Low-viscosity high-durability ferrite-aluminate cement concrete and preparation method thereof

Abstract

The application belongs to the field of special concrete, and particularly relates to a low-viscosity high-durability ferrite-aluminate cement concrete and a preparation method thereof. First, ferrite-aluminate cement, steel slag powder, viscosity-reducing modification material, 60% water-reducing agent, fine aggregate and 70% water are put into a mixer according to formula amounts, and are rapidly stirred at a linear speed of 4-6 m / s for 80-90 s to prepare ferrite-aluminate cement mortar; then, 40% water-reducing agent, 30% water and coarse aggregate are put into the mixer according to formula amounts, and are uniformly stirred at a linear speed of 1-3 m / s for 50-60 s to prepare the low-viscosity high-durability ferrite-aluminate cement concrete. The concrete of the application solves the problem of reducing the viscosity of the concrete, improves the erosion resistance of the cement itself, avoids the problems of non-continuous air entraining, time rupture, concrete late water bleeding and setting, and improves the durability of the concrete.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of special concrete, and particularly relates to a low-viscosity high-durability ferrite-aluminate cement concrete and a preparation method thereof. BACKGROUND

[0002] Ferrite-aluminate cement is a special cement independently researched and developed by China, and is a third series cement recognized at home and abroad. Main minerals thereof are anhydrous calcium sulphoaluminate, dicalcium silicate, iron phase solid solution and gypsum, etc. The ferrite-aluminate cement has the characteristics of fast setting, fast hardening, low shrinkage, high crack resistance, corrosion resistance, wear resistance and high durability, and is usually used in rush repair and construction engineering, GRC products and special functional mortar, etc. At present, the ferrite-aluminate cement is basically blank in the field of large-scale application in entity structure pumping and pouring at home and abroad, and lacks matching admixtures and corresponding technical specifications.

[0003] Due to the influence of the hydration characteristics of the ferrite-aluminate cement, the hydration rate is high, the hydration heat release rate is fast, the hydration products are rapidly generated, and the strength of the matrix is rapidly built, so that the concrete quickly loses workability. Compared with the portland cement concrete, the single cementitious material consumption of the ferrite-aluminate cement concrete is relatively high by about 20% under the same strength grade. Under the condition of the same water consumption, the concrete has large viscosity and poor fluidity, which easily causes problems such as high concrete pump pressure and difficult pumping.

[0004] In order to reduce the viscosity of the concrete and ensure construction, if the method of simply increasing the water consumption of the single concrete is used, the cohesiveness of the concrete will be affected, and the concrete slurry and aggregate are easily separated and segregated. At the same time, because the water-binder ratio is increased, the water consumption required to ensure the fluidity of the concrete is obviously increased in addition to the water consumption required for hydration. The excess water will generate more capillary pores, which increases the porosity on the one hand, and increases the pore size of the pore structure on the other hand, reduces the impermeability of the concrete, and makes it easier for harmful media from the outside to enter the interior of the concrete, thereby accelerating the performance deterioration of the concrete. Therefore, it is unreasonable and undesirable to adjust the viscosity of the concrete by simply increasing the water consumption of the concrete from the aspects of the mechanical properties and durability of the concrete.

[0005] With the urgent needs and long-term service requirements of national key infrastructure construction in complex environments, the demand for special cementitious materials with high corrosion resistance and high durability is increasing. Obviously, under this background, the traditional ferrite-aluminate cement concrete only has the characteristics of fast setting and fast hardening, and does not consider the engineering application requirements of low viscosity and easy pumping, so it is not suitable for large-scale site cast-in-place. Therefore, it is urgent to develop a low-viscosity high-durability ferrite-aluminate cement concrete which is economic and reasonable, easy to obtain materials, and meets the needs of national key engineering construction. SUMMARY

[0006] The main purpose of the present application is to provide a low viscosity and high durability ferrite-aluminate cement concrete and a preparation method thereof, and the technical problems to be solved are: on the one hand, the problems of high viscosity, high pump pressure and easy pump blockage of the ferrite-aluminate cement concrete are solved, the adaptability of the concrete to the external environment characteristics is ensured, especially the temperature change, so that the 90 min slump of the concrete remains above 200 mm even at a high temperature of 40 DEG C. On the other hand, the high crack resistance, high corrosion resistance and high durability characteristics are endowed to the concrete, so that the long-term service performance is still met in the complex environment.

