A method for preparing fiber-reinforced modified concrete

Abstract

The present invention relates to the technical field of concrete, and discloses a method for preparing fiber-reinforced modified concrete. The present invention adds steel fiber, cement, gravel, sand, cellulose sulfonate water-reducing agent, ferrocene-modified polyurethane and water into a mixer, stirs evenly, and stirs to obtain fiber-reinforced modified concrete. Ferrocene-modified polyurethane contains ferrocene groups, cyclodextrin groups and hydroxyl groups, wherein the hydroxyl groups can react chemically with silicates in concrete to form stable complexes, thereby increasing the bonding ability between cements and improving the strength of concrete. When ferrocene is added to concrete, stable compounds can be formed in the concrete, thereby improving the overall performance of the concrete. Cyclodextrin can promote the concrete to be more compact, thereby improving its durability. The polyurethane contained therein can also improve the toughness of the concrete.

Description

Technical Field

[0001] The invention relates to the technical field of concrete, in particular to a method for preparing fiber-reinforced modified concrete. Background Art

[0002] Concrete is an artificial stone made of gel material, aggregate, water and admixture in a certain proportion. It has the characteristics of abundant raw materials and simple production process. The role of steel fiber in concrete is mainly reflected in improving tensile and bending properties, enhancing toughness and durability, improving shrinkage and cracks, and improving construction performance. For example, patent CN202010204096.9 discloses a green environmentally friendly concrete and its preparation method. The green environmentally friendly concrete in the invention has a slow carbonization rate in long-term application and can maintain good and stable compressive strength as a whole, but its anti-permeability performance has not been improved. Summary of the invention

[0003] 1. Technical issues to be resolved

[0004] In view of the deficiencies of the prior art, the present invention provides a method for preparing fiber-reinforced modified concrete, which has good strength and impermeability.

[0005] (II) Technical solution

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a method for preparing fiber-reinforced modified concrete, wherein the method for preparing fiber-reinforced modified concrete comprises: adding 6-12 parts by weight of steel fiber, 100-120 parts by weight of cement, 80-110 parts by weight of gravel, 150-180 parts by weight of sand, 2-3 parts by weight of cellulose sulfonate water reducer, 3-6 parts by weight of ferrocene modified polyurethane, and 60-80 parts by weight of water into a mixer, stirring evenly for 50-100 seconds to obtain fiber-reinforced modified concrete.

[0007] Preferably, the preparation method of the ferrocene-modified polyurethane is:

[0008] (1) Add 1,1-bis(dimethylsilyl)iron and 4-maleimidophenol to N,N-dimethylformamide solvent, introduce nitrogen protection, continue to add chloroplatinic acid catalyst, react at 50-75°C for 40-60 minutes, cool to room temperature after reaction, filter and dry to obtain an intermediate;

[0009] (2) adding 5-10 parts by weight of 2,2-bis(bromomethyl)-1,3-propylene glycol and 7-12 parts by weight of the intermediate to an acetone solvent, stirring evenly, and then continuing to add 3-5 mol / L of a sodium hydroxide aqueous solution, reacting at 60-80° C., and after the reaction is completed, neutralizing, concentrating, filtering, washing and drying to obtain a ferrocene chain extender;

[0010] (3) adding allyl glycidyl ether, tetrahydrofuran solvent and chloroplatinic acid into a reactor, activating at 40-55°C for 35-50 minutes, then dropping 1,1,3,3-tetramethyldisiloxane for 50-60 minutes, continuing the reaction at 55-65°C for 4-6 hours, cooling to room temperature after completion, adding activated carbon adsorbent, ultrasonically shaking for 30-40 minutes, removing the catalyst chloroplatinic acid, filtering, and rotary evaporation to obtain epoxy-modified siloxane;

[0011] (4) adding 6-10 parts by weight of β-cyclodextrin to a sodium hydroxide solution, stirring evenly, and then adding 10-16 parts by weight of epoxy-modified siloxane thereto, ultrasonically shaking at 50-60° C. for 30-40 minutes, cooling to room temperature, adding hydrochloric acid dropwise until neutral, washing and drying to obtain a silicon-modified β-cyclodextrin chain extender;

[0012] (5) Toluene diisocyanate and polyether polyol are added to a reactor, and then dibutyltin dilaurate is added to carry out prepolymerization under a nitrogen atmosphere at a temperature of 70-90°C for 2-4 hours. Then, silicon-modified β-cyclodextrin chain extender and ferrocene chain extender are added and stirred for chain extension reaction for 20-25 minutes. After the reaction is completed, the mixture is cooled naturally to obtain ferrocene-modified polyurethane.

