Superplasticized concrete and method for making same

Abstract

The application discloses super-delayed-setting concrete and a preparation method thereof, which comprises the following raw materials in parts by weight: cement: 240-250 parts; fly ash: 75-85 parts; sand: 750-800 parts; stone: 1000-1100 parts; super-delayed-setting water reducing agent: 5-8 parts; water: 160-180 parts; melamine formaldehyde resin: 10-20 parts; plant extract: 15-25 parts; modified acrylonitrile-butadiene-styrene copolymer: 20-30 parts; borax: 8-16 parts; and the modified acrylonitrile-butadiene-styrene copolymer is prepared from acrylonitrile-butadiene-styrene copolymer, acrylic acid and sodium bicarbonate. The application has the effect of prolonging the setting time of concrete.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of concrete, in particular to a super-retarding concrete and a preparation method thereof. BACKGROUND

[0002] With the development of society and the needs of various large-scale projects, the application range of concrete is continuously expanding, and the performance requirements of concrete are also increasingly high. In many large-scale projects, in order to meet the needs of construction procedures and construction time, it is required to prolong the setting time of concrete.

[0003] The setting time of concrete is an important indicator of the workability of concrete, directly affecting the operable time of concrete, the arrangement of construction procedures and the construction period, and also affecting other workability indicators and the hardening performance of concrete and the performance after hardening. The setting time of concrete is divided into initial setting and final setting. The time required from adding water to the beginning of the loss of plasticity and the reduction of flowability of concrete is called initial setting time. The time required from adding water to the complete loss of plasticity and the beginning of a certain structural strength of concrete is called final setting time. If the concrete sets quickly, it is easy to block the delivery pipeline, so it is necessary to add a retarding agent to the concrete to delay the setting of the concrete and reduce the blocking of the pipeline.

[0004] Although the existing concrete can achieve a certain retarding effect after adding a retarding agent, when the concrete needs to be transported over a long distance, the retarding effect of the retarding agent on the concrete often does not meet the requirements, resulting in the setting of the concrete during the long-distance transportation, which affects the delivery of the concrete by the pipeline. SUMMARY

[0005] In order to prolong the setting time of concrete, the present application provides a super-retarding concrete and a preparation method thereof.

[0006] In a first aspect, the super-retarding concrete provided by the present application adopts the following technical solution:

[0007] A super-retarding concrete, comprising the following raw materials by weight:

[0008] Cement: 240-250 parts;

[0009] Fly ash: 75-85 parts;

[0010] Sand: 750-800 parts;

[0011] Stone: 1000-1100 parts;

[0012] Super-retarding water-reducing agent: 5-8 parts;

[0013] Water: 160-180 parts;

[0014] Melamine formaldehyde resin: 10-20 parts;

[0015] Plant extract: 15-25 parts;

[0016] Modified acrylonitrile-butadiene-styrene copolymer: 20-30 parts;

[0017] Borax: 8-16 parts;

[0018] The modified acrylonitrile-butadiene-styrene copolymer is modified by acrylonitrile-butadiene-styrene copolymer, acrylic acid and sodium bicarbonate.

[0019] By adopting the technical scheme, the super-retarding water-reducing agent is added to control the initial setting time of the concrete to be delayed to 48 hours or more, thereby prolonging the setting time of the prepared concrete and facilitating the transportation. The melamine formaldehyde resin and the modified acrylonitrile-butadiene-styrene copolymer are added to the raw materials for preparing the concrete. The modified acrylonitrile-butadiene-styrene copolymer forms a stable water film on the surface of the cement particles, reduces the direct contact between the cement particles, and further inhibits the hydration process of the cement. The borax is adsorbed on the surface of the cement to inhibit the agglomeration between the cements, thereby producing a retarding effect. The melamine formaldehyde resin, the plant extract and the modified acrylonitrile-butadiene-styrene copolymer together promote the uniform distribution of the hydrates, effectively delay the hydration of the cement, and inhibit the crystallization and precipitation of calcium hydroxide. The two resin materials are wrapped on the surface of the sand and stone and fill the gaps between the sand and stone, so that the sand and stone can be tightly bonded together. The plant extract fills the capillary gaps between the concrete mixtures, improves the stability of the interface bonding and the compactness of the whole concrete mixture, and further improves the compressive strength of the concrete.