[0007] The specific technical scheme of the present application is:

[0008] A low viscosity and high durability ferrite-aluminate cement concrete, which comprises, by weight:

[0009] Ferrite-aluminate cement: 300-450 parts;

[0010] Steel slag powder: 30-60 parts;

[0011] Viscosity-reducing modified material: 40-80 parts;

[0012] Water reducing agent: 3-6 parts;

[0013] Fine aggregate: 680-750 parts;

[0014] Coarse aggregate: 1020-1100 parts;

[0015] Water: 155-170 parts.

[0016] Preferably, the ferrite-aluminate cement is a high belite high-iron phase ferrite-aluminate cement with a strength grade of 42.5 MPa or more, and the Blaine specific surface area thereof is (370±20) m 2 / kg; the cement clinker mineral phase for preparing the ferrite-aluminate cement contains 30.0-38.0% of anhydrous calcium sulphoaluminate, 30.0-40.0% of dicalcium silicate and 30.0-35.0% of iron phase solid solution by weight percentage. By means of chemical regulation, the anhydrous calcium sulphoaluminate content in the clinker for the ferrite-aluminate cement is reduced, the hydration rate of the cement itself is slowed down, and the problem of high viscosity of the concrete caused by the fast hydration of the cement is weakened. By increasing the iron phase solid solution in the clinker, the corrosion resistance of the cement itself is improved, and the high corrosion resistance of the concrete is further improved and endowed.

[0017] Preferably, the steel slag powder is a steel slag powder prepared by superfine grinding and high-efficiency powder selection process of carbon dioxide gas-cooled steel slag, and the D 50 ≤2.0 μm, and the Blaine specific surface area is (980±20) m 2 / kg, and the weight ratio of f-CaO is 3.5-5.0% and the weight ratio of f-MgO is 3.0-5.0% after the steel slag powder is cooled by carbon dioxide gas. The steel slag powder has the dual effects of supplementing the alkalinity of the ferrite-aluminate cement concrete and compensating for shrinkage to increase the crack resistance. On the one hand, the alkalinity of the hydration product of the ferrite-aluminate cement is lower than that of the hydration product of the Portland cement, which results in a relatively low alkalinity of the pore solution, a large carbonation depth of the matrix, and the introduction of the steel slag powder, which can improve the alkalinity of the ferrite-aluminate cement concrete and thus improve the protection of the steel bars and the corrosion resistance of the concrete. On the other hand, the carbon dioxide gas cooling and the superfine grinding eliminate the poor stability problem of the traditional steel slag. The f-CaO and f-MgO in the carbon dioxide gas cooled steel slag remain at a certain content, and the expansion product generated by the hydration thereof can further reduce the shrinkage of the concrete and improve the crack resistance of the matrix, thereby imparting high durability to the concrete.

[0018] Preferably, the viscosity-reducing modifying material comprises, in terms of weight percentage:

[0019] Superfine fly ash: 84.0-91.0%;

[0020] Secondary aluminum ash: 8.0-15.0%;

[0021] Dextrin: 0.5-0.7%;

[0022] Sodium gluconate: 0.5-0.8%.

[0023] The above-mentioned viscosity-reducing modifying material functions to reduce the viscosity of the ferrite-aluminate cement concrete, and through physical / chemical synergistic regulation technology, the ferrite-aluminate cement concrete has high fluidity, low viscosity, no segregation, and no air bubble layer.

[0024] Preferably, the superfine fly ash is fly ash after superfine grinding, and glass beads in the fly ash are selected out by air separation technology. The content of the glass beads in the superfine fly ash is more than 90%, and the D 50 ≤3.0 μm. The superfine fly ash fully plays the morphological effect and filling effect. On the one hand, it plays a "ball bearing" role to reduce the friction between the aggregates, thereby increasing the fluidity. On the other hand, the superfine fly ash and the ferrite-aluminate cement form a particle size distribution optimization, fill the voids between the cement particles, and release more free water. The two effects are superimposed to reduce the viscosity of the ferrite-aluminate cement concrete from a physical point of view.

