Impermeable concrete containing polycarboxylate early-strength water reducer and its preparation method

Abstract

The present invention relates to the technical field of concrete materials, and specifically discloses an impermeable concrete containing a polycarboxylate early-strength water reducer and a preparation method thereof. The impermeable concrete containing a polycarboxylate early-strength water reducer comprises the following components in parts by mass: 100 parts of water; 310-320 parts of cement; 33-37 parts of fly ash; 300-310 parts of fine aggregate; 670-680 parts of coarse aggregate; 210-220 parts of modified desert sand; 5.7-6.1 parts of polycarboxylate early-strength water reducer; the modified desert sand is obtained by modifying desert sand with a modifier; the modifying solution is a compound of water, stearylamidopropyldimethyl tertiary amine, dodecyltrimethylammonium bromide, and benzalkonium bromide. The present invention has the advantage of improving the impermeability of concrete.

Description

Technical Field

[0001] The present invention relates to the field of concrete materials, and particularly to an impermeable concrete containing a polycarboxylate early-strength water reducer and a preparation method thereof. Background Art

[0002] Concrete is a composite material in which a cementitious material binds aggregates into a whole. Cement is usually used as the cementitious material in concrete. After the cement comes into contact with water, a hydration reaction occurs, which causes the concrete to solidify, enabling the concrete to form various shapes and determining whether the concrete is suitable as a building material.

[0003] The aggregates of concrete mainly use sand and stone. The cement paste fills the gaps between the sand and stone to bond the sand and stone to form a solidified whole. Ordinary cement paste has poor fluidity and needs to increase the amount of water to improve the fluidity of the cement paste. As a result, the excess water will evaporate during the solidification of the concrete, causing a large number of micropores to appear in the solidified concrete, resulting in relatively general impermeability of ordinary concrete. In the prior art, a polycarboxylate early-strength water reducer is mainly added to reduce the amount of water used and improve the fluidity of the cement paste. Adding a polycarboxylate early-strength water reducer can improve the impermeability of the concrete to a certain extent. However, due to the relatively large number of gaps between the internal aggregates of the concrete, it is difficult for the cement paste to fully fill them, resulting in limited improvement in the impermeability of the concrete.

[0004] In order to further improve the impermeability of the concrete, powder fillers with smaller particle sizes are usually filled, hoping to fill the gaps in the concrete through the fillers. However, the addition of a large amount of powder will increase the viscosity of the cement paste, making it more difficult for the cement paste to penetrate into the gaps between the aggregates, and instead causing a significant decrease in the strength of the concrete and worse impermeability. Therefore, only a small amount of powder fillers can be incorporated, and the addition of a small amount of powder fillers is difficult to fully fill the gaps between the aggregates, resulting in the effect of improving the impermeability being difficult to meet expectations. Therefore, there is still room for improvement. Summary of the Invention

[0005] In order to improve the impermeability of the concrete, the present application provides an impermeable concrete containing a polycarboxylate early-strength water reducer and a preparation method thereof.

[0006] In the first aspect, the present application provides an impermeable concrete containing a polycarboxylate early-strength water reducer, adopting the following technical solution:

[0007] An impermeable concrete containing a polycarboxylate early-strength water reducer, comprising the following components in parts by mass:

[0008] Water 100 parts;

[0009] Cement 310 - 320 parts;

[0010] Fly ash 33 - 37 parts;

[0011] Fine aggregate: 300 - 310 parts

[0012] Coarse aggregate: 670 - 680 parts

[0013] Modified desert sand: 210 - 220 parts

[0014] Polycarboxylate early strength water reducer: 5.7 - 6.1 parts

[0015] The modified desert sand is obtained by modifying desert sand with a modifier.

[0016] The modifying solution is a compound of water, stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide.

[0017] By adopting the above technical solution, after modifying desert sand with a modifying solution composed of stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide, the surface activity of desert sand can be changed. After a large amount of desert sand is used as powder filler, the viscosity of cement slurry will not increase. Thus, under the action of polycarboxylate early strength water reducer, the cement slurry can obtain good fluidity. At the same time, when desert sand is used to fill the gaps between aggregates, the compactness of concrete is significantly improved, and thus the strength and impermeability of concrete are significantly improved.

[0018] Moreover, a large amount of desert sand used can also reduce the consumption of sand and stone, make full use of desert resources, and better achieve green environmental protection.

[0019] Preferably, the mass ratio of stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide is 9 - 11:16 - 18:4 - 6.

