A kind of concrete containing modified living fossil powder and its preparation method

Abstract

The present invention belongs to the technical field of concrete, and specifically relates to a concrete containing modified fossil powder and a preparation method thereof. The concrete comprises the following raw materials in parts by mass: 200 - 300 parts of cement, 30 - 50 parts of fly ash, 30 - 50 parts of slag, 40 - 60 parts of modified granite powder, 30 - 40 parts of modified limestone powder, 5 - 10 parts of silica fume, 600 - 800 parts of manufactured sand, 900 - 1300 parts of crushed stone, 15 - 25 parts of crosslinked polyurethane resin, 5 - 10 parts of water reducing agent, and 130 - 160 parts of water. The modified stone powders activated by two different modifiers in the present invention have a cooperative effect, and in combination with the crosslinked polyurethane resin, the interweaving of the stone powder and the hydration products is increased, so that the early strength, late strength and freeze-thaw resistance of the concrete are simultaneously improved, and the fluidity of the concrete is not adversely affected.

Description

Technical Field

[0001] The present invention belongs to the technical field of concrete, and particularly relates to a concrete containing modified activated stone powder and a preparation method thereof. Background Art

[0002] As a bulk building material, concrete is widely used, which poses great requirements for the demand of concrete. Fly ash and slag are known to be the main components of concrete admixtures. However, with the extremely rapid growth rate of concrete usage, the prices of fly ash and slag are rising day by day. It is reported in the literature that stone powder can be used as an admixture in the preparation of concrete, which can promote cement hydration and improve the performance of concrete. Stone powder can fill the voids between concrete aggregates, improve the compactness of concrete, and thus increase the strength. Stone powder has a wide source and is cheap and easy to obtain. If it can be widely applied to concrete, it can reduce the usage amount of cement and also lower the cost. However, the use of stone powder in concrete has not been widely applied yet. Stone powder is generally inert and cannot react with substrates such as cement to form gels, belonging to inert fillers in concrete. Currently, concrete mixed with stone powder is mainly used in low-strength grade concrete. This is because directly adding stone powder to concrete has no effect on the later strength and even has an adverse effect. Moreover, the use of stone powder will also reduce the time-dependent loss performance of the slump of concrete.

[0003] CN103524062A discloses a modified limestone powder for making concrete, which is prepared from the following raw materials in parts by weight: 80 - 90 of limestone, 0.5 - 0.8 of isobutyl methacrylate, 1 - 2 of slaked lime, 2 - 4 of polypropylene fiber, 1 - 2 of alum, 0.2 - 0.4 of calcium formate, 1.2 - 1.5 of silane coupling agent KH550, 5 - 8 of fly ash, 0.6 - 0.8 of dioctyl maleate, 1 - 2 of styrene-butadiene latex, 15 - 18 of modified jade powder; the preparation method of the modified jade powder is as follows: mix 30 - 40 parts of jade, 5 - 8 parts of glass powder, and 3 - 5 parts of starch, flash burn in a flash kiln at 800 - 900 °C for 4 - 6 seconds, take out, mix with 3 - 5 parts of alumina and 2 - 3 parts of silicon carbide, add an appropriate amount of water and grind, adjust the pH to 5 - 6 with a hydrochloric acid solution with a concentration of 10 - 12%, grind the slurry to 600 - 800 mesh, then adjust to neutral with a sodium hydroxide solution, dry, add 0.4 - 0.6 part of sodium silicate and 0.7 - 0.9 part of chlorinated paraffin to the obtained powder and mix evenly, and grind into nano powder to obtain. This patent uses jade as a raw material, which is expensive; and it needs to go through steps such as flash burning, pickling, and high-speed kneading, and is not suitable for large-scale industrial production.