[0013] Preferably, the mass ratio of 1,1-bis(dimethylsilyl)iron, 4-maleimidophenol and chloroplatinic acid catalyst in (1) is 1:1.1-1.3:0.01-0.03.

[0014] Preferably, the reaction time in (2) is 3-6 hours.

[0015] Preferably, the mass ratio of allyl glycidyl ether, chloroplatinic acid and 1,1,3,3-tetramethyldisiloxane in (3) is 1.1-1.4:0.02-0.03:1.

[0016] Preferably, the mass fraction of hydrochloric acid in (4) is 12-14%.

[0017] Preferably, the mass ratio of toluene diisocyanate, polyether polyol, dibutyltin dilaurate, silicon-modified β-cyclodextrin chain extender, and ferrocene chain extender in (5) is 1:0.8-1.4:0.01-0.02:1.1-1.2:0.9-1.0.

[0018] 3. Beneficial technical effects

[0019] The present invention prepares fiber-reinforced modified concrete by adding steel fiber, cement, gravel, sand, cellulose sulfonate water reducing agent, ferrocene modified polyurethane and water into a mixer, stirring the mixture evenly.

[0020] The silicon-hydrogen bond in 1,1-bis(dimethylsilyl)iron and the alkenyl in 4-maleimidophenol undergo an addition reaction, and a phenolic hydroxyl group is introduced at the same time, thereby obtaining an intermediate; the bromine in 2,2-bis(bromomethyl)-1,3-propanediol undergoes a substitution reaction with the phenolic hydroxyl in the intermediate, and a large number of hydroxyl groups are introduced at the same time, thereby obtaining a ferrocene chain extender; the double bond in allyl glycidyl ether and the hydrogen in 1,1,3,3-tetramethyldisiloxane undergo an addition reaction, and The epoxy groups in β-cyclodextrin are reacted with the epoxy groups in the epoxy-modified siloxane to generate a large number of hydroxyl groups, thereby obtaining a silicon-modified β-cyclodextrin chain extender; toluene diisocyanate and polyether polyol are added into a reaction kettle, and then dibutyltin dilaurate is added to carry out prepolymerization under a nitrogen atmosphere; then the silicon-modified β-cyclodextrin chain extender and the ferrocene chain extender are added to react, thereby obtaining a ferrocene-modified polyurethane.

[0021] Ferrocene modified polyurethane contains ferrocene group, cyclodextrin group and hydroxyl group, wherein the hydroxyl group can react chemically with silicate in concrete to form a stable complex, thereby increasing the bonding ability between cements and improving the strength of concrete. When ferrocene is added to concrete, it can form a stable compound in concrete, thereby improving the overall performance of concrete and accelerating cement hydration. Moreover, the iron ions in ferrocene will combine with the hydroxide ions in water to form ferric hydroxide hydrate, which can catalyze the hydration reaction of cement, making concrete harden faster and enhancing its mechanical properties. At the same time, after the reaction, 1,1-di(dimethylsilyl) iron increases the degree of substitution of its ferrocene group, making it more effective in concrete. Cyclodextrin can promote the compaction of concrete, thereby improving its durability. The compacted concrete can better resist external erosion. Cyclodextrin can effectively disperse these particles and reduce their aggregation through interaction with cement particles in concrete, thereby improving the fluidity of concrete. The polyurethane contained therein can also improve the toughness and impermeability of concrete. DETAILED DESCRIPTION

[0022] Example 1

[0023] (1) adding 1,1-bis(dimethylsilyl)iron and 4-maleimidophenol to N,N-dimethylformamide solvent, introducing nitrogen protection, and continuously adding chloroplatinic acid catalyst thereto, wherein the mass ratio of 1,1-bis(dimethylsilyl)iron, 4-maleimidophenol and chloroplatinic acid catalyst is 1:1.1:0.01, reacting at 50°C for 40 minutes, cooling to room temperature after the reaction, filtering and drying to obtain an intermediate;