[0020] By adopting the above technical solution, by specifically selecting the mass ratio of stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide, the modifying effect of the modifying solution on desert sand is better, and the strength and impermeability of concrete after curing are better.

[0021] Preferably, the mass ratio of water, stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide is 300:9 - 11:16 - 18:4 - 6.

[0022] By adopting the above technical solution, by specifically selecting the mass ratio of water, stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide, the modifying solution has a good modifying effect on desert sand, can effectively control costs, and has higher economic value.

[0023] Preferably, the particle size of the desert sand is 0.1 - 0.2 mm.

[0024] By adopting the above technical solution, by specifically selecting the particle size of desert sand to be 0.1 - 0.2 mm, the effect of filling the concrete cracks with the modified desert sand is better, which can better improve the compactness of the concrete, make the concrete have higher strength and better impermeability performance.

[0025] Preferably, the preparation method of the modified desert sand includes the following steps:

[0026] Step 1), mix water, stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide evenly to obtain a modified liquid;

[0027] Step 2), put the desert sand into the modified liquid, stir for 90 - 120 min, filter and dry to obtain the modified desert sand.

[0028] By adopting the above technical solution, the modification effect on the desert sand is better, and a large amount of the modified desert sand can be incorporated to significantly improve the strength and impermeability performance of the concrete.

[0029] Preferably, in the said Step 2), after putting the desert sand into the modified liquid, first heat it to 50 - 60 °C, and then stir for 90 - 120 min.

[0030] By adopting the above technical solution, by carrying out the modification at 50 - 60 °C, the modification effect is better, the compactness of the prepared concrete is higher, and the strength and impermeability performance are better.

[0031] Preferably, in the said Step 2), the mass ratio of the desert sand to the modified liquid is 1:2 - 3.

[0032] By adopting the above technical solution, by specifically selecting the mass ratio of the desert sand to the modified liquid, while ensuring the modification effect, the consumption of the modified liquid is well controlled, resource waste is reduced, and it has high economic value.

[0033] In the second aspect, the present application provides a preparation method of impermeable concrete containing polycarboxylate early - strength water - reducing agent, adopting the following technical solution:

[0034] A preparation method of the above - mentioned impermeable concrete containing polycarboxylate early - strength water - reducing agent includes the following steps:

[0035] Step 01), stir cement, fly ash, fine aggregate, coarse aggregate, modified desert sand, and polycarboxylate early - strength water - reducing agent evenly to obtain a premix;

[0036] Step 02), add water to the premix and stir evenly to obtain a concrete mixture;

[0037] Step 03), inject the concrete mixture into a mold, cure, and demold to obtain the impermeable concrete containing polycarboxylate early - strength water - reducing agent.

[0038] By adopting the above technical solution, the impermeable concrete prepared with the polycarboxylic acid early strength water reducing agent has a high density, and the strength and impermeability of the concrete are relatively high. It can be well applied to projects with relatively high impermeability requirements, and has high economic value and application prospects.

[0039] In summary, the present application has the following beneficial effects:

[0040] 1. Since the desert sand in the present application is modified by a modification liquid composed of stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide, the surface activity of the desert sand can be changed. After a large amount of desert sand is used as a powder filler, the viscosity of the cement slurry will not be increased. Therefore, the cement slurry can obtain good fluidity under the action of the polycarboxylic acid early strength water reducing agent. At the same time, in combination with the desert sand filling the gaps between the aggregates, the density of the concrete is significantly increased, thereby significantly improving the strength and impermeability of the concrete.

[0041] 2. In the present application, by specifically selecting the mass ratio of stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide, the modification effect of the modification liquid on the desert sand is better, and the strength and impermeability of the cured concrete are better.

[0042] 3. In the present application, by specifically selecting the mass ratio of water, stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide, the modification liquid has a good modification effect on the desert sand, can effectively control the cost, and has higher economic value. Detailed implementation mode

[0043] The following further elaborates on the present application with reference to the embodiments.

[0044] Embodiment 1

[0045] An impermeable concrete containing a polycarboxylic acid early strength water reducing agent comprises the following components in parts by mass:

[0046] Water, cement, fly ash, fine aggregate, coarse aggregate, modified desert sand, polycarboxylic acid early strength water reducing agent.

[0047] The cement is ordinary Portland cement, Jidong Cement, specification, P.O42.5.

[0048] The fly ash is commercially available, class I fly ash.

[0049] The fine aggregate is commercially available, natural river sand, with a particle size of 3 - 5mm.

