Anti-freezing durable ardealite kerb and preparation method thereof

Abstract

The invention discloses an anti-freezing durable ardealite kerb, which is prepared from the following components in parts by weight: 200 to 500 parts of phosphorus building gypsum, 200 to 600 parts of granulated blast furnace slag, 0 to 50 parts of quick lime, 0 to 150 parts of fly ash, 800 to 1500 parts of coarse aggregate, 500 to 1300 parts of fine aggregate, 0 to 10 parts of organic silicon water repellent, 0 to 10 parts of silane impregnant, 2 to 15 parts of water reducing agent, 0 to 10 parts of retarder, 0.4 to 10 parts of composite air entraining agent and 250 to 300 parts of water. The composite air entraining agent is prepared from sodium alpha-olefin sulfonate and triterpenoid saponin. The ardealite, the slag powder, the fly ash and other industrial solid waste materials are used as main raw materials, and the problems that a traditional curb is insufficient in early strength, high in water absorption, poor in freezing resistance, poor in water resistance, poor in chloride ion penetration resistance, long in maintenance time, high in cost and the like can be effectively solved; the related preparation cost is low, the period is short, and the method is suitable for popularization and application.

Description

Technical Field

[0001] The present invention belongs to the technical field of building materials, and particularly relates to an anti-freezing and durable phosphogypsum curbstone and a preparation method thereof. Background Art

[0002] A curbstone refers to a strip-shaped object made of stone or cast with concrete and used as a boundary stone at the edge of a road surface. The main production materials of curbstones include cement concrete, granite, marble, etc. Their production costs are relatively high, the maintenance time is long, and the process is cumbersome. Currently, curbstones are generally divided into two types according to materials: natural stone curbstones and ordinary concrete curbstones. Among them, natural stone curbstones have strong durability and good weather resistance, but there are certain deficiencies in terms of cost, construction, maintenance, and environmental protection; ordinary concrete curbstones prepared from cement, sand, gravel, water, etc. have a lower cost than natural stone curbstones, but there are some deficiencies in terms of erosion resistance, freeze-thaw cycle, chemical erosion resistance (such as chloride ion erosion resistance, snow melting agents, etc.), and environmental protection.

[0003] Phosphogypsum is an industrial by-product during wet-process phosphoric acid production, with the main component being calcium sulfate dihydrate (CaSO4·2H2O). Calcined building phosphogypsum has certain gelling properties. Currently, the comprehensive utilization rate of phosphogypsum is relatively low, the stockpile is relatively high, occupying a large amount of land resources, and at the same time, it will cause serious environmental pollution and potential safety hazards to the surrounding ecological environment.

[0004] There have been a few reports on using phosphogypsum to prepare curbstones. For example: Patent Application CN 114685134A discloses a phosphogypsum-based water-resistant curbstone, which is made from the following raw materials in parts by weight: 87 - 95 parts of phosphogypsum powder, 3 - 8 parts of seven-eye sand, 0.2 - 0.5 parts of water-reducing agent, 0.05 - 0.12 parts of retarder, and 0.2 - 0.5 parts of water-repellent agent; using phosphogypsum to replace ordinary cement concrete as the main material to prepare curbstones, and obtaining curbstones with relatively high strength, but the corresponding improvement in waterproof performance is limited (the water absorption rate is above 7%, up to 16%). Patent Application CN 109734404A discloses a high-strength water-resistant gypsum-based curbstone, and its raw materials are composed of the following components in mass percentages: 20 - 30% of phosphogypsum, 2 - 5% of cement, 8 - 12% of sand, 40 - 60% of crushed stone, 3 - 8% of volcanic ash, 2 - 3% of water-repellent agent, 0.2 - 0.4% of activator, 0.3 - 0.5% of water-reducing agent, 0.02 - 0.04% of water-retaining agent, 0.1 - 0.3% of retarder, and 0.03 - 0.05% of defoaming agent; the gypsum-based curbstone has high strength and strong water resistance (the water absorption rate is below 7%), but the corresponding curing period is relatively long, and the curing time is not less than 20 days. In addition, the existing curbstone formulations lack components specifically designed for anti-freezing performance, and only relying on the self-anti-freezing ability of conventional materials such as cement cannot meet the requirements of specific environments. Summary of the Invention

[0005] The main purpose of the present invention is to provide an anti-freezing and durable phosphogypsum curbstone in view of the problems or deficiencies existing in the prior art. The curbstone is prepared mainly from industrial solid waste materials such as phosphogypsum, slag powder and fly ash, so as to solve the problems of insufficient early strength, high water absorption, poor anti-freezing property, poor water resistance, poor anti-chloride ion penetration performance, long curing time and high cost of traditional curbstones.

