Fine aggregate high-density concrete and its production process

Abstract

The present invention discloses a fine-grained high-density concrete and its production process, which relates to the field of concrete technology. The concrete comprises solid granular material, cement, water, and nano anti-shrinkage additives; the unit volume of the solid granular material is 1m 3 The weight of each component is based on G A :G c :G js :G a； Among them, G A is the weight of solid particulate material per unit volume, G c is the weight G A The weight of cement filled in the void volume of solid particulate material, G js For the weight of external water, including G c The sum of the weight of water required for cement hydration and rheological properties of concrete before curing minus the weight G A The weight of water in the solid particulate material; G a The weight of the nano-anti-shrinkage additive added to the pore volume after cement hydration, minus the excess free water volume. Fine-aggregate, high-density concrete has a much lower porosity than ordinary concrete, significantly improving the concrete's compressive, flexural, and durability properties.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete, in particular to a fine aggregate high-density concrete and a production process thereof. BACKGROUND

[0002] Concrete is one of the most important civil engineering materials in the contemporary era, and is an important building material widely used in the fields of building, road, bridge, etc. Traditional concrete is a kind of artificial stone formed by mixing cementitious materials, aggregates, water and admixtures according to the volume weight ratio, and achieving homogenization, fluidity, plasticity and hardening. It is widely used in construction engineering. Cement binds aggregates into a whole through hydration reaction; fine aggregate (sand) fills the gaps between coarse aggregates to improve the density; coarse aggregate (stone) forms a skeleton to bear the main load; water triggers the hydration reaction of cement; and admixtures optimize the performance. Different structures require concrete to meet the "four performances": working performance (slump, compactness); durability performance (impermeability, frost resistance, wear resistance, air void spacing factor, chloride ion penetration resistance, sulfate resistance, and drying shrinkage test); physical and chemical performance (apparent density, air content, chloride ion content, and setting time); and mechanical performance (compressive strength, flexural strength, splitting tensile strength, and elastic modulus).

[0003] The volume weight method is used for the mixing ratio of traditional concrete, and the concrete bulk density of 2400 kg / m 3 is assumed to calculate the mixing ratio. The specific steps include: first, according to the concrete grade, slump, and durability requirements, the cement content, water-cement ratio and sand ratio are obtained by looking up the table; then, according to the total bulk density of cement, sand, stone and water in the concrete, which is 2400 kg / m 3 , the weight of cement, yellow sand, gravel and water in each cubic meter of concrete is determined to obtain the calculated mixing ratio for concrete production; the calculated mixing ratio is used to produce the concrete sample, and the working performance, durability performance and mechanical performance of the sample concrete are tested and analyzed to adjust the gradation of gravel, sand ratio, water and dosage of admixtures, and finally the production mixing ratio is obtained through test verification.

[0004] However, a large amount of sand and stone materials are needed in concrete production, which damages the environment and consumes resources in sand and stone mining, and is not conducive to environmental protection. The production of fine aggregate high-density concrete does not require sand and stone materials. In concrete production, particle materials with a particle size of less than 5 mm are usually used, and they generally refer to inorganic solid waste materials dominated by fine particles, which widely include construction waste soil, completely weathered rock, strongly weathered rock, wind-blown sand, stone powder, various soils, mine tailings and other inorganic fine particle materials. This can eliminate the use of sand and stone aggregates in traditional concrete production, and fully utilize waste soil, tailings and construction solid waste for concrete production, which is conducive to environmental protection, resource saving and can greatly reduce production costs. It is a low-carbon and resource recycling production mode.

[0005] However, the existing concrete mix design method cannot be used for the preparation of concrete made of inorganic solid waste materials mainly composed of fine particles. In order to protect the environment and improve resource utilization, the present invention proposes a fine-grained high-density concrete and its production process. Summary of the Invention

[0006] (1) Technical problems solved

[0007] In view of the deficiencies in the prior art, the present invention provides a fine-aggregate high-density concrete and a production process thereof, which solves at least one technical problem raised in the background art.

[0008] (2) Technical solution

[0009] In order to achieve the above object, the technical solution adopted by the present invention is:

[0010] A first aspect provides a method for preparing high-performance concrete using slag, wherein the fine-grained high-density concrete comprises solid particulate material, cement, water, and a nano anti-shrinkage additive;

[0011] Among them, solid particle materials, cement, water, nano anti-shrinkage additives, with the unit volume of solid particle materials being 1m 3 The weight of each component is based on G A :G c :G js :G a；

[0012] Among them, G A is the weight of natural solid particulate material per unit volume, G c is the weight G A The weight of cement filled in the void volume of solid particulate material, G js is the weight of added water, G js = G wx -G wh , where G wx G c The sum of the weight of water required for cement hydration and rheological properties of concrete before curing, G wh is the weight G A The natural water content of the solid particulate material; G a The weight of the nano anti-shrinkage additive that can be added to the cement pores after removing the volume occupied by free water in the porosity.

[0013] Preferably, the unit volume of the solid particulate material is 1m 3 When the unit pore volume Vp A =1×(1-ρ A / d A ), where ρ Ais the dry bulk density of solid granular material, in kg / m 3 ;d A is the specific gravity of solid granular material, in kg / m 3 .

[0014] Preferably, the weight of the cement G c =Vp A ·ρ c =1×(1-ρ A / d A )·ρ c , unit is kg.

[0015] Preferably, the pore volume Vp of the cement c =G c / ρ c × (1-ρ c / d c ) = 1 × (1-ρ A / d A )×(1-ρ c / d c ),ρ c is the dry bulk density of cement, d c is the specific gravity of cement, in kg / m 3 , Vp c is the weight G c The pore volume of solid granular material, in m 3 .

[0016] Preferably, the G c Weight of water required for cement hydration G w =0.23G c ; and considering the evaporation loss of water during the concrete preparation and mixing process and the sum of water required for rheological properties before solidification G wx = (0.25~0.50) Gc, the unit is kg.