[0004] CN107986657A discloses a kind of active stone powder for concrete and its preparation method, which is prepared from the following raw materials in parts by weight: 100 parts of ordinary stone powder, 5 - 25 parts of active modifier; the active modifier is at least one of active modifier A, active modifier B, and active modifier C; the active modifier A is prepared by the following method: according to the mass ratio of tetraethyl orthosilicate to ethanol - water - ammonia aqueous solution of 1 - 2:2 - 12, disperse tetraethyl orthosilicate in the ethanol - water - ammonia aqueous solution, and stir until the solution changes from colorless and transparent to turbid, and a large amount of flocculates appear to obtain; the active modifier B is prepared by the following method: according to the mass ratio of sodium silicate to water of 1 - 2:3 - 5, disperse sodium silicate in water, and stir until the solid is completely dissolved to obtain; the active modifier C is prepared by the following method: according to the mass ratio of silica sol to water of 1 - 3:0 - 6, dissolve silica sol in water to obtain. Through the modification of the stone powder, the activity index of the modified stone powder can reach the standard of class II fly ash.

[0005] In the concrete containing stone powder provided in the prior art, the content of stone powder cannot be too high, otherwise it will affect the final performance of the concrete, especially the long - term strength. This is because the stone powder belongs to inert components and basically makes no contribution to the later strength. Moreover, after adding stone powder, the stone powder is dispersed in the pores as a filler, and the dispersion state of the stone powder changes during the freeze - thaw cycle, resulting in poor freeze - thaw cycle performance. Summary of the Invention

[0006] In order to solve the prior art. Specifically, the present invention provides the following technical solutions to solve the above - mentioned technical problems:

[0007] A kind of concrete containing modified activated stone powder, including the following raw materials in parts by mass: 200 - 300 parts of cement, 30 - 50 parts of fly ash, 30 - 50 parts of slag, 40 - 60 parts of modified granite stone powder, 30 - 40 parts of modified limestone powder, 5 - 10 parts of silica fume, 600 - 800 parts of manufactured sand, 900 - 1300 parts of crushed stone, 15 - 25 parts of cross - linked polyurethane resin, 5 - 10 parts of water - reducing agent, 130 - 160 parts of water; the modified granite stone powder is obtained by modifying granite stone powder with silane coupling agent; the modified limestone powder is obtained by first calcining limestone powder and then modifying it with aluminate coupling agent and stearate; the cross - linked polyurethane resin is obtained by polycondensation of diisocyanate, hydroxyl - terminated silicone oil, small - molecule diol, and small - molecule polyol.

[0008] Further, the specific surface area of the granite stone powder and the limestone powder is independently 300 - 350m 2 / kg.

[0009] Further, in the preparation of the modified granite powder, the silane coupling agent is selected from at least one of amino silane coupling agents and mercapto silane coupling agents; the dosage of the silane coupling agent is 20-30 wt% of the mass of the granite powder; further, the amino silane coupling agent is selected from at least one of γ-aminopropyltrimethoxysilane (KH-540), 3-aminopropyltriethoxysilane (KH-550), N-2-aminoethyl-3-aminopropyltrimethoxysilane (KH-792), γ-diethenyltriaminepropylmethyldimethoxysilane (Si-603), N-2-aminoethyl-3-aminopropylmethyldimethoxysilane (Si-602); the mercapto silane coupling agent is selected from at least one of 3-mercaptopropyltriethoxysilane (KH-580), 3-mercaptopropyltrimethoxysilane (KH-590), bis-[γ-(triethoxysilyl)propyl]tetrasulfide (Si-69).

[0010] Preferably, the silane coupling agent is a compound of an amino silane coupling agent and a mercapto silane coupling agent in a mass ratio of 1-5:1-5, more preferably a compound of an amino silane coupling agent and a mercapto silane coupling agent in a mass ratio of 1-2:1-2.

[0011] Further, the modified granite powder is prepared by a preparation method including the following steps:

[0012] Under ultrasonic conditions, the granite powder is dispersed in an alcohol aqueous solution, the silane coupling agent is added, the temperature is raised for reaction, after cooling, filtration, alcohol washing, and drying are carried out to obtain the modified granite powder. Among them, the alcohol accounts for 40-60 vol% in the alcohol aqueous solution, the alcohol is selected from at least one of methanol, ethanol, isopropanol, ethylene glycol, and propylene glycol, the temperature is raised to 30-40 °C, and the reaction time is 4-6 h.