[0025] Preferably, the secondary aluminum ash is finely ground secondary aluminum ash with a fineness of 45 μm residue ≤ 2.0%, an aluminum nitride content of 6.0-10.0%, and an elemental aluminum content of 2.0-3.0%. The secondary aluminum ash acts to continuously introduce micro-bubbles into the concrete under the synergistic excitation of dicalcium silicate in the ferrite cement and calcium hydroxide, a hydration product of f-CaO in the steel slag, to release hydrogen and ammonia gas in a gradient, to play a lubricating role, and to further reduce the viscosity of the concrete from a physical perspective to improve the workability. At the same time, the phenomenon of air entrainment not being sustained, air bubbles breaking over time, concrete bleeding, and concrete sinking over time in traditional chemical admixtures is avoided.

[0026] Preferably, the dextrin is β-cyclodextrin with a specific optical rotation of +(162±2)° and a particle size distribution of 20.0-30.0 μm. The dextrin acts to achieve gradient control of the hydration rate of the ferrite cement by using the particle size distribution of the dextrin, mainly to control the hydration of the calcium sulphoaluminate mineral phase, and to reduce the problem of increased concrete viscosity caused by the hydration process. The sodium gluconate is industrial-grade sodium gluconate. The sodium gluconate acts to control the hydration rate of dicalcium silicate in the ferrite cement and to reduce the hydration of the ferrite cement concrete. The sodium gluconate is superimposed and synergized with the dextrin to achieve low concrete viscosity from a chemical perspective. At the same time, the sodium gluconate can also act as a water reducing agent to further improve the flowability of the concrete and to improve the durability of the concrete.

[0027] Preferably, the water reducing agent is a melamine and polycarboxylic acid composite water reducing agent, which is a liquid with a water reducing rate of ≥ 25.0%, and a sodium retarding component and a viscosity reducing mother liquor are internally added. The water reducing agent acts to reduce the water content of the ferrite cement concrete and to improve the durability. The water reducing agent gives the concrete a suitable setting time and simultaneously chemically reduces the viscosity.

[0028] Preferably, the fine aggregate is natural sand or machine-made sand, wherein the machine-made sand has a specific particle size of 5.0-6.0, an MB value of ≤ 1.0, a stone powder content of ≤ 10.0%, and a flaky particle content of ≤ 5.0%. The coarse aggregate is pebble or shaped gravel, two-stage, three-stage, or multi-stage aggregate, with a close-packed void ratio of 35.0-37.0%, an irregular particle content of ≤ 3.0%. The use of multi-stage aggregate can minimize the aggregate void ratio, so the amount of mortar required to fill the voids is minimized, the water demand of the concrete is minimized, the pore structure is better, and the durability of the concrete is improved. The water is tap water, and its performance indicators meet the requirements of JGJ 63 "Standard for Water for Concrete".

[0029] A method for preparing a low-viscosity high-durability ferrite cement concrete, comprising the following steps:

[0030] (1) Feeding ferrite cement, steel slag powder, viscosity-reducing modification material, 60% water reducing agent, fine aggregate, and 70% water into a mixer according to the formula amount, and rapidly stirring at a linear speed of 4-6 m / s for 80-90 s to prepare ferrite cement mortar;

[0031] (2) Add 40% water-reducing agent, 30% water and coarse aggregate into the mixer according to the formula, and mix at a uniform speed of 1-3m / s for 50-60s to obtain low viscosity and high durability ferroaluminate cement concrete.

[0032] The present invention, by adopting the above technical solution, has the following advantages:

[0033] 1. It slows down the hydration rate of cement, mitigating the problem of high concrete viscosity caused by excessive cement hydration, and improving the cement's corrosion resistance, thereby further enhancing and endowing concrete with high corrosion resistance. It also supplements the alkalinity of aluminoferrite cement concrete and compensates for shrinkage to increase crack resistance, achieving aluminoferrite cement concrete with high fluidity, low viscosity, no segregation, and no air bubble layer.

[0034] 2. It reduces the friction between aggregates, thereby increasing fluidity, filling the voids in cement packing, releasing more free water, and physically reducing the viscosity of aluminoferrite cement concrete. The gradient release of hydrogen and ammonia continuously introduces micro-bubbles into the concrete, acting as a lubricant and further reducing concrete viscosity and improving workability. Simultaneously, it avoids the problems of discontinuous air entrainment and eventual cracking in traditional chemical admixtures, leading to later-stage bleeding and settling in the concrete.