[0020] Preferably, the super-retarding water-reducing agent comprises one or more of hypophosphite-based polyacrylic acid and salicylic acid; and the weight ratio of the hypophosphite-based polyacrylic acid, the salicylic acid and the borax is (0.3-0.4):(0.15-0.24):1.

[0021] By adopting the technical scheme, the hypophosphite-based polyacrylic acid and the salicylic acid are used as the super-retarding water-reducing agent, which can reduce the amount of water in the concrete. Under the action of the hypophosphite-based polyacrylic acid and the salicylic acid, a water film is wrapped on the surface of the concrete particles to improve the fluidity of the concrete, so that the borax can enter the gaps in the concrete mixtures to increase the compressive strength of the concrete. The three together can also prolong the initial setting time and the final setting time of the concrete.

[0022] Preferably, the plant extract comprises the following raw materials: bamboo leaves 15-35 parts; spiny amaranth 10-30 parts; camphor leaves 10-20 parts; lemon leaves 5-10 parts; and solvent 20-40 parts.

[0023] Preferably, the preparation method of the plant extract solution is as follows: the solvent, bamboo leaves, spilanthes acmella, cinnamomum camphora leaves and lemon leaves are mixed and soaked together to obtain a mixed solution; the mixed solution is filtered, and the filtrate is the plant extract solution; the weight ratio of the bamboo leaves, spilanthes acmella, cinnamomum camphora leaves and lemon leaves is (1-3) : 1.

[0024] Preferably, the solvent comprises water and ethanol, and the weight ratio of the water and ethanol is (1-3) : 1.

[0025] By using the above technical solution, the bamboo leaves, spilanthes acmella, cinnamomum camphora leaves and lemon leaves are soaked in the solvent, and the filtrate obtained by filtering is the corresponding plant extract solution. The various raw materials leach important substances in the long-term mutual contact. In the leaching process, the important substances cooperate and act with each other, so that the effects of the various raw materials can be fully played in a period of time, the retention of active substances in the plant is greatly increased, the active substances of the plant act on the concrete mixture, the slump of the concrete is enhanced, and the hydration reaction is effectively inhibited, thereby prolonging the initial setting time and final setting time of the concrete.

[0026] Preferably, the preparation method of the modified acrylonitrile-butadiene-styrene copolymer is as follows: 20-40 parts by weight of acrylonitrile-butadiene-styrene copolymer, 15-25 parts by weight of acrylic acid and 2-8 parts by weight of emulsifier are uniformly mixed and stirred, then 10-20 parts by weight of sodium bicarbonate is ultrasonically dispersed and then heated in a water bath to obtain the modified acrylonitrile-butadiene-styrene copolymer; the weight ratio of the acrylonitrile-butadiene-styrene copolymer, the acrylic acid and the sodium bicarbonate is (4-4.5) : 1 : (2-2.5).

[0027] By using the above technical solution, the acrylonitrile-butadiene-styrene copolymer is modified. The acrylonitrile-butadiene-styrene copolymer is mixed with the acrylic acid, the emulsifier and the sodium bicarbonate, so that the acrylic acid is attached to the surface of the acrylonitrile-butadiene-styrene copolymer, the adhesion and stability of the acrylonitrile-butadiene-styrene copolymer are increased, and thus the modified acrylonitrile-butadiene-styrene copolymer can form a more stable water film of the dissolving agent on the surface of the cement particles, the direct contact between the cement particles is reduced, and thus the hydration process of the cement is inhibited and the initial setting time of the concrete is prolonged.

[0028] Preferably, the weight ratio of the melamine formaldehyde resin, the plant extract mixed solution and the modified acrylonitrile-butadiene-styrene copolymer is (0.8-0.9) : 1 : (1.3-1.4).

[0029] By adopting the technical scheme, when melamine formaldehyde resin, plant extract and modified acrylonitrile-butadiene-styrene copolymer are in a specific proportion, the viscosity of the system is enhanced, the compressive strength of the concrete is improved, a stable network structure is formed on the surface of the concrete mixture, the concrete mixture is wrapped, the hydration reaction speed is better delayed, and the effect of further delaying the setting of the concrete is achieved.

[0030] Preferably, the cement is Portland P.0 42.5.

[0031] Preferably, the particle size range of the stone is 5-15mm.

[0032] By adopting the technical scheme, the cement can be better attached to the stone by selecting appropriate cement and stone particle size range, and then the concrete with a slower setting time is prepared.