[0013] Further, in the preparation of the modified limestone powder, the aluminate coupling agent is selected from at least one of isopropoxydistearoyl aluminate, diisostearoyl isopropyl aluminate, triisopropoxyaluminum, and tributoxyaluminum; the stearate is selected from at least one of magnesium stearate, calcium stearate, sodium stearate, and potassium stearate. The mass ratio of limestone powder, aluminate coupling agent, and stearate is 100:25-40:6-10; the calcination is carried out at 700-900 °C for 4-6 h. After calcination, the crystal structure is destroyed at high temperature to improve the activity, and it is also beneficial to the subsequent modification. However, the calcination temperature needs to be controlled to avoid overcalcination.

[0014] Further, the modified limestone powder is prepared by a preparation method including the following steps: after the limestone powder is dried, it is added to a muffle furnace and calcined at 700 - 900 °C for 4 - 6 h in an air atmosphere. After cooling, it is ground, added to a high-speed kneader for stirring and preheating, then an aluminate coupling agent and a stearate are added, and high-speed kneading is performed to mix evenly to obtain the modified limestone powder. The working parameters of the high-speed kneader are well-known in the art. For example, the rotation speed is 20 - 50 rpm, the pressure is 0.6 - 0.8 Mpa, and the electric heating power is 5 - 15 kW.

[0015] The inventor unexpectedly found that when modifying two kinds of stone powders, namely granite stone powder and limestone powder, the granite stone powder is modified by the wet method with a silane coupling agent, and the limestone powder is modified by the dry method with an aluminate coupling agent and a stearate. The combined effect of the two modified stone powders obtained by this specific modification method is the best, and concrete with the most excellent comprehensive performance can be obtained. In the present invention, the stone powder not only fills the voids between materials and plays the role of a filling skeleton, but also the combination of two different stone powders adopted in the present invention can induce cement hydration, thereby improving the long-term strength of the solidified concrete. The limestone powder also has a blocking effect on the conversion of ettringite to monosulfate type, increasing stability. In addition, the compounded modified stone powder can also inhibit the cracks generated during the freeze-thaw process, thereby improving the freeze-thaw resistance of the concrete.

[0016] Further, in the preparation of the crosslinked polyurethane resin, the molar ratio of the diisocyanate, the hydroxyl-terminated silicone oil, the small molecule diol, and the small molecule polyol is 1 - 1.2: 0.1 - 0.2: 0.8 - 0.9: 0.005 - 0.01; the diisocyanate is selected from at least one of isophorone diisocyanate, toluene - 2,4 - diisocyanate, and dicyclohexylmethane diisocyanate; the number average molecular weight of the hydroxyl-terminated silicone oil is 30000 - 50000, the small molecule diol is selected from C2 - 4 diols, preferably at least one of ethylene glycol, 1,3 - propanediol, and 1,4 - butanediol; the small molecule polyol is selected from at least one of pentaerythritol, dipentaerythritol, and tris(hydroxymethyl)aminomethane.

[0017] Further, the crosslinked polyurethane resin is prepared by a preparation method including the following steps: the diisocyanate is added to a reaction vessel, the hydroxyl-terminated silicone oil, the small molecule diol, and the small molecule polyol are added under an inert atmosphere and mixed evenly, then an organotin catalyst is added, and stirring reaction is carried out at 20 - 40 °C for 4 - 6 h until the NCO content no longer changes, and then the temperature is lowered to obtain the crosslinked polyurethane resin. Further, the organotin catalyst is selected from at least one of dioctyltin dilaurate, dibutyltin dilaurate, and dibutyltin diacetate, and the dosage of the organotin catalyst is 1 - 5% of the total mass of the monomers.

[0018] Further, the cement is Portland cement with a strength of 42.5 or above; the fly ash is Class II fly ash, and the slag powder is S95 fly ash; the silicon powder has a particle size of 100 - 300 nm; the crushed stone has a continuous gradation of 5 - 25 mm, and the manufactured sand has a fineness modulus of 2.2 - 3.1, Class II; the water reducing agent is a polycarboxylate water reducing agent with a water reducing rate of 25 - 30%.