[0017] Preferably, the G c The weight of the cement pore volume is the weight of the free water volume that is not combined in the process of forming concrete. The remaining pore volume should be filled with nano anti-shrinkage additives. The nano anti-shrinkage additives can be inorganic materials such as calcium sulfoaluminate, calcium oxide, magnesium oxide, fly ash, silica fume, or a mixture of one or more of the organic materials such as polyether and alkyl alcohol, or an inorganic-organic composite of one or more of the above materials.

[0018] Preferably, after the fine-grained high-density concrete is cured, the weight of the remaining free water in the pores of the concrete is G wy =(0.02~0.27)G c , in kg; the volume of free water in the pores of concrete after cement solidification Vwy =(0.02~0.27)G c / ρ w , where ρ w is the theoretical bulk density of water, take 1000kg / m 3 .

[0019] Preferably, the filling volume Vp of the nano anti-shrinkage additive is cy =Vp c -V wy Unit: m 3 ;Nano anti-shrinkage additive material weight G a =ρ a ·Vp cy , unit kg, where ρ a is the bulk density of the nano anti-shrinkage additive material, in kg / m 3 .

[0020] Preferably, the added water weight G js =G wx -G wh ; The G wx G c The sum of the weight of water required for cement hydration and concrete preparation and mixing; G wh is the weight G A The weight of water naturally present in a solid particulate material.

[0021] Preferably, the solid particulate material is a particulate material with a particle size of less than 5 mm, including waste soil,

[0022] Any one or more of fully weathered rock, strongly weathered rock, aeolian sand, stone powder, various types of soil and mine tailings.

[0023] Also provided is a production process for fine aggregate high-density concrete, the production process comprising the following steps:

[0024] Step S1: solid granular material is subjected to a hammering process with a speed greater than 300 r / min and a force of 50 to 500 kN.

[0025] The hammer crusher ensures that the granular material will not be broken or decomposed under the compressive strength of 50-200Mpa.

[0026] Step S2: testing the moisture content, bulk density, dry density, and specific gravity of the crushed solid particulate material, and testing the dry bulk density and specific gravity of the cement and nano anti-shrinkage additive;

[0027] Step S3: Calculate the mix ratio of materials to be used and verify through sample testing to determine the concrete mix ratio;

[0028] Step S4: according to the mixing ratio, the usage amount of various materials is calculated, and the crushed raw materials after metering are put into a multi-source coupled strong mixer with a blade type, anchor type or turbine type under the condition of ultrasonic, vibration and negative pressure, and the rotating speed is 100-800 revolutions per minute;

[0029] Step S5: the metered cement, water and external admixture are added into the mixer, the vacuum switch is first opened, the negative pressure is kept at-0.02 to-0.09 Mpa, the vacuum is continuously kept for 0.5-1 minute, then the vibration and high-speed stirring are started, the vibration, stirring and vacuum are kept for 3-4 minutes, then the vacuum is stopped and the vacuum pressure relief valve is opened, but the stirring is continuously kept for 0.5-1 minute until the cylinder pressure returns to normal, that is, the concrete mixing is completed, and the finished product concrete is discharged from the mixer.

[0030] (Three) beneficial effects

[0031] The application provides a fine aggregate high-density concrete and a production process thereof, and has the following beneficial effects compared with the prior art.

[0032] (1) The fine aggregate high-density concrete has a porosity much smaller than that of ordinary concrete, and the porosity is generally less than 5%, the durability is greatly improved, the permeability resistance under the same compressive strength is improved by more than 3-5 grades, the bending and flexural strength is improved by more than 2 times, the extension and contraction rate is improved by more than 10 times, and the production cost is reduced by more than 25%.

[0033] (2) The application can maximize control and reduction of the porosity of the concrete, optimize the performance of the concrete, accurately match the materials, optimize the material usage, further achieve dispersion and densification of the mixed materials through multi-source coupled stirring, reduce the weak links of the cement solidification structure, and significantly improve the compressive strength, bending strength and durability of the concrete. BRIEF DESCRIPTION OF DRAWINGS

[0034] The application will be further described below in combination with the drawings and embodiments:

[0035] Figure 1 The application is an embodiment production process flow diagram. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the embodiments of the application more clear, the technical scheme in the embodiments of the application is described clearly and completely, obviously, the described embodiments are part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the application.

[0037] In order to better understand the above technical solution, the above technical solution will be described in detail below with reference to the accompanying drawings and specific implementation methods:

[0038] In a first aspect, an embodiment of the present invention provides a fine-aggregate high-density concrete, which includes solid particulate material, cement, water, and a nano anti-shrinkage additive; the mix ratio is calculated according to the principle of the unit pore volume densification method; in specific implementation, the nano anti-shrinkage additive can be a nano inorganic anti-shrinkage additive.

[0039] Among them, solid particle materials, cement, water, nano anti-shrinkage additives, with the unit volume of solid particle materials being 1m 3 The weight of each component is based on G A :G c :G js :G a；

[0040] Among them, G A is the weight of natural solid particulate material per unit volume, G c is the weight G A The weight of cement filled in the void volume of solid particulate material, G js is the weight of added water, G js = G wx -G wh , where G wx G c The sum of the weight of water required for cement hydration and rheological properties of concrete before curing, G wh is the weight G A The natural water content of the solid particulate material; G a The weight of the nano anti-shrinkage additive that can be added to the cement pores after removing the volume occupied by free water in the porosity.

[0041] Specifically, the solid granular material is a granular material with a particle size of less than 5 mm, including waste soil,

[0042] Any one or more of fully weathered rock, strongly weathered rock, aeolian sand, stone powder, various types of soil and mine tailings.