[0006] The present invention is realized by adopting the following technical solutions:

[0007] An anti-freezing and durable phosphogypsum curbstone, the components and their respective weight parts include: 200-500 parts of phosphogypsum building gypsum, 200-600 parts of granulated blast furnace slag, 0-50 parts of quicklime, 0-150 parts of fly ash, 800-1500 parts of coarse aggregate, 500-1300 parts of fine aggregate, 0-10 parts of organosilicon water repellent, 0-10 parts of silane impregnating agent, 2-15 parts of water reducing agent, 0-10 parts of retarder, 0.4-10 parts of compound air-entraining agent, 250-300 parts of water; the compound air-entraining agent contains sodium α-olefin sulfonate and triterpenoid saponin.

[0008] In the above scheme, the phosphogypsum building gypsum is β-type hemihydrate gypsum (β-CaSO4·0.5H2O), which is obtained by calcining phosphogypsum at 107-170°C, and the pH value is 5.4-5.8.

[0009] In the above scheme, in the compound air-entraining agent, the chemical components and their respective mass percentages include: 70-85% of sodium α-olefin sulfonate, 15-30% of triterpenoid saponin. The introduced triterpenoid saponin reduces the surface tension and promotes the generation of microbubbles, and sodium α-olefin sulfonate regulates the bubble distribution to prevent aggregation. The two are compounded to introduce a large number of uniform, stable and closed "elastic bubble networks" during the preparation process of the curbstone; these bubbles are like buffer pads, which can effectively relieve the stress generated by the freezing and expansion of water when the curbstone is subjected to freeze-thaw cycles, prevent the internal structure from being damaged, and thus effectively reduce the quality loss caused by freeze-thaw cycles and improve the freeze-thaw resistance.

[0010] In the above scheme, the granulated blast furnace slag has a density of 2.8-3.0 g·cm -3 , and a specific surface area of 395-400 m 2 ·kg -1 .

[0011] In the above scheme, the coarse aggregate is continuously graded gravel with a particle size of 4.75-25 mm.

[0012] In the above scheme, the fine aggregate is natural sand, and the fineness modulus is 2.3-3.0.

[0013] In the above scheme, the particle size of the fly ash is 0.63-478.63 μm.

[0014] Furthermore, the characteristic particle size of the fly ash satisfies the following distribution: D 10 is 2.0 - 4.0 μm, D 50 is 12.0 - 18.0 μm, D 90 is 60.0 - 80.0 μm; preferably, the characteristic particle sizes are 2.84 μm (D 10 ), 14.37 μm (D 50 ), and 69.94 μm (D 90 ).

[0015] The fly ash adopted in the present invention can undergo a pozzolanic reaction with other cementitious materials to generate cementitious hydration products, optimize the performance of the cementitious materials, and enhance the strength of the curbstone; it can also increase the fluidity and plasticity of the mixture, improve the workability, and facilitate construction operations; at the same time, it can fill the pores and refine the structure, reduce the water absorption rate, enhance the water resistance, improve the durability of the curbstone, and extend its service life.

[0016] In the above - mentioned solution, the pH value of the silicone water - repellent agent is 10 - 11, and the density is 1.02 - 1.12 g·cm -3 . During the curing stage of the curbstone, spraying the surface of the specimen with the solution prepared from it can form a water - repellent protective film on the surface of the curbstone, reducing the water absorption rate of the curbstone.