[0024] (2) Add 5 parts by weight of 2,2-bis(bromomethyl)-1,3-propylene glycol and 7 parts by weight of the intermediate to an acetone solvent, stir evenly, then continue to add 3 mol / L sodium hydroxide aqueous solution, react at 60° C. for 3 h, and after the reaction is completed, neutralize, concentrate, filter, wash and dry to obtain a ferrocene chain extender;

[0025] (3) adding allyl glycidyl ether, tetrahydrofuran solvent and chloroplatinic acid into a reactor, activating at 40°C for 35 minutes, then dropping 1,1,3,3-tetramethyldisiloxane, wherein the mass ratio of allyl glycidyl ether, chloroplatinic acid and 1,1,3,3-tetramethyldisiloxane is 1.1:0.02:1, the dropping time is 50 minutes, and the reaction is continued at 55°C for 4 hours. After the reaction is completed, it is cooled to room temperature, an activated carbon adsorbent is added, ultrasonically vibrated for 30 minutes, the catalyst chloroplatinic acid is removed, filtered, and rotary evaporated to obtain epoxy-modified siloxane;

[0026] (4) Add 6 parts by weight of β-cyclodextrin to a sodium hydroxide solution, stir evenly, and continue to add 10 parts by weight of epoxy-modified siloxane thereto, ultrasonically vibrate at 50° C. for 30 min, cool to room temperature after the end, dropwise add 12% hydrochloric acid until neutral, wash and dry to obtain a silicon-modified β-cyclodextrin chain extender;

[0027] (5) Add toluene diisocyanate and polyether polyol into a reactor, then add dibutyltin dilaurate, and perform prepolymerization under a nitrogen atmosphere at a temperature of 70°C for 2 hours, then add silicon-modified β-cyclodextrin chain extender and ferrocene chain extender, wherein the mass ratio of toluene diisocyanate, polyether polyol, dibutyltin dilaurate, silicon-modified β-cyclodextrin chain extender, and ferrocene chain extender is 1:0.8:0.01:1.1:0.9, stir to perform chain extension reaction, react for 20 minutes, wait for the reaction to be completed, cool naturally, and obtain ferrocene-modified polyurethane;

[0028] (6) Add 6 parts by weight of steel fiber, 100 parts by weight of cement, 80 parts by weight of gravel, 150 parts by weight of sand, 2 parts by weight of cellulose sulfonate water reducer, 3 parts by weight of ferrocene modified polyurethane, and 60 parts by weight of water into a mixer, stir evenly, and stir for 50 seconds to obtain fiber reinforced modified concrete.

[0029] Example 2

[0030] (1) adding 1,1-bis(dimethylsilyl)iron and 4-maleimidophenol to N,N-dimethylformamide solvent, introducing nitrogen protection, and continuously adding chloroplatinic acid catalyst thereto, wherein the mass ratio of 1,1-bis(dimethylsilyl)iron, 4-maleimidophenol and chloroplatinic acid catalyst is 1:1.3:0.03, reacting at 75°C for 60 minutes, cooling to room temperature after completion, filtering and drying to obtain an intermediate;

[0031] (2) Add 10 parts by weight of 2,2-bis(bromomethyl)-1,3-propylene glycol and 12 parts by weight of the intermediate to an acetone solvent, stir evenly, then continue to add 5 mol / L sodium hydroxide aqueous solution, react at 80° C. for 6 hours, and after the reaction is completed, neutralize, concentrate, filter, wash and dry to obtain a ferrocene chain extender;

[0032] (3) adding allyl glycidyl ether, tetrahydrofuran solvent and chloroplatinic acid into a reactor, activating at 55°C for 50 minutes, then dropping 1,1,3,3-tetramethyldisiloxane, wherein the mass ratio of allyl glycidyl ether, chloroplatinic acid and 1,1,3,3-tetramethyldisiloxane is 1.4:0.03:1, the dropping time is 60 minutes, and the reaction is continued at 65°C for 6 hours. After the reaction is completed, it is cooled to room temperature, an activated carbon adsorbent is added, ultrasonically vibrated for 40 minutes, the catalyst chloroplatinic acid is removed, filtered, and rotary evaporated to obtain epoxy-modified siloxane;