[0019] The present invention also provides a method for preparing the above - mentioned concrete containing modified fossil powder, comprising the following steps:

[0020] (S1) After dry - mixing the crushed stone and the manufactured sand, add cement, fly ash, slag, silicon powder, modified granite powder, and modified limestone powder and mix evenly to obtain a dry - mixed material;

[0021] (S2) Mix water, water reducing agent, and cross - linked polyurethane resin evenly to obtain a dispersion;

[0022] (S3) Mix the dry - mixed material and the dispersion evenly to obtain concrete.

[0023] There is no particular limitation on the way of mixing evenly in steps (S1) and (S2), as long as the materials can be fully and evenly mixed. For example, a high - speed mixer is used in step (S1), and stirring, ultrasonic treatment, etc. are used in step (S2).

[0024] Further, after obtaining the concrete, pour it into a mold, cure and form it. The curing conditions are 20 - 25°C and a relative humidity of 85 - 95%.

[0025] The content of stone powder in the concrete of the present invention is relatively high, but it still has excellent workability and late - stage strength, overcoming the defect that the content of stone powder in concrete cannot be too high otherwise it will affect its performance. The increase in the content of stone powder can reduce the use of relatively expensive fly ash and slag powder, and reduce the cost of concrete. Through the cooperation of two kinds of modified stone powder and cross - linked polyurethane polymer, the present invention improves the defect of poor workability caused by a high content of stone powder. The two kinds of modified stone powder have a synergistic cooperation effect. While improving the hydration activity of stone powder, it will not overly reduce the strength of the cured concrete. The late - stage strength of concrete mainly depends on the formation of calcium silicate hydrate and calcium aluminate hydrate. If the stone powder is not modified, it does not contribute to the late - stage strength. The modified stone powder activated by two different modifiers of the present invention has a cooperation effect. Combined with the cross - linked polyurethane resin, it increases the interweaving of stone powder and hydration products, improving the early - stage strength, late - stage strength, and freeze - thaw resistance of the concrete simultaneously, and the fluidity of the concrete is not adversely affected. Specific Embodiments

[0026] The following further explains and illustrates the technical solutions of the present invention through specific embodiments.

[0027] The cement is P.O42.5 Portland cement, the stone powder is granite stone powder, the mineral powder is S95 grade mineral powder, the fly ash is Class II fly ash, the average particle size of silica fume is 100 nm, the crushed stone has a continuous gradation of 5 - 25 mm, the water reducing rate of the polycarboxylate water reducer is 28%, and the manufactured sand has a fineness modulus of 2.6, Class II.

[0028] Preparation Example 1 - 1

[0029] Under the condition of 100 kHz ultrasonic wave, 100 parts by mass of granite stone powder (BET = 320 m 2 / kg) is dispersed in an ethanol - aqueous solution (the volume fraction of ethanol is 50%), 20 parts by mass of silane coupling agent is added. The silane coupling agent is a compound of KH - 550 and KH - 580 in a mass ratio of 1:1. It is heated to 35 °C and reacted for 5 h, cooled, filtered, washed with ethanol, and dried to obtain modified granite stone powder 1.

[0030] Preparation Example 1 - 2

[0031] Other conditions are the same as those in Preparation Example 1 - 2, the difference is that the silane coupling agent is 20 parts by mass of KH - 550, and modified granite stone powder 2 is obtained.

[0032] Preparation Example 1 - 3

[0033] Other conditions are the same as those in Preparation Example 1 - 2, the difference is that the silane coupling agent is 20 parts by mass of KH - 580, and modified granite stone powder 3 is obtained.

[0034] Comparative Preparation Example 1

[0035] 100 parts by mass of granite stone powder (BET = 320 m 2 / kg) is added to a high - speed kneader, stirred and pre - heated to 70 °C, 35 parts by mass of diisostearoyl aluminum aluminate and 8 parts by mass of magnesium stearate are added, and they are stirred and mixed evenly at high speed to obtain modified granite stone powder 4.