[0035] 3. Using multi-graded aggregates can minimize the aggregate porosity, thus minimizing the amount of mortar required to fill the voids. This results in the lowest water consumption per cubic meter of concrete, a better pore structure, and improved concrete durability.

[0036] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below. Detailed Implementation

[0037] To further illustrate the technical means and effects adopted by the present invention to achieve the intended purpose, the following detailed description, in conjunction with preferred embodiments, provides a specific implementation method for a low-viscosity, high-durability aluminoferrite cement concrete according to the present invention. Furthermore, specific features, structures, or characteristics in one or more embodiments may be combined in any suitable form.

[0038] Example 1

[0039] A low-viscosity, high-durability aluminoferrite cement concrete, comprising, by weight:

[0040] Ferroaluminate cement: 300 parts;

[0041] Steel slag powder: 52 parts;

[0042] Viscosity reducing modifier: 40 parts;

[0043] Water reducing agent: 3 parts;

[0044] Fine aggregate: 750 parts;

[0045] Coarse aggregate: 1100 parts;

[0046] Water: 155 parts.

[0047] The ferrite-aluminate cement is a high belite high-iron phase ferrite-aluminate cement with a strength grade of 42.5 MPa or above, and a Blaine specific surface area of (370±20) m 2 / kg. The cement clinker mineral phase for preparing the ferrite-aluminate cement contains, by weight percentage, 30.0-38.0% of anhydrous calcium sulphoaluminate, 30.0-40.0% of dicalcium silicate, and 30.0-35.0% of an iron phase solid solution.

[0048] The steel slag powder is a steel slag powder prepared by superfine grinding and high-efficiency powder selection process of carbon dioxide gas-cooled steel slag, with a D 50 ≤2.0 μm and a Blaine specific surface area of (980±20) m 2 / kg. After the carbon dioxide gas cooling, the steel slag powder has a f-CaO weight ratio of 3.5-5.0% and a f-MgO weight ratio of 3.0-5.0%.

[0049] The viscosity reducing modifier includes, by weight percentage:

[0050] Superfine fly ash: 84.0%;

[0051] Secondary aluminum ash: 15%;

[0052] Dextrin: 0.5%;

[0053] Sodium gluconate: 0.5%.

[0054] The viscosity reducing modifier has the effect of reducing the viscosity of the ferrite-aluminate cement concrete, and through physical / chemical synergistic regulation technology, realizes high flow state, low viscosity, no segregation and no bubble layer of the ferrite-aluminate cement concrete.

[0055] The superfine fly ash is fly ash after superfine grinding, and the glass beads in the fly ash are selected out by air separation technology, and the content of the glass beads in the superfine fly ash is more than 90%, with a D 50 ≤3.0 μm.

[0056] The secondary aluminum ash is finely ground secondary aluminum ash, with a fineness of 45 μm residue ≤2.0%, an aluminum nitride content of 6.0-10.0%, and an elemental aluminum content of 2.0-3.0%.

[0057] Dextrin is beta cyclodextrin, specific rotation = + (162 ± 2) °, particle size distribution: 20.0 ~ 30.0 μm, sodium gluconate is industrial grade sodium gluconate.

[0058] Water reducing agent is melamine and polycarboxylic acid composite water reducing agent, liquid, water reducing rate ≥ 25.0%, internal mixing retarder sodium and viscosity reducing mother liquor.

[0059] Fine aggregate is natural sand or machine-made sand, wherein the specific particle size of machine-made sand is 5.0 ~ 6.0, the MB value is ≤1.0, the stone powder content is ≤10.0%, and the flaky particle content is ≤5.0%. Coarse aggregate is pebble or shaped gravel, two-stage, three-stage or multi-stage aggregate, close-packed void ratio 35.0 ~ 37.0%, irregular particle content ≤3.0%, water is tap water.

[0060] A preparation method of low viscosity and high durability ferrite aluminate cement concrete, comprising the following steps:

[0061] (1) ferrite aluminate cement, steel slag powder, viscosity reducing modifier, 60% water reducing agent, fine aggregate and 70% water are put into the mixer according to the formula amount, and stirred at a linear speed of 4 m / s for 90 s to prepare ferrite aluminate cement mortar;

[0062] (2) 40% water reducing agent, 30% water, coarse aggregate are put into the mixer according to the formula amount, and stirred at a linear speed of 3 m / s for 50 s to prepare low viscosity and high durability ferrite aluminate cement concrete.