[0043] The above embodiment utilizes solid particulate material as the particle filling material of concrete, which is actually fine-grained material. The embodiment of the present invention is centered around utilizing these solid waste materials to produce fine-grained high-density concrete. The embodiment of the present invention proposes a mix ratio calculation theory of the "pore volume densification method" and a fine-grained high-density concrete production process. Through the theoretical algorithm of the unit pore volume densification method, the porosity of concrete can be controlled and reduced to the greatest extent, the concrete performance can be optimized, the material ratio can be accurately determined, the material usage can be optimized, and the compressive strength, flexural strength and durability of the concrete can be significantly improved.

[0044] The pore volume densification method provided by the embodiment of the application is combined with the mixing ratio calculation method, and the sample raw materials such as solid particulate material, cement, water and nano anti-shrinkage additive are calculated according to the following steps:

[0045] (1) First, a sample of solid particulate material is prepared. The sample material is sampled from the raw material A used in production, and then the natural bulk density γ A (kg / m 3 ), the moisture content ω A (%), the dry bulk density ρ A (kg / m 3 ) and the specific gravity d A (kg / m 3 ) of the sample material are measured according to the national standard method GB / T 16913-2008 Dust Physical Test Method;

[0046] (2) The porosity calculation formula is P=(1-ρ / d)×100%;

[0047] (3) Assuming that the unit volume of the fine aggregate raw material A is 1 m 3 , the unit pore volume Vp A of the material A is 1×(1-ρ A / d A )(m 3 );

[0048] (4) The calculation theory of the pore volume densification method is that the voids in the unit volume of the material A are filled with cement and water with smaller particle sizes. The dry bulk density ρ c (kg / m 3 ) and the specific gravity d c (kg / m 3 ) of the cement are measured by experiment, the theoretical bulk density of water is ρ w =1000 kg / m 3 , and according to the pore filling theory of the pore volume densification method, the pore volume Vp A of the fine aggregate raw material A is 1×(1-ρ A / d A )(m 3 ). After calculation, the weight G c of the cement required is Vp A ·ρ c =1×(1-ρ A / d A )·ρ c (kg); the pore volume Vp c of the cement with the weight G c is G c / ρ c ×(1-ρ c / d A )=1×(1-ρA / d A )×(1-ρ c / d c )(m 3 ),ρ c is the dry bulk density of cement, d c is the specific gravity of cement, in kg / m 3 , Vp c is the weight G c The pore volume of solid granular material, in m 3 .

[0049] (5) The test shows that after hydration, cement forms hydrated compounds, the bound water of which is 23% of the weight of cement. A Assuming the weight of the filling cement G c (kg), then the weight of water required for hydration is G w =0.23G c (kg). In order to ensure that the cement is fully hydrated and to prevent the evaporation loss of water molecules during concrete mixing, and to meet the rheological requirements before solidification, the water consumption can be slightly increased when calculating the mix ratio. The required water consumption G wx =(0.25~0.50)G c (kg). Unit volume 1m 3 Fine aggregate raw material A weight G A , its natural bulk density γ A , moisture contentω A , dry bulk density ρ A , the unit volume is 1m 3 When the natural weight G A =1 · γ A (kg), including the weight of water G wh =ω A· G A (kg), then the additional water consumption G in the mix ratio calculation of fine aggregate raw material A is js =G wx -G wh =(0.25~0.50)G c -ω A· G A (kg), G wx G c The sum of the weight of water required for cement hydration and concrete preparation and mixing; G wh is the weight G A The natural water content weight in the solid particulate material, taking into account the evaporation of water during mixing, should not be less than 0.25, within the range of (0.25 to 0.50), and should be determined by the specific adjustment during the mix ratio test based on the required working performance.

[0050] (6) G c The weight of the cement pore volume is the weight of the free water volume that is not combined in the process of forming concrete. The remaining pore volume should be filled with nano anti-shrinkage additives. The nano anti-shrinkage additives can be inorganic materials such as calcium sulfoaluminate, calcium oxide, magnesium oxide, fly ash, silica fume, or a mixture of one or more of the organic materials such as polyether and alkyl alcohol, or an inorganic-organic composite of one or more of the above materials.

[0051] (7) Pore volume Vp in the cement used c Remove the free water volume V wy After that, the remaining pore volume Vp cy =(Vp c -V wy )(m 3 ), which is filled with nano anti-shrinkage additives with finer particle size, and the bulk density of the nano anti-shrinkage additive material ρ a (kg / m 3 ), nano anti-shrinkage additive weight G a =ρ a· Vp cy (kg), namely: G a =ρ a ·Vp cy =ρ a ·(Vp c -V wy ) = ρ a ·{1×(1-ρ A / d A )×(1-ρ c / d c )-[(0.25~0.50)-0.23]G c / ρ w} (kg), it can be completely filled;

[0052] Among them, the weight of free water remaining in the pores of the concrete after the fine-grained high-density concrete is solidified is G wy =(0.02~0.27)G c , in kg; the volume of free water in the pores of concrete after cement solidification V wy =G wy / ρ w =(0.02~0.27)G c / ρ w , where ρ w is the theoretical bulk density of water, take 1000kg / m 3 .

[0053] (8) The nano anti-shrinkage additive is one or several mixtures of calcium aluminate, aluminum sulfate, aluminum oxide, calcium sulfate, potassium aluminum sulfate, calcium oxide, silicon oxide, magnesium oxide, etc. The production process is as follows: crushing at room temperature, calcining at a temperature of 1300 DEG C or above for 0.5-2 hours, rapid cooling, and then crushing again. The first crushing is performed by using a jaw crusher or a hammer crusher with a crushing force of 50 KN or above, and the final crushing is performed by using air crushing with the following parameters: air pressure of 0.5 MPa or above, air speed of 50 m / s or above, impact frequency of 2000 times / min or above, and particle diameter of 600 nm or below.

