A frost-resistant concrete and a method for producing the same

Abstract

The application relates to the technical field of concrete, and particularly discloses an anti-freezing concrete and a preparation method thereof. The anti-freezing concrete comprises the following components in parts by mass: 150-180 parts of cement, 65-78 parts of fly ash, 370-430 parts of sand, 560-720 parts of gravel, 1.5-2 parts of a polycarboxylate water reducing agent, 1.2-1.5 parts of sodium dodecyl benzene sulfonate, 1.7-2.1 parts of a triphenyl ethenyl phenol polyoxyethylene ether, 1.6-1.9 parts of a polyglycerol fatty acid ester and 75-90 parts of water. The preparation method of the anti-freezing concrete is mixing the components to obtain the anti-freezing concrete. The anti-freezing concrete prepared by the application has good anti-freezing performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of concrete, in particular to an anti-freezing concrete and a preparation method thereof. BACKGROUND

[0002] Concrete is a kind of porous composite material composed of cement, sand, stone and the like. In order to ensure good workability of concrete during construction, more mixing water than the water required for hydration of cement is added to concrete, and this part of excess water remains in the concrete in the form of free water, forming connected capillary pores occupying a certain volume. These connected capillary pores are the main cause of freezing damage of concrete.

[0003] China has vast territory, and the average annual temperature changes greatly in most areas, especially during seasonal transition, the diurnal temperature difference changes more obviously, especially when the temperature changes continuously above and below the freezing point, the temperature change will cause the water contained in the capillary pores of concrete to freeze and thaw continuously. When the concrete is in a saturated state, the water in the capillary pores of the concrete will produce an expansion pressure when crystallizing, thereby damaging and extruding the internal structure of the concrete to cause microcracks in the concrete. In the process of repeated freezing and thawing, the microcracks in the concrete will gradually grow and expand, further damaging the concrete structure, seriously affecting the durability of the concrete, and thus seriously affecting the engineering quality of the concrete building.

[0004] In view of the related art above, the inventors believe that it is necessary to improve the frost resistance of concrete. SUMMARY

[0005] In order to improve the frost resistance of concrete, the present application provides an anti-freezing concrete and a preparation method thereof.

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

[0007] An anti-freezing concrete comprises the following components in mass fraction: 150-180 parts of cement, 65-78 parts of fly ash, 370-430 parts of sand, 560-720 parts of crushed stone, 1.5-2 parts of polycarboxylate superplasticizer, 1.2-1.5 parts of sodium dodecyl benzene sulfonate, 1.7-2.1 parts of triphenyl ethylene phenol polyoxyethylene ether, 1.6-1.9 parts of polyglycerol fatty acid ester, and 75-90 parts of water.

[0008] In the technical scheme, the sodium dodecyl benzene sulfonate, the triphenyl styryl phenol polyoxyethylene ether and the polyglycerol fatty acid ester are added to effectively reduce the surface tension of the water phase in the concrete, promote the formation of the micro crystal nucleus, inhibit the generation of the large ice crystal, and change the shape of the ice crystal. The ice crystal structure formed has loose texture and low strength, and the expansion pressure of the ice crystal is significantly reduced. Meanwhile, the sodium dodecyl benzene sulfonate, the triphenyl styryl phenol polyoxyethylene ether and the polycarboxylic acid water reducing agent are used in combination to form stable micro bubbles in the concrete mixture, reduce the breakage of the bubbles, and form a certain volume of closed bubbles in the concrete. The closed bubbles not only block the capillary channel in the concrete and reduce the capillary effect, but also release the expansion pressure inside the ice crystal in the freezing process of the concrete, avoid the damage to the internal structure of the concrete, and significantly improve the frost resistance of the concrete.

[0009] Preferably, the mass ratio of the sodium dodecyl benzene sulfonate, the triphenyl styryl phenol polyoxyethylene ether and the polyglycerol fatty acid ester is 1.4:1.8:1.7.

[0010] In the technical scheme, the mass ratio of the sodium dodecyl benzene sulfonate, the triphenyl styryl phenol polyoxyethylene ether and the polyglycerol fatty acid ester is further limited to 1.4:1.8:1.7 to achieve the best effect of reducing the surface tension of the water phase in the concrete, promoting the formation of the micro crystal nucleus, inhibiting the generation of the large ice crystal, changing the shape of the ice crystal, further reducing the expansion pressure of the ice crystal, and significantly improving the frost resistance of the concrete.

[0011] Preferably, the frost-resistant concrete further comprises 1.2-1.5 parts of polyacrylamide.

[0012] In the technical scheme, the polyacrylamide is further added. The polyacrylamide has strong adsorption capacity, and is used in combination with the sodium dodecyl benzene sulfonate, the triphenyl styryl phenol polyoxyethylene ether and the polyglycerol fatty acid ester to be stably adsorbed on the surface of the micro crystal nucleus formed by the sodium dodecyl benzene sulfonate, the triphenyl styryl phenol polyoxyethylene ether and the polyglycerol fatty acid ester, obviously inhibit the further growth of the crystal nucleus, further inhibit the formation of the large ice crystal, further promote the formation of the ice crystal structure with loose texture, further reduce the expansion pressure of the ice crystal, and significantly improve the frost resistance of the concrete.