[0036] Preparation Example 2 - 1

[0037] 100 parts by mass of limestone powder (BET = 330 m 2 / kg) is dried, added to a muffle furnace, calcined at 750 °C for 6 h in an air atmosphere, cooled, ground, added to a high - speed kneader, stirred and pre - heated to 70 °C, 35 parts by mass of diisostearoyl aluminum aluminate and 8 parts by mass of magnesium stearate are added, and they are stirred and mixed evenly at high speed to obtain modified limestone powder 1.

[0038] Preparation Example 2 - 2

[0039] 100 parts by mass of limestone powder (BET = 330 m 2After drying at ( / kg), it was added to a muffle furnace and calcined at 750 °C for 6 h in an air atmosphere. After cooling, it was ground, added to a high-speed kneader and stirred to preheat to 70 °C. 25 parts by mass of aluminum triisopropoxide and 10 parts by mass of calcium stearate were added, and high-speed kneading was carried out to mix evenly to obtain modified limestone powder 2.

[0040] Comparative Preparation Example 2

[0041] 100 parts by mass of limestone powder (BET = 330 m 2 / kg) was dispersed in an ethanol aqueous solution (ethanol volume ratio 50%). 20 parts by mass of a silane coupling agent was added. The silane coupling agent was a compound of KH-550 and KH-580 in a mass ratio of 1:1. The temperature was raised to 35 °C and reacted for 5 h. After cooling, it was filtered, washed with ethanol, and dried to obtain modified limestone powder 3.

[0042] Preparation Example 3-1

[0043] Isophorone diisocyanate was added to the reaction vessel, and hydroxyl-terminated silicone oil (number-average molecular weight 42000), ethylene glycol, and pentaerythritol were added under a nitrogen atmosphere. The feeding ratio was controlled so that the molar ratio of isophorone diisocyanate, hydroxyl-terminated silicone oil, ethylene glycol, and pentaerythritol was 1.1:0.2:0.8:0.05. After feeding, the materials were stirred to mix evenly, and dibutyltin dilaurate was added as a catalyst. The addition amount of the catalyst was 2 wt% of the total monomer mass. The temperature was raised to 30 °C and stirred for 5 h until the NCO content no longer changed, and then the temperature was lowered to obtain crosslinked polyurethane resin 1.

[0044] Preparation Example 3-2

[0045] Other conditions were the same as those in Preparation Example 3-1, except that the monomers were a mixture of isophorone diisocyanate, hydroxyl-terminated silicone oil, ethylene glycol, and tris(hydroxymethyl)aminomethane in a molar ratio of 1.1:0.1:0.9:0.1, and crosslinked polyurethane resin 2 was prepared.

[0046] Comparative Preparation Example 3

[0047] Other conditions were the same as those in Preparation Example 3-1, except that pentaerythritol was not added, and non-crosslinked polyurethane resin was prepared.

[0048] Example 1

[0049] (S1) 1053 parts by mass of crushed stone and 705 parts by mass of manufactured sand were dry-mixed and then 246 parts by mass of cement, 40 parts by mass of Class II fly ash, 42 parts by mass of slag, 8 parts by mass of silica fume, 50 parts by mass of modified granite powder 1 prepared in Preparation Example 1-1, and 36 parts by mass of modified limestone powder 1 prepared in Preparation Example 2-1 were mixed evenly by a high-speed mixer to obtain a dry mix.

[0050] (S2) Under ultrasonic conditions, 140 parts by mass of water, 6.8 parts by mass of polycarboxylate superplasticizer, and 21.4 parts by mass of the crosslinked polyurethane resin prepared in Preparation Example 3-1 were mixed evenly to obtain a dispersion;

[0051] (S3) The dry mix and the dispersion were mixed evenly to obtain concrete, which was poured into a mold and cured under the conditions of 20-25 °C and 90-95 RH%.

[0052] Example 2

[0053] Other conditions were the same as those in Example 1. The difference was that in step (S1), the modified limestone powder 1 prepared in Preparation Example 2-1 was replaced with the modified limestone powder 2 prepared in Preparation Example 2-2.