[0054] According to the above-mentioned "void volume densification method", the 1m 3 The use amounts of various materials required for producing concrete from raw materials are calculated, and the results are as follows: "cement weight G c ", "natural weight of fine aggregate A G A ", "calculated water amount G js ", and "nano anti-shrinkage additive G a ". A high-efficiency water reducing agent such as polycarboxylic acid ether graft copolymer (or naphthalene sulfonate formaldehyde condensate, melamine sulfonate condensate) is added in an amount of 0.5-5% of the cement weight.

[0055] Based on the above-mentioned proportioning of concrete samples, the water amount, the weight of nano inorganic additive, and the addition amount of high-efficiency water reducing agent are adjusted slightly in the actual implementation process according to the requirements of the working performance, durability, and mechanical properties of concrete, so as to obtain the final production mix proportion.

[0056] Further, the production process includes the following steps:

[0057] For various inorganic fine-grained particle materials such as waste slag, fully weathered rock, strongly weathered rock, aeolian sand, stone powder, various soils, and mine tailings, which may contain agglomerated blocks and blocks with low compressive strength, in order to ensure the durability and mechanical properties of concrete, the fine-grained particles must be crushed and decomposed to the smallest particles, and the particles must meet the compressive strength index of the design strength of concrete and not continue to be decomposed. Of course, the particle size of the raw material is not required in the actual production process, and the particle size can be controlled to be less than 5 mm during preparation.

[0058] Thus, for soft rock, fully weathered rock, strong weathered rock, building solid waste, wind-blown sand, stone powder, mine tailings and various spoil, can be first through 50-500KN impact force hammer or jaw crusher for strong crushing; Then into the blade paddle, anchor or turbine type strong stirring, vibration and negative pressure coupling of multi-source coupling mixer strong stirring, multi-source coupling mixer speed 100-800 revolutions per minute, amplitude 0.5-2.0mm, vibration frequency 170-220Hz, pressure-0.01-0.09Mpa. After hammering, various waste solid materials into multi-source coupling mixing equipment and cement, water, nano anti-shrinkage additive, high efficiency water reducing agent mixing stirring 4-6 minutes. Process flow as shown in Figure 1

[0059] The specific steps are as follows:

[0060] (1) various types of slag and other waste solid materials, can be first through the speed greater than 300r / min, impact hammering force 50-500KN hammer crusher, to ensure that the compressive strength of 50-200Mpa pressure, the particle material will not be broken down;

[0061] (2) to the broken raw materials, moisture content, bulk density, dry density, specific gravity test, and test the use of cement, nano anti-shrinkage additive dry bulk density, specific gravity;

[0062] (3) to calculate the mix ratio of the material, through the sample test to determine the concrete mix ratio;

[0063] (4) according to the mix ratio of the use of various materials, metering after the broken raw materials into the speed 100-800 revolutions per minute of the blade or turbine type strong mixer;

[0064] (5) at the same time into the mixer after the metering of cement, water, various admixtures, first open the vacuum switch, the negative pressure is maintained at-0.02-0.09Mpa, 0.5-1 minutes of continuous vacuum, open vibration, high speed stirring, keep vibration, stirring, vacuum 3-4 minutes, then stop vacuum, open the vacuum relief valve, but continue to stir 0.5~1 minutes until the cylinder pressure returns to normal, that is, the completion of the concrete mixing, finished concrete from the mixer.

[0065] The beneficial effects of the production process are as follows:

[0066] ​Multi-source coupled mixing further disperses and densifies the mixed materials, reducing structural weaknesses after cement solidification and significantly improving the concrete's compressive, flexural, and durability properties. Specifically, high-speed paddle or turbine mixing can enhance the destructive power of fine-grained raw material agglomerates and improve mixing uniformity. Vibration mixing can firstly break up particle agglomerates, secondly reduce stratification and segregation, and thirdly improve mixing efficiency. Negative pressure mixing can effectively suppress dust, reduce bubbles, and conserve cementitious materials. The addition of nano-anti-shrinkage additives can effectively resist shrinkage during concrete solidification and use, eliminating deformation defects in concrete under no-load conditions.

[0067] The porosity of fine-grained high-density concrete is much smaller than that of ordinary concrete, and the porosity is generally less than 5%. Its durability is greatly improved. Under the same compressive strength grade, its impermeability is increased by more than 3 to 5 levels, its flexural and bending strength is increased by more than 2 times, and its elongation and expansion rate is increased by more than 10 times, reducing production costs by more than 25%.

[0068] Further, detailed examples are provided for specific explanation: the calculation process of the present invention is relatively cumbersome and there are many examples and comparative examples, so the solid particle material is selected as copper ore fine tailings as an example. The mix ratio is calculated according to the principle of unit pore volume densification method. The detailed calculation process is shown below:

[0069] After measurement, the natural bulk density of copper mine fine tailings γ A =1526(kg / m 3 ), moisture content ω A =9.3%, dry bulk density

[0070] ρ A =1396(kg / m 3 ) and specific gravity d A =3086(kg / m 3 ); Dry density of 425# Portland cement ρ c =1172(kg / m 3 ), specific gravity d c =3153(kg / m 3 ); Nano anti-shrinkage additive ρ a =909.6(kg / m 3 ).