[0063] Example 2

[0064] A low viscosity and high durability ferrite aluminate cement concrete, which comprises, by weight:

[0065] Ferrite aluminate cement: 450 parts;

[0066] Steel slag powder: 30 parts;

[0067] Viscosity reducing modifier: 50 parts;

[0068] Water reducing agent: 6 parts;

[0069] Fine aggregate: 680 parts;

[0070] Coarse aggregate: 1020 parts;

[0071] Water: 170 parts.

[0072] Ferrite aluminate cement is high belite high ferrite phase ferrite aluminate cement with strength grade of 42.5 MPa or more, and its Blaine specific surface area is (370 ± 20) m 2The cement clinker mineral phase for preparing the ferrite cement contains 30.0-38.0% anhydrous calcium sulphoaluminate, 30.0-40.0% dicalcium silicate and 30.0-35.0% iron phase solid solution by weight percentage.

[0073] The steel slag powder is prepared by superfine grinding and high-efficiency powder separation process of carbon dioxide gas-cooled steel slag, and has a D 50 ≤2.0 μm and a Blaine specific surface area of (980±20) m 2 / kg, and the f-CaO content is 3.5-5.0% and the f-MgO content is 3.0-5.0% by weight after the steel slag powder is cooled by carbon dioxide gas.

[0074] The viscosity-reducing modifying material comprises, by weight percentage:

[0075] Superfine fly ash: 91.0%;

[0076] Secondary aluminum ash: 8%;

[0077] Dextrin: 0.5%;

[0078] Sodium gluconate: 0.5%.

[0079] The viscosity-reducing modifying material has the effect of reducing the viscosity of the ferrite cement concrete, and through physical / chemical synergistic regulation technology, the ferrite cement concrete has high fluidity, low viscosity, no segregation and no air bubble layer.

[0080] The superfine fly ash is prepared by superfine grinding of fly ash, and the glass beads in the fly ash are separated out by air separation technology, and the content of the glass beads in the superfine fly ash is more than 90%, and the D 50 ≤3.0 μm.

[0081] The secondary aluminum ash is fine secondary aluminum ash, and the fineness is 45 μm, the sieve residue is ≤2.0%, the aluminum nitride content is 6.0-10.0%, and the elemental aluminum content is 2.0-3.0%.

[0082] The dextrin is β-cyclodextrin, the specific optical rotation is +(162±2)°, the particle size distribution is 20.0-30.0 μm, and the sodium gluconate is industrial-grade sodium gluconate.

[0083] The water reducing agent is a complex water reducing agent of melamine and polycarboxylic acid, which is a liquid, and the water-reducing rate is ≥25.0%, and the internal admixture retarding component is sodium retarding and viscosity-reducing mother liquor.

[0084] The fine aggregate is natural sand or machine-made sand, wherein the machine-made sand has a specific particle size of 5.0-6.0, an MB value of ≤1.0, a stone powder content of ≤10.0%, and a flaky particle content of ≤5.0%. The coarse aggregate is pebble or shaped gravel, double-grade, triple-grade or multi-grade aggregate, has a close-packed void ratio of 35.0-37.0%, an irregular particle content of ≤3.0%, and the water is tap water.

[0085] A preparation method of low-viscosity high-durability ferrite-aluminate cement concrete, comprising the following steps:

[0086] (1) Fe-Al cement, steel slag powder, viscosity-reducing modifier, 60% water-reducing agent, fine aggregate and 70% water are put into a mixer according to the formula amount, and fast stirring is carried out at a linear speed of 6 m / s for 80 s to prepare Fe-Al cement mortar;

[0087] (2) 40% water-reducing agent, 30% water and coarse aggregate are put into a mixer according to the formula amount, and uniform stirring is carried out at a linear speed of 1 m / s for 60 s to prepare low-viscosity high-durability Fe-Al cement concrete.

[0088] Example 3

[0089] A low-viscosity high-durability ferrite-aluminate cement concrete, comprising, by weight:

[0090] Fe-Al cement: 370 parts;

[0091] Steel slag powder: 60 parts;

[0092] Viscosity-reducing modifier: 80 parts;

[0093] Water-reducing agent: 4 parts;

[0094] Fine aggregate: 700 parts;

[0095] Coarse aggregate: 1026 parts;

[0096] Water: 160 parts.