[0033] In the second aspect, the application provides a preparation method of super-retarding concrete, which adopts the following technical scheme:

[0034] A preparation method of super-retarding concrete, comprising the following steps:

[0035] Melamine formaldehyde resin, plant extract and modified acrylonitrile-butadiene-styrene copolymer and water are heated and stirred to obtain a premix solution;

[0036] After the fly ash and the cement are uniformly mixed with the premix solution, the sand, the stone, the borax and the super-retarding water reducing agent are added, and after being uniformly mixed, the super-retarding concrete is obtained.

[0037] By adopting the technical scheme, the various raw materials of the concrete are mixed in steps, the components of the concrete are more uniformly mixed, and then the concrete with a slower hydration reaction and a delayed setting time is obtained.

[0038] In summary, the application has the following beneficial effects:

[0039] 1. The application joins the super-retarding water-reducing agent, can control the concrete to make the initial setting time delay after 48 hours, thereby prolonging the setting time of the prepared concrete, facilitating the delivery, adding melamine formaldehyde resin and modified acrylonitrile-butadiene-styrene copolymer in the raw materials for preparing the concrete, the modified acrylonitrile-butadiene-styrene copolymer is the stable dissolving agent water film formed on the surface of the cement particles, reducing the direct contact between the cement particles, and then inhibiting the hydration process of the cement, borax is adsorbed on the surface of the cement, inhibiting the agglomeration between the cement, producing the retarding effect, while the melamine formaldehyde resin, plant extract and modified acrylonitrile-butadiene-styrene copolymer together can promote the uniform distribution of hydrates, effectively delay the hydration of cement, inhibit the crystallization of calcium hydroxide, and the two kinds of resin materials are wrapped on the surface of sand and stone and fill the gap between sand and stone, so that the sand and stone can be tightly bonded together, the plant extract fills the capillary gap between the concrete mixture, improves the stability of the interface bonding and the compactness of the whole concrete mixture, and further improves the compressive strength of the concrete.

[0040] 2. The application uses hypophosphorous acid-based polyacrylic acid and salicylic acid as a super-retarding water-reducing agent, which can reduce the amount of water in the concrete, and under the action of hypophosphorous acid-based polyacrylic acid and salicylic acid, a water film is wrapped on the surface of the concrete particles, improving the fluidity of the concrete, so that borax can enter the gap in the concrete mixture, increasing the compressive strength of the concrete, and the three together can also prolong the initial setting time and final setting time of the concrete.

[0041] 3. The bamboo leaves, spilanthes, cinnamomum leaf and lemon leaf are soaked in a solvent, and the filtrate obtained by filtration is the corresponding plant extract. Important substances are leached out from various raw materials during long-term mutual contact. During the leaching process, important substances cooperate and interact with each other, so that the effects of each raw material can be fully played within a certain period of time, and the retention of active substances in the plant is greatly increased. The active substances of the plant act on the concrete mixture, enhance the slump of the concrete, and effectively inhibit the occurrence of hydration reaction, prolong the initial setting time and final setting time of the concrete. DETAILED DESCRIPTION

[0042] The application will be further described in detail in combination with examples and comparative examples.

[0043] Preparation Example

[0044] Preparation Example 1

[0045] A preparation method of a plant extract:

[0046] Put water, ethanol, bamboo leaves, spilanthes, cinnamomum leaf and lemon leaf into a closed storage tank, and mix and soak the various raw materials and solvents together for 60 days to obtain a mixed solution;

[0047] The mixed solution is filtered with a 600-mesh filter cloth, and after the filtration is completed, the solution is filtered with a 1000-mesh filter cloth, and the filtrate part is the plant extract solution.

[0048] After the various plant raw materials are soaked, the plant extracts exist in the plant extract solution in the form of plant extracts.

[0049] Preparation Example 2-5

[0050] The plant extract solution raw material in Preparation Example 2-5 is the same as that in Preparation Example 1, except that the addition amount of various raw materials is different, and the addition amount of various raw materials in Preparation Example 1-5 is shown in Table 1:

[0051] Table 1

[0052] Preparation Example 1 Preparation Example 2 Preparation Example 3 Preparation Example 4 Preparation Example 5 Bamboo leaves 15 35 28 30 30 Purslane 10 30 12 15 15 Camphor leaves 10 20 16 18 18 Lemon leaves 5 10 10 10 10 Water 10 20 20 20 10 Ethanol 10 20 20 20 30

[0053] Example

[0054] Example 1

[0055] A preparation method of the super-retarding concrete:

[0056] 1 kg of melamine formaldehyde resin, 1.5 kg of the plant extract solution prepared in Preparation Example 1, and 2 kg of modified acrylonitrile-butadiene-styrene copolymer and 16 kg of water are heated to 80°C, and stirred at a rotation speed of 60 r / min for 2 min to obtain a premix solution; 7.5 kg of fly ash and 24 kg of cement are mixed and stirred with the premix solution at a rotation speed of 60 r / min for 5 min, and then 75 kg of sand, 100 kg of stone, 0.8 kg of borax, and 0.5 kg of super-retarding water reducing agent are added, and mixed and stirred at a rotation speed of 50 r / min for 30 s to obtain the super-retarding concrete.

[0057] The cement is selected from Tai cement P.0 42.5; the stone is selected from crushed stone with a particle size range of 5-15 mm; and the super-retarding water reducing agent is hypophosphite-based polyacrylic acid.

[0058] The preparation method of the modified acrylonitrile-butadiene-styrene copolymer is as follows: 20 kg of acrylonitrile-butadiene-styrene copolymer, 15 kg of acrylic acid, and 2 kg of sodium dodecyl sulfate emulsifier are added to a reaction kettle, and uniformly mixed and stirred at a rotation speed of 40 r / min for 5 min, then 10 kg of sodium bicarbonate is ultrasonically dispersed for 40 min, and water bath heating is performed at a temperature of 50°C, and stirring is performed while heating for 30 min to obtain the modified acrylonitrile-butadiene-styrene copolymer; wherein the acrylonitrile-butadiene-styrene copolymer is selected from a type of Japan UMG NTV35, and the Rockwell strength is 100R.

[0059] Example 2

[0060] A preparation method of super-delayed setting concrete

[0061] 2 kg of melamine formaldehyde resin, 2.5 kg of the plant extract prepared in Preparation Example 1, and 3 kg of modified acrylonitrile-butadiene-styrene copolymer and 18 kg of water are heated to 80℃, and stirred at a rotation speed of 60 r / min for 2 min to obtain a premix; 8.5 kg of fly ash and 25 kg of cement are mixed with the premix at a rotation speed of 60 r / min for 5 min, and then 80 kg of sand, 110 kg of stone, 1.6 kg of borax, and 0.8 kg of super-delayed setting water reducing agent are added, and mixed and stirred at a rotation speed of 50 r / min for 30 s to obtain the super-delayed setting concrete.

[0062] The cement is selected from Taiji P.0 42.5; the stone is selected from crushed stone with a particle size range of 5-15 mm; and the super-delayed setting water reducing agent is salicylic acid.

[0063] The preparation method of the modified acrylonitrile-butadiene-styrene copolymer is as follows: 20 kg of acrylonitrile-butadiene-styrene copolymer, 15 kg of acrylic acid, and 2 kg of sodium dodecyl sulfate emulsifier are added to a reaction kettle, and uniformly mixed and stirred at a rotation speed of 40 r / min for 5 min, then 10 kg of sodium bicarbonate is ultrasonically dispersed for 40 min, and heated in a water bath at a temperature of 50℃, while stirring for 30 min to obtain the modified acrylonitrile-butadiene-styrene copolymer; wherein the acrylonitrile-butadiene-styrene copolymer is selected from UMG NTV35 of Japan, with a Rockwell strength of 100R.

[0064] Example 3

[0065] 1.5 kg of melamine formaldehyde resin, 2 kg of the plant extract prepared in Preparation Example 1, and 2.5 kg of modified acrylonitrile-butadiene-styrene copolymer and 17.4 kg of water are heated to 80℃, and stirred at a rotation speed of 60 r / min for 2 min to obtain a premix;

[0066] 8.1 kg of fly ash and 24.3 kg of cement are mixed with the premix at a rotation speed of 60 r / min for 5 min, and then 77.7 kg of sand, 103 kg of stone, 1.2 kg of borax, and 0.68 kg of super-delayed setting water reducing agent are added, and mixed and stirred at a rotation speed of 50 r / min for 30 s to obtain the super-delayed setting concrete.

[0067] The cement is selected from Taiji P.0 42.5; the stone is selected from crushed stone with a particle size range of 5-15 mm; and the super-delayed setting water reducing agent is salicylic acid.