[0054] Example 3

[0055] Other conditions were the same as those in Example 1. The difference was that in step (S1), the modified granite powder 1 prepared in Preparation Example 1-1 was replaced with the modified granite powder 2 prepared in Preparation Example 1-2 of the same mass.

[0056] Example 4

[0057] Other conditions were the same as those in Example 1. The difference was that in step (S1), the modified granite powder 1 prepared in Preparation Example 1-1 was replaced with the modified granite powder 3 prepared in Preparation Example 1-3 of the same mass.

[0058] Example 5

[0059] Other conditions were the same as those in Example 1. The difference was that in step (S2), the crosslinked polyurethane resin 1 prepared in Preparation Example 3-1 was replaced with the crosslinked polyurethane resin 2 prepared in Preparation Example 3-2 of the same mass.

[0060] Comparative Example 1

[0061] Other conditions were the same. The difference was that in step (S1), the modified granite powder 1 prepared in Preparation Example 1-1 was replaced with the modified granite powder 4 prepared in Comparative Preparation Example 1 of the same mass.

[0062] Comparative Example 2

[0063] Other conditions were the same. The difference was that in step (S1), the modified limestone powder 1 prepared in Preparation Example 2-1 was replaced with the modified limestone powder 3 prepared in Comparative Preparation Example 2 of the same mass.

[0064] Comparative Example 3

[0065] Other conditions were the same. The difference was that in step (S2), the crosslinked polyurethane resin 1 prepared in Preparation Example 3-1 was replaced with the non-crosslinked polyurethane resin prepared in Comparative Preparation Example 3 of the same mass.

[0066] Comparative Example 4

[0067] Under the same other conditions, the difference is that in step (S1), the modified granite powder 1 prepared in Preparation Example 1-1 is replaced with the same mass of granite powder, and the modified limestone powder 1 prepared in Preparation Example 2-1 is replaced with the same mass of limestone powder. That is, the granite powder and limestone powder are not modified.

[0068] Application Example

[0069] The concrete obtained from the above examples and comparative examples was cured and its properties were tested. The compressive strength was tested in accordance with standard GB / T 50081-2019, and the freeze-thaw cycle resistance was tested with reference to GB / T 50085-2009. The number of freeze-thaw cycles corresponding to the appearance of visible cracks on the test block was recorded. The results are shown in Table 1 below:

[0070] Table 1 Concrete Properties

[0071]

[0072] From the data in Table 1, it can be seen that the present invention uses two stone powders with different chemical compositions. Among them, the granite powder is modified with a silane coupling agent, and the limestone powder is modified with an aluminate coupling agent and a stearate. Two modified stone powders are obtained. Then, in combination with a crosslinked polyurethane resin, concrete with excellent comprehensive properties and a high stone powder content can be prepared. If the modification method is changed, or not modified, or the polyurethane resin is not crosslinked, the purpose of the present invention cannot be achieved smoothly. It shows that the two modified stone powders and the crosslinked polyurethane resin can play a cooperative role and jointly improve the properties of the concrete.

Claims

1. A concrete containing modified living fossil powder, characterized in that, It comprises raw materials in the following parts by mass: 200 - 300 parts of cement, 30 - 50 parts of fly ash, 30 - 50 parts of slag, 40 - 60 parts of modified granite powder, 30 - 40 parts of modified limestone powder, 5 - 10 parts of silica fume, 600 - 800 parts of manufactured sand, 900 - 1300 parts of crushed stone, 15 - 25 parts of crosslinked polyurethane resin, 5 - 10 parts of water reducing agent, and 130 - 160 parts of water; the modified granite powder is obtained by modifying granite powder with a silane coupling agent; the modified limestone powder is prepared by a preparation method including the following steps: after drying the limestone powder, it is added to a muffle furnace and calcined at 700 - 900 °C for 4 - 6 h in an air atmosphere, cooled, ground, added to a high-speed kneader for stirring and preheating, and then an aluminate coupling agent and a stearate are added, and kneaded at high speed and mixed evenly to obtain the modified limestone powder; The mass ratio of the limestone powder, the aluminate coupling agent, and the stearate is 100:25 - 40:6 - 10; the crosslinked polyurethane resin is obtained by polycondensation of a diisocyanate, a hydroxyl-terminated silicone oil, a small molecule diol, and a small molecule polyol.

