Weather-resistant fiber cement board as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of cement products, and particularly relates to a weather-resistant fiber cement board as well as a preparation method and application thereof. By doping a large amount of mineral admixtures with high activity and micro-filling and micro-expansion effects and introducing fibers with relatively high elastic modulus and tensile strength, the weather-resistant fiber cement plate has relatively high compactness and relatively low contractibility, the weather resistance and long-term mechanical property are improved, the service life is long, and the weather-resistant fiber cement plate is suitable for being used in the field of building materials. And the later maintenance and reinforcement cost is reduced. According to the weather-resistant fiber cement board provided by the invention, the cracking risk is reduced, and the use safety is improved. The waste stone powder is produced from coarse and fine aggregates for concrete, stone processing and mining processes, most of the waste stone powder is used for backfilling engineering at present, the waste stone powder is used as an inert filling material, the cost is close to zero, and meanwhile, high value-added utilization of the waste stone powder is realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of cement products, and particularly relates to a weather-resistant fiber cement plate and a preparation method and application thereof. BACKGROUND

[0002] As a representative of integrated external wall insulation systems, the thermal insulation decorative plate industry develops rapidly. The thermal insulation decorative plate is a kind of external wall building material integrating decoration, thermal insulation and construction convenience, mainly including fiber cement plates, calcium silicate plates, metal plates and ceramic plates, among which the fiber cement plates and the calcium silicate plates are mainstream varieties.

[0003] Most of the fiber cement plates have low density, poor compactness, high water absorption and high wet swelling rate, and the apparent density is 0.8-1.5 g / cm 3 , the wet swelling rate is 0.15-0.5%, and the bending strength is not higher than 15 MPa, resulting in poor weather resistance. If it is used outdoors to face light, sunshine, rain or freeze-thaw environment, the outer surface needs to be closed, but the weather resistance cannot be guaranteed.

[0004] A small part of the fiber cement plates has a density of 1.65 g / cm 3 above, high compactness, low water absorption and high strength, but it is made of a large amount of cement as a cementitious material, and has a large dry shrinkage or wet swelling rate, generally about 1%. When used as an external wall thermal insulation and decoration integrated plate, the fiber cement plate is easily affected by environmental humidity and continuously expands and shrinks, is prone to cracking, and still has poor weather resistance.

[0005] The calcium silicate plate has high crystallinity and strong structural stability, and the wet swelling rate is below 0.15%, and is not easily deformed or cracked due to changes in environmental humidity. However, the internal structure of the calcium silicate plate is loose, the water absorption is large, the strength is low, the weather resistance is insufficient, and the calcium silicate plate is not suitable for high-temperature and high-humidity places such as external walls.

[0006] In summary, the existing mainstream thermal insulation decorative plates cannot simultaneously have high density and compactness, low water absorption and wet swelling rate, and poor weather resistance. SUMMARY

[0007] The application aims to provide a weather-resistant fiber cement plate and a preparation method and application thereof, and the weather-resistant fiber cement plate provided by the application has good weather resistance.

[0008] In order to achieve the above-mentioned purpose, the application provides the following technical scheme:

[0009] The application provides a weather-resistant fiber cement plate, which is prepared from the following raw materials in parts by mass: cement 20-40 parts, mineral admixture 10-30 parts, waste stone powder 20-50 parts, fiber 6-10 parts and defoaming agent 0.1-0.5 parts; the mineral admixture comprises metakaolin and first mineral powder; and the fiber comprises first fiber material and cellulose fiber.

[0010] Preferably, the metakaolin in the mineral admixture accounts for 5-15 parts by mass; the SiO2 content of the metakaolin is not less than 50 wt%, the Al2O3 content is not less than 35 wt%, the water demand ratio is not more than 120%, and the 28d activity index is not less than 105%.

[0011] Preferably, the first mineral powder comprises one or more of fly ash, mineral powder, volcanic ash and silica fume; the specific surface area of the silica fume is not less than 15000 m 2 / kg, the water demand ratio is not more than 125%, the loss on ignition is not more than 4%, the activity index (7d rapid method) is not less than 105%, the SiO2 content is not less than 85 wt%, and the total alkali content is not more than 1.5 wt%.

[0012] Preferably, the first fiber material comprises one or more of chemical synthetic fiber and mineral fiber; the elastic modulus of the chemical synthetic fiber is not less than 10 GPa, and the length is 4-12 mm; and the elastic modulus of the mineral fiber is not less than 80 GPa, and the length is 4-12 mm.

[0013] Preferably, the cellulose fiber in the fiber accounts for 4-8 parts by mass; the beating degree of the cellulose fiber is 25-40 °SR, and the wet weight is 8-15 g.

[0014] The application further provides a preparation method of the weather-resistant fiber cement plate.

[0015] (1) mixing cement, mineral admixture, waste stone powder slurry, cellulose fiber slurry, first fiber material, defoaming agent and water to obtain a slurry;

[0016] (2) sequentially performing plate making, plate blank pressurizing, pre-curing and curing on the slurry to obtain the weather-resistant fiber cement plate; the plate making is by the papermaking method or the flow slurry method.

[0017] Preferably, the plate making by the papermaking method comprises the following steps: conveying the slurry into a net box for the papermaking method, and dragging the slurry out in the form of a thin layer with water by the woolen cloth of the net box and then dehydrating; and the plate making by the flow slurry method comprises the following steps: conveying the slurry into a flow slurry box for the flow slurry method, and dehydrating the slurry after the slurry flows out of the flow slurry box and is laid on a running woolen cloth.

[0018] Preferably, the slab pressing comprises the following steps: after the slab is stacked, the slab is pressed to remove water; the pressing time of the water removal is 30-60 minutes, the constant pressure of the single stack is 5000-7000T, and the pressure maintaining time is 20-30 minutes.

[0019] Preferably, the curing comprises steam curing and / or natural curing; the curing system of the steam curing is as follows: the temperature rising rate is not higher than 15 DEG C / h, the constant temperature is 80-90 DEG C, the constant temperature time is 24-48h, and the temperature falling rate is not higher than 20 DEG C / h; the temperature of the natural curing is 20-40 DEG C, and the temperature maintaining curing time is not less than 14d; the plate is covered and kept moist during the natural curing.

[0020] The application further provides application of the weather-resistant fiber cement plate in the energy-saving building field.

[0021] The application provides a weather-resistant fiber cement plate. The weather-resistant fiber cement plate provided by the application has low cracking risk and high use safety. The waste stone powder is generated in the production of coarse and fine aggregates for concrete, stone processing and mining, and at present, most of the waste stone powder is used for backfill engineering. The weather-resistant fiber cement plate provided by the application uses the waste stone powder as an inert filling material, has a cost close to zero, realizes high value-added utilization of the waste stone powder, and greatly reduces the production cost.

