compression strength of 2h reaches more than 2.5MPa and 6.0MPa respectively, and the bending and compression strength of 28d reaches more than 4.0MPa and 15.0MPa respectively; the special medicament is prepared by compounding a trapping agent, an inhibitor and an activator, and specifically comprises the following raw materials in parts by weight: 85 parts of trapping agent, 15 parts of inhibitor and 6 parts of activating agent; the trapping agent is composed of an inorganic acid regulator, a modified fatty acid collecting agent and an ethioamine ester auxiliary agent, and specifically comprises the following raw materials in parts by weight: 70 parts of inorganic acid regulator, 30 parts of modified fatty acid and 8 parts of ethionamide auxiliary agent; the inhibitor is prepared by compounding humic acid, calcium hydroxide, sulfonated phenol tar and an L-type organic inhibitor, and specifically comprises the following raw materials in parts by weight: 55 parts of humic acid, 15 parts of calcium hydroxide, 13 parts of sulfonated phenol tar and 4 parts of L-type organic inhibitor; the activating agent is composed of water glass, aluminum sulfate, ammonium salt, oxalic acid and organic silicon, and specifically comprises the following raw materials in parts by weight: 70 parts of water glass, 18 parts of aluminum sulfate, 12 parts of ammonium salt, 15 parts of oxalic acid and 5 parts of organic silicon.

Furthermore, the sand rate of the sand stone is controlled between 35 percent and 45 percent, the water-cement ratio is designed to be 0.30 to 0.40, namely the water accounts for 30 to 40 percent of the compound phosphogypsum active powder; the sand stone is prepared by shaping and screening according to a certain gradation, the sand stone has uniform size and complete particle type, the content of needle-shaped particles in the shaped sand stone is reduced, the content of cubic particles is more than or equal to 98 percent, the content of stone powder is less than or equal to 0.5 percent, the content of broken stone with particle size distribution of more than 31.5mm is 0, the content of 30 percent in the particle size distribution of 19.0-31.5 mm, and the content of 70 percent in the particle size distribution of 9.5-19.0 mm; the content of sand and stone is less than or equal to 1.0 percent; the sand stone contains more than or equal to 90 percent of cubic particles, less than or equal to 2.0 percent of stone powder, less than or equal to 1.4 percent of mud, and the fineness modulus is between 2.1 and 3.2; the additive is prepared from the following raw materials in parts by weight: 8 parts of water reducing agent, 5 parts of retarder, 3-6 parts of lubricant, 6 parts of waterproofing agent, 2 parts of pumping aid and 3 parts of modification reinforcing agent; the water reducing agent is polycarboxylic acid ether or other materials suitable for phosphorus building gypsum; the retarder is protein, inorganic salt or multifunctional other materials suitable for the phosphorous building gypsum; the lubricant is magnesium aluminum sulfate; the waterproof agent is paraffin, modified organic silicon or other materials which are used with ardealite products and can improve the fluidity and the waterproof performance; the pumping agent is modified calcium lignosulfonate or other specially-made organic high polymer materials capable of improving the activity dispersibility and the flowability of the phosphogypsum; the modified reinforcing agent is cement, lime calcium, silicon steel element, aluminum hydroxide, calcium aluminate, aluminum metasilicate, calcium oxalate or other materials capable of enhancing the strength and hardness of the phosphogypsum active powder.

The preparation method of the gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder comprises the steps of putting the compounded phosphogypsum active powder and an additive into a stirrer in proportion, uniformly stirring, putting sandstone and water into the stirrer in proportion, continuously uniformly stirring, and measuring the slump and the extensibility of the concrete to be qualified to obtain the gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder; the gypsum-based indoor floor self-leveling concrete prepared from the phosphogypsum active powder is qualified when the slump is more than 250mm and the expansion degree is more than 650 mm.

Comparative example 1

The difference from the embodiment is that: the compound phosphogypsum active powder, the additive and the sandstone are mixed according to the following weight parts: 900 parts of compound phosphogypsum active powder, 5 parts of additive and 1900 parts of sandstone; the compound phosphogypsum active powder is prepared from mixed-phase gypsum and alpha-type high-strength gypsum according to 1:6; other conditions were not changed.

Comparative example 2

The difference from the embodiment is that: the compound phosphogypsum active powder, the additive and the sandstone are mixed according to the following weight parts: 100 parts of compound phosphogypsum active powder, 14 parts of additive and 1500 parts of sandstone; the compound phosphogypsum active powder is prepared from mixed-phase gypsum and alpha-type high-strength gypsum according to the weight ratio of 1; other conditions were unchanged.