2. The concrete containing modified living fossil powder according to claim 1, characterized in that, The specific surface areas of granite powder and limestone powder are independently 300 - 350 m 2 / kg.

3. The concrete containing modified living fossil powder according to claim 1, characterized in that, In the preparation of the modified granite powder, the silane coupling agent is selected from at least one of an amino silane coupling agent and a mercapto silane coupling agent; the dosage of the silane coupling agent is 20 - 30 wt% of the mass of the granite powder.

4. The concrete containing modified living fossil powder according to claim 3, characterized in that, The amino silane coupling agent is selected from at least one of γ-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, γ-diethenyltriaminepropylmethyldimethoxysilane, and N-2-aminoethyl-3-aminopropylmethyldimethoxysilane; the mercapto silane coupling agent is selected from at least one of 3-mercaptopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, and bis-[γ-(triethoxysilyl)propyl]tetrasulfide.

5. The concrete containing modified living fossil powder according to claim 3, characterized in that The silane coupling agent is a compound of an amino silane coupling agent and a mercapto silane coupling agent in a mass ratio of 1 - 2:1 - 2.

6. The concrete containing modified living fossil powder according to claim 1, characterized in that In the preparation of the modified limestone powder, the aluminate coupling agent is selected from at least one of isopropoxydistearoyl aluminate, distearoyl isopropyl aluminate, triisopropoxyaluminum, and tributoxyaluminum; the stearate is selected from at least one of magnesium stearate, calcium stearate, sodium stearate, and potassium stearate.

7. The concrete containing modified living fossil powder according to claim 1, characterized in that, In the preparation of the crosslinked polyurethane resin, the molar ratio of the diisocyanate, the hydroxyl-terminated silicone oil, the small molecule diol, and the small molecule polyol is 1 - 1.2:0.1 - 0.2:0.8 - 0.9:0.005 - 0.01; the diisocyanate is selected from at least one of isophorone diisocyanate, toluene-2,4-diisocyanate, and dicyclohexylmethane diisocyanate; the number average molecular weight of the hydroxyl-terminated silicone oil is 30000 - 50000, the small molecule diol is selected from C2 - 4 diols; the small molecule polyol is selected from at least one of pentaerythritol, dipentaerythritol, and tris(hydroxymethyl)aminomethane.

8. The concrete containing modified living fossil powder according to claim 7, characterized in that, The crosslinked polyurethane resin is prepared by a preparation method including the following steps: Add diisocyanate into a reaction vessel, add hydroxyl-terminated silicone oil, small molecule diol, and small molecule polyol under an inert atmosphere, mix evenly, add an organotin catalyst, stir and react at 20-40 °C for 4-6 h until the NCO content no longer changes, and cool down to obtain the crosslinked polyurethane resin.

9. The concrete containing modified living fossil powder according to claim 1, wherein, The cement is Portland cement with a strength of more than 42.5; and / or The fly ash is Class II fly ash; and / or The slag powder is S95 grade fly ash; and / or The particle size of the silica fume is 100-300 nm; and / or The crushed stone has a continuous gradation of 5-25 mm; and / or The manufactured sand has a fineness modulus of 2.2-3.1 and is Class II; and / or The water reducing agent is a polycarboxylate water reducing agent with a water reducing rate of 25-30%.

10. The preparation method of the concrete containing modified living fossil powder according to any one of claims 1-9, characterized in that, It includes the following steps: (S1) After dry mixing the crushed stone and the manufactured sand, add cement, fly ash, slag, silica fume, modified granite powder, and modified limestone powder and mix evenly to obtain a dry mixture; (S2) Mix water, water reducing agent, and crosslinked polyurethane resin evenly to obtain a dispersion; (S3) Mix the dry mixture and the dispersion evenly to obtain concrete.

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