[0071] ① Take 1m³ of copper ore fine tailings, its unit pore volume Vp A =1×(1-ρ A / d A )=0.548(m 3 ),That

[0072] Weight G A =γ A V A=1×1526=1526 (kg);

[0073] ②Required cement weight G c =Vp A ·ρ c =0.548×1172=642 (kg);

[0074] ③The void volume of cement is Vp c =G c / ρ c × (1-ρ c / d c ) = Vp A × (1-ρ c / d c ) = 0.548×

[0075] (1-1172 / 3153)=0.344(m 3 );

[0076] ④The weight of bound water required for cement hydration G w =0.23G c =148 (kg), in order to ensure that the cement is fully hydrated and to prevent the evaporation loss of water molecules during concrete mixing, the slump is guaranteed to be 80-100 mm. When calculating the mix ratio, the water consumption is G wx =0.40G c =0.40×642=257 (kg), free water weight G wy =G wx -G w =109 (kg);

[0077] ⑤ Water content in raw material copper ore fine tailings G wh =ω A G A =9.3%×1526=142 (kg);

[0078] ⑥ Calculation of additional water consumption G in the mix ratio calculation of copper ore fine tailings js =G wx -G wh =115 (kg),

[0079] The water volume V wy =G wy / ρ w =0.109m 3 , the pore volume V in the cement used pc Remove the free water volume V wy After that, the remaining pore volume Vp cy =Vp c -V wy=0.344-0.109=0.235(m 3 );

[0080] ⑦ The remaining volume is filled with nano anti-shrinkage additives, then the weight of nano anti-shrinkage additives is G a =

[0081] ρ a· Vp cy =909.6×0.235=214 (kg). The nano anti-shrinkage additive used in this project is actually expansive cement, which can replace cement. Therefore, the actual cement dosage can be adjusted to G c ， =642-214=428 (kg), at this time the porosity of cement Vp c ， =G c / ρ c × (1-ρ c / d c )=428 / 1172×0.628=0.229(m 3 )≥0.109(m 3 ), the solution is feasible; adding polycarboxylic acid high-efficiency water reducer is 0.5% of the total cement dosage, that is, 642×0.5%=3.2 (kg). According to the actual water consumption reduction of 13%, the actual water consumption G ’ js =115×(1-13%)=100 (kg). After calculation, the actual mix ratio is as follows:

[0082] Natural copper mine fine tailings: cement: nano anti-shrinkage additive: external water: water reducer

[0083] It is 1526kg:428kg:214kg:100kg:3.2kg.

[0084] Table 1 below shows the specific process parameters, raw materials and proportions of Example 1, Example 2, Example 3, and Example 4, as well as the performance parameters of the prepared concrete;

[0085] Example 1: Concrete was prepared using fine tailings from the Chuzhou copper mine in Anhui Province as raw material:

[0086] Process steps: the copper mine fine tailings first crushed by hammer crusher, to ensure that the compressive strength of 50Mpa pressure, the particle material will not be broken down; measure the moisture content, bulk density, dry density, specific gravity test of the broken copper mine fine tailings, and measure the dry bulk density, specific gravity of the cement, nano anti-shrinkage additive; according to the invention technology to calculate the amount of various materials (detailed calculation reference to the above copper mine fine tailings calculation process); according to the mixing ratio of natural state copper mine fine tailings: cement: nano anti-shrinkage additive: water: water reducing agent = 1526kg: 428kg: 214kg: 100kg: 3.2kg measurement of various materials, the metering of the broken raw materials into the speed of 800r / min blade type strong mixer, at the same time into the mixer measured after the cement, water, various admixtures, open the vacuum switch, continue to vacuum 1 minute, the negative pressure is maintained at -0.09Mpa, and then open the vibration, vacuum side stirring 3 minutes, then stop vacuum, open the vacuum relief valve, but continue to stir 0.5 minutes to the cylinder pressure returns to normal, that is, the completion of the concrete mixing, finished concrete from the mixer, mold curing, and measure the corresponding parameters.

[0087] Example 2: preparation of concrete with strong weathered phyllite in Sichuan Tibetan area as raw material:

[0088] Process steps: the strong weathered phyllite first crushed by hammer crusher, to ensure that the compressive strength of 50Mpa pressure, the particle material will not be broken down; measure the moisture content, bulk density, dry density, specific gravity test of the broken strong weathered phyllite, and measure the dry bulk density, specific gravity of the cement, nano anti-shrinkage additive; according to the invention technology to calculate the amount of various materials (detailed calculation reference to the above copper mine fine tailings calculation process); according to the mixing ratio of natural state strong weathered phyllite: cement: nano anti-shrinkage additive: water: water reducing agent = 1762kg: 441kg: 81kg: 147kg: 2.2kg measurement of various materials, the metering of the broken raw materials into the speed of 800r / min blade type strong mixer, at the same time into the mixer measured after the cement, water, various admixtures, open the vacuum switch, continue to vacuum 1 minute, the negative pressure is maintained at -0.09Mpa, and then open the vibration, vacuum side stirring 3 minutes, then stop vacuum, open the vacuum relief valve, but continue to stir 0.5 minutes to the cylinder pressure returns to normal, that is, the completion of the concrete mixing, finished concrete from the mixer, mold curing, and measure the corresponding parameters.

[0089] Example 3: preparation of concrete with strong weathered mudstone in Sichuan Tibetan area as raw material:

[0090] Process steps: the strongly weathered mudstone is first crushed by a hammer crusher to ensure that the granular material will not be broken down under a pressure of 50 MPa; the water content, bulk density, dry density and specific gravity of the crushed strongly weathered mudstone are measured, and the dry bulk density and specific gravity of the used cement and nano anti-shrinkage additive are measured; the use amount of various materials is calculated according to the present technology (for detailed calculation, refer to the calculation process of the copper mine fine tailings above); various materials are measured according to the mixing ratio natural state strongly weathered mudstone: cement: nano anti-shrinkage additive: additional water: water reducing agent = 1927 kg: 415 kg: 138 kg: 59 kg: 2.1 kg, the crushed raw materials after measurement are put into a blade type strong mixer with a rotating speed of 800 revolutions per minute, and the measured cement, water and various admixtures are added into the mixer at the same time; a vacuum switch is turned on, vacuum is continuously extracted for 1 minute, the negative pressure is kept at -0.09 MPa, vibration is started again, and the mixer is stirred for 3 minutes while vacuum is extracted; then vacuum extraction is stopped, a vacuum pressure relief valve is opened, but the stirring is continued for 0.5 minutes until the pressure in the cylinder returns to normal, that is, the concrete mixing is completed, the finished concrete is discharged from the mixer, is molded and cured, and the corresponding parameters are measured.