[0017] In the above - mentioned solution, the chemical composition of the silane impregnating agent is n - octyltriethoxysilane, the content is not less than 99%, and the density is 0.8 - 0.9 g·cm -3 . It can greatly improve the waterproof and anti - permeability performance of the curbstone. It can penetrate deep into the interior of the curbstone, react chemically with the components in the concrete, form a water - repellent layer on the surface of the pores and capillary pores, effectively preventing the intrusion of external harmful substances such as water and chloride ions. This not only reduces the water absorption rate of the curbstone, enhances the water resistance, but also significantly improves its chloride ion penetration resistance and freeze - thaw resistance, enabling it to be used stably for a long time and greatly extending its service life.

[0018] In the above - mentioned solution, the retarder is a gypsum retarder, the moisture content ≤ 3%, which can adjust the setting time, ensure the full reaction of the materials, optimize the internal structure, and enhance the frost resistance.

[0019] In the above - mentioned solution, the water - reducing agent is a polycarboxylate - based water - reducing agent, and the water - reducing rate is 30 - 40%, which can reduce the water consumption, lower the porosity, enhance the density, and improve the frost resistance;

[0020] The preparation method of the phosphogypsum curbstone in the above - mentioned solution includes the following steps:

[0021] 1) Weigh the raw materials. The components and their weight parts are as follows: 200 - 500 parts of phosphogypsum for construction, 200 - 600 parts of granulated blast furnace slag, 0 - 50 parts of quicklime, 0 - 150 parts of fly ash, 800 - 1500 parts of coarse aggregate, 500 - 1300 parts of fine aggregate, 0 - 10 parts of organosilicon water repellent, 0 - 10 parts of silane impregnating agent, 2 - 15 parts of water reducing agent, 0 - 10 parts of setting retarder, 0.4 - 10 parts of compound air-entraining agent, and 250 - 300 parts of water.

[0022] 2) First, mix the phosphogypsum for construction, granulated blast furnace slag, quicklime, fly ash, coarse aggregate, and fine aggregate evenly according to the proportion to obtain a premix; then add the organosilicon water repellent, silane impregnating agent, water reducing agent, setting retarder, and compound air-entraining agent into water and stir evenly to obtain a premixed liquid.

[0023] 3) Stir and process the obtained premix and premixed liquid, pour, and cure to obtain the phosphogypsum curbstone.

[0024] In the above solution, the stirring time is 1 - 5 min.

[0025] In the above solution, the pouring time is within 10 min.

[0026] In the above solution, natural curing conditions are adopted, the humidity is ≥95%, and the surface of the specimen is sprayed with an organosilicon water repellent solution during curing.

[0027] Further, the concentration of the organosilicon water repellent solution is 40 - 50%; the spraying amount per unit area is 0.2 - 0.5 mL·cm -2 .

[0028] Compared with the existing technology, the beneficial effects of the present invention are as follows:

[0029] 1) The production plan of the frost-resistant and durable phosphogypsum curbstone of the present invention is efficient and of high quality. The stirring time during the production process is controlled within 1 - 5 min, the pouring time is controlled within 10 min, natural curing conditions with a humidity ≥95% are adopted, and an organosilicon water repellent solution with a concentration of 40 - 50% (0.2 - 0.5 mL·cm -2 ) is sprayed, which can achieve the effects of improving efficiency and reducing costs, enhancing the water repellency and durability of the product, improving the mechanical properties, and ensuring long-term stable use, and solves the problems of low production efficiency, high cost, and insufficient performance of traditional curbstones that are difficult to use stably for a long time.

[0030] 2) By using phosphogypsum as a sulfate activator, the present invention effectively promotes the hydration reaction of slag, generating dense hydration products. These products can fill the internal pores of concrete, refine the pore size, significantly reduce the proportion of connected pores, thereby greatly reducing water permeability and effectively alleviating the expansion pressure caused by freeze-thaw cycles. In addition, by introducing industrial solid wastes such as fly ash and combining the synergistic effects of various admixtures, the present invention further optimizes the performance of the curbstone. The synergistic effect of multiple materials can significantly improve the early strength of the curbstone, reduce the water absorption rate, improve the water resistance, enhance the chloride ion penetration resistance and frost resistance; it can effectively solve the deficiencies of traditional curbstones in terms of early strength, water absorption rate, water resistance, chloride ion penetration resistance and frost resistance.

