Anti-crack concrete and preparation method thereof

Abstract

The invention relates to anti-crack concrete which comprises the following components: cement, fly ash, slag powder, river sand, gravel, a water reducing agent, an air entraining agent and water, and the water reducing agent comprises the following components: 3-(allylamino) butyric acid, methoxy polyethylene glycol methacrylate, ammonium persulfate and dichloromethane; the invention further relates to a preparation method of the anti-crack concrete. According to the invention, ammonium persulfate is taken as an initiator, methoxy polyethylene glycol methacrylate and 3-(allylamino) butyric acid react to obtain the polycarboxylic acid water reducer with a polycarboxylic acid main chain and a polyethylene glycol-carrying side chain, the water cement ratio is obviously reduced on the premise of ensuring the fluidity, and the compactness of concrete can be improved; capillary apertures in the concrete are greatly reduced, so that shrinkage cracks caused by water evaporation are reduced, and the crack resistance of the concrete is improved; by adding a proper amount of high-quality admixtures such as the fly ash and the mineral powder, the microstructure of the concrete can be improved, and the porosity is reduced, so that the crack resistance of the concrete is improved.

Description

Technical Field

[0001] The present application relates to the technical field of concrete, and in particular to a crack-resistant concrete and a preparation method thereof. Background Art

[0002] Concrete is a general term for engineering composite materials that are made of aggregates bonded together by cementitious materials. It uses cement as the cementitious material, sand and stone as aggregates, and can be mixed with water, admixtures, etc. in a certain proportion and obtained by stirring. It is widely used in the engineering industry.

[0003] With respect to the above-mentioned related technologies, the inventors believe that the existing concrete is easily affected by the external environment after construction, resulting in cracks, and therefore still needs to be improved. Summary of the Invention

[0004] In order to improve the crack resistance of concrete, the present application provides a crack-resistant concrete and a preparation method thereof.

[0005] In the first aspect, the present application provides a crack-resistant concrete adopting the following technical solution: A crack-resistant concrete comprising the following components in parts by weight: 200-260 parts of cement; 40-60 parts of fly ash; 60-80 parts of slag powder; 800-900 parts of river sand; 1000-1050 parts of crushed stone; 4-6 parts of water reducer; Air entraining agent 0.1-0.2 parts; 160-180 parts water; The water reducer comprises the following components in parts by weight: 20-25 parts of 3-(allylamino)butyric acid, 8-10 parts of methoxy polyethylene glycol methacrylate, 0.5-0.6 parts of ammonium persulfate and 10-12 parts of dichloromethane.

[0006] By adopting the above technical solution, a polycarboxylic acid water-reducing agent having a polycarboxylic acid main chain and polyethylene glycol side chains is obtained by reacting methoxy polyethylene glycol methacrylate and 3-(allylamino)butyric acid in the presence of an initiator ammonium persulfate. The water-cement ratio is significantly reduced while ensuring fluidity, thereby improving the density of concrete, significantly reducing the capillary pores inside the concrete, and enhancing the impermeability. This helps to reduce shrinkage cracks caused by water evaporation and improve the crack resistance of concrete. The appropriate addition of high-quality admixtures such as fly ash and mineral powder can improve the microstructure of concrete, reduce porosity, and thus improve the crack resistance of concrete.

[0007] Preferably, the water reducer further comprises, by weight, 3-5 parts of 2-ethylacrolein, 6-8 parts of dichloromethane and 0.2-0.3 parts of triethylamine.

[0008] By adopting the above technical solution, the amino group carried in the reaction product of methoxy polyethylene glycol methacrylate and 3-(allylamino)butyric acid is further subjected to Michael addition with the α,β-unsaturated carbonyl compound 2-ethylacrolein using triethylamine as an alkaline catalyst and polar dimethyl sulfoxide as a solvent. The formed side chain helps to enhance the interaction between the water reducer and the cement particles and provides additional steric hindrance, thereby effectively dispersing the cement particles and preventing the cement particles from re-aggregating, thereby reducing water consumption and improving the density of the concrete.

[0009] Preferably, the water reducer further comprises, by weight, 3-5 parts of polypropylene fiber, 6-8 parts of 2-octenylsuccinic anhydride, 0.3-0.5 parts of dicumyl peroxide and 8-9 parts of toluene.