[0033] (4) Add 10 parts by weight of β-cyclodextrin to a sodium hydroxide solution, stir evenly, and continue to add 16 parts by weight of epoxy-modified siloxane thereto, ultrasonically shake at 60° C. for 40 minutes, cool to room temperature after the end, dropwise add 14% hydrochloric acid until neutral, wash and dry to obtain a silicon-modified β-cyclodextrin chain extender;

[0034] (5) Add toluene diisocyanate and polyether polyol into a reactor, then add dibutyltin dilaurate, and perform prepolymerization under a nitrogen atmosphere at a temperature of 90°C for 4 hours, then add silicon-modified β-cyclodextrin chain extender and ferrocene chain extender, wherein the mass ratio of toluene diisocyanate, polyether polyol, dibutyltin dilaurate, silicon-modified β-cyclodextrin chain extender, and ferrocene chain extender is 1:1.4:0.02:1.2:1.0, stir to perform chain extension reaction, react for 25 minutes, wait for the reaction to be completed, cool naturally, and obtain ferrocene-modified polyurethane;

[0035] (6) Add 12 parts by weight of steel fiber, 120 parts by weight of cement, 110 parts by weight of gravel, 180 parts by weight of sand, 3 parts by weight of cellulose sulfonate water reducer, 6 parts by weight of ferrocene modified polyurethane, and 80 parts by weight of water into a mixer, stir evenly, and stir for 100 seconds to obtain fiber reinforced modified concrete.

[0036] Example 3

[0037] (1) adding 1,1-bis(dimethylsilyl)iron and 4-maleimidophenol to N,N-dimethylformamide solvent, introducing nitrogen protection, and continuously adding chloroplatinic acid catalyst thereto, wherein the mass ratio of 1,1-bis(dimethylsilyl)iron, 4-maleimidophenol and chloroplatinic acid catalyst is 1:1.2:0.02, reacting at 62°C for 50 minutes, cooling to room temperature after completion, filtering and drying to obtain an intermediate;

[0038] (2) Add 7.5 parts by weight of 2,2-bis(bromomethyl)-1,3-propylene glycol and 9.5 parts by weight of the intermediate to an acetone solvent, stir evenly, then continue to add a 4 mol / L sodium hydroxide aqueous solution, react at 70° C. for 4.5 hours, and after the reaction is completed, neutralize, concentrate, filter, wash and dry to obtain a ferrocene chain extender;

[0039] (3) adding allyl glycidyl ether, tetrahydrofuran solvent and chloroplatinic acid into a reactor, activating at 47°C for 42.5 minutes, then dropping 1,1,3,3-tetramethyldisiloxane, wherein the mass ratio of allyl glycidyl ether, chloroplatinic acid and 1,1,3,3-tetramethyldisiloxane is 1.25:0.05:1, the dropping time is 55 minutes, and the reaction is continued at 60°C for 5 hours. After the reaction is completed, it is cooled to room temperature, an activated carbon adsorbent is added, ultrasonically vibrated for 35 minutes, the catalyst chloroplatinic acid is removed, filtered and rotary evaporated to obtain epoxy-modified siloxane;

[0040] (4) Add 8 parts by weight of β-cyclodextrin to a sodium hydroxide solution, stir evenly, and continue to add 13 parts by weight of epoxy-modified siloxane thereto, ultrasonically vibrate at 55° C. for 35 minutes, cool to room temperature after the end, dropwise add 13% hydrochloric acid until neutral, wash and dry to obtain a silicon-modified β-cyclodextrin chain extender;

[0041] (5) Add toluene diisocyanate and polyether polyol into a reactor, then add dibutyltin dilaurate, and perform prepolymerization under a nitrogen atmosphere at a temperature of 80°C for 3 hours, then add silicon-modified β-cyclodextrin chain extender and ferrocene chain extender, wherein the mass ratio of toluene diisocyanate, polyether polyol, dibutyltin dilaurate, silicon-modified β-cyclodextrin chain extender, and ferrocene chain extender is 1:1.1:0.015:1.15:0.95, stir to perform chain extension reaction, react for 22.5 minutes, wait for the reaction to be completed, cool naturally, and obtain ferrocene-modified polyurethane;

[0042] (6) Add 9 parts by weight of steel fiber, 110 parts by weight of cement, 95 parts by weight of gravel, 165 parts by weight of sand, 2.5 parts by weight of cellulose sulfonate water reducer, 4.5 parts by weight of ferrocene modified polyurethane, and 70 parts by weight of water into a mixer and stir evenly for 75 seconds to obtain fiber reinforced modified concrete.