[0022] The application further provides a preparation method of the weather-resistant fiber cement plate. The weather-resistant fiber cement plate provided by the application has low cracking risk and high use safety. The waste stone powder is generated in the production of coarse and fine aggregates for concrete, stone processing and mining, and at present, most of the waste stone powder is used for backfill engineering. The weather-resistant fiber cement plate provided by the application uses the waste stone powder as an inert filling material, has a cost close to zero, realizes high value-added utilization of the waste stone powder, and greatly reduces the production cost.

[0023] The application further provides application of the weather-resistant fiber cement plate in the energy-saving building field. The weather-resistant fiber cement plate provided by the application has a density greater than 1.65g / cm3 , the wet swelling rate is less than 0.10%, the water absorption rate is less than 10%, the dry flexural strength is greater than 25 MPa, the saturated flexural strength is greater than 18 MPa, the hot water test flexural strength ratio is greater than 90%, the hot rain test flexural strength ratio is greater than 95%, the soaking-drying test flexural strength ratio is greater than 95%, and the resistance test flexural strength ratio is greater than 90%. The weather-resistant fiber cement plate provided by the application has good weather resistance and is suitable for use in the field of energy-saving buildings, especially for use in the outer walls of energy-saving buildings. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0025] Figure 1 It is a schematic diagram of the principle of the copying plate machine;

[0026] Figure 2 It is a schematic diagram of the principle of the flow slurry plate machine;

[0027] The drawings are as follows: 1 is slurry, 2 is a net cylinder, 3 is a couch roll, 4 is a first vacuum box, 5 is a first wool cloth, 6 is a first forming cylinder, 7 is a first breast roll, 8 is a first tensioning roll, 9 is a first cloth beater, 10 is a net box, 11 is a slurry outlet, 12 is a flow slurry box, 13 is a second vacuum box, 14 is a second wool cloth, 15 is a second forming cylinder, 16 is a second breast roll, 17 is a guide roll, 18 is a second cloth beater, and 19 is a second tensioning roll. DETAILED DESCRIPTION

[0028] The present application provides a kind of weather-resistant fiber cement plate, according to mass fraction, including the following raw materials prepared:

[0029] Cement 20-40 parts, mineral admixture 10-30 parts, waste stone powder 20-50 parts, fiber 6-10 parts and defoaming agent 0.1-0.5 parts.

[0030] According to mass fraction, the weather-resistant fiber cement plate provided by the application includes cement 20-40 parts, which can be 24 parts, 27 parts, 30 parts, 33 parts or 36 parts.

[0031] In the present application, the cement can be Portland cement; the Portland cement can be P.O52.5 cement Portland cement or P.Ⅱ52.5 cement Portland cement.

[0032] In the present application, the 28d mortar strength of the cement can be no less than 52.5 MPa, and specifically can be 55 MPa.

[0033] In the present application, the water requirement for standard consistency of the cement can be no more than 28%, and specifically can be 26% or 25%. The hydration product Ca(OH)2 of the cement in the present application can have a secondary hydration reaction with other mineral admixtures such as fly ash, mineral powder, pozzolana, metakaolin or silica fume, etc., to promote the hydration degree of the cement, optimize the hydration product, and improve the compactness and strength of the system.

[0034] In the present application, the weather-resistant fiber cement plate provided by the present application contains 10-30 parts of mineral admixtures, and specifically can contain 14 parts, 17 parts, 20 parts, 24 parts or 28 parts of mineral admixtures, based on the mass fraction of the cement.

[0035] In the present application, the mineral admixtures can contain metakaolin and first mineral powder; the first mineral powder can contain one or more of fly ash, mineral powder, pozzolana and silica fume.

[0036] In the present application, the SiO2 content of the metakaolin can be no less than 50wt%, and specifically can be 60wt%, the Al2O3 content can be no less than 35wt%, and specifically can be 40wt%, the water requirement ratio can be no more than 120%, and specifically can be 110% or 100%, and the 28d activity index can be no less than 105%, and specifically can be 110% or 120%.

[0037] In the present application, the mass fraction of metakaolin in the mineral admixtures can be 5-15 parts, and specifically can be 8 parts or 12 parts, based on the mass fraction of the cement.

[0038] The metakaolin in the present application is a high-activity mineral admixture, which has significant "activity effect" and "micro-aggregate effect", accelerates the hydration of the cement in the system, has a secondary hydration reaction with the hydration product Ca(OH)2 of the cement, promotes the hydration degree of the cement, optimizes the hydration product, and improves the early strength; at the same time, the generated aluminosilicate gel has a micro-expansion effect, which can compensate for the shrinkage. The metakaolin has a large specific surface area, which can fill the micro-pores in the system and also play a micro-filling effect, reduce the total porosity of the concrete, improve the compactness of the cement stone, reduce the volume shrinkage of the concrete, and thus improve the volume stability of the concrete and improve the crack resistance.

[0039] In the present application, the fly ash can be I-class fly ash or II-class fly ash.

[0040] In the present application, the mineral powder can be S95 mineral powder or S105 mineral powder.

[0041] In the present application, the activity index (28d) of the volcanic ash can be not less than 70%, the water requirement ratio can be not more than 100%, and the fineness can be not more than 30%.

[0042] In the present application, the specific surface area of the silica ash can be not less than 15000 m 2 / kg, and specifically can be 17000 m 2 The water requirement ratio can be not more than 125%, and specifically can be 110%, the loss on ignition can be not more than 4%, and specifically can be 3%, the activity index (7d rapid method) can be not less than 105%, and specifically can be 120%, the SiO2 content can be not less than 85wt%, and specifically can be 90wt%, and the total alkali content can be not more than 1.5wt%, and specifically can be 1wt%.

[0043] In the present application, the mineral admixture specifically can be metakaolin, silica ash and fly ash, wherein the mass fraction of the fly ash can be 5-10 parts, and the mass fraction of the silica ash can be 5-10 parts.

[0044] The weather-resistant fiber cement plate provided by the present application includes 20-50 parts of waste stone powder, specifically 25 parts, 30 parts, 35 parts, 40 parts or 45 parts, based on the mass fraction of the cement. Waste stone powder is a by-product generated in the process of stone processing, mining and aggregate production, and is generally treated by landfill. The present application uses waste stone powder as raw material, realizes high-value utilization of waste stone powder, and releases the land resources used for landfill.