[0031] 3) The water absorption rate of the curbstone obtained by the present invention is below 6%, and the softening coefficient is greater than 1, far exceeding the conventional water resistance standard. After being saturated with water, the compressive strength does not decrease but increases instead, with excellent water resistance, and it can well adapt to environments such as humidity and rain erosion, effectively reducing the problems of strength decline and durability reduction caused by water erosion.

[0032] 4) The chloride ion erosion resistance (by the electric flux method) of the curbstone obtained by the present invention is less than 300 C, with excellent chloride ion erosion resistance, which can greatly extend the service life of the curbstone, reduce the maintenance cost, and ensure the stability of road infrastructure.

[0033] 5) The present invention can effectively shorten the curing time of the phosphogypsum curbstone. The required curbstone can be obtained after 3 days of curing, which can greatly improve the mold turnover efficiency, speed up the construction progress, reduce the risk of construction period delay, and thus reduce the project cost. Description of the Drawings

[0034] Figure 1 It is a surface state diagram of the concrete curbstone obtained in Examples 1 to 3 after 25 freeze-thaw cycles.

[0035] Figure 2 It is a surface state diagram of the concrete curbstone obtained in Examples 1 to 3 after 50 freeze-thaw cycles.

[0036] Figure 3 It is a surface state diagram of the concrete curbstone obtained in Examples 1 to 3 after being soaked for 30 d. Detailed Embodiments

[0037] In order to make the objectives, technical solutions and advantages of the present invention clearer, the following further describes the present invention in detail with reference to specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] In the following examples, the phosphate building gypsum used was from Hubei Chuxing Chemical Co., Ltd., with a measured pH value of 5.6, and the S95 grade granulated blast furnace slag was produced from Wuhan Wuxin New Building Materials Co., Ltd., with a density of 2.9 g cm -3 , with a specific surface area of ​​396m 2 kg -1 , 7d and 28d activity index are not less than 76% and 101% respectively. The characteristic particle size of fly ash is 2.84μm (D 10 )、14.37μm(D 50 ) and 69.94μm(D 90 ), the particle size distribution range is 0.63-478.63 μm. The calcium oxide uses quicklime produced by Tianjin Zhonglian Chemical Reagent Co., Ltd., and the calcium oxide content is not less than 98%.

[0039] The sand used is river sand with a fineness modulus of 2.56, the coarse aggregate is crushed stone, and the continuous particle grading of crushed stone is 4.75 to 25 mm.

[0040] The water reducer is a polycarboxylic acid water reducer produced by Wuhan Xingxiang Technology Co., Ltd. with a water reduction rate of 35%. The retarder is a protein gypsum retarder produced by Shanghai Chenqi Chemical Technology Co., Ltd. The water repellent uses the organosilicon water repellent and silane impregnating agent produced by Beijing Jiasheng Building Materials Co., Ltd. The silane impregnating agent model is KJ-100, the main component is isobutyl triethoxysilane, and the density is 0.8-0.9 g cm -3 The silicone water repellent model is JSC01, the pH value is 10-11, and the density is 1.02-1.12 g·cm -3 The air-entraining agent is composed of sodium α-olefin sulfonate and triterpenoid saponin, and the mass ratio of the two is 8:2.

[0041] Example 1

[0042] A concrete curbstone is composed of the following mass proportions: 257 parts of phosphorus building gypsum (parts by weight, the same below), 448 parts of granulated blast furnace slag, 15 parts of quicklime, 843 parts of coarse aggregate, 562 parts of fine aggregate, 1.8 parts of organosilicon water repellent, 3.0 parts of water reducer, 0.72 parts of retarder, 0.73 parts of composite air entraining agent, and 274 parts of water; the specific preparation method comprises the following steps:

[0043] 1) The weighed phosphate building gypsum, granulated blast furnace slag, quicklime, coarse aggregate and fine aggregate are uniformly mixed and put into a mixer for dry mixing for 2 minutes to ensure that the materials are fully mixed to obtain a premix;

[0044] 2) Add the weighed organic silicon water repellent, water reducing agent and retarder to water and stir thoroughly to ensure that the admixtures are completely dissolved to obtain a premixed solution;