[0043] Example 4

[0044] (1) adding 1,1-bis(dimethylsilyl)iron and 4-maleimidophenol to N,N-dimethylformamide solvent, introducing nitrogen protection, and continuously adding chloroplatinic acid catalyst thereto, wherein the mass ratio of 1,1-bis(dimethylsilyl)iron, 4-maleimidophenol and chloroplatinic acid catalyst is 1:1.1:0.01, reacting at 50°C for 40 minutes, cooling to room temperature after the reaction, filtering and drying to obtain an intermediate;

[0045] (2) Add 5 parts by weight of 2,2-bis(bromomethyl)-1,3-propylene glycol and 7 parts by weight of the intermediate to an acetone solvent, stir evenly, then continue to add 3 mol / L sodium hydroxide aqueous solution, react at 60° C. for 3 h, and after the reaction is completed, neutralize, concentrate, filter, wash and dry to obtain a ferrocene chain extender;

[0046] (3) adding allyl glycidyl ether, tetrahydrofuran solvent and chloroplatinic acid into a reactor, activating at 55°C for 50 minutes, then dropping 1,1,3,3-tetramethyldisiloxane, wherein the mass ratio of allyl glycidyl ether, chloroplatinic acid and 1,1,3,3-tetramethyldisiloxane is 1.4:0.03:1, the dropping time is 60 minutes, and the reaction is continued at 65°C for 6 hours. After the reaction is completed, it is cooled to room temperature, an activated carbon adsorbent is added, ultrasonically vibrated for 40 minutes, the catalyst chloroplatinic acid is removed, filtered, and rotary evaporated to obtain epoxy-modified siloxane;

[0047] (4) Add 10 parts by weight of β-cyclodextrin to a sodium hydroxide solution, stir evenly, and continue to add 16 parts by weight of epoxy-modified siloxane thereto, ultrasonically shake at 60° C. for 40 minutes, cool to room temperature after the end, dropwise add 14% hydrochloric acid until neutral, wash and dry to obtain a silicon-modified β-cyclodextrin chain extender;

[0048] (5) Add toluene diisocyanate and polyether polyol into a reactor, then add dibutyltin dilaurate, and perform prepolymerization under a nitrogen atmosphere at a temperature of 80°C for 3 hours, then add silicon-modified β-cyclodextrin chain extender and ferrocene chain extender, wherein the mass ratio of toluene diisocyanate, polyether polyol, dibutyltin dilaurate, silicon-modified β-cyclodextrin chain extender, and ferrocene chain extender is 1:1.1:0.015:1.15:0.95, stir to perform chain extension reaction, react for 22.5 minutes, wait for the reaction to be completed, cool naturally, and obtain ferrocene-modified polyurethane;

[0049] (6) Add 9 parts by weight of steel fiber, 110 parts by weight of cement, 95 parts by weight of gravel, 165 parts by weight of sand, 2.5 parts by weight of cellulose sulfonate water reducer, 4.5 parts by weight of ferrocene modified polyurethane, and 70 parts by weight of water into a mixer and stir evenly for 75 seconds to obtain fiber reinforced modified concrete.

[0050] Comparative Example 1

[0051] The difference between this comparative example and Example 4 is that no ferrocene-modified polyurethane is added.

[0052] Comparative Example 2

[0053] Compared with Example 4, the difference between this comparative example and Example 4 is that no steel fiber is added.

[0054] 1. Splitting tensile strength test: According to GB / T50081-2019 "Standard for Test Methods for Physical and Mechanical Properties of Concrete", the fiber-reinforced modified concrete obtained in Examples 1-4 and Comparative Examples 1-2 was tested, and the obtained concrete was made into a 150 mm × 150 mm × 150 mm cubic specimen.