[0010] By adopting the above technical solution, in the presence of the initiator dicumyl peroxide, 2-octenyl succinic anhydride is grafted and copolymerized with the main chain of the polypropylene fiber to enhance the mechanical interlocking ability between the polypropylene fiber and the cement matrix, improve the compatibility and adhesion with the cement matrix, effectively disperse stress concentration points, prevent crack expansion, and increase the toughness and ductility of the concrete. At the same time, the long chain branches also increase steric hindrance, which plays an auxiliary role in promoting the dispersion of cement particles and is beneficial to improving the crack resistance of the concrete.

[0011] Preferably, the cement is 52.5 grade low-alkali cement; in terms of weight ratio, the cement: river sand: crushed stone = 60:207:253.

[0012] By adopting the above technical solution and using low-alkaline cement, the expansion and cracks caused by alkali-aggregate reaction can be reduced, and the proportion of cement, river sand and crushed stone can be adjusted to improve the crack resistance of concrete.

[0013] Preferably, the air entraining agent is sodium alkylbenzene sulfonate, and the water reducer further comprises 1-2 parts of an expansion agent.

[0014] By adopting the above technical solution, an expansive agent is added to generate moderate volume expansion during the concrete hardening process to compensate for the shrinkage of the concrete and reduce the risk of splitting and cracking.

[0015] Preferably, the expansion agent is calcium sulfoaluminate.

[0016] In a second aspect, the present application provides a method for preparing crack-resistant concrete, which adopts the following technical solution: A method for preparing crack-resistant concrete comprises the following steps: 3-(allylamino)butyric acid, ammonium persulfate and dichloromethane are mixed, methoxy polyethylene glycol methacrylate is added, and the mixture is stirred at 30-35° C. for 2-3 hours, and the dichloromethane is evaporated to remove the dichloromethane, and the ammonium persulfate is washed with water to obtain a water reducer; Cement, fly ash, slag powder, river sand, crushed stone, water reducer, air entraining agent and water are uniformly mixed to prepare crack-resistant concrete.

[0017] Preferably, the method further comprises the following steps: blending 20-25 parts of 3-(allylamino)butyric acid, 0.5-0.6 parts of ammonium persulfate, and 10-12 parts of dichloromethane, adding 8-10 parts of methoxy polyethylene glycol methacrylate, stirring and reacting at 30-35° C. for 2-3 hours, then evaporating to remove dichloromethane, and washing with water to remove ammonium persulfate to obtain a mixture A; Then, 3-5 parts of 2-ethylacrolein, 6-8 parts of dichloromethane and 0.2-0.3 parts of triethylamine are uniformly mixed with the mixture A, stirred and reacted at 30-35° C. for 1-2 hours, and the dichloromethane is evaporated again to further obtain a water reducer; Mix 3-5 parts of polypropylene fiber and 8-9 parts of toluene at 50-60°C, introduce nitrogen, add 6-8 parts of 2-octenylsuccinic anhydride and 0.3-0.5 parts of dicumyl peroxide, then heat to 80-90°C, stir and reflux for 1-2 hours, cool to room temperature, and remove toluene by filtration to obtain mixture C; 200-260 parts of cement, 40-60 parts of fly ash, 60-80 parts of slag powder, 800-900 parts of river sand, 1000-1050 parts of crushed stone, 4-6 parts of the above-mentioned water reducer, mixture C, 0.1-0.2 parts of air entraining agent, 1-2 parts of expansive agent and 160-180 parts of water are uniformly mixed to prepare crack-resistant concrete.

[0018] In summary, this application has the following beneficial technical effects: 1. In the presence of initiator ammonium persulfate, methoxy polyethylene glycol methacrylate and 3-(allylamino)butyric acid react to obtain a polycarboxylic acid main chain and a polyglycol side chain polycarboxylic acid water reducer. While ensuring fluidity, it significantly reduces the water-cement ratio, which can improve the density of concrete, greatly reduce the capillary pores inside the concrete, improve the impermeability, help reduce shrinkage cracks caused by water evaporation, and improve the crack resistance of concrete. Adding appropriate amounts of high-quality admixtures such as fly ash and mineral powder can improve the microstructure of concrete and reduce porosity. 2. The amino groups carried in the reaction product of methoxy polyethylene glycol methacrylate and 3-(allylamino)butyric acid undergo Michael addition reaction with the α,β-unsaturated carbonyl compound 2-ethylacrolein using triethylamine as an alkaline catalyst and polar dimethyl sulfoxide as a solvent. The formed side chains help enhance the interaction between the water reducer and cement particles and provide additional steric hindrance, thereby effectively dispersing the cement particles and preventing them from reaggregating, thereby reducing water consumption and improving the density of the concrete. 3. In the presence of the initiator dicumyl peroxide, 2-octenyl succinic anhydride is grafted and copolymerized with the main chain of polypropylene fiber to enhance the mechanical interlocking ability between polypropylene fiber and cement matrix, improve the compatibility and adhesion with the cement matrix, effectively disperse stress concentration points, prevent crack expansion, and increase the toughness and ductility of concrete. At the same time, the long chain branches also increase the steric hindrance, which plays an auxiliary role in promoting the dispersion of cement particles and is beneficial to improving the crack resistance of concrete. DETAILED DESCRIPTION