Comparative example 3

The difference from the embodiment is that: the compound phosphogypsum active powder, the additive and the sandstone are mixed according to the following weight parts: compounding 1000 parts of phosphogypsum active powder, 14 parts of additive and 1900 parts of sandstone; the compound phosphogypsum active powder is prepared from phosphorus building gypsum and alpha-type high-strength gypsum according to 1:4; other conditions were unchanged.

Comparative example 4

The difference from the embodiment is that: the compound phosphogypsum active powder, the additive and the sandstone are mixed according to the following weight parts: 580 parts of compound phosphogypsum active powder, 14 parts of additive and 1900 parts of sandstone; the compound phosphogypsum active powder is prepared by mixing phase gypsum and alpha-type high-strength gypsum according to 1:1-1:5; other conditions were not changed.

To further illustrate that the present invention can achieve the technical effects, the following experiments were performed:

the gypsum-based self-leveling concrete is prepared by the methods of examples 1 to 5 and comparative examples 1 to 4, then the concrete is constructed by the construction method in the invention content, and the physical performance of the construction surface is tested according to the standard of GBT 14902-2012 'premixed concrete', but the maintenance condition is natural maintenance. The experimental results are shown in table 1 below.

TABLE 1

To sum up, the slump of the gypsum-based indoor terrace self-leveling concrete prepared by the method is more than 250mm, the expansibility is more than 650mm, the 1d compressive strength can reach more than 10.0MPa, the 14d natural curing can meet the design strength requirement, the cost is lower than that of the same grade cement concrete, the shrinkage and micro-expansion are avoided, and the aims of saving energy and reducing carbon and reducing cost can be achieved after the gypsum-based indoor terrace self-leveling concrete is used. The application changes waste into valuable, reduces the construction cost of concrete, saves energy, and can reduce 150-180 kg of carbon per cube according to the consumption of 300kg of gypsum; the carbon of each cube can be reduced by 200-240 kg according to the dosage of 400kg gypsum; the carbon of each cube can be reduced by 250-300 kg according to the dosage of 500kg gypsum; the carbon consumption of each cube is reduced by 300-360 kg according to 600kg of gypsum.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

Claims

1. The gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder is characterized in that: the gypsum-based indoor floor self-leveling concrete prepared from the phosphogypsum active powder is prepared from compound phosphogypsum active powder, an additive, gravel and water, wherein the compound phosphogypsum active powder, the additive and the gravel are mixed according to the following weight parts: 300 to 580 parts of compound phosphogypsum active powder, 5 to 14 parts of additive and 1500 to 1900 parts of sandstone; the compound phosphogypsum active powder is prepared by mixing phase gypsum and alpha-type high-strength gypsum according to 1:1-1:3 or phosphorus building gypsum and alpha-type high-strength gypsum according to 1:1-1:4.

2. The gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder according to claim 1 is characterized in that: the compound phosphogypsum active powder is mixed-phase gypsum calcined at 230-500 ℃, the phase composition of the compound phosphogypsum active powder is that the anhydrous content of the anhydrous calcium is less than or equal to 5 percent, the composition of the compound phosphogypsum active powder is that the anhydrous calcium content is greater than or equal to 20 percent, the beta-type semi-hydrated gypsum content is greater than or equal to 60 percent, the dihydrate gypsum content is less than or equal to 5 percent, the initial setting time is greater than or equal to 10min, the final setting time is less than or equal to 120min, the bending and compression strength of 2h reaches more than 2.5MPa and 6.0MPa respectively, and the bending and compression strength of 28d reaches more than 4.0MPa and 15.0MPa respectively; the special medicament is prepared by compounding a trapping agent, an inhibitor and an activating agent, and specifically comprises the following raw materials in parts by weight: 80-90 parts of trapping agent, 10-20 parts of inhibitor and 2-10 parts of activating agent; the trapping agent is composed of an inorganic acid regulator, a modified fatty acid collecting agent and an ethioamine ester auxiliary agent, and specifically comprises the following raw materials in parts by weight: 60-80 parts of inorganic acid regulator, 20-40 parts of modified fatty acid and 5-10 parts of ethioamine ester auxiliary agent; the inhibitor is prepared by compounding humic acid, calcium hydroxide, sulfonated phenol tar and an L-type organic inhibitor, and specifically comprises the following raw materials in parts by weight: 40-70 parts of humic acid, 10-20 parts of calcium hydroxide, 5-20 parts of sulfonated phenol tar and 2-6 parts of L-shaped organic inhibitor; the activating agent is composed of water glass, aluminum sulfate, ammonium salt, oxalic acid and organic silicon, and specifically comprises the following raw materials in parts by weight: 60-80 parts of water glass, 10-25 parts of aluminum sulfate, 5-20 parts of ammonium salt, 10-20 parts of oxalic acid and 3-7 parts of organic silicon.