[0045] In the present application, the material of the waste stone powder can include one or more of limestone, granite, quartzite, tuff, basalt, diorite, gneiss and iron tailings. The waste stone powder in the present application is mainly used to replace the conventional material ultra-fine quartz powder, mainly plays a filling role, can reduce the shrinkage rate of the plate, improve the weather resistance, and at the same time can reduce the cost.

[0046] In the present application, the methylene blue value MB F of the waste stone powder can be not more than 6.0 (reference to "High Performance Concrete Aggregate" JG / T 568-2019), and D90 can be not more than 150 μm (particle size analysis is carried out by using a laser particle size analyzer, D90 is the particle size corresponding to the cumulative particle size distribution percentage of 90% of the waste stone powder).

[0047] The weather-resistant fiber cement plate provided by the present application includes 6-10 parts of fiber, specifically 7 parts or 8 parts, based on the mass fraction of the cement.

[0048] In the present application, the fiber can include a first fiber material and cellulose fiber; the first fiber material can include one or several of chemical synthetic fiber and mineral fiber.

[0049] In the present application, the chemical synthetic fiber can include one or several of polyvinyl alcohol fiber (PVA), polyacrylonitrile fiber (PAN) and polyoxymethylene fiber (POM); the elastic modulus of the chemical synthetic fiber can be no less than 10 GPa, specifically can be 15 GPa, the length can be 4-12 mm, specifically can be 6 mm, 8 mm or 10 mm.

[0050] In the present application, the mineral fiber can include one or several of basalt fiber and alkali-resistant glass fiber; the elastic modulus of the mineral fiber can be no less than 80 GPa, specifically can be 100 GPa, the length can be 4-12 mm, specifically can be 6 mm, 8 mm or 10 mm.

[0051] In the present application, the beating degree of the cellulose fiber can be 25-40°SR, specifically can be 30°SR or 35°SR, the wet weight can be 8-15 g, specifically can be 10 g or 12 g.

[0052] In the present application, the cellulose fiber can be raw pulp paperboard.

[0053] In the present application, the main role of the fiber is to enhance the tensile strength and toughness of the board, in addition to the above-mentioned role of the cellulose fiber, on the one hand, it has good water filtration performance, which can ensure that the excess water in the blank can be quickly filtered out during the preparation process, on the other hand, due to its good fanning phenomenon, it has good adsorption capacity for materials, especially for the papermaking process. However, the tensile strength and elastic modulus of the cellulose fiber itself are relatively low, while the tensile strength and elastic modulus of the synthetic fiber or mineral fiber are relatively high, which can greatly improve the strength of the board, and the two have a synergistic effect.

[0054] In the present application, the mass fraction of the cellulose fiber in the fiber can be 4-8 parts, specifically can be 6 parts, based on the mass fraction of the cement; the mass fraction of the first fiber material can be 0.5-3 parts, specifically can be 1 part or 2 parts.

[0055] Based on the mass fraction of the cement, the weather-resistant fiber cement board provided in the present application includes 0.1-0.5 parts of defoaming agent, specifically can be 0.2 parts, 0.3 parts or 0.4 parts. The defoaming agent can greatly eliminate the harmful bubbles generated during the production of the weather-resistant fiber cement board, and improve the compactness and weather resistance of the weather-resistant fiber cement board.

[0056] In the present application, the defoaming agent can include one or more of a silicon and oil composite type defoaming agent, a silicon ether copolymer type defoaming agent, and an organosiloxane type defoaming agent; the silicon and oil composite type defoaming agent can be a silicon oil and polyether composite defoaming agent; the silicon ether copolymer type defoaming agent can be GSK-712 defoaming agent (Wuhan Jiyesheng Chemical Co., Ltd.); and the organosiloxane type defoaming agent can be polydimethylsiloxane.

[0057] The present application also provides a preparation method of the weather-resistant fiber cement board described in the above-mentioned scheme, which comprises the following steps:

[0058] (1) mixing cement, mineral admixtures, waste stone powder slurry, cellulose fiber slurry, first fiber material, defoaming agent, and water to obtain a slurry;

[0059] (2) sequentially performing board making, green board pressing, pre-curing, and curing on the slurry to obtain the weather-resistant fiber cement board; the board making is by the papermaking method or the flow slurry method.

[0060] In the present application, cement, mineral admixtures, waste stone powder slurry, cellulose fiber slurry, first fiber material, defoaming agent, and water are mixed (denoted as first mixing) to obtain a slurry. In the present application, the concentration of the waste stone powder slurry can be 50-60 wt%, and specifically can be 54 wt% or 57 wt%.

[0061] In the present application, the preparation method of the waste stone powder slurry can comprise the following steps: mixing waste stone powder with water; the mixing can be stirring mixing; and the waste stone powder slurry can be sent to a stone powder slurry storage tank for standby use.

[0062] In the present application, the concentration of the cellulose fiber slurry can be 3-4 wt%, and specifically can be 3.5 wt%.

[0063] In the present application, when the subsequent board making is by the papermaking method, the beating degree of the cellulose fiber slurry can be 30-40 °SR, and specifically can be 35 °SR; and when the subsequent board making is by the flow slurry method, the beating degree of the cellulose fiber slurry can be 25-35 °SR, and specifically can be 30 °SR.

[0064] In the present application, the preparation method of the cellulose fiber slurry can comprise the following steps: mixing raw pulp paperboard and part of water to perform pulping to obtain a premixed slurry, and mixing the premixed slurry and the remaining water (to obtain a mixed slurry) to perform grinding.

[0065] In the present application, the pulping time can be 30-50 minutes, and specifically can be 35 minutes, 40 minutes, or 45 minutes.

[0066] In the present application, the concentration of the premixed slurry can be 5-15wt%, specifically 8wt%, 10wt% or 12wt%; the premixed slurry can be pumped into a pulp storage tank for standby.

[0067] In the present application, the concentration of the mixed slurry can be 4-6wt%, specifically 5wt%.

[0068] In the present application, the first mixing can include the following steps: water, cellulose fiber slurry, first fiber material, defoaming agent, waste stone powder slurry, cement and mineral admixture are sequentially put into a beater for mixing.

[0069] In the present application, the mixing time (starting from the completion of adding mineral admixture) can be 15-20 minutes, specifically 18 minutes. The present application ensures uniform mixing of the slurry through the above mixing.

[0070] In the present application, the solid content of the slurry can be 12-18wt%, specifically 15wt%.