[0013] Preferably, the mass ratio of the sodium dodecyl benzene sulfonate, the triphenyl styryl phenol polyoxyethylene ether, the polyglycerol fatty acid ester and the polyacrylamide is 1.4:1.8:1.7:1.2.

[0014] In the technical solution, the mass ratio of sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether, polyglycerol fatty acid ester and polyacrylamide is 1.4:1.8:1.7:1.2, and the sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether, polyglycerol fatty acid ester and polyacrylamide have better cooperation, which can further promote the water molecules to form a loose ice crystal structure, further reduce the expansion pressure of the ice crystals, and significantly improve the frost resistance of the concrete.

[0015] Preferably, the frost-resistant concrete further comprises 6-7.5 parts of cellulose fibers.

[0016] Preferably, the cellulose fibers have a length of 3-5 mm and a diameter of 30-50 μm.

[0017] In the technical solution, the further addition of 6-7.5 parts of cellulose fibers can not only promote the full hydration of the concrete, but also form a three-dimensional structure in the concrete to effectively inhibit the expansion of cracks in the concrete during repeated freezing and thawing. Meanwhile, part of the cellulose fibers are inserted into the micro-pores formed by the cooperation of sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether and polycarboxylic acid water reducing agent, which can absorb more free water in the micro-pores and further inhibit the formation of large ice crystals, thereby avoiding the damage of the large ice crystals to the internal structure of the concrete and significantly improving the frost resistance of the concrete.

[0018] In a second aspect, the application provides a preparation method of a frost-resistant concrete, which adopts the following technical solution:

[0019] The preparation method of the frost-resistant concrete comprises the following steps:

[0020] Step 1: mixing and stirring water, polycarboxylic acid water reducing agent, sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether and polyglycerol fatty acid ester until uniform, then adding cement and fly ash, and stirring and mixing until uniform to obtain a slurry;

[0021] Step 2: adding sand and gravel into the slurry obtained in step 1 and stirring until uniform to obtain the frost-resistant concrete.

[0022] Preferably, the preparation method comprises the following steps:

[0023] Step 1: mixing and stirring water, polycarboxylic acid water reducing agent, sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether, polyglycerol fatty acid ester and polyacrylamide until uniform, then adding cement and fly ash, and stirring and mixing until uniform to obtain a slurry;

[0024] Step 2: adding sand and gravel into the slurry obtained in step 1 and stirring until uniform to obtain the frost-resistant concrete.

[0025] Preferably, comprising the following steps:

[0026] Step 1: mix and stir water, polycarboxylic acid water reducing agent, sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether, polyglycerol fatty acid ester, polyacrylamide, cellulose fiber, then add cement, fly ash, and stir to obtain a slurry;

[0027] Step 2: add sand and gravel to the slurry obtained in step 1, and stir to obtain the anti-freezing concrete.

[0028] In the above technical solution, the anti-freezing concrete prepared by the preparation method has good anti-freezing performance.

[0029] In summary, the present application has at least one of the following beneficial technical effects:

[0030] 1. By adding sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether and polyglycerol fatty acid ester to the concrete, the surface tension of the water phase in the concrete can be effectively reduced, the formation of micro-crystal nuclei is promoted, the generation of large ice crystals is inhibited, and the morphology of the ice crystals is changed. The ice crystal structure formed in this way has loose texture and low strength, and the expansion pressure of the ice crystals is significantly reduced.

[0031] 2. By using sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether and polycarboxylic acid water reducing agent together, stable micro-bubbles can be formed in the concrete mixture, and the breaking of the bubbles is reduced, thereby forming a certain volume of closed bubbles in the concrete. These closed bubbles not only block the capillary pore channels in the concrete and reduce the capillary effect, but also release the internal expansion pressure of the ice crystals during the freezing process of the concrete, avoiding damage to the internal structure of the concrete, and significantly improving the anti-freezing performance of the concrete.

[0032] 3. By adding polyacrylamide to the concrete, polyacrylamide has strong adsorption capacity, and when used with sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether and polyglycerol fatty acid ester, it can stably adsorb on the surface of the micro-crystal nuclei formed by water molecules, significantly inhibit the further growth of the crystal nuclei, further inhibit the formation of large ice crystals, further promote the formation of loose ice crystal structure, further reduce the expansion pressure of the ice crystals, and significantly improve the anti-freezing performance of the concrete.

[0033] 4. The application can promote the full hydration of concrete by adding cellulose fibers in concrete, and can form a three-dimensional structure in concrete to effectively inhibit the expansion of cracks in concrete during repeated freeze-thaw process. At the same time, part of the cellulose fibers are inserted into the micro pores formed by the combination of sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether and polycarboxylic acid water reducing agent, which can absorb more free water in the micro pores, further inhibit the formation of large ice crystals, avoid the damage of large ice crystals to the internal structure of concrete, and significantly improve the frost resistance of concrete. DETAILED DESCRIPTION

[0034] For the purpose, technical scheme and advantages of the present application, the present application will be further described below in combination with specific examples.