3. The gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder according to claim 1 is characterized in that: the mixed phase gypsum is gypsum calcined at 230-500 ℃, the phase composition of the mixed phase gypsum comprises anhydrous type III gypsum with the content less than or equal to 5%, anhydrous type II gypsum with the content more than or equal to 20%, beta type semi-hydrated gypsum with the content more than or equal to 60%, dihydrate gypsum with the content less than or equal to 5%, the initial setting time of the mixed phase gypsum is more than or equal to 10min, the final setting time is less than or equal to 120min, the bending and compression strength of 2h reaches more than 2.5MPa and 6.0MPa respectively, and the bending and compression strength of 28d reaches more than 4.0MPa and 15.0MPa respectively.

4. The gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder according to claim 1 is characterized in that: the alpha-type high-strength gypsum is the alpha-type high-strength gypsum produced by crystallization at the temperature of 120-150 ℃ and the pressure of 0.13-0.50 MPa, and comprises the components of alpha-type semi-hydrated gypsum content of more than or equal to 70 percent, dihydrate gypsum content of less than or equal to 5 percent, initial setting time of more than or equal to 10min, final setting time of less than or equal to 40min, bending strength of 2h of more than 4.5MPa and drying compressive strength of more than 40.0 MPa.

5. The gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder according to claim 1 is characterized in that: the phosphorus building gypsum is produced at the low temperature of 110-170 ℃, and comprises the components of beta-type semi-hydrated gypsum content more than or equal to 80%, dihydrate gypsum content less than or equal to 5%, anhydrous content less than or equal to 8%, initial setting time more than or equal to 3min, final setting time less than or equal to 9min, and bending and compression strength of 2h reaching more than 3.0MPa and 6.

6. The gypsum-based indoor floor self-leveling concrete prepared from the phosphogypsum active powder according to claim 1 is characterized in that: the sand rate of the sand stone is controlled between 35 percent and 45 percent, the water-cement ratio is designed to be 0.30 to 0.40, namely the water accounts for 30 to 40 percent of the compound phosphogypsum active powder; the sand stone is prepared by shaping and screening according to a certain gradation, the sand stone has uniform size and complete particle type, the content of needle-shaped particles in the shaped sand stone is reduced, the content of cubic particles is more than or equal to 98 percent, the content of stone powder is less than or equal to 0.5 percent, the content of broken stone with particle size distribution of more than 31.5mm is 0, the content of 30 percent in the particle size distribution of 19.0-31.5 mm, and the content of 70 percent in the particle size distribution of 9.5-19.0 mm; the content of sand and stone is less than or equal to 1.0 percent; the sand cube particle content in the sand stone is more than or equal to 90 percent, the stone powder content is less than or equal to 2.0 percent, the mud content is less than or equal to 1.4 percent, and the fineness modulus is between 2.1 and 3.2.

7. The gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder according to claim 1 is characterized in that: the additive is prepared from the following raw materials in parts by weight: 3-12 parts of water reducing agent, 2-7 parts of retarder, 3-6 parts of lubricant, 3-10 parts of waterproofing agent, 1-3 parts of pumping aid and 1-5 parts of modification reinforcing agent.

8. The preparation method of the gypsum-based indoor floor self-leveling concrete prepared from the phosphogypsum active powder is characterized by comprising the following steps of: and putting the compounded phosphogypsum active powder and the additive into a stirrer according to a proportion, uniformly stirring, then putting the sandstone and water into the stirrer according to a proportion, continuously uniformly stirring, and measuring the slump and the extensibility of the mixture to be qualified to obtain the gypsum-based indoor floor self-leveling concrete prepared from the phosphogypsum active powder.

9. The preparation method of the gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder according to claim 8 is characterized by comprising the following steps: the gypsum-based indoor floor self-leveling concrete prepared from the phosphogypsum active powder is qualified when the slump is more than 250mm and the expansion degree is more than 650 mm.

10. The gypsum-based indoor terrace self-leveling concrete prepared from the phosphogypsum active powder and prepared by the preparation method is applied to indoor terrace construction.