[0091] Example 4: Preparation of concrete with Guangxi Pingguo city aluminum oxide tailings solid waste red mud as raw material:

[0092] Process steps: the red mud is first crushed by a hammer crusher to ensure that the granular material will not be broken down under a pressure of 50 MPa; the water content, bulk density, dry density and specific gravity of the crushed red mud are measured, and the dry bulk density and specific gravity of the used cement and nano anti-shrinkage additive are measured; the use amount of various materials is calculated according to the present technology (for detailed calculation, refer to the calculation process of the copper mine fine tailings above); various materials are measured according to the mixing ratio natural state red mud: cement: nano anti-shrinkage additive: additional water: water reducing agent = 780 kg: 917 kg: 305 kg: 170 kg: 4.6 kg, the crushed raw materials after measurement are put into a blade type strong mixer with a rotating speed of 800 revolutions per minute, and the measured cement, water and various admixtures are added into the mixer at the same time; a vacuum switch is turned on, vacuum is continuously extracted for 1 minute, the negative pressure is kept at -0.09 MPa, vibration is started again, and the mixer is stirred for 3 minutes while vacuum is extracted; then vacuum extraction is stopped, a vacuum pressure relief valve is opened, but the stirring is continued for 0.5 minutes until the pressure in the cylinder returns to normal, that is, the concrete mixing is completed, the finished concrete is discharged from the mixer, is molded and cured, and the corresponding parameters are measured.

[0093] In the multi-source coupling mixing equipment, different raw material test data are used as shown in Table 1, and different raw material mixing ratios are realized

[0094] Examples and performance parameters thereof.

[0095] Table 1

[0096]

[0097] In order to better illustrate the effect of the above-mentioned embodiments of the present application, Table 2 below is a specific performance parameter of the concrete prepared by changing the corresponding process parameters with copper mine fine tailings as raw materials for Comparative Examples 1-8.

[0098] Comparative Example 1: The concrete is prepared without vacuum during the mixing process.

[0099] Process steps: The copper mine fine tailings are first crushed by a hammer crusher to ensure that the granular material will not be broken down under a compressive strength of 50 MPa. The water content, bulk density, dry density, and specific gravity of the crushed copper mine fine tailings are measured, and the dry bulk density and specific gravity of the cement and nano anti-shrinkage additive used are also measured. The usage amounts of various materials are calculated according to the present application technology (the detailed calculation is referred to the above-mentioned calculation process of copper mine fine tailings). The various materials are measured according to the mixing ratio of natural state copper mine fine tailings: cement: nano anti-shrinkage additive: additional water: water reducing agent = 1526 kg: 428 kg: 214 kg: 100 kg: 3.2 kg. The measured crushed raw materials are put into a blade type powerful mixer with a rotation speed of 800 rpm, and the measured cement, water, and various admixtures are added into the mixer. The vacuum is started and maintained for 1 minute, and the negative pressure is kept at -0.05 MPa. The vibration is started, and the mixing is carried out for 3 minutes while the vacuum is maintained. Then the vacuum is stopped, the vacuum relief valve is opened, and the mixing is continued for 0.5 minutes until the cylinder pressure returns to normal. The concrete mixing is completed, and the finished concrete is discharged from the mixer, molded, cured, and the corresponding parameters are measured.

[0100] Comparative Example 2: The concrete is prepared with a vacuum degree of -0.05 MPa during the mixing process.

[0101] Process steps: The copper mine fine tailings are first crushed by a hammer crusher to ensure that the granular material will not be broken down under a compressive strength of 50 MPa. The water content, bulk density, dry density, and specific gravity of the crushed copper mine fine tailings are measured, and the dry bulk density and specific gravity of the cement and nano anti-shrinkage additive used are also measured. The usage amounts of various materials are calculated according to the present application technology (the detailed calculation is referred to the above-mentioned calculation process of copper mine fine tailings). The various materials are measured according to the mixing ratio of natural state copper mine fine tailings: cement: nano anti-shrinkage additive: additional water: water reducing agent = 1526 kg: 428 kg: 214 kg: 100 kg: 3.2 kg. The measured crushed raw materials are put into a blade type powerful mixer with a rotation speed of 800 rpm, and the measured cement, water, and various admixtures are added into the mixer. The vacuum is started and maintained for 1 minute, and the negative pressure is kept at -0.05 MPa. The vibration is started, and the mixing is carried out for 3 minutes while the vacuum is maintained. Then the vacuum is stopped, the vacuum relief valve is opened, and the mixing is continued for 0.5 minutes until the cylinder pressure returns to normal. The concrete mixing is completed, and the finished concrete is discharged from the mixer, molded, cured, and the corresponding parameters are measured.

[0102] Comparative Example 3: The concrete is prepared without vibration during the mixing process.

[0103] Process steps: the copper mine fine tailings are first crushed by a hammer crusher to ensure that the granular material will not be broken down under a pressure of 50 Mpa; the water content, bulk density, dry density and specific gravity of the crushed copper mine fine tailings are measured, and the dry bulk density and specific gravity of the used cement and nano anti-shrinkage additive are measured; the use amount of various materials is calculated according to the present technology (for detailed calculation, refer to the calculation process of the copper mine fine tailings above); various materials are measured according to the mixing ratio of natural state copper mine fine tailings: cement: nano anti-shrinkage additive: additional water: water reducing agent = 1526 kg: 428 kg: 214 kg: 100 kg: 3.2 kg, and the measured crushed raw materials are put into a blade type strong stirrer with a rotating speed of 800 revolutions per minute, while the measured cement, water and various admixtures are added into the stirrer; a vacuum switch is turned on, vacuum is continuously extracted for 1 minute, the negative pressure is kept at -0.09 Mpa, and stirring is carried out while vacuum extraction for 3 minutes; then vacuum extraction is stopped, a vacuum pressure relief valve is opened, but stirring is continued for 0.5 minutes until the cylinder pressure returns to normal, that is, the concrete mixing is completed, the finished concrete is discharged from the stirrer, is molded and cured, and the corresponding parameters are measured.