[0050] The coarse aggregate is commercially available, basalt gravel, with a particle size of 15 - 20mm.

[0051] The polycarboxylate early-strength water reducer was purchased from Kunming Baiyi Building Materials Manufacturing Co., Ltd., model: G454.

[0052] The modified desert sand is obtained by modifying desert sand with a modifier.

[0053] The modification liquid is a compound of water, stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide.

[0054] Stearamidopropyl dimethyl tertiary amine is commercially available, CAS number: 7651-02-7.

[0055] Dodecyl trimethyl ammonium bromide is commercially available, CAS number: 1119-94-4.

[0056] Benzalkonium bromide is commercially available, CAS number: 7281-04-1.

[0057] Desert sand is commercially available, with a particle size of 0.1 - 0.2 mm.

[0058] The preparation method of the modified desert sand includes the following steps:

[0059] Step 1), Put 900 kg of water, 27 kg of stearamidopropyl dimethyl tertiary amine, 48 kg of dodecyl trimethyl ammonium bromide, and 12 kg of benzalkonium bromide into a stirring kettle, with a rotation speed of 120 r / min, stir for 10 min, and mix evenly to obtain the modification liquid.

[0060] Step 2), Take 600 kg of the modification liquid and put it into a stirring kettle, then put 300 kg of desert sand, heat to 50 °C, with a rotation speed of 60 r / min, stir for 90 min, filter through a filter cloth, take the solid, and air-dry naturally to obtain the modified desert sand.

[0061] The preparation method of the impermeable concrete containing polycarboxylate early-strength water reducer includes the following steps:

[0062] Step 01), Put 310 kg of cement, 33 kg of fly ash, 300 kg of fine aggregate, 670 kg of coarse aggregate, 210 kg of modified desert sand, and 5.7 kg of polycarboxylate early-strength water reducer into a stirring kettle, with a rotation speed of 60 r / min, stir for 15 min, and mix evenly to obtain a premix.

[0063] Step 02), Add 100 kg of water to the premix, with a rotation speed of 60 r / min, stir for 5 min, and mix evenly to obtain the concrete mixture.

[0064] Step 03), Inject the concrete mixture into a mold, sprinkle water for curing for 3 days, demold, sprinkle water for curing until 7 days, and statically cure until 28 days to obtain the impermeable concrete containing polycarboxylate early-strength water reducer.

[0065] Example 2

[0066] An impermeable concrete containing a polycarboxylate early-strength water reducer, comprising the following components in parts by mass:

[0067] Water, cement, fly ash, fine aggregate, coarse aggregate, modified desert sand, polycarboxylate early-strength water reducer.

[0068] The cement is ordinary Portland cement, Jidong Cement, specification, P.O42.5.

[0069] The fly ash is commercially available, Class I fly ash.

[0070] The fine aggregate is commercially available, natural river sand, with a particle size of 3 - 5 mm.

[0071] The coarse aggregate is commercially available, basalt gravel, with a particle size of 15 - 20 mm.

[0072] The polycarboxylate early-strength water reducer is purchased from Kunming Baiyi Building Materials Manufacturing Co., Ltd., model: G454.

[0073] The modified desert sand is prepared by modifying desert sand with a modifier.

[0074] The modification liquid is a compound of water, stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide.

[0075] Stearamidopropyl dimethyl tertiary amine is commercially available, CAS number: 7651 - 02 - 7.

[0076] Dodecyl trimethyl ammonium bromide is commercially available, CAS number: 1119 - 94 - 4.

[0077] Benzalkonium bromide is commercially available, CAS number: 7281 - 04 - 1.

[0078] The desert sand is commercially available, with a particle size of 0.1 - 0.2 mm.

[0079] The preparation method of the modified desert sand includes the following steps:

[0080] Step 1), put 900 kg of water, 30 kg of stearamidopropyl dimethyl tertiary amine, 51 kg of dodecyl trimethyl ammonium bromide, and 15 kg of benzalkonium bromide into a stirring kettle, with a rotation speed of 120 r / min, stir for 10 min, and mix evenly to obtain a modification liquid.

[0081] Step 2), take 750 kg of the modification liquid and put it into a stirring kettle, then put 300 kg of desert sand, heat to 55 °C, with a rotation speed of 60 r / min, stir for 105 min, filter through a filter cloth, take the solid, and air-dry naturally to obtain the modified desert sand.