[0019] The following is a further detailed description of this application.

[0020] In this application, the cement is 52.5 grade low-alkali cement provided by Chongqing Xinjianan Building Materials Co., Ltd.; the fly ash is the first-grade fly ash provided by Lingshou County Qiangdong Mineral Products Processing Plant, with the product number qd-590; the slag powder is S95 granulated blast furnace slag powder provided by Lingshou County Erping Mineral Products Processing Plant, with the product number 59-1; the river sand is medium sand with a fineness modulus MX=2.83 and gradation zone II; the crushed stone has a particle size of 5-25 mm and is continuously graded; the air entraining agent is from Shanghai Fengyang Industrial Co., Ltd. The SJ-2 water-soluble concrete air-entraining agent produced by the company; 3-(allylamino)butyric acid, CAS No.: 116679-59-5; methoxy polyethylene glycol methacrylate, CAS No.: 26915-72-0; 2-ethylacrolein, CAS No.: 922-63-4; polypropylene fiber provided by Laiwu Xingtai Engineering Materials Co., Ltd., specification 19mm, compressive strength 550; 2-octenylsuccinic anhydride, CAS No.: 26680-54-6.

[0021] Unless otherwise specified, the raw materials used in the following embodiments can be obtained from common commercial sources. Example

[0022] Example 1 This embodiment discloses a crack-resistant concrete and a preparation method thereof; the crack-resistant concrete comprises the following components: cement, fly ash, slag powder, river sand, crushed stone, a water reducer, an air entraining agent, and water, wherein the air entraining agent is sodium alkylbenzene sulfonate, and the contents of each component are shown in Table 1 below.

[0023] The water reducing agent includes the following components in parts by weight: 20 parts of 3-(allylamino)butyric acid, 8 parts of methoxy polyethylene glycol methacrylate, 0.5 parts of ammonium persulfate and 10 parts of dichloromethane.

[0024] A method for preparing crack-resistant concrete comprises the following steps: 3-(allylamino)butyric acid, ammonium persulfate and dichloromethane were mixed, methoxy polyethylene glycol methacrylate was added, and the mixture was stirred at 30°C for 2 hours, and then the dichloromethane was evaporated to remove the ammonium persulfate, and the water reducing agent was obtained by washing with water to remove the ammonium persulfate. Cement, fly ash, slag powder, river sand, crushed stone, water reducer, air entraining agent and water are uniformly mixed to prepare crack-resistant concrete.

[0025] Example 2 This embodiment discloses a crack-resistant concrete and a preparation method thereof; the crack-resistant concrete comprises the following components: cement, fly ash, slag powder, river sand, crushed stone, a water reducer, an air entraining agent, and water, wherein the air entraining agent is sodium alkylbenzene sulfonate, and the contents of each component are shown in Table 1 below.

[0026] The water reducing agent includes the following components in parts by weight: 25 parts of 3-(allylamino)butyric acid, 10 parts of methoxy polyethylene glycol methacrylate, 0.6 parts of ammonium persulfate and 12 parts of dichloromethane.

[0027] A method for preparing crack-resistant concrete comprises the following steps: 3-(allylamino)butyric acid, ammonium persulfate and dichloromethane were mixed, methoxy polyethylene glycol methacrylate was added, and the mixture was stirred at 35°C for 3 hours, and then the dichloromethane was evaporated to remove the ammonium persulfate, and the water reducing agent was obtained by washing with water to remove the ammonium persulfate. Cement, fly ash, slag powder, river sand, crushed stone, water reducer, air entraining agent and water are uniformly mixed to prepare crack-resistant concrete.