[0045] Subsequently, the treated aqueous solution is added into a concrete mixer and stirred at a stirring speed of 48 r / min for 1 to 3 minutes to obtain a mixture;

[0046] 3) The obtained mixture is placed into a mold and mechanically vibrated three times, each vibration lasting 20 to 40 seconds to ensure the density of the concrete; the pouring process must be completed within 10 minutes and hardened into shape;

[0047] 4) The hardened specimens were naturally cured (humidity ≥ 95%). During the curing period, the ambient humidity was maintained and the surface was moisturized with a mixed solution of a silicone hydrophobic agent and water in a ratio of 1:15 (spraying volume of 0.2-0.5 mL cm -2 ), and the phosphogypsum curbstone can be obtained after curing for 3 days.

[0048] Example 2

[0049] A concrete curbstone is composed of the following mass proportions: 268 parts of phosphorus building gypsum, 437 parts of granulated blast furnace slag, 15 parts of quicklime, 843 parts of coarse aggregate, 562 parts of fine aggregate, 1.8 parts of organic silicon water repellent, 3.0 parts of water reducer, 0.72 parts of retarder, 0.63 parts of composite air entraining agent, and 274 parts of water; the specific preparation method comprises the following steps:

[0050] 1) The weighed phosphate building gypsum, granulated blast furnace slag, quicklime, coarse aggregate and fine aggregate are uniformly mixed according to a set ratio, and put into a mixer for dry mixing for 2 minutes to ensure that the materials are fully mixed to obtain a premix;

[0051] 2) Add the weighed organic silicon water repellent, water reducing agent and retarder into water according to a predetermined ratio, and stir thoroughly to ensure that the admixtures are completely dissolved; obtain a premixed solution;

[0052] Subsequently, the treated aqueous solution is added into a concrete mixer and stirred at a stirring speed of 48 r / min for 1 to 3 minutes to obtain a mixture;

[0053] 3) The obtained mixture is placed into a mold and mechanically vibrated three times, each vibration lasting 20 to 40 seconds to ensure the density of the concrete; the pouring process must be completed within 10 minutes and hardened into shape;

[0054] 4) The hardened specimens were naturally cured (humidity ≥ 95%). During the curing period, the ambient humidity was maintained and the surface was moisturized with a mixed solution of a silicone hydrophobic agent and water in a ratio of 1:15 (spraying volume of 0.2-0.5 mL cm -2 ), and the phosphogypsum curbstone can be obtained after curing for 3 days.

[0055] Example 3

[0056] A kind of concrete curbstone is composed of the following mass ratios: 288 parts of phosphogypsum, 360 parts of granulated blast furnace slag, 15 parts of quicklime, 843 parts of coarse aggregate, 562 parts of fine aggregate, 1.8 parts of silicone waterproofing agent, 3.0 parts of water reducing agent, 0.72 parts of retarder, 0.53 parts of compound air-entraining agent, and 274 parts of water; the specific preparation method includes the following steps:

[0057] 1) Uniformly mix phosphogypsum, granulated blast furnace slag, quicklime, coarse aggregate and fine aggregate according to the set ratio, and put them into a mixer for 2 minutes of dry mixing to ensure full mixing of the materials.

[0058] 2) Add the silicone waterproofing agent, water reducing agent and retarder to water according to the predetermined ratio, and stir well to ensure complete dissolution of the admixtures. Subsequently, add the treated aqueous solution to the concrete mixer, and stir at a stirring speed of 48 revolutions per minute for 1 - 3 minutes.

[0059] 3) Put the obtained mixture into a mold and perform mechanical vibration three times, with each vibration lasting for 20 - 40 s to ensure the density of the concrete; the pouring process needs to be completed within 8 minutes and then hardened and formed.

[0060] 4) Naturally cure the hardened and formed specimens (humidity ≥ 95%), maintain the environmental humidity during the curing period, and use a mixed solution prepared by mixing the silicone waterproofing agent and water in a ratio of 1:15 for surface moisturizing (spraying amount is 0.2 - 0.5 mL·cm -2 ), and cure for 3 days to obtain the phosphogypsum curbstone.