[0082] The preparation method of impermeable concrete containing polycarboxylate early-strength water reducer comprises the following steps:

[0083] Step 01), put 315 kg of cement, 35 kg of fly ash, 305 kg of fine aggregate, 675 kg of coarse aggregate, 215 kg of modified desert sand, and 5.9 kg of polycarboxylate early-strength water reducer into a stirring kettle, with a rotation speed of 60 r / min, stir for 15 min, and stir evenly to obtain a premix.

[0084] Step 02), add 100 kg of water to the premix, with a rotation speed of 60 r / min, stir for 5 min, and stir evenly to obtain concrete mixture.

[0085] Step 03), inject the concrete mixture into a mold, sprinkle water for curing for 3 days, demold, sprinkle water for curing until 7 days, and statically cure until 28 days to obtain impermeable concrete containing polycarboxylate early-strength water reducer.

[0086] Example 3

[0087] An impermeable concrete containing polycarboxylate early-strength water reducer comprises the following components in parts by mass:

[0088] Water, cement, fly ash, fine aggregate, coarse aggregate, modified desert sand, polycarboxylate early-strength water reducer.

[0089] The cement is ordinary Portland cement, Jidong Cement, specification, P.O42.5.

[0090] The fly ash is commercially available, first-class fly ash.

[0091] The fine aggregate is commercially available, natural river sand, with a particle size of 3 - 5 mm.

[0092] The coarse aggregate is commercially available, basalt gravel, with a particle size of 15 - 20 mm.

[0093] The polycarboxylate early-strength water reducer is purchased from Kunming Baiyi Building Materials Manufacturing Co., Ltd., model: G454.

[0094] The modified desert sand is obtained by modifying desert sand with a modifier.

[0095] The modifying liquid is a compound of water, stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide.

[0096] Stearamidopropyl dimethyl tertiary amine is commercially available, CAS number: 7651 - 02 - 7.

[0097] Dodecyl trimethyl ammonium bromide is commercially available, CAS number: 1119 - 94 - 4.

[0098] Benzalkonium bromide is commercially available, CAS number: 7281 - 04 - 1.

[0099] The desert sand is commercially available, with a particle size of 0.1 - 0.2 mm.

[0100] The preparation method of the modified desert sand includes the following steps:

[0101] Step 1), Put 900 kg of water, 33 kg of stearamidopropyl dimethyl tertiary amine, 54 kg of dodecyl trimethyl ammonium bromide, and 18 kg of benzalkonium bromide into a stirring kettle, with a rotation speed of 120 r / min, stir for 10 min, mix evenly to obtain a modified liquid.

[0102] Step 2), Take 900 kg of the modified liquid and put it into a stirring kettle, then put 300 kg of desert sand, heat to 60 °C, with a rotation speed of 60 r / min, stir for 120 min, filter through a filter cloth, take the solid, and air-dry naturally to obtain the modified desert sand.

[0103] The preparation method of the impermeable concrete containing polycarboxylate early-strength water reducer includes the following steps:

[0104] Step 01), Put 320 kg of cement, 37 kg of fly ash, 310 kg of fine aggregate, 680 kg of coarse aggregate, 220 kg of modified desert sand, and 6.1 kg of polycarboxylate early-strength water reducer into a stirring kettle, with a rotation speed of 60 r / min, stir for 15 min, stir evenly to obtain a premix.

[0105] Step 02), Add 100 kg of water to the premix, with a rotation speed of 60 r / min, stir for 5 min, stir evenly to obtain the concrete mixture.

[0106] Step 03), Pour the concrete mixture into a mold, sprinkle water for curing for 3 days, demold, sprinkle water for curing until 7 days, and statically cure until 28 days to obtain the impermeable concrete containing polycarboxylate early-strength water reducer.

[0107] Comparative Example 1

[0108] An impermeable concrete containing polycarboxylate early-strength water reducer, compared with Example 2, the difference is only that:

[0109] In the modified liquid, sodium dodecylbenzenesulfonate is used to replace stearamidopropyl dimethyl tertiary amine in equal amount.

[0110] Sodium dodecylbenzenesulfonate is commercially available, CAS No.: 25155 - 30 - 0.

[0111] Comparative Example 2

[0112] An impermeable concrete containing polycarboxylate early-strength water reducer, compared with Example 2, the difference is only that:

[0113] In the modified liquid, diethanolamine is used to replace dodecyl trimethyl ammonium bromide in equal amount.

[0114] Diethylene glycol amine is commercially available, CAS No.: 929-06-6.