[0028] Example 3 This embodiment discloses a crack-resistant concrete and a preparation method thereof; the crack-resistant concrete comprises the following components: cement, fly ash, slag powder, river sand, crushed stone, a water reducer, an air entraining agent, and water, wherein the air entraining agent is sodium alkylbenzene sulfonate, and the contents of each component are shown in Table 1 below.

[0029] The water reducing agent includes the following components in parts by weight: 22 parts of 3-(allylamino)butyric acid, 9 parts of methoxy polyethylene glycol methacrylate, 0.6 parts of ammonium persulfate and 11 parts of dichloromethane.

[0030] A method for preparing crack-resistant concrete comprises the following steps: 3-(allylamino)butyric acid, ammonium persulfate and dichloromethane were mixed, methoxy polyethylene glycol methacrylate was added, and the mixture was stirred at 33°C for 2.5 hours, and the dichloromethane was evaporated to remove the ammonium persulfate, and the water reducing agent was obtained by washing with water to remove the ammonium persulfate. Cement, fly ash, slag powder, river sand, crushed stone, water reducer, air entraining agent and water are uniformly mixed to prepare crack-resistant concrete.

[0031] Example 4 The difference from Example 1 is that this embodiment discloses a crack-resistant concrete and a preparation method thereof; it includes the following components: cement, fly ash, slag powder, river sand, gravel, water reducer, air entraining agent, expansion agent and water, the air entraining agent is sodium alkylbenzene sulfonate, and the expansion agent is calcium sulfoaluminate.

[0032] The water reducer includes the following components in parts by weight: 20 parts of 3-(allylamino)butyric acid, 8 parts of methoxypolyethylene glycol methacrylate, 0.5 parts of ammonium persulfate, 16 parts of dichloromethane, 3 parts of 2-ethylacrolein, 0.2 parts of triethylamine, 3 parts of polypropylene fiber, 6 parts of 2-octenylsuccinic anhydride, 0.3 parts of diisopropylbenzene peroxide and 8 parts of toluene.

[0033] 3-(Allylamino)butyric acid, ammonium persulfate and 10 parts of dichloromethane were mixed, methoxy polyethylene glycol methacrylate was added, and the mixture was stirred at 30°C for 2 hours, and then the dichloromethane was evaporated and the ammonium persulfate was removed by washing with water to obtain a mixture A; Then, 2-ethylacrolein, 6 parts of dichloromethane and triethylamine were uniformly mixed with the mixture A, stirred and reacted at 30°C for 1 hour, and the dichloromethane was evaporated again to further obtain a water reducer; Polypropylene fiber and toluene were mixed at 50°C, nitrogen was introduced, 2-octenylsuccinic anhydride and dicumyl peroxide were added, and the temperature was raised to 80°C, stirred and refluxed for 1 hour, cooled to room temperature, and the toluene was removed by filtration to obtain a mixture C; Cement, fly ash, slag powder, river sand, crushed stone, water reducer, mixture C, air entraining agent, expansion agent and water are uniformly mixed to prepare crack-resistant concrete.

[0034] Example 5 The difference from Example 2 is that this embodiment discloses a crack-resistant concrete and a preparation method thereof; it includes the following components: cement, fly ash, slag powder, river sand, gravel, water reducer, air entraining agent, expansion agent and water, the air entraining agent is sodium alkylbenzene sulfonate, and the expansion agent is calcium sulfoaluminate.

[0035] The water reducer includes the following components in parts by weight: 25 parts of 3-(allylamino)butyric acid, 10 parts of methoxypolyethylene glycol methacrylate, 0.6 parts of ammonium persulfate and 20 parts of dichloromethane; 5 parts of 2-ethylacrolein and 0.3 parts of triethylamine; 5 parts of polypropylene fiber, 8 parts of 2-octenylsuccinic anhydride, 0.5 parts of diisopropylbenzene peroxide and 9 parts of toluene.

[0036] Blend 3-(allylamino)butyric acid, ammonium persulfate, and 12 parts of dichloromethane, and add methoxy polyethylene glycol methacrylate; Then, 2-ethylacrolein, 8 parts of dichloromethane and triethylamine were uniformly mixed with the mixture A, stirred and reacted at 35°C for 2 hours, and the dichloromethane was evaporated again to further obtain a water reducer; Polypropylene fiber and toluene were mixed at 60°C, nitrogen was introduced, 2-octenylsuccinic anhydride and dicumyl peroxide were added, and the mixture was heated to 90°C, stirred and refluxed for 2 hours, cooled to room temperature, and filtered to remove toluene to obtain mixture C; Cement, fly ash, slag powder, river sand, crushed stone, water reducer, mixture C, air entraining agent, expansion agent and water are uniformly mixed to prepare crack-resistant concrete.