[0104] Comparative example 4: concrete prepared without adding nano anti-shrinkage additive according to the mixing ratio

[0105] Process steps: the copper mine fine tailings are first crushed by a hammer crusher to ensure that the granular material will not be broken down under a pressure of 50 Mpa; the water content, bulk density, dry density and specific gravity of the crushed copper mine fine tailings are measured, and the dry bulk density and specific gravity of the used cement and nano anti-shrinkage additive are measured; the use amount of various materials is calculated according to the present technology (for detailed calculation, refer to the calculation process of the copper mine fine tailings above); various materials are measured according to the mixing ratio of natural state copper mine fine tailings: cement: nano anti-shrinkage additive: additional water: water reducing agent = 1526 kg: 428 kg: 214 kg: 100 kg: 3.2 kg, and the measured crushed raw materials are put into a blade type strong stirrer with a rotating speed of 800 revolutions per minute, while the measured cement, water and various admixtures are added into the stirrer; a vacuum switch is turned on, vacuum is continuously extracted for 1 minute, the negative pressure is kept at -0.09 Mpa, and stirring is carried out while vacuum extraction for 3 minutes; then vacuum extraction is stopped, a vacuum pressure relief valve is opened, but stirring is continued for 0.5 minutes until the cylinder pressure returns to normal, that is, the concrete mixing is completed, the finished concrete is discharged from the stirrer, is molded and cured, and the corresponding parameters are measured.

[0106] Comparative example 5: concrete prepared by stirring at a low rotating speed (100 revolutions per minute)

[0107] The copper mine fine tailings are firstly crushed by a hammer crusher to ensure that the granular materials will not be broken and decomposed under a pressure of 50 MPa. The water content, bulk density, dry density and specific gravity of the crushed copper mine fine tailings are measured, and the dry bulk density and specific gravity of the used cement and nano anti-shrinkage additive are measured. The usage amount of various materials is calculated according to the present application technology (for detailed calculation, refer to the above calculation process of the copper mine fine tailings). Various materials are measured according to the mixing ratio of the natural state copper mine fine tailings, cement, nano anti-shrinkage additive, additional water and water reducing agent = 1526 kg, 428 kg, 214 kg, 100 kg and 3.2 kg respectively. The measured crushed raw materials are put into a blade type strong stirrer with a rotating speed of 100 revolutions per minute, and the measured cement, water and various admixtures are added into the stirrer. The vacuum switch is turned on, and vacuum is continuously extracted for 1 minute. The negative pressure is kept at -0.09 MPa, and then the vibration is started. The vacuum is extracted and stirred for 3 minutes, and then the vacuum is stopped, the vacuum pressure relief valve is opened, but the stirring is continued for 0.5 minutes until the cylinder pressure returns to normal. The concrete mixing is completed, the finished concrete is discharged from the stirrer, is molded and cured, and the corresponding parameters are measured.

[0108] Comparative Example 6: Preparation of concrete in a stirring process at an equal rotating speed (400 revolutions per minute):

[0109] The copper mine fine tailings are firstly crushed by a hammer crusher to ensure that the granular materials will not be broken and decomposed under a pressure of 50 MPa. The water content, bulk density, dry density and specific gravity of the crushed copper mine fine tailings are measured, and the dry bulk density and specific gravity of the used cement and nano anti-shrinkage additive are measured. The usage amount of various materials is calculated according to the present application technology (for detailed calculation, refer to the above calculation process of the copper mine fine tailings). Various materials are measured according to the mixing ratio of the natural state copper mine fine tailings, cement, nano anti-shrinkage additive, additional water and water reducing agent = 1526 kg, 428 kg, 214 kg, 100 kg and 3.2 kg respectively. The measured crushed raw materials are put into a blade type strong stirrer with a rotating speed of 400 revolutions per minute, and the measured cement, water and various admixtures are added into the stirrer. The vacuum switch is turned on, and vacuum is continuously extracted for 1 minute. The negative pressure is kept at -0.09 MPa, and then the vibration is started. The vacuum is extracted and stirred for 3 minutes, and then the vacuum is stopped, the vacuum pressure relief valve is opened, but the stirring is continued for 0.5 minutes until the cylinder pressure returns to normal. The concrete mixing is completed, the finished concrete is discharged from the stirrer, is molded and cured, and the corresponding parameters are measured.

[0110] Comparative Example 7: Preparation of concrete in a stirring process at an equal rotating speed (400 revolutions per minute):

[0111] The copper mine fine tailings are first crushed by a hammer crusher to ensure that the granular material will not be broken down under a pressure of 50 MPa. The water content, bulk density, dry density and specific gravity of the crushed copper mine fine tailings are measured, and the dry bulk density and specific gravity of the used cement and nano anti-shrinkage additive are measured. The usage amount of various materials is calculated according to the present application (for detailed calculation, refer to the above calculation process of the copper mine fine tailings). According to the mixing ratio of the natural state copper mine fine tailings: cement: nano anti-shrinkage additive: additional water: water reducing agent = 1526 kg: 428 kg: 214 kg: 100 kg: 3.2 kg, various materials are measured, and the measured crushed raw materials are put into a conventional horizontal strong mixer, and the measured cement, water and various admixtures are added into the mixer. After continuous stirring for 3 minutes, the concrete mixing is completed, the finished concrete is discharged from the mixer, is molded and cured, and the corresponding parameters are measured

[0112] Comparative Example 8: Stone and sand are used to prepare traditional C40 strength concrete

[0113] The coarse and fine aggregates and sandstone materials with hard texture, good gradation, and meeting the requirements of mud content and crushing value are selected. The mixing ratio of cement: stone: sand: water: water reducing agent = 400 kg: 1100 kg: 700 kg: 170 kg: 2 kg is designed and calculated according to the ordinary “Ordinary Concrete Mixing Ratio Design Regulations”. According to the mixing ratio, various materials are measured, and the measured raw materials are put into a horizontal forced mixer with a rotation speed of 100 revolutions per minute. After stirring for 3 minutes, the concrete mixing is completed, the finished concrete is discharged from the mixer, is molded and cured, and the corresponding parameters are measured.