[0068] The preparation method of the modified acrylonitrile-butadiene-styrene copolymer is as follows: 20 kg of acrylonitrile-butadiene-styrene copolymer, 15 kg of acrylic acid, and 2 kg of sodium dodecyl sulfate emulsifier are added to a reaction kettle, and after being uniformly mixed and stirred at a rotation speed of 40 r / min for 5 min, 10 kg of sodium bicarbonate is added and ultrasonically dispersed for 40 min, and then water bath heating is performed at a temperature of 50°C while stirring for 30 min to obtain the modified acrylonitrile-butadiene-styrene copolymer; wherein the acrylonitrile-butadiene-styrene copolymer is selected from a type of Japanese UMG NTV35, and the Rockwell strength is 100R.

[0069] Example 4

[0070] A preparation method of super-retarding concrete, different from example 3, is that the super-retarding water reducing agent is hypophosphite-based polyacrylic acid and salicylic acid, wherein the input amount of hypophosphite-based polyacrylic acid is 0.34 kg, and the input amount of salicylic acid is 0.34 kg.

[0071] Example 5

[0072] A preparation method of super-retarding concrete, different from example 3, is that the super-retarding water reducing agent is hypophosphite-based polyacrylic acid and salicylic acid, wherein the input amount of hypophosphite-based polyacrylic acid is 0.48 kg, and the input amount of salicylic acid is 0.2 kg.

[0073] Example 6

[0074] A preparation method of super-retarding concrete, different from example 3, is that the super-retarding water reducing agent is hypophosphite-based polyacrylic acid and salicylic acid, wherein the input amount of hypophosphite-based polyacrylic acid is 0.40 kg, and the input amount of salicylic acid is 0.28 kg.

[0075] Example 7

[0076] A preparation method of super-retarding concrete, different from example 6, is that the plant extract prepared in preparation example 1 is replaced with an equal amount of the plant extract prepared in preparation example 2.

[0077] Example 8

[0078] A preparation method of super-retarding concrete, different from example 6, is that the plant extract prepared in preparation example 1 is replaced with an equal amount of the plant extract prepared in preparation example 3.

[0079] Example 9

[0080] A preparation method of super-retarding concrete, different from example 6, is that the plant extract prepared in preparation example 1 is replaced with an equal amount of the plant extract prepared in preparation example 4.

[0081] Example 10

[0082] A method for preparing super-retarded concrete, which is different from that of Example 6 in that the plant extract solution prepared in Preparation Example 1 is replaced with the plant extract solution prepared in Preparation Example 5 in equal amount.

[0083] Example 11

[0084] A method for preparing super-retarded concrete, which is different from that of Example 9 in that, in the process of preparing the modified acrylonitrile-butadiene-styrene copolymer, 40 kg of acrylonitrile-butadiene-styrene copolymer, 25 kg of acrylic acid, and 8 kg of emulsifier are added to a reaction kettle, and after being uniformly mixed and stirred at a rotation speed of 40 r / min for 5 min, 20 kg of sodium bicarbonate is ultrasonically dispersed for 40 min, and then heated in a water bath at a temperature of 50°C while stirring for 30 min to obtain the modified acrylonitrile-butadiene-styrene copolymer.

[0085] Example 12

[0086] A method for preparing super-retarded concrete, which is different from that of Example 11 in that, in the process of preparing the modified acrylonitrile-butadiene-styrene copolymer, the input amount of acrylonitrile-butadiene-styrene copolymer is 24 kg, the input amount of acrylic acid is 6 kg, and the input amount of sodium bicarbonate is 12 kg.

[0087] Example 13

[0088] A method for preparing super-retarded concrete, which is different from that of Example 11 in that, in the process of preparing the modified acrylonitrile-butadiene-styrene copolymer, the input amount of acrylonitrile-butadiene-styrene copolymer is 27 kg, the input amount of acrylic acid is 6 kg, and the input amount of sodium bicarbonate is 15 kg.

[0089] Example 14

[0090] A method for preparing super-retarded concrete, which is different from that of Example 13 in that the input amount of melamine formaldehyde resin is 1.6 kg, the input amount of the plant extract mixture prepared in Preparation Example 4 is 2 kg, and the input amount of the modified acrylonitrile-butadiene-styrene copolymer is 2.6 kg.

[0091] Example 15

[0092] A method for preparing super-retarded concrete, which is different from that of Example 13 in that the input amount of melamine formaldehyde resin is 1.8 kg, the input amount of the plant extract mixture prepared in Preparation Example 4 is 2 kg, and the input amount of the modified acrylonitrile-butadiene-styrene copolymer is 2.8 kg.