[0061] Example 4

[0062] A kind of concrete curbstone is composed of the following mass ratios: 288 parts of phosphogypsum, 382 parts of granulated blast furnace slag, 39 parts of fly ash, 15 parts of quicklime, 843 parts of coarse aggregate, 562 parts of fine aggregate, 1.8 parts of silane impregnating agent, 3.0 parts of water reducing agent, 0.72 parts of retarder, 0.43 parts of air-entraining agent, and 274 parts of water. The specific preparation method includes the following steps:

[0063] 1) Uniformly mix the weighed phosphogypsum, granulated blast furnace slag, quicklime, coarse aggregate and fine aggregate, and put them into a mixer for 2 minutes of dry mixing to ensure full mixing of the materials to obtain a premix.

[0064] 2) Add the weighed silane impregnating agent, water reducing agent and retarder to water, and stir well to ensure complete dissolution of the admixtures; obtain a premixed solution.

[0065] Subsequently, add the treated aqueous solution to the concrete mixer and stir at a stirring speed of 48 r / min for 1 - 3 minutes of stirring; obtain a mixture.

[0066] 3) The obtained mixture is placed into a mold and mechanically vibrated three times, each vibration lasting 20 to 40 seconds to ensure the density of the concrete; the pouring process must be completed within 10 minutes and hardened into shape;

[0067] 4) The hardened specimens were naturally cured (humidity ≥ 95%). During the curing period, the ambient humidity was maintained and the surface was moisturized with a mixed solution of a silicone hydrophobic agent and water in a ratio of 1:15 (spraying volume of 0.2-0.5 mL cm -2 ), and the phosphogypsum curbstone can be obtained after curing for 3 days.

[0068] Example 5

[0069] A concrete curbstone is composed of the following mass proportions: 288 parts of phosphorus building gypsum, 382 parts of granulated blast furnace slag, 39 parts of fly ash, 15 parts of quicklime, 843 parts of coarse aggregate, 562 parts of fine aggregate, 3.6 parts of silane impregnating agent, 3.0 parts of water reducing agent, 0.72 parts of retarder, 0.43 parts of air entraining agent, and 274 parts of water. The specific preparation method thereof comprises the following steps:

[0070] 1) The weighed phosphate building gypsum, granulated blast furnace slag, quicklime, coarse aggregate and fine aggregate are uniformly mixed and put into a mixer for dry mixing for 2 minutes to ensure that the materials are fully mixed to obtain a premix;

[0071] 2) Add the weighed silane impregnating agent, water reducing agent and retarder to water and stir thoroughly to ensure that the admixtures are completely dissolved to obtain a premixed solution;

[0072] Subsequently, the treated aqueous solution is added into a concrete mixer and stirred at a stirring speed of 48 r / min for 1 to 3 minutes to obtain a mixture;

[0073] 3) The obtained mixture is placed into a mold and mechanically vibrated three times, each vibration lasting 20 to 40 seconds to ensure the density of the concrete; the pouring process must be completed within 10 minutes and hardened into shape;

[0074] 4) The hardened specimens were naturally cured (humidity ≥ 95%). During the curing period, the ambient humidity was maintained and the surface was moisturized with a mixed solution of a silicone hydrophobic agent and water in a ratio of 1:15 (spraying volume of 0.2-0.5 mL cm -2 ), and the phosphogypsum curbstone can be obtained after curing for 3 days.

[0075] Example 6

[0076] A kind of concrete curbstone is composed of the following mass ratios: 288 parts of phosphogypsum, 382 parts of granulated blast furnace slag, 39 parts of fly ash, 15 parts of quicklime, 843 parts of coarse aggregate, 562 parts of fine aggregate, 5.4 parts of silane impregnating agent, 3.0 parts of water reducing agent, 0.72 parts of setting retarder, 0.43 parts of air entraining agent, and 274 parts of water. Its specific preparation method includes the following steps:

[0077] 1) Weigh the phosphogypsum, granulated blast furnace slag, quicklime, coarse aggregate and fine aggregate, mix them evenly, and put them into a mixer for 2 minutes of dry mixing to ensure that the materials are fully mixed to obtain a premix;