[0071] After obtaining the slurry, the present application sequentially performs plate making, green board pressing, pre-curing and curing on the slurry to obtain the weather-resistant fiber cement board, and the plate making is by the papermaking method or the flow slurry method. In the present application, the plate making by the papermaking method can include the following steps: the slurry is transported into a net box used for forming by the papermaking method, and the slurry is dragged out in the form of a thin material layer with water by the wool cloth of the net box and then dehydrated.

[0072] In the present application, the slurry before use can also include dilution of the slurry by adding water; the dilution equipment can be a pre-mixer; the target solid content of the dilution can be 2-10wt%, specifically 4wt%, 6wt% or 8wt%.

[0073] In the present application, the diluted slurry can be transported into the net box of the papermaking machine through different outlets of the pre-mixer; a stirrer can be arranged in the net box; the stirrer can be operated to prevent the diluted slurry from precipitating.

[0074] In the present application, the dehydration can include vacuum suction and water filtration and extrusion water removal; the target water content of the dehydration can be 28-35wt%, specifically 30wt% or 32wt%. The principle of the papermaking machine is shown in Figure 1 The wool cloth sequentially passes through the net box and the vacuum box, and most of the water is removed by vacuum suction and water filtration; then it is gradually wound on the forming cylinder of the papermaking machine, and the water is removed by the chest roll; when the thin material layer wound on the forming cylinder reaches the set thickness, the system controls the forming cylinder to automatically cut off the material blank, and the unfolded green board is transported to the cutting position of the green board machine for cutting.

[0075] In the present application, the flow method of making board can include the following steps: the pulp is transported into the flow box used in the flow method, and the pulp flows out of the flow box and is laid on the running wire cloth for dewatering.

[0076] In the present application, the pulp can also be diluted with water before use; the dilution device can be a pre-mixing tank; the target solid content of the dilution can be 10-17wt%, specifically 12wt%, 14wt% or 16wt%.

[0077] In the present application, the diluted pulp can be transported into the flow box of the flow method board making machine through different outlets of the pre-mixing tank; the flow box can be provided with a stirrer and a leveling roller; the stirrer can be operated to prevent the diluted pulp from precipitating.

[0078] In the present application, the dewatering can include vacuum suction and extrusion; the target moisture content of the dewatering can be 28-32wt%, specifically 29wt%, 30wt% or 31wt%. The principle of the flow method board making machine is shown in Figure 2 The wire cloth is dewatered by vacuum suction through the vacuum box, and then is wound on the forming cylinder of the flow method board making machine, and is dewatered by extrusion through the breast roll; when the thin layer wound on the forming cylinder reaches the set thickness, the system controls the forming cylinder to automatically cut off the blank, and the unfolded board is transported to the cutting position of the water cutting blank splicer for cutting.

[0079] In the present application, the board blank pressing can include the following steps: the board blank is stacked and then is pressed for dewatering.

[0080] In the present application, the pressing time of the press dewatering can be 30-60 minutes, specifically 40 minutes or 50 minutes, the constant pressure of the single stack can be 5000-7000T, specifically 5500T, 6000T or 6500T, and the pressure holding time can be 20-30 minutes, specifically 25 minutes.

[0081] In the present application, the pre-curing device can be a curing kiln; the pre-curing temperature can be 30-40℃, specifically 35℃, and the heat preservation and static time can be 6-8h, specifically 7h.

[0082] In the present application, the pre-cured board can also be demolded after pre-curing.

[0083] In the present application, the curing can comprise steam curing and / or natural curing; the steam curing can be carried out in a curing kiln; the curing system of the steam curing can be: a temperature rising rate of no more than 15℃ / h, specifically 10℃ / h or 5℃ / h, a constant temperature of 80-90℃, specifically 85℃, a constant temperature time of 24-48h, specifically 30h, 36h or 42h, and a temperature falling rate of no more than 20℃ / h, specifically 15℃ / h or 10℃ / h.

[0084] In the present application, the natural curing can be carried out in an indoor environment; the temperature of the natural curing can be 20-40℃, specifically 25℃, 30℃ or 35℃, and the heat preservation curing time can be no less than 14d, specifically 15d, 20d or 30d; the board can be covered with moisture during the natural curing.

[0085] In the present application, the curing can further comprise post-treatment of the obtained board; the post-treatment can comprise drying, surface sanding and edge grinding of the obtained board in sequence; the drying can be baking; the edge grinding can comprise board edge grinding and chamfering. The present application reduces the water content through baking, improves the surface flatness and appearance quality through surface sanding, and improves the appearance size accuracy through edge grinding.

[0086] The present application also provides application of the weather-resistant fiber cement board described in the above scheme or the weather-resistant fiber cement board obtained by the preparation method described in the above scheme in the field of energy-saving buildings.

[0087] The weather-resistant fiber cement board provided by the present application has a density of greater than 1.65g / cm 3 , a wet swelling rate of less than 0.10%, a water absorption rate of less than 10%, a dry flexural strength of greater than 25MPa, a saturated water flexural strength of greater than 18MPa, a hot water test flexural strength ratio of greater than 90%, a hot rain test flexural strength ratio of greater than 95%, a soaking-drying test flexural strength ratio of greater than 95%, and a resistance test flexural strength ratio of greater than 90%.

[0088] The weather-resistant fiber cement board provided by the present application has good weather resistance and is suitable for use in the field of energy-saving buildings, and is especially suitable for use in the outer wall of energy-saving buildings.

[0089] In order to further illustrate the present application, the schemes of the present application are described in detail below in combination with the drawings and examples, but they should not be understood as limiting the protection scope of the present application.

[0090] In the specific embodiments of the present application, the experimental methods used are all common methods, and the raw materials used are all commercially available products, unless otherwise specified.

[0091] Example 1

[0092] The embodiment provides a weather-resistant fiber cement plate, which is prepared from the following raw materials in parts by mass: cement 30 parts, mineral admixture 13 parts (metakaolin 6 parts and fly ash 7 parts), waste stone powder 50 parts, fiber 7 parts (cellulose fiber (pulp) 4 parts and PVA fiber 3 parts), and defoaming agent (polydimethylsiloxane) 0.1 part.

[0093] The cement in the embodiment is P.O 52.5 ordinary portland cement.

[0094] The metakaolin in the embodiment has a SiO2 content of 56wt%, an Al2O3 content of 38wt%, a water demand ratio of 115%, and a 28d activity index of 110%.

[0095] The fly ash in the embodiment is grade I fly ash.

[0096] The waste stone powder in the embodiment is limestone powder, and the stone powder methylene blue value MB is 3.0, and D90 is 70μm. F

[0097] The PVA fiber in the embodiment has a length of 6mm.