[0097] The Fe-Al cement is a high-Belite high-iron phase Fe-Al cement with a strength grade of 42.5 MPa or above, and has a Blaine specific surface area of (370±20) m 2 / kg; the cement clinker mineral phase for preparing the Fe-Al cement contains, by weight percentage, 30.0-38.0% anhydrous calcium sulphoaluminate, 30.0-40.0% dicalcium silicate and 30.0-35.0% iron phase solid solution.

[0098] The steel slag powder is a steel slag powder prepared by superfine grinding and high-efficiency powder selection process from carbon dioxide gas-cooled steel slag, and has a D 50 ≤2.0 μm and a Blaine specific surface area of (980±20) m 2 / kg, the weight ratio of f-CaO is 3.5-5.0%, and the weight ratio of f-MgO is 3.0-5.0%.

[0099] The viscosity-reducing modifying material comprises, in percentage by weight:

[0100] Ultrafine fly ash: 87.0%;

[0101] Secondary aluminum ash: 11.5%;

[0102] Dextrin: 0.7%;

[0103] Sodium gluconate: 0.8%.

[0104] The viscosity-reducing modifying material has the effect of reducing the viscosity of the ferrite aluminate cement concrete, and through the physical / chemical synergistic regulation technology, the ferrite aluminate cement concrete with high flow state, low viscosity, no segregation and no bubble layer is realized.

[0105] The ultrafine fly ash is obtained by ultrafine grinding of fly ash, and the glass beads in the ultrafine fly ash are selected out by air separation technology, and the content of the glass beads in the ultrafine fly ash is more than 90%, and the D 50 ≤3.0 μm.

[0106] The secondary aluminum ash is fine secondary aluminum ash, the fineness of which is less than or equal to 2.0% at 45 μm, the content of aluminum nitride is 6.0-10.0%, and the content of elemental aluminum is 2.0-3.0%.

[0107] The dextrin is β-cyclodextrin, the specific optical rotation is +(162±2)°, and the particle size distribution is 20.0-30.0 μm. The sodium gluconate is industrial-grade sodium gluconate.

[0108] The water reducing agent is a complex water reducing agent of melamine and polycarboxylic acid, which is a liquid, and the water reducing rate is greater than or equal to 25.0%. The internal admixture retarding component is sodium retarder and viscosity-reducing mother liquor.

[0109] The fine aggregate is natural sand or machine-made sand, wherein the specific particle size of the machine-made sand is 5.0-6.0, the MB value is less than or equal to 1.0, the stone powder content is less than or equal to 10.0%, and the flaky particle content is less than or equal to 5.0%. The coarse aggregate is pebble or shaped gravel, double-graded, triple-graded or multi-graded aggregate, the close-packed void ratio is 35.0-37.0%, the irregular particle content is less than or equal to 3.0%, and the water is tap water.

[0110] A preparation method of low-viscosity high-durability ferrite aluminate cement concrete comprises the following steps:

[0111] (1) Fe-Al cement, steel slag powder, viscosity-reducing modifying material, 60% water reducing agent, fine aggregate and 70% water are put into a mixer according to the formula amount, and stirred at a linear speed of 5 m / s for 85 s to prepare Fe-Al cement mortar;

[0112] (2) 40% water-reducing agent, 30% water, coarse aggregate are put into the mixer according to the formula amount, and stirred at a linear speed of 2 m / s for 55 s to prepare low-viscosity high-durability ferrite-aluminate cement concrete.

[0113] According to GB / T 50080-2016 "Standard Test Methods for Properties of Fresh Ordinary Concrete", the prepared low-viscosity high-durability ferrite-aluminate cement concrete mixture is tested, the inverted slump cone concrete mixture emptying time is 5.0-7.0 s, and the extension time T500 is 3.0-5.0 s. According to GB / T 50081-2019 "Standard Test Methods for Physical and Mechanical Properties of Concrete", GB / T 50082-2009 "Standard Test Methods for Long-Term Performance and Durability of Ordinary Concrete", the prepared low-viscosity high-durability ferrite-aluminate cement concrete hardened body is tested, the 28d compressive strength is 38.5-59.2 MPa, the 28d electric flux is 400-600C, and the compressive strength corrosion resistance coefficient after 150 times of dry-wet cycles is 90%-95%.