[0037] Example 6 The difference from Example 3 is that this embodiment discloses a crack-resistant concrete and a preparation method thereof; it includes the following components: cement, fly ash, slag powder, river sand, gravel, water reducer, air entraining agent, expansion agent and water, the air entraining agent is sodium alkylbenzene sulfonate, and the expansion agent is calcium sulfoaluminate.

[0038] The water reducer comprises the following components by weight: 23 parts of 3-(allylamino)butyric acid, 9 parts of methoxy polyethylene glycol methacrylate, 0.6 parts of ammonium persulfate and 18 parts of dichloromethane; 4 parts of 2-ethylacrolein and 0.3 parts of triethylamine, 4 parts of Polypropylene fiber, 7 parts of 2-octenylsuccinic anhydride, 0.4 parts of dicumyl peroxide and 8 parts of toluene.

[0039] 3-(Allylamino)butyric acid, ammonium persulfate and 11 parts of dichloromethane were mixed, methoxy polyethylene glycol methacrylate was added, and the mixture was stirred at 33°C for 2.5 hours, and then the dichloromethane was evaporated and the ammonium persulfate was removed by washing with water to obtain a mixture A; 2-ethylacrolein, 7 parts of dichloromethane and triethylamine were then uniformly mixed with the mixture A, stirred and reacted at 33°C for 1.5 hours, and the dichloromethane was evaporated again to further obtain a water reducer; Polypropylene fiber and toluene were mixed at 55°C, nitrogen was introduced, 2-octenylsuccinic anhydride and dicumyl peroxide were added, and the temperature was raised to 85°C, stirred and refluxed for 1.5 hours, cooled to room temperature, and the toluene was removed by filtration to obtain a mixture C; Cement, fly ash, slag powder, river sand, crushed stone, water reducer, mixture C, air entraining agent, expansion agent and water are uniformly mixed to prepare crack-resistant concrete.

[0040] Example 7 The difference from Example 1 is that the water reducing agent further includes 3 parts of 2-ethylacrolein, 6 parts of dichloromethane and 0.2 parts of triethylamine.

[0041] Example 8 The difference from Example 7 is that 2-ethylacrolein is replaced by phenylacetaldehyde.

[0042] Example 9 The difference from Example 1 is that the water reducer further includes 3 parts of polypropylene fiber, 6 parts of 2-octenyl succinic anhydride, 0.3 parts of Dicumyl peroxide and 8 parts toluene.

[0043] Example 10 The difference from Example 9 is that 2-octenylsuccinic anhydride is replaced by maleic anhydride. The contents of each component are shown in Table 2 below.

[0044] Example 11 The difference from Example 1 is that, by weight, the ratio of cement: river sand: crushed stone is 60:207:253, i.e., 240 parts of cement, 828 parts of river sand, and 1012 parts of crushed stone.

[0045] Comparative Example Comparative Example 1 The difference from Example 1 is that the water reducer is replaced by BASF F10 water reducer.

[0046] Comparative Example 2 The difference from Example 1 is that 3-(allylamino)butyric acid is replaced by trans-2-pentenoic acid.

[0047] Comparative Example 3 The difference from Comparative Example 2 is that methoxy polyethylene glycol methacrylate is replaced by vinyl decanoate.

[0048] Table 1 Component contents of Examples 1-6 The performance test took the crack-resistant concrete prepared in Examples 1-11 and Comparative Examples 1-3 as test samples, and the test samples were annular concrete specimens with a diameter of 150 mm and a thickness of 50 mm; after curing for 28 days at a curing temperature of 25°C and a relative humidity of 40%, the cracking time was tested according to the ring test, and the loading rate was increased by 0.7 MPa per second until failure occurred; the compressive strength of the concrete was determined in accordance with GB / T50081-2019 "Standard for Test Methods for Mechanical Properties of Ordinary Concrete". The longer the cracking time and the greater the compressive strength, the better the crack resistance of the concrete; the test results are shown in Table 2 below.