[0098] The weather-resistant fiber cement plate in the embodiment is prepared by the papermaking method, and the preparation process comprises the following steps:

[0099] (1) Pulp preparation: after the raw pulp paperboard (air-dried weight) is weighed and added into a pulper, water is added and fully pulped, the pulping concentration is controlled to be 10wt%, the pulping time is 40 minutes, the pulped pulp is pumped into a pulp storage tank, the concentration of the pulped pulp is diluted to 5wt% by adding water, and the pulped pulp is transported to a pulp mill for pulp refining treatment, the pulp concentration is 4wt%, and the beating degree is controlled to be 35°SR, so that the pulp is obtained.

[0100] (2) Stone powder slurry preparation: the waste stone powder and water are continuously added into a slurry tank for stirring, and then are sent into a stone powder slurry storage tank, the stone powder slurry concentration is controlled to be 50wt%, and the stone powder slurry is obtained.

[0101] (3) Slurry preparation: water, pulp, PVA fiber, defoaming agent, stone powder slurry, cement and mineral admixture are sequentially added into a beater, and after all the raw materials are added, the beater is operated for 20 minutes to uniformly mix the raw materials, so that the slurry is obtained.

[0102] (4) Slurry placement: the slurry is transported into a pre-agitator tank, and water is added for preliminary dilution; then the agitated and diluted slurry is transported into each net box for the papermaking method forming through different outlets of the pre-agitator tank, the solid content in the net box is controlled to be 2-10wt%, and an agitator in the net box is operated to prevent sedimentation.

[0103] ​(5) Plate making: The slurry is uniformly dragged out by the industrial woolen cloth running through each net box in the form of a thin slurry layer with water, and most of the water is removed after filtration by the vacuum system, to obtain a thin slurry layer; the thin slurry layer passes through multiple net boxes in turn, and the industrial woolen cloth passes through the main vacuum box and is gradually wound on the forming cylinder of the plate making machine, and is dehydrated by the chest roll under pressure; when the thin slurry layer wound on the chest roll reaches the set thickness (the moisture content of the plate blank is controlled at 28-35%), the PLC controls the forming cylinder to automatically cut off the plate blank, and the unfolded plate blank is conveyed to the cutting position of the plate blank connecting machine for cutting.

[0104] (6) Plate blank pressurization: After the plate blanks are stacked, they are transferred to the pressurization equipment for pressurization and dehydration treatment: the pressurization time is 30 minutes, the constant pressure of a single stack is 5000T, and the pressure maintaining time is 30 minutes.

[0105] (7) Pre-curing: After the plate is pressurized, it is placed in a curing kiln with a temperature of 30°C and is static for 8 hours.

[0106] (8) Curing: The plate after pre-curing is demolded and then cured; the curing method is steam curing, and the curing system is: the heating rate is 10°C / h, the constant temperature is 80°C, the constant temperature time is 48h, and the cooling rate is 15°C / h.

[0107] (9) Post-treatment and finished product storage: The plate after curing is dried to reduce the moisture content, sanded to improve the surface flatness and appearance quality, edge ground and chamfered to improve the appearance size accuracy, and stored as finished products.

[0108] Example 2

[0109] The weather-resistant fiber cement plate is prepared from the following raw materials in parts by mass: cement 25 parts, mineral admixture 19 parts (metakaolin 6 parts, silica fume 6 parts, and fly ash 7 parts), waste stone powder 50 parts, fiber 7 parts (cellulose fiber 4 parts and PVA fiber 3 parts), and defoaming agent (polydimethylsiloxane) 0.1 part.

[0110] The cement in this example is P.O 52.5 ordinary portland cement.

[0111] The metakaolin in this example has a SiO2 content of 56wt%, an Al2O3 content of 38wt%, a water requirement ratio of 115%, and a 28d activity index of 110%.

[0112] The silica fume in this example has a specific surface area of 18000m 2 / kg, a water requirement ratio of 120%, an activity index (7d rapid method) of 115%, and a SiO2 content of 92wt%.

[0113] The fly ash in this example is grade I fly ash.

[0114] The waste stone powder in this embodiment is granite stone powder, and the stone powder methylene blue value MB F is 4.5, and D90 is 80 μm.

[0115] The length of the PVA fiber in this embodiment is 8 mm.

[0116] This embodiment adopts the method of taking to prepare the weather-resistant fiber cement board, which comprises the following steps:

[0117] (1) Paper pulp preparation, stone powder slurry preparation, slurry preparation, slurry placement and board preparation, the method is the same as that in Embodiment 1.

[0118] (2) Board blank pressurization: after the board blank is stacked, it is moved to a pressurization equipment for pressurization dewatering treatment: the pressurization time is 40 minutes, the constant pressure of single stack is 6000T, and the pressure maintaining time is 25 minutes.

[0119] (3) Pre-curing: after the board is pressurized, it is placed in a curing kiln, the temperature is controlled at 40℃, and the static stop is 6h.

[0120] (4) Curing: the board after pre-curing is demolded and then cured; the curing mode is steam curing, and the curing system is: the temperature rising rate is 10℃ / h, the constant temperature is 90℃, the constant temperature time is 24h, and the temperature falling rate is 15℃ / h.

[0121] (5) Post-treatment and finished product storage, the method is the same as that in Embodiment 1.

[0122] Embodiment 3

[0123] This embodiment provides a weather-resistant fiber cement board, which is prepared from the following raw materials in mass parts: cement 35 parts, mineral admixture 17 parts (metakaolin 8 parts and volcanic ash 9 parts), waste stone powder 40 parts, fiber 8 parts (cellulose fiber 6 parts and PAN fiber 2 parts) and defoaming agent (polydimethylsiloxane) 0.3 parts.

[0124] The cement in this embodiment is P.O 52.5 cement ordinary portland cement.

[0125] The metakaolin in this embodiment has a SiO2 content of 56wt%, an Al2O3 content of 38wt%, a water requirement ratio of 115%, and a 28d activity index of 110%.

[0126] The volcanic ash in this embodiment has an activity index (28d) of 76%, a water requirement ratio of 96%, and a fineness of 15%.

[0127] The waste stone powder in this embodiment is quartz stone powder, and the stone powder methylene blue value MB F is 2.0, and D90 is 90 μm.

[0128] The length of the PAN fiber in the embodiment is 8 mm.

[0129] The weather-resistant fiber cement board in the embodiment is prepared by the papermaking method, including the following steps:

[0130] (1) Paper pulp preparation, stone powder slurry preparation, slurry preparation, slurry placement and board preparation, the method is the same as that in Embodiment 1.