[0115] Comparative Example 3

[0116] An impermeable concrete containing a polycarboxylate early strength water reducing agent, compared with Example 2, the difference is only that:

[0117] In the modification liquid, isomeric tridecyl alcohol polyoxyethylene ether is used to replace benzalkonium bromide in equal amount.

[0118] Isomeric tridecyl alcohol polyoxyethylene ether is commercially available, CAS No.: 9043-30-5.

[0119] Comparative Example 4

[0120] An impermeable concrete containing a polycarboxylate early strength water reducing agent, compared with Example 2, the difference is only that:

[0121] In the modification liquid, sodium dodecylbenzenesulfonate is used to replace stearamide propyl dimethyl tertiary amine in equal amount; diethylene glycol amine is used to replace dodecyl trimethyl ammonium bromide in equal amount; isomeric tridecyl alcohol polyoxyethylene ether is used to replace benzalkonium bromide in equal amount.

[0122] Sodium dodecylbenzenesulfonate is commercially available, CAS No.: 25155-30-0.

[0123] Diethylene glycol amine is commercially available, CAS No.: 929-06-6.

[0124] Isomeric tridecyl alcohol polyoxyethylene ether is commercially available, CAS No.: 9043-30-5.

[0125] Comparative Example 5

[0126] An impermeable concrete containing a polycarboxylate early strength water reducing agent, comprising the following components in parts by mass:

[0127] Water, cement, fly ash, fine aggregate, coarse aggregate, desert sand, polycarboxylate early strength water reducing agent.

[0128] The cement is ordinary Portland cement, Jidong Cement, specification, P.O42.5.

[0129] Fly ash is commercially available, first-class fly ash.

[0130] The fine aggregate is commercially available, natural river sand, particle size 3-5mm.

[0131] The coarse aggregate is commercially available, basalt crushed stone, particle size 15-20mm.

[0132] The polycarboxylate early strength water reducing agent is purchased from Kunming Baiyi Building Materials Manufacturing Co., Ltd., model: G454.

[0133] The desert sand is commercially available with a particle size of 0.1 - 0.2 mm.

[0134] The preparation method of the impermeable concrete containing polycarboxylate early-strength water reducer includes the following steps:

[0135] Step 01), put 315 kg of cement, 35 kg of fly ash, 305 kg of fine aggregate, 675 kg of coarse aggregate, 215 kg of desert sand, and 5.9 kg of polycarboxylate early-strength water reducer into the stirring kettle, with a rotation speed of 60 r / min, stir for 15 min, and stir evenly to obtain a premix.

[0136] Step 02), add 100 kg of water to the premix, with a rotation speed of 60 r / min, stir for 5 min, and stir evenly to obtain a concrete mixture.

[0137] Step 03), inject the concrete mixture into the mold, sprinkle water for curing for 3 days, demold, sprinkle water for curing until 7 days, and statically cure until 28 days to obtain the impermeable concrete containing polycarboxylate early-strength water reducer.

[0138] Comparative Example 6

[0139] An impermeable concrete containing polycarboxylate early-strength water reducer, comprising the following components in parts by mass:

[0140] Water, cement, fly ash, fine aggregate, coarse aggregate, polycarboxylate early-strength water reducer.

[0141] The cement is ordinary Portland cement, Jidong Cement, specification, P.O42.5.

[0142] The fly ash is commercially available, class I fly ash.

[0143] The fine aggregate is commercially available, natural river sand, with a particle size of 3 - 5 mm.

[0144] The coarse aggregate is commercially available, basalt crushed stone, with a particle size of 15 - 20 mm.

[0145] The polycarboxylate early-strength water reducer is purchased from Kunming Baiyi Building Materials Manufacturing Co., Ltd., model: G454.

[0146] The preparation method of the impermeable concrete containing polycarboxylate early-strength water reducer includes the following steps:

[0147] Step 01), put 315 kg of cement, 35 kg of fly ash, 405 kg of fine aggregate, 790 kg of coarse aggregate, and 5.9 kg of polycarboxylate early-strength water reducer into the stirring kettle, with a rotation speed of 60 r / min, stir for 15 min, and stir evenly to obtain a premix.

[0148] Step 02): Add 100 kg of water to the premix, stir at a speed of 60 r / min for 5 min until evenly mixed to obtain the concrete mixture.

[0149] Step 03): Pour the concrete mixture into the mold, sprinkle water for curing for 3 days, demold, sprinkle water for curing until 7 days, and statically cure until 28 days to obtain the impermeable concrete containing polycarboxylate early-strength water-reducing agent.