[0078] 2) Add the weighed silane impregnating agent, water reducing agent and setting retarder to water, and stir well to ensure that the admixtures are completely dissolved to obtain a premixed solution;

[0079] Subsequently, add the treated aqueous solution to a concrete mixer and stir at a stirring speed of 48 r / min for 1 - 3 minutes to obtain a mixture;

[0080] 3) Put the obtained mixture into a mold and perform mechanical vibration three times, with each vibration lasting for 20 - 40 s to ensure the density of the concrete; the pouring process needs to be completed within 10 minutes and hardened and formed;

[0081] 4) Naturally cure the hardened and formed specimens (humidity ≥ 95%). During the curing period, maintain the environmental humidity, and use a mixed solution prepared by mixing silicone water repellent and water in a ratio of 1:15 for surface moisture retention (spraying amount is 0.2 - 0.5 mL·cm -2 ), and cure for 3 days to obtain the phosphogypsum curbstone.

[0082] Comparative Example 1

[0083] An anti - freezing and durable phosphogypsum curbstone, whose preparation method is roughly the same as that of Example 1, except that it is made of the following raw materials in parts by weight: 504 parts of phosphogypsum, 201 parts of granulated blast furnace slag, 1.8 parts of silicone water repellent, 3.0 parts of water reducing agent, 0.72 parts of setting retarder, 274 parts of water, and other conditions remain unchanged.

[0084] Comparative Example 2

[0085] An anti - freezing and durable phosphogypsum curbstone, whose preparation method is roughly the same as that of Example 1, except that it is made of the following raw materials in parts by weight: 601 parts of phosphogypsum, 104 parts of granulated blast furnace slag, 1.8 parts of silicone water repellent, 3.0 parts of water reducing agent, 0.72 parts of setting retarder, 274 parts of water, and other conditions remain unchanged.

[0086] Comparative Example 3

[0087] An anti-freezing and durable phosphogypsum curbstone, the preparation method of which is substantially the same as that of Example 2, except that the air-entraining agent used is a single component of sodium α-olefin sulfonate; it is made from the following raw materials in parts by weight: 268 parts of phosphogypsum for building, 437 parts of granulated blast furnace slag, 15 parts of quicklime, 843 parts of coarse aggregate, 562 parts of fine aggregate, 1.8 parts of silicone water repellent, 3.0 parts of water reducing agent, 0.72 parts of retarder, 0.63 parts of air-entraining agent (sodium α-olefin sulfonate), 274 parts of water, and other conditions remain unchanged.

[0088] Comparative Example 4

[0089] An anti-freezing and durable phosphogypsum curbstone, the preparation method of which is substantially the same as that of Example 2, except that the air-entraining agent used is a single component of triterpenoid saponin. It is made from the following raw materials in parts by weight: 268 parts of phosphogypsum for building, 437 parts of granulated blast furnace slag, 15 parts of quicklime, 843 parts of coarse aggregate, 562 parts of fine aggregate, 1.8 parts of silicone water repellent, 3.0 parts of water reducing agent, 0.72 parts of retarder, 0.63 parts of air-entraining agent (triterpenoid saponin), 274 parts of water, and other conditions remain unchanged.

[0090] The curbstones obtained in Examples 1 to 6 and Comparative Examples 1 to 2 were respectively subjected to performance tests such as mechanical properties, water resistance, freeze-thaw resistance, hydration heat, and chloride ion penetration resistance. The results are shown in Tables 1 and 2 respectively.

[0091] Table 1 Test results of compressive strength and water absorption of specimens in Examples 1-6

[0092]

[0093] Table 2 Test results of durability and hydration heat of specimens in Examples 1-3

[0094]

[0095] According to the characterization results of Example 1, Example 2 and Example 3, it can be seen that the compressive strength of the obtained concrete meets the requirements of C40 grade, and no cracking and surface corrosion occurred on the surface after soaking for 30 days (such as Figure 3as shown, where the water absorption rates of Examples 1 to 6 are all below 6%, meeting the water absorption requirements corresponding to JC / T 899-2016 "Concrete Kerbstone"; after 50 freeze-thaw cycles in Examples 1 to 3, the mass loss meets the requirement of being below 3% in JC / T 899-2016 "Concrete Kerbstone", and has the best chloride ion permeability resistance ability; the heat release of cement hydration is much less than the 7-day heat release of low-heat cement specified in GB / T 200-2017 "Medium Heat Portland Cement, Low Heat Portland Cement". The water absorption rates of Examples 1 to 3 increase continuously, and their softening coefficients decrease accordingly, but the softening coefficients are all greater than 1. The kerbstones prepared in this application have a short cycle, a simple preparation process, high early strength, good frost resistance, low water absorption, good water resistance, and good chloride ion permeability resistance performance.