[0131] (2) Board blank pressurization: after the board blank is stacked, it is moved to a pressurization device for pressurization dewatering treatment: pressurization time 50 minutes, constant pressure of single stack 7000T, pressure maintaining time 20 minutes.

[0132] (3) Pre-curing: after the board is pressurized, it is placed in a curing kiln, the temperature is controlled at 35℃, and the static stop is 7h.

[0133] (4) Curing: the board after pre-curing is demolded and then cured; the curing method is steam curing, and the curing system is: temperature rising rate 10℃ / h, constant temperature 85℃, constant temperature time 36h, temperature falling rate 15℃ / h.

[0134] (5) Post-treatment and finished product storage, the method is the same as that in Embodiment 1.

[0135] Embodiment 4

[0136] The weather-resistant fiber cement board in the embodiment is prepared from the following raw materials in mass parts: cement 30 parts, mineral admixture 22 parts (metakaolin 7 parts, mineral powder 7 parts and fly ash 8 parts), waste stone powder 40 parts, fiber 8 parts (cellulose fiber 6 parts and PAN fiber 2 parts) and defoaming agent (GSK-712 defoaming agent) 0.3 parts.

[0137] The cement in the embodiment is P.Ⅱ 52.5 ordinary portland cement.

[0138] The metakaolin in the embodiment has a SiO2 content of 56wt%, an Al2O3 content of 38wt%, a water requirement ratio of 115% and a 28d activity index of 110%.

[0139] The mineral powder in the embodiment is S95 mineral powder.

[0140] The fly ash in the embodiment is grade II fly ash.

[0141] The waste stone powder in the embodiment is tuff stone powder, and the stone powder methylene blue value MB F is 5.5 and D90 is 100μm.

[0142] The length of the PAN fiber in the embodiment is 10 mm.

[0143] The weather-resistant fiber cement board in the embodiment is prepared by the flow slurry method, including the following steps:

[0144] (1) The method for preparing the pulp is the same as in Example 1, except that the beating degree of the pulp is controlled at 30°SR.

[0145] (2) The method for preparing the stone powder slurry is the same as in Example 1.

[0146] (3) The method for preparing the slurry is the same as in Example 1.

[0147] (4) The pulp is delivered to a pre-agitation tank while water is added for initial dilution; then the agitated and diluted slurry is delivered to a headbox through two outlets of the pre-agitation tank, with the solid content of the slurry controlled at 10-17wt%, and the agitator in the headbox is operated to prevent sedimentation.

[0148] (5) The board is prepared as follows: the headbox is provided with an agitator and a smoothing roller, the slurry is uniformly discharged from the headbox and laid on a running felt, the thin layer of the slurry after being filtered by the suction of a vacuum system is wound on a forming drum, and when the wound layers reach the set thickness of the green board (with the moisture content of the green board controlled at 28-32wt%), the green board is automatically cut off, and then delivered to a water cutting and green board splicing machine.

[0149] (6) The green board is pressed as follows: after the green boards are stacked, they are moved to a pressing device for dewatering treatment: the pressing time is 30 minutes, the constant pressure of a single stack is 5000T, and the pressure maintaining time is 30 minutes.

[0150] (7) The green board is pre-cured as follows: after being pressed, the green board is placed in a curing kiln, the temperature is controlled at 30℃, and the green board is statically stopped for 8h.

[0151] (8) The green board is cured as follows: after pre-curing, the green board is demolded and then cured; the curing is steam curing and natural curing which are sequentially performed; the steam curing is performed in a curing kiln, and the curing system is as follows: the heating rate is 10℃ / h, the constant temperature is 80℃, the constant temperature time is 48h, and the cooling rate is 15℃ / h; the natural curing is performed in an indoor environment, the temperature is 20-40℃, and the curing time is not less than 14d, and the green board is covered and moisturized during the natural curing.

[0152] (9) The post-treatment and finished product storage are the same as in Example 1.

[0153] Example 5

[0154] The weather-resistant fiber cement board is prepared from the following raw materials in parts by mass: cement 40 parts, mineral admixture 21 parts (metakaolin 7 parts, silica fume 7 parts, and fly ash 7 parts), waste stone powder 30 parts, fiber 9 parts (cellulose fiber 8 parts and POM fiber 1 part), and defoaming agent (silicone oil and polyether composite defoaming agent) 0.5 part.

[0155] The cement used in this example is P.Ⅱ 52.5 ordinary Portland cement.

[0156] The metakaolin used in this example has a SiO2 content of 56wt%, an Al2O3 content of 38wt%, a water requirement ratio of 115%, and a 28d activity index of 110%.

[0157] The silica fume used in this example has a specific surface area of 18000m 2 / kg, a water requirement ratio of 120%, an activity index (7d rapid method) of 115%, and a SiO2 content of 92wt%.

[0158] The fly ash used in this example is Class Ⅱ fly ash.

[0159] The waste stone powder used in this example is basalt stone powder, which has a stone powder methylene blue value MB F of 5.0 and a D90 of 90μm.

[0160] The POM fiber used in this example has a length of 6mm.

[0161] This example uses the flow slurry method to prepare a weather-resistant fiber cement board, which comprises the following steps:

[0162] (1) Paper pulp preparation, stone powder slurry preparation, slurry preparation, slurry placement, and board making, the method being the same as that of Example 4.

[0163] (2) Pressurization of the board blank: after the board blank is stacked, it is moved to a pressurization device for pressurization and dewatering treatment: pressurization time 40 minutes, constant pressure of a single stack 6000T, pressure maintaining time 25 minutes.

[0164] (3) Pre-curing: after the board is pressurized, it is placed in a curing kiln, the temperature is controlled at 40℃, and it is statically stopped for 6h.

[0165] (4) Curing: after pre-curing, the board is demolded and then naturally cured, the natural curing is carried out in an indoor environment, the temperature is 20-40℃, the curing time is not less than 14d, and the board is covered and moisturized during the curing period.

[0166] (5) Post-treatment and finished product storage, the method being the same as that of Example 4.

[0167] Example 6

[0168] This example provides a weather-resistant fiber cement board, which is prepared from the following raw materials in mass parts: cement 35 parts, mineral admixture 26 parts (metakaolin 13 parts, silica fume 7 parts, and volcanic ash 6 parts), waste stone powder 30 parts, fiber 9 parts (cellulose fiber 8 parts and POM fiber 1 part), and defoaming agent (polydimethylsiloxane) 0.5 part.

[0169] The cement used in this example is P.Ⅱ 52.5 ordinary Portland cement.