[0150] Experiment 1

[0151] According to GB / T50081-2019 "Standard Test Method for Physical and Mechanical Properties of Concrete", test the 7-day compressive strength (standard specimen) and 28-day compressive strength (standard specimen) of the specimens prepared from the impermeable concrete containing polycarboxylate early-strength water-reducing agent in each example and comparative example.

[0152] Experiment 2

[0153] According to GB / T50082-2009 "Standard Test Method for Long-Term Performance and Durability of Ordinary Concrete", use the step-by-step pressure method in the water penetration resistance test to test the impermeability grade of the specimens prepared from the impermeable concrete containing polycarboxylate early-strength water-reducing agent in each example and comparative example.

[0154] The specific test data of Experiments 1-2 are shown in Table 1.

[0155] Table 1

[0156]

[0157]

[0158] According to the data comparison of each example and comparative example in Table 1, the compressive strength and impermeability grade of each example are significantly higher than those of each comparative example. It can be seen that after the desert sand is modified by the modification liquid composed of stearamide propyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide in each example, while a large amount of desert sand is used, the influence on the viscosity of the cement paste can be reduced, so that both the cement paste and the desert sand can well penetrate into the gaps between the aggregates, thus greatly improving the compactness of the concrete, and the strength and impermeability performance of the concrete are significantly improved.

[0159] Although Comparative Examples 1-4 also modified the desert sand and their strength and impermeability performance are higher than those of Comparative Example 5 and Comparative Example 6, due to the destruction of the compounding system of stearamide propyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide, the modification effect is not good, and the strength and impermeability performance of the concrete are significantly weaker than those of each example.

[0160] In Comparative Example 5, the desert sand was not modified. The compressive strength of Comparative Example 5 was significantly lower than that of Comparative Example 6, and the impermeability of Comparative Example 5 was similar to that of Comparative Example 6. It can be seen that a large amount of unmodified desert sand is difficult to improve the impermeability of concrete and will also cause a decrease in the strength of concrete.

[0161] This specific embodiment is only an interpretation of the present application, and it is not a limitation of the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as it is within the scope of the claims of the present application, it is protected by the patent law.

Claims

1. An impermeable concrete containing a polycarboxylate early-strength water reducer, characterized in that: Comprising the following components in parts by mass: Water 100 parts; Cement 310 - 320 parts; Fly ash 33 - 37 parts; Fine aggregate 300 - 310 parts; Coarse aggregate 670 - 680 parts; Modified desert sand 210 - 220 parts; Polycarboxylate early strength water reducer 5.7 - 6.1 parts; The modified desert sand is obtained by modifying desert sand with a modifying liquid; The modifying liquid is a compound of water, stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide; The mass ratio of stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide is 9 - 11:16 - 18:4 - 6.

2. The impermeable concrete containing polycarboxylate early-strength water reducer according to claim 1, characterized in that: In the modifying liquid, the mass ratio of water, stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide is 300:9 - 11:16 - 18:4 - 6.

3. An impermeable concrete containing a polycarboxylate early-strength water reducer according to claim 2, characterized in that: The particle size of the desert sand is 0.1 - 0.2 mm.

4. An impermeable concrete containing a polycarboxylate early-strength water reducer according to claim 3, characterized in that: The preparation method of the modified desert sand comprises the following steps: Step 1), Mix water, stearamidopropyl dimethyl tertiary amine, dodecyl trimethyl ammonium bromide, and benzalkonium bromide evenly to obtain a modifying liquid; Step 2), Put the desert sand into the modifying liquid, stir for 90 - 120 min, filter and dry to obtain the modified desert sand.

5. An impermeable concrete containing a polycarboxylate early strength water reducing agent according to claim 4, characterized in that: In Step 2), after putting the desert sand into the modifying liquid, first heat it to 50 - 60 °C, and then stir for 90 - 120 min.

6. An impermeable concrete containing a polycarboxylate early-strength water reducer according to claim 5, characterized in that: In Step 2), the mass ratio of the desert sand to the modifying liquid is 1:2 - 3.

7. A preparation method of impermeable concrete containing polycarboxylate early-strength water reducer according to any one of claims 1-6, characterized in that: Comprising the following steps: Step 01), Stir cement, fly ash, fine aggregate, coarse aggregate, modified desert sand, and polycarboxylate early strength water reducer evenly to obtain a premix; Step 02), Add water to the premix and stir evenly to obtain a concrete mixture; Step 03), Inject the concrete mixture into a mold, cure, and demold to obtain impermeable concrete containing polycarboxylate early strength water reducer.

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