[0096] The specific embodiments of the present invention described above do not constitute a limitation on the protection scope of the present invention. Any other corresponding changes and deformations made according to the technical concept of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A frost-resistant and durable phosphogypsum curbstone, characterized in that: The components and their weight proportions include: 200-500 parts of phosphate building gypsum, 200-600 parts of granulated blast furnace slag, 0-50 parts of quicklime, 0-150 parts of fly ash, 800-1500 parts of coarse aggregate, 500-1300 parts of fine aggregate, 0-10 parts of organic silicon water repellent, 0-10 parts of silane impregnating agent, 2-15 parts of water reducer, 0-10 parts of retarder, 0.4-10 parts of composite air entraining agent and 250-300 parts of water; the composite air entraining agent contains sodium α-olefin sulfonate and triterpenoid saponin.

2. The frost-resistant and durable phosphogypsum curbstone according to claim 1, characterized in that: The phosphogypsum is beta-type hemihydrate gypsum, which is obtained by calcining phosphogypsum at 107-170° C. and has a pH value of 5.4-5.

8.

3. The frost-resistant and durable phosphogypsum curbstone according to claim 1, characterized in that: The components and their mass percentages in the composite air entraining agent include: 70-85% of sodium α-olefin sulfonate and 15-30% of triterpenoid saponin.

4. The frost-resistant and durable phosphogypsum curbstone according to claim 1, characterized in that: The density of the granulated blast furnace slag is 2.8 to 3.0 g·cm -3 , with a specific surface area of ​​395-400m 2 kg -1 .

5. The frost-resistant and durable phosphogypsum curbstone according to claim 1, characterized in that: The coarse aggregate is crushed stone with continuous grading of 4.75-25 mm; the fineness modulus of the fine aggregate is 2.3-3.

0.

6. The frost-resistant and durable phosphogypsum curbstone according to claim 1, characterized in that: The particle size of the fly ash is 0.63-478.63 μm.

7. The frost-resistant and durable phosphogypsum curbstone according to claim 1, characterized in that: The retarder is a gypsum retarder with a water content of ≤3%.

8. The frost-resistant and durable phosphogypsum curbstone according to claim 1, characterized in that: The water reducing agent is a polycarboxylic acid water reducing agent, and the water reducing rate is 30-40%.

9. The method for preparing the frost-resistant and durable phosphogypsum curbstone according to any one of claims 1 to 8, characterized in that: The steps include: 1) Weigh the raw materials, and the components and their weight proportions include: 200-500 parts of phosphorus building gypsum, 200-600 parts of granulated blast furnace slag, 0-50 parts of quicklime, 0-150 parts of fly ash, 800-1500 parts of coarse aggregate, 500-1300 parts of fine aggregate, 0-10 parts of organic silicon water repellent, 0-10 parts of silane impregnating agent, 2-15 parts of water reducing agent, 0-10 parts of retarder, 0.4-10 parts of composite air entraining agent, and 250-300 parts of water; 2) firstly, the phosphorus building gypsum, granulated blast furnace slag, quicklime, fly ash, coarse aggregate and fine aggregate are mixed uniformly in proportion to obtain a premix; then, the organosilicon water repellent, silane impregnating agent, water reducing agent, retarder and composite air entraining agent are added to water and stirred uniformly to obtain a premixed liquid; 3) The obtained premix and premix liquid are stirred, poured, and cured to obtain the phosphogypsum curbstone.

10. The preparation method according to claim 9, characterized in that: The spraying amount of silicone water repellent solution per unit area is 0.2~0.5mL·cm -2 .

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