[0170] The metakaolin described in this example has a SiO2 content of 56wt%, an Al2O3 content of 38wt%, a water requirement ratio of 115%, and a 28d activity index of 110%.

[0171] The silica ash described in this example has a specific surface area of 18000m 2 / kg, a water requirement ratio of 120%, an activity index (7d rapid method) of 115%, and a SiO2 content of 92wt%.

[0172] The volcanic ash described in this example has an activity index (28d) of 76%, a water requirement ratio of 96%, and a fineness of 15%.

[0173] The waste stone powder described in this example is diorite stone powder, and has a stone powder methylene blue value MB F of 3.0 and a D90 of 70μm.

[0174] The POM fiber described in this example has a length of 6mm.

[0175] The weather-resistant fiber cement board prepared in this example by the flow slurry method comprises the following steps:

[0176] (1) Paper pulp preparation, stone powder slurry preparation, slurry preparation, slurry placement, and board preparation, by the method of Example 4.

[0177] (2) Pressurization of the board blank: after the board blank is stacked, it is moved to a pressurization device for pressurization and dewatering treatment: pressurization time 50 minutes, constant pressure of 7000T for a single stack, and pressure retention time 20 minutes.

[0178] (3) Pre-curing: after the board is pressurized, it is placed in a curing kiln, with the temperature controlled at 35℃, and is allowed to stand for 7h.

[0179] (4) Curing: after pre-curing, the board is demolded and is then naturally cured, with the natural curing being performed in an indoor environment, at a temperature of 20-40℃, for a curing time of no less than 14d, and the board is covered and kept moist during the curing period.

[0180] (5) Post-treatment and finished product storage, by the method of Example 4.

[0181] Comparative Example 1

[0182] This comparative example provides a weather-resistant fiber cement board prepared from the following raw materials in mass parts: cement 50 parts, mineral admixture 22 parts (metakaolin 7 parts, silica ash 7 parts, and fly ash 8 parts), waste stone powder 20 parts, fiber 8 parts (cellulose fiber 6 parts and PVA fiber 2 parts), and defoaming agent 0.3 parts.

[0183] The specific types of each type of raw material used in this comparative example are the same as in Example 4.

[0184] A comparative example was prepared by using a pulp flow method to prepare a weather-resistant fiber cement board, and the preparation method was the same as that of Example 4.

[0185] Comparative Example 2

[0186] A comparative example was prepared by using a pulp flow method to prepare a weather-resistant fiber cement board, and the preparation method was the same as that of Example 4.

[0187] The specific types of each type of raw material used in the comparative example were the same as those of Example 4.

[0188] A comparative example was prepared by using a pulp flow method to prepare a weather-resistant fiber cement board, and the preparation method was the same as that of Example 4.

[0189] Comparative Example 3

[0190] A comparative example was prepared by using a pulp flow method to prepare a weather-resistant fiber cement board, and the preparation method was the same as that of Example 4.

[0191] The specific types of each type of raw material used in the comparative example were the same as those of Example 4.

[0192] A comparative example was prepared by using a pulp flow method to prepare a weather-resistant fiber cement board, and the preparation method was the same as that of Example 4.

[0193] Comparative Example 4

[0194] A comparative example was prepared by using a pulp flow method to prepare a weather-resistant fiber cement board, and the preparation method was the same as that of Example 4.

[0195] The specific types of each type of raw material used in the comparative example were the same as those of Example 4.

[0196] A comparative example was prepared by using a pulp flow method to prepare a weather-resistant fiber cement board, and the preparation method was the same as that of Example 4.

[0197] (1) Paper pulp preparation, stone powder pulp preparation, slurry preparation, pulp placement and board preparation, method same as Example 4.

[0198] (2) Pressurization of the board blank: after stacking the board blank, it was transferred to a pressurization device for pressurization and dewatering treatment: pressurization time 20 minutes, constant pressure of single stack 4000T, pressure holding time 10 minutes.

[0199] (3) Pre-cultivation, maintenance, post-treatment and finished product storage, the method is the same as example 4.

[0200] Comparative Example 5

[0201] This comparative example provides a weather-resistant fiber cement board, which is prepared from the following raw materials in mass parts: cement 30 parts, mineral admixture 22 parts (metakaolin 7, silica fume 7 parts and fly ash 8 parts), waste stone powder 40 parts, fiber 8 parts (cellulose fiber 6 parts and PVA fiber 2 parts) and defoaming agent 0.3 parts.

[0202] The specific types of each type of raw material used in this comparative example are the same as in example 4.

[0203] This comparative example uses the flow slurry method to prepare a weather-resistant fiber cement board, including the following steps:

[0204] (1) Paper pulp preparation, stone powder slurry preparation, slurry preparation, slurry placement, board preparation, board blank pressing and pre-cultivation, the method is the same as example 4.

[0205] (2) Maintenance: After pre-cultivation, the board is demolded and then maintained; the maintenance is steam curing and natural curing in sequence, the steam curing is carried out in a curing kiln, and the curing schedule is: heating rate 10℃ / h, constant temperature 60℃, constant temperature time 48h, cooling rate 15℃ / h; the natural curing is carried out in an indoor environment, the temperature is 20-40℃, the curing time is not less than 14d, and the board is covered and moisturized during the natural curing.

[0206] (3) Post-treatment and finished product storage, the method is the same as example 4.

[0207] Test Example 1

[0208] The apparent density, water absorption, wet swelling rate, dry flexural strength, saturated water flexural strength, hot water test, hot rain test and immersion-drying strength of the weather-resistant fiber cement boards of examples 1-6 and comparative examples 1-5 were tested, the test method referred to JC / T 412.1-2018 "Asbestos-free fiber cement flat board", and the test results are shown in table 1 and table 2.