[0093] Comparative Example 1

[0094] Comparative Example 1

[0095] A method for preparing super-retarded concrete, which is different from Example 1 in that the modified acrylonitrile-butadiene-styrene copolymer is replaced by an equal amount of acrylonitrile-butadiene-styrene copolymer.

[0096] Comparative Example 2

[0097] A method for preparing super-retarded concrete, which is different from Example 1 in that no plant extract is added.

[0098] Comparative Example 3

[0099] A method for preparing super-retarded concrete, which is different from Example 1 in that the melamine formaldehyde resin is replaced by an equal amount of modified acrylonitrile-butadiene-styrene copolymer.

[0100] Comparative Example 4

[0101] A method for preparing super-retarded concrete, which is different from Example 1 in that no melamine formaldehyde resin is added.

[0102] Comparative Example 5

[0103] A method for preparing super-retarded concrete, which is different from Example 1 in that no borax is added.

[0104] Comparative Example 6

[0105] A method for preparing super-retarded concrete, which is different from Example 1 in that the melamine formaldehyde resin is replaced by an equal amount of polyacrylic acid resin.

[0106] Performance detection test:

[0107] According to GB / T 1346-2001 "Cement Standard Consistency Water Consumption, Setting Time, and Stability Detection Method", the initial setting time and final setting time of the super-retarded concrete prepared in Examples 1-15 and Comparative Examples 1-6 were detected.

[0108] Compressive strength test: According to GB / T 50081-2019 "Concrete Physical and Mechanical Properties Test Method Standard", the compressive strength test was performed, wherein the standard sample was made into a 100mm x 100mm x 100mm cube, and the compressive strength of the concrete prepared in Examples 1-15 and Comparative Examples 1-6 was tested after 7d and 28d of curing, respectively.

[0109] Slump test: The concrete prepared in Examples 1-15 and Comparative Examples 1-6 was tested according to GB / T 50204-2002 "Standard for Test of Workmanship of Concrete Structure" and GBJ 107-87 "Standard for Test and Evaluation of Concrete Strength".

[0110]

[0111] According to the data comparison of Examples 1-3 and Comparative Examples 1-6, the super-retarding water-reducing agent added in the present application can control the initial setting time of the concrete to be delayed to 48 hours or more, thereby prolonging the setting time of the prepared concrete, facilitating the delivery, and adding melamine formaldehyde resin and modified acrylonitrile-butadiene-styrene copolymer in the raw materials for preparing the concrete. The modified acrylonitrile-butadiene-styrene copolymer forms a stable water film on the surface of the cement particles, reduces the direct contact between the cement particles, and further inhibits the hydration process of the cement. The borax is adsorbed on the surface of the cement, inhibits the agglomeration between the cements, and produces a retarding effect. The melamine formaldehyde resin, the plant extract and the modified acrylonitrile-butadiene-styrene copolymer together can promote the uniform distribution of the hydrates, effectively delay the hydration of the cement, and inhibit the crystallization and precipitation of calcium hydroxide. The two kinds of resin materials wrap the surface of the sand and stone and fill the voids between the sand and stone, so that the sand and stone can be tightly bonded together. The plant extract fills the capillary voids between the concrete mixture, improves the stability of the interfacial bonding and the compactness of the whole concrete mixture, and further improves the compressive strength of the concrete.

[0112] According to the data comparison of Examples 3-6, the present application uses phosphinic acid-based polyacrylic acid and salicylic acid as super-retarding water-reducing agents, which can reduce the amount of water in the concrete. Under the action of the phosphinic acid-based polyacrylic acid and the salicylic acid, a water film is wrapped on the surface of the concrete particles, the fluidity of the concrete is improved, the borax can enter the voids in the concrete mixture, and the compressive strength of the concrete is increased. The three together can also prolong the initial setting time and the final setting time of the concrete.

[0113] According to the data comparison of Examples 6-10, the bamboo leaves, the gota, the camphor leaves and the lemon leaves are soaked in a solvent, and the filtrate obtained by filtration is the corresponding plant extract. The important substances are leached out from the various raw materials in a long time of mutual contact. In the leaching process, the important substances cooperate and act with each other, so that the effects of the various raw materials can be fully played in a certain period of time, and the retention of the active substances in the plants is greatly increased. The active substances of the plants act on the concrete mixture, enhance the slump of the concrete, and effectively inhibit the occurrence of the hydration reaction, thereby prolonging the initial setting time and the final setting time of the concrete.