[0055] 2. The concrete water penetration resistance test was carried out in accordance with GB / T50082-2009 "Standard for Test Methods for Long-term Performance and Durability of Ordinary Concrete"; the test results are shown in Table 1.

[0056] Table 1: Mechanical properties and impermeability test

[0057] project Splitting tensile strength (MPa) Maximum water seepage pressure (MPa) Example 1 5.61 1.8 Example 2 5.68 1.9 Example 3 5.27 1.8 Example 4 5.63 1.8 Comparative Example 1 3.16 1.2 Comparative Example 2 3.11 1.6

[0058] It can be seen from Table 1 that the splitting tensile strength of the toughened and impermeable concrete of the present invention reaches 5.27-5.68 MPa; the impermeable water pressure reaches a maximum of 1.9 MPa.

[0059] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing fiber-reinforced modified concrete, characterized in that: The preparation method of the fiber-reinforced modified concrete is as follows: 6-12 parts by weight of steel fiber, 100-120 parts by weight of cement, 80-110 parts by weight of gravel, 150-180 parts by weight of sand, 2-3 parts by weight of cellulose sulfonate water reducer, 3-6 parts by weight of ferrocene modified polyurethane, and 60-80 parts by weight of water are added into a mixer, and stirred evenly for 50-100 seconds to obtain the fiber-reinforced modified concrete; The preparation method of the ferrocene modified polyurethane is: (1) Add 1,1-bis(dimethylsilyl)iron and 4-maleimidophenol to N,N-dimethylformamide solvent, introduce nitrogen protection, continue to add chloroplatinic acid catalyst, react at 50-75°C for 40-60 minutes, cool to room temperature after reaction, filter and dry to obtain an intermediate; (2) adding 5-10 parts by weight of 2,2-bis(bromomethyl)-1,3-propylene glycol and 7-12 parts by weight of the intermediate to an acetone solvent, stirring evenly, and then continuing to add 3-5 mol / L of a sodium hydroxide aqueous solution, reacting at 60-80° C., and after the reaction is completed, neutralizing, concentrating, filtering, washing and drying to obtain a ferrocene chain extender; (3) adding allyl glycidyl ether, tetrahydrofuran solvent and chloroplatinic acid into a reactor, activating at 40-55°C for 35-50 minutes, then dropping 1,1,3,3-tetramethyldisiloxane for 50-60 minutes, continuing the reaction at 55-65°C for 4-6 hours, cooling to room temperature after completion, adding activated carbon adsorbent, ultrasonically shaking for 30-40 minutes, removing the catalyst chloroplatinic acid, filtering, and rotary evaporation to obtain epoxy-modified siloxane; (4) adding 6-10 parts by weight of β-cyclodextrin to a sodium hydroxide solution, stirring evenly, and then adding 10-16 parts by weight of epoxy-modified siloxane thereto, ultrasonically shaking at 50-60° C. for 30-40 minutes, cooling to room temperature, adding hydrochloric acid dropwise until neutral, washing and drying to obtain a silicon-modified β-cyclodextrin chain extender; (5) Add toluene diisocyanate and polyether polyol into a reactor, then add dibutyltin dilaurate, and perform prepolymerization under a nitrogen atmosphere at a temperature of 70-90°C for 2-4 hours. Then add silicon-modified β-cyclodextrin chain extender and ferrocene chain extender, stir to perform chain extension reaction, react for 20-25 minutes, wait for the reaction to be completed, cool naturally, and obtain ferrocene-modified polyurethane; The mass ratio of 1,1-bis(dimethylsilyl) iron, 4-maleimidophenol and chloroplatinic acid catalyst in (1) is 1:1.1-1.3:0.01-0.03; The reaction time in (2) is 3-6h; The mass ratio of allyl glycidyl ether, chloroplatinic acid and 1,1,3,3-tetramethyldisiloxane in (3) is 1.1-1.4:0.02-0.03:1; The mass fraction of hydrochloric acid in (4) is 12-14%; The mass ratio of toluene diisocyanate, polyether polyol, dibutyltin dilaurate, silicon-modified β-cyclodextrin chain extender, and ferrocene chain extender in (5) is 1:0.8-1.4:0.01-0.02:1.1-1.2:0.9-1.0.