[0209] Table 1 Test results of basic properties of weather-resistant fiber cement boards

[0210]

[0211] Table 2 Test results of weather resistance of weather-resistant fiber cement boards

[0212]

[0213]

[0214] According to the test results in Table 1 and Table 2, the weather-resistant fiber cement board of Examples 1-6 has high compactness and mechanical properties, and low water absorption and wet expansion rate, and the apparent density is greater than 1.65 g / cm 3 , the wet expansion rate is less than 0.10%, the water absorption is less than 10%, the dry flexural strength is greater than 25 MPa, and the saturated flexural strength is greater than 18 MPa. These properties enable the weather-resistant fiber cement board of Examples 1-6 to be used in the field of exterior walls, with good weather resistance and long-term mechanical ability, improving service life and reducing maintenance and reinforcement costs in the later stage; the weather-resistant fiber cement board of Examples 1-6 has excellent weather resistance, with a hot water test flexural strength ratio of greater than 90%, a hot rain test flexural strength ratio of greater than 95%, a soaking-drying test flexural strength ratio of greater than 95%, and a resistance test flexural strength ratio of greater than 90%; at the same time, the weather-resistant fiber cement board of Examples 1-6 is made by pressure-free steaming curing, which can reduce initial equipment investment and maintenance costs, improve safety during production, reduce energy consumption and production costs, and reduce carbon emissions, which is conducive to energy saving and environmental protection, and has great social and economic benefits; at the same time, a large amount of waste stone powder is used as an inert filler material in the present application, with a dosage of 30-50%, and its cost is close to zero, which is applied in the present application, the waste stone powder is used with high added value, which alleviates the problem of long-term storage and land occupation, and also greatly reduces the production cost of the weather-resistant fiber cement board.

[0215] According to the test results in Table 1 and Table 2, the weather-resistant fiber cement board of Examples 1-6 has high compactness and mechanical properties, and low water absorption and wet expansion rate, and the apparent density is greater than 1.65 g / cm 3 , the wet expansion rate is less than 0.10%, the water absorption is less than 10%, the dry flexural strength is greater than 25 MPa, and the saturated flexural strength is greater than 18 MPa. These properties enable the weather-resistant fiber cement board of Examples 1-6 to be used in the field of exterior walls, with good weather resistance and long-term mechanical ability, improving service life and reducing maintenance and reinforcement costs in the later stage; the weather-resistant fiber cement board of Examples 1-6 has excellent weather resistance, with a hot water test flexural strength ratio of greater than 90%, a hot rain test flexural strength ratio of greater than 95%, a soaking-drying test flexural strength ratio of greater than 95%, and a resistance test flexural strength ratio of greater than 90%; at the same time, the weather-resistant fiber cement board of Examples 1-6 is made by pressure-free steaming curing, which can reduce initial equipment investment and maintenance costs, improve safety during production, reduce energy consumption and production costs, and reduce carbon emissions, which is conducive to energy saving and environmental protection, and has great social and economic benefits; at the same time, a large amount of waste stone powder is used as an inert filler material in the present application, with a dosage of 30-50%, and its cost is close to zero, which is applied in the present application, the waste stone powder is used with high added value, which alleviates the problem of long-term storage and land occupation, and also greatly reduces the production cost of the weather-resistant fiber cement board. 3Compared with the comparative example 4, the curing temperature is reduced, although the compactness is ensured, but because of the insufficient curing, the mechanical property of the weather-resistant fiber cement plate is reduced significantly.

[0216] From the above examples, the weather-resistant fiber cement plate provided by the application has good weather resistance, low cost, realizes high-value utilization of solid waste, and has good economic and social benefits.

[0217] Although the above examples have made a detailed description of the application, it is only a part of the examples of the application, not all examples, and other examples can be obtained under the premise of no creativity according to the examples, and these examples all belong to the protection scope of the application.

Claims

1. A weather resistant fiber cement sheet material, characterized by, According to the mass fraction, the following raw materials are prepared: cement 20-40 parts, mineral admixture 10-30 parts, waste stone powder 20-50 parts, fiber 6-10 parts and defoaming agent 0.1-0.5 parts; the mineral admixture includes metakaolin and first mineral powder; the fiber includes first fiber material and cellulose fiber.

2. The weather resistant fiber cement sheet according to claim 1, wherein, The mass fraction of metakaolin in the mineral admixture is 5-15 parts; the SiO2 content of the metakaolin is not less than 50wt%, the Al2O3 content is not less than 35wt%, the water requirement ratio is not more than 120%, and the 28d activity index is not less than 105%.

3. The weather resistant fiber cement sheet according to claim 1 or 2, characterized in that, the first mineral powder includes one or more of fly ash, mineral powder, volcanic ash and silica fume; The specific surface area of the silica ash is not less than 15000 m 2 / kg, the water demand ratio is not more than 125%, the loss on ignition is not more than 4%, the 7d activity index is not less than 105%, the SiO2 content is not less than 85wt%, and the total alkali content is not more than 1.5wt%.

4. The weather resistant fiber cement sheet according to claim 1, wherein, the first fiber material includes one or more of chemical synthetic fiber and mineral fiber; the elastic modulus of the chemical synthetic fiber is not less than 10GPa, and the length is 4-12mm; the elastic modulus of the mineral fiber is not less than 80GPa, and the length is 4-12mm.

5. The weather resistant fiber cement sheet according to claim 1 or 4, wherein The mass fraction of cellulose fiber in the fiber is 4-8 parts; the beating degree of the cellulose fiber is 25-40°SR, and the wet weight is 8-15g.

6. The method of producing the weather resistant fiber cement sheet according to any one of claims 1 to 5, characterized in that, including the following steps: (1) mixing cement, mineral admixture, waste stone powder slurry, cellulose fiber slurry, first fiber material, defoaming agent and water to obtain a slurry; (2) sequentially performing plate making, plate blank pressing, pre-curing and curing on the slurry to obtain the weather-resistant fiber cement plate; the plate making is by the papermaking method or the flow slurry method.

7. The preparation method according to claim 6, characterized in that, the plate making by the papermaking method includes the following steps: conveying the slurry into a net box used for the papermaking method, and dragging the slurry out in the form of a thin layer with water by the wool cloth of the net box and then dehydrating; the plate making by the flow slurry method includes the following steps: conveying the slurry into a flow slurry box used for the flow slurry method, and dehydrating the slurry after flowing out of the flow slurry box and being laid on the running wool cloth.

8. The preparation method according to claim 6, characterized in that, the plate blank pressing includes the following steps: pressing and dehydrating the plate blank after stacking; the pressing and dehydrating has a pressing time of 30-60 minutes, a constant pressure of 5000-7000T for a single stack, and a pressure maintaining time of 20-30 minutes.

9. The production method according to claim 6 or 8, characterized by, the curing includes steam curing and / or natural curing; the curing system of the steam curing has an ascending temperature rate of not higher than 15℃ / h, a constant temperature of 80-90℃, a constant temperature time of 24-48h, and a descending temperature rate of not higher than 20℃ / h; the temperature of the natural curing is 20-40℃, and the temperature maintaining curing time is not less than 14d; the plate is covered and kept moist during the natural curing.

10. Application of the weather-resistant fiber cement plate of any one of claims 1-5 or the weather-resistant fiber cement plate prepared by the preparation method of any one of claims 6-9 in the field of energy-saving buildings.

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