[0114] According to the data comparison of the embodiments 9 and 11-13, the acrylic acid is attached to the surface of the ABS resin after the ABS resin is mixed with the acrylic acid, the emulsifier and the sodium bicarbonate, so as to increase the adhesion and stability of the ABS resin, so that the modified ABS resin can form a more stable water film of the dissolving agent on the surface of the cement particles, reduce the direct contact between the cement particles, and further inhibit the hydration process of the cement, thereby prolonging the initial setting time of the concrete.

[0115] According to the data comparison of the embodiments 13-15, when the melamine formaldehyde resin, the plant extract and the modified ABS resin are in a specific ratio, the viscosity of the reinforcing system is increased, the compressive strength of the concrete is improved, a stable network structure is formed on the surface of the concrete mixture, the concrete mixture is wrapped, the hydration reaction is better delayed, and the effect of further delaying the setting of the concrete is achieved.

[0116] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, and the modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A super-retarded concrete, characterized in that: Made from the following ingredients by weight: Cement: 240-250 parts; Fly ash: 75-85 parts; Sand: 750-800 parts; Stone: 1000-1100 portions; Super retarder water-reducing agent: 5-8 parts; Water: 160-180 parts; Melamine-formaldehyde resin: 10-20 parts; Plant extract: 15-25 parts; Modified acrylonitrile-butadiene-styrene copolymer: 20-30 parts; Borax: 8-16 parts; The modified acrylonitrile-butadiene-styrene copolymer is prepared by modifying acrylonitrile-butadiene-styrene copolymer, acrylic acid, emulsifier and sodium bicarbonate; The modified acrylonitrile-butadiene-styrene copolymer is prepared by mixing 20-40 parts by weight of the acrylonitrile-butadiene-styrene copolymer, 15-25 parts by weight of acrylic acid and 2-8 parts by weight of emulsifier together and stirring evenly, then adding 10-20 parts by weight of sodium bicarbonate and ultrasonically dispersing, followed by water bath heating to obtain the modified acrylonitrile-butadiene-styrene copolymer.

2. The super-retarded concrete according to claim 1, characterized in that: The super-retarding water-reducing agent includes one or more of phosphonic acid-based polyacrylic acid and salicylic acid; the weight ratio of phosphonic acid-based polyacrylic acid, salicylic acid and borax is (0.3-0.4):(0.15-0.24):

1.

3. The super-retarded concrete according to claim 1, characterized in that: The plant extract comprises the following raw materials: 15-35 parts bamboo leaves; 10-30 parts purslane; 10-20 parts camphor leaves; and 5-10 parts lemon leaves. Solvent 20-40 parts.

4. The super-retarded concrete according to claim 3, characterized in that: The method for preparing the plant extract is as follows: a solvent, bamboo leaves, purslane, camphor leaves, and lemon leaves are mixed and soaked together to obtain a mixture; the mixture is then filtered, and the filtrate is the plant extract.

5. The super-retarded concrete according to claim 4, characterized in that: The solvent comprises water and ethanol, wherein the weight ratio of water to ethanol is (1-3):

1.

6. The super-retarded concrete according to claim 1, characterized in that: The weight ratio of the acrylonitrile-butadiene-styrene copolymer, acrylic acid, and sodium bicarbonate is (4-4.5):1:(2-2.5).

7. The super-retarded concrete according to claim 6, characterized in that: The weight ratio of the melamine-formaldehyde resin, the plant extract mixture, and the modified acrylonitrile-butadiene-styrene copolymer is (0.8-0.9):1:(1.3-1.4).

8. The super-retarded concrete according to claim 1, characterized in that: The cement used is Taiwan Cement P.O42.

5.

9. The super-retarded concrete according to claim 1, characterized in that: The particle size of the stone ranges from 5 to 15 mm.

10. A method for preparing super-retarded concrete, characterized in that: The preparation of an ultra-retarded concrete according to any one of claims 1-8 includes the following steps: Melamine-formaldehyde resin, plant extract, modified acrylonitrile-butadiene-styrene copolymer, and water were heated and stirred to obtain a premixed solution. After the fly ash and cement are mixed evenly with the premixed liquid, sand, stone, borax and super-retarding water-reducing agent are added and mixed evenly to obtain the super-retarding concrete.

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