[0114] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A low-viscosity, high-durability aluminoferrite cement concrete, characterized in that, On a weight basis, it comprises: Ferroaluminate cement: 300-450 parts; Steel slag powder: 30-60 parts; Viscosity-reducing modified material: 40-80 parts; Water-reducing agent: 3-6 parts; Fine aggregate: 680-750 parts; Coarse aggregate: 1020-1100 parts; Water: 155-170 parts; The steel slag powder mentioned is steel slag powder obtained by ultrafine grinding and high-efficiency powder classification of carbon dioxide gas-cooled steel slag, and its D 50 ≤2.0μm, Blaine specific surface area is (980±20)m² 2 / kg, the steel slag powder is cooled with carbon dioxide gas. f- The CaO weight ratio is 3.5%–5.0%. f- The MgO weight ratio is 3.0–5.0%; The viscosity-reducing modified material, by weight percentage, comprises: Ultrafine fly ash: 84.0–91.0%; Secondary aluminum ash: 8.0–15.0%; Dextrin: 0.5–0.7%; Sodium gluconate: 0.5-0.8%.

2. The low-viscosity, high-durability aluminoferrite cement concrete according to claim 1, characterized in that: The aluminoferrite cement mentioned is a high-belite, high-ferrophase aluminoferrite cement with a strength grade of 42.5 MPa or higher, and its Blaine specific surface area is (370±20) m². 2 / kg; the cement clinker mineral phase for preparing the ferroaluminate cement contains, by weight percentage, 30.0-38.0% anhydrous calcium sulfoaluminate, 30.0-40.0% dicalcium silicate and 30.0-35.0% iron phase solid solution.

3. The low-viscosity, high-durability aluminoferrite cement concrete according to claim 1, characterized in that: The ultrafine fly ash is produced by ultrafine grinding of general fly ash, followed by air classification to separate glass microspheres from the general fly ash. The ultrafine fly ash contains over 90% microspheres, and its D... 50 ≤3.0μm.

4. The low-viscosity, high-durability aluminoferrite cement concrete according to claim 1, characterized in that: The secondary aluminum ash is finely ground secondary aluminum ash with a fineness of ≤2.0% on a 45μm sieve, an aluminum nitride content of 6.0-10.0%, and an elemental aluminum content of 2.0-3.0%.

5. The low-viscosity, high-durability aluminoferrite cement concrete according to claim 1, characterized in that: The dextrin is β-cyclodextrin with a specific rotation of + (162 ± 2)° and a particle size distribution of 20.0–30.0 μm. The sodium gluconate is industrial grade sodium gluconate.

6. The low-viscosity, high-durability aluminoferrite cement concrete according to claim 1, characterized in that: The water-reducing agent is a melamine and polycarboxylate composite water-reducing agent, liquid, with a water reduction rate ≥25.0%, and contains a retarding component, sodium retarder, and a viscosity-reducing mother liquor.

7. The low-viscosity, high-durability aluminoferrite cement concrete according to claim 1, characterized in that: The fine aggregate is natural sand or manufactured sand, wherein the manufactured sand has a specific particle size of 5.0-6.0, an MB value of ≤1.0, a stone powder content of ≤10.0%, and a flaky particle content of ≤5.0%. The coarse aggregate is pebbles or shaped crushed stone, which is a multi-grade aggregate with a compacted porosity of 35.0-37.0% and an irregular particle content of ≤3.0%. The water is tap water.

8. A method for preparing low-viscosity, high-durability aluminoferrite cement concrete according to any one of claims 1 to 7, characterized in that, Includes the following steps: (1) Add aluminoferrite cement, steel slag powder, viscosity-reducing modifier, 60% water-reducing agent, fine aggregate and 70% water into a mixer according to the formula and mix rapidly at a linear speed of 4-6 m / s for 80-90s to obtain aluminoferrite cement mortar. (2) Add 40% water-reducing agent, 30% water and coarse aggregate into the mixer according to the formula, and mix at a uniform speed of 1-3m / s for 50-60s to obtain low viscosity high durability ferroaluminate cement concrete.