[0049] Table 2 Performance test results of various embodiments and comparative examples Cracking time (min) 28d compressive strength (Mpa) Example 1 1269 52 Example 2 1342 56 Example 3 1306 54 Example 4 1434 69 Example 5 1517 75 Example 6 1485 72 Example 7 1343 57 Example 8 1270 52 Example 9 1362 59 Example 10 1340 55 Example 11 1278 54 Comparative Example 1 1262 50 Comparative Example 2 1121 44 Comparative Example 3 1103 43 This specific implementation manner is merely an explanation of the present application and is not intended to limit the scope of protection of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present implementation manner as needed, but as long as they are within the scope of the claims of the present application, they are protected by patent law.

Claims

1. A crack-resistant concrete, characterized in that: The composition comprises the following components in parts by weight: 200-260 parts of cement; 40-60 parts of fly ash; 60-80 parts of slag powder; 800-900 parts of river sand; 1000-1050 parts of crushed stone; 4-6 parts of water reducer; Air entraining agent 0.1-0.2 parts; 160-180 parts water; The water reducer comprises the following components in parts by weight: 20-25 parts of 3-(allylamino)butyric acid, 8-10 parts of methoxy polyethylene glycol methacrylate, 0.5-0.6 parts of ammonium persulfate and 10-12 parts of dichloromethane.

2. The crack-resistant concrete according to claim 1, characterized in that: In parts by weight, the water reducer further comprises 3-5 parts of 2-ethylacrolein, 6-8 parts of dichloromethane and 0.2-0.3 parts of triethylamine.

3. The crack-resistant concrete according to claim 1, characterized in that: In parts by weight, the water reducer further comprises 3-5 parts of polypropylene fiber, 6-8 parts of 2-octenylsuccinic anhydride, 0.3-0.5 parts of dicumyl peroxide and 8-9 parts of toluene.

4. The crack-resistant concrete according to claim 1, characterized in that: The cement is 52.5 grade low-alkali cement; in terms of weight ratio, the cement: river sand: crushed stone = 60:207:

253.

5. The crack-resistant concrete according to claim 1, characterized in that: The water reducing agent also includes an expansion agent in parts by weight.

6. The crack-resistant concrete according to claim 5, characterized in that: The expansion agent is calcium sulphoaluminate.

7. The method for preparing crack-resistant concrete according to claim 1, characterized in that: The steps include: 3-(allylamino)butyric acid, ammonium persulfate and dichloromethane are mixed, methoxy polyethylene glycol methacrylate is added, and the mixture is stirred at 30-35° C. for 2-3 hours, and the dichloromethane is evaporated to remove the dichloromethane, and the ammonium persulfate is washed with water to obtain a water reducer; Cement, fly ash, slag powder, river sand, crushed stone, water reducer, air entraining agent and water are uniformly mixed to prepare crack-resistant concrete.

8. The method for preparing crack-resistant concrete according to claim 7, characterized in that: The method further comprises the following steps: mixing 20-25 parts of 3-(allylamino)butyric acid, 0.5-0.6 parts of ammonium persulfate and 10-12 parts of dichloromethane, adding 8-10 parts of methoxy polyethylene glycol methacrylate, stirring and reacting at 30-35° C. for 2-3 hours, then evaporating to remove the dichloromethane, and washing with water to remove the ammonium persulfate to obtain a mixture A; Then, 3-5 parts of 2-ethylacrolein, 6-8 parts of dichloromethane and 0.2-0.3 parts of triethylamine are uniformly mixed with the mixture A, stirred and reacted at 30-35° C. for 1-2 hours, and the dichloromethane is evaporated again to further obtain a water reducer; Mix 3-5 parts of polypropylene fiber and 8-9 parts of toluene at 50-60°C, introduce nitrogen, add 6-8 parts of 2-octenylsuccinic anhydride and 0.3-0.5 parts of dicumyl peroxide, then heat to 80-90°C, stir and reflux for 1-2 hours, cool to room temperature, and remove toluene by filtration to obtain mixture C; 200-260 parts of cement, 40-60 parts of fly ash, 60-80 parts of slag powder, 800-900 parts of river sand, 1000-1050 parts of crushed stone, 4-6 parts of the above-mentioned water reducer, mixture C, 0.1-0.2 parts of air entraining agent and 160-180 parts of water are uniformly mixed to prepare crack-resistant concrete.

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