[0114] Table 2

[0115]

[0116] In summary, Examples 1-4 and Comparative Examples 1-8 prove that the multi-source coupled mixing equipment (vacuum-0.09 MPa, vibration, high rotation speed) can significantly improve the compressive strength, flexural strength, reduce the porosity, and improve the impermeability grade compared with the traditional conventional forced mixing equipment. The use of nano additives can obviously optimize the corresponding compressive strength, flexural strength, porosity and impermeability grade. Compared with the C40 concrete calculated by the traditional unit volume mass method, the corresponding compressive strength, flexural strength, porosity and impermeability grade are significantly improved. At the same time, the present application is suitable for different strong weathered rocks and tailings solid waste (alumina tailings solid waste red mud).

[0117] It should be noted that in this text, the terms “include”, “contain” or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or equipment.

[0118] The above examples are only used to illustrate the technical solutions of the present application, but not to limit the present application; although the present application has been described in detail with reference to the foregoing examples, those ordinarily skilled in the art should understand that they can modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for some technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A fine aggregate high-density concrete, characterized by, The fine aggregate high-density concrete comprises solid particle material, cement, water, and nano anti-shrinkage additive; the solid particle material is particle material with particle size less than 5 mm, and comprises any one or more of discarded spoil, fully weathered rock, strongly weathered rock, wind-blown sand, stone powder, and mine tailings; wherein the solid particulate material, cement, water, nano anti-shrinkage additive, in the unit volume of 1 m 3 of the solid particulate material, with the weight of the cement, water, nano anti-shrinkage additive as the reference, the weight ratio of each component is G A :G c :G js :G a ; Wherein, the mix ratio is calculated according to the principle of unit pore volume compaction method: G A is the weight of unit volume of natural solid granular material; G c is the weight of solid granular material A is the weight of cement filled in the void volume of solid granular material G js is the weight of additional water, G js = G wx - G wh , wherein G wx is the sum of G c weight of cement hydration and water required for rheological properties before concrete curing, G wh is the weight of solid granular material G A natural water content; G a is the weight of nano anti-shrinkage additive that can be added in the cement pore except the volume of free water in the porosity 1 m 3 When the solid granular material has a unit pore volume Vp A = 1 x (1 - p A / d A ), wherein p A is the dry bulk density of the solid granular material, in kg / m 3 ; d A is the specific gravity of the solid granular material, in kg / m 3 ; The pore volume Vp of the cement c =G c / ρ c × (1-ρ c / d c ) = 1 × (1-ρ A / d A )×(1-ρ c / d c ),ρ c is the dry bulk density of cement, d c is the specific gravity of cement, in kg / m 3 , Vp c is the weight G c The pore volume of solid granular material, in m 3 .

2. The high-density fine aggregate concrete according to claim 1, wherein: The weight G of the cement c = Vp A · p c = 1 x (1 - p A / d A ) x p c , in kg.

3. The high-density fine aggregate concrete according to claim 1, wherein: The G c The weight of water required for cement hydration G w = 0.23G c ; and considering the sum of water loss due to evaporation during the mixing process of concrete preparation and the water required for rheological properties before solidification G wx = (0.25-0.50)Gc, both in kg.

4. The high-density fine aggregate concrete according to claim 3, wherein the amount of free water in the internal pores of the hardened concrete is G = (0.02-0.27)G, kg wy c , wherein G is the weight of the free water in the internal pores of the hardened concrete, V is the volume of the free water in the internal pores of the hardened concrete, and p is the density of the free water in the internal pores of the hardened concrete. wy c w w Theoretical bulk density of water, taken as 1000 kg / m 3 . ​​​​ 5. The high-density fine aggregate concrete according to claim 4, wherein: The packing volume Vp of the anti-shrinkage nano-additive cy = Vp c -V wy , in m 3 .

6. The high-density fine aggregate concrete according to claim 5, wherein: The nano-shrinkage additive material weight G a = p a · Vp cy , in kg, where p a is the bulk density of the nano-shrinkage additive material, in kg / m 3 .

7. Process for the production of high-density concrete in the form of granules according to any one of claims 1 to 6, characterized in that: The production process comprises the following steps: Step S1: the solid particle material is crushed by a hammer crusher with a rotation speed greater than 300 r / min and an impact hammering force of 50-500 KN, so that the particle material will not be broken and decomposed under a compressive strength of 50-200 Mpa; Step S2: the solid particle material after crushing is tested for moisture content, bulk density, dry density, and specific gravity, and the dry bulk density and specific gravity of the cement and nano anti-shrinkage additive are tested; Step S3: the mix proportion is calculated according to the principle of the unit pore volume compaction method, and the concrete mix proportion is determined through sample test verification; Step S4: the use amount of each material is calculated according to the mix proportion, and the crushed raw material after metering is put into a multi-source coupled strong mixer with a rotation speed of 100-800 r / min under an ultrasonic, vibration, and negative pressure environment; Step S5: the metered cement, water, and admixture are added to the mixer, the vacuum switch is turned on, the negative pressure is kept at-0.02 to-0.09 Mpa, the vacuum is kept for 0.5-1 min, the vibration and high-speed stirring are started, the vibration, stirring, and vacuum are kept for 3-4 min, then the vacuum is stopped, the vacuum pressure relief valve is opened, but the stirring is continued for 0.5-1 min until the cylinder pressure returns to normal, that is, the concrete mixing is completed, and the finished concrete is discharged from the mixer. ​

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