[0035] Example 1

[0036] A kind of frost-resistant concrete, including the following components: 150 kg cement, 65 kg fly ash, 370 kg sand, 560 kg gravel, 1.5 kg polycarboxylic acid water reducing agent, 1.2 kg sodium dodecyl benzene sulfonate, 1.7 kg triphenyl styryl phenol polyoxyethylene ether, 1.6 kg polyglycerol fatty acid ester, 75 kg water.

[0037] Among them, the cement is p.o42.5R British gold cement.

[0038] Among them, the fly ash is secondary fly ash.

[0039] Among them, the sand has a fineness modulus of 2.7.

[0040] Among them, the gravel is continuous grade gravel with a particle size of 4.75-19 mm.

[0041] Among them, the polycarboxylic acid water reducing agent is purchased from Guangxi Hengyong Building Material Co., Ltd., with the item number Q8012.

[0042] Among them, the sodium dodecyl benzene sulfonate is purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd., with the item number PHR1305.

[0043] Among them, the triphenyl styryl phenol polyoxyethylene ether is purchased from Nantong Chenrun Chemical Co., Ltd., with the CAS number 99734-09-5.

[0044] Among them, the polyglycerol fatty acid ester is purchased from Shenzhen Jinfuluan Biological Technology Co., Ltd., with the CAS number 67784-82-1.

[0045] Among them, the preparation method of the frost-resistant concrete comprises the following steps:

[0046] Step 1: mix and stir water, polycarboxylic acid water reducing agent, sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether, polyglycerol fatty acid ester uniformly, then add cement, fly ash, mix and stir uniformly to obtain a slurry.

[0047] Step 2: add sand and gravel to the slurry obtained in step 1, and stir uniformly to obtain the frost-resistant concrete.

[0048] Example 2-4

[0049] A kind of frost-resistant concrete, unlike example 1, the amount of each component is different, the specific amount of each component of example 1-4 is shown in table 1.

[0050] Table 1:

[0051]

[0052]

[0053] Example 5

[0054] A kind of frost-resistant concrete, unlike example 4, further includes 1.2 kg of polyacrylamide.

[0055] Wherein, polyacrylamide is purchased from Sigma Aldrich (Shanghai) Trading Co., Ltd., item number 92560.

[0056] Wherein, the preparation method of the frost-resistant concrete comprises the following steps:

[0057] Step 1: mix and stir water, polycarboxylic acid water reducing agent, sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether, polyglycerol fatty acid ester, polyacrylamide uniformly, then add cement, fly ash, mix and stir uniformly to obtain a slurry.

[0058] Step 2: add sand and gravel to the slurry obtained in step 1, and stir uniformly to obtain the frost-resistant concrete.

[0059] Example 6

[0060] A kind of frost-resistant concrete, unlike example 4, further includes 1.5 kg of polyacrylamide.

[0061] Example 7

[0062] A kind of frost-resistant concrete, unlike example 5, further includes 6 kg of cellulose fiber.

[0063] Wherein, the length of the cellulose fiber is between 3-5 mm, and the diameter is between 30-50 μm.

[0064] Wherein, the preparation method of the frost-resistant concrete comprises the following steps:

[0065] Step 1: Mix and stir water, polycarboxylic acid water reducing agent, sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether, polyglycerol fatty acid ester, polyacrylamide, cellulose fiber until uniform, then add cement, fly ash, and stir until uniform to obtain a slurry.

[0066] Step 2: Add sand and gravel to the slurry obtained in Step 1, and stir until uniform to obtain a freeze-resistant concrete.

[0067] Example 8

[0068] A freeze-resistant concrete, different from Example 5, further comprises 7.5 kg of cellulose fiber.

[0069] Comparative Example 1

[0070] A concrete, different from Example 1, does not contain sodium dodecyl benzene sulfonate.

[0071] Comparative Example 2

[0072] A concrete, different from Example 1, does not contain triphenyl styryl phenol polyoxyethylene ether.

[0073] Comparative Example 3

[0074] A concrete, different from Example 1, does not contain polyglycerol fatty acid ester.

[0075] Comparative Example 4

[0076] A concrete, different from Example 1, the addition amount of sodium dodecyl benzene sulfonate is changed to 0.9 kg, the addition amount of triphenyl styryl phenol polyoxyethylene ether is changed to 1.4 kg, and the addition amount of polyglycerol fatty acid ester is changed to 1.3 kg.

[0077] Comparative Example 5

[0078] A concrete, different from Example 1, the addition amount of sodium dodecyl benzene sulfonate is changed to 1.8 kg, the addition amount of triphenyl styryl phenol polyoxyethylene ether is changed to 2.4 kg, and the addition amount of polyglycerol fatty acid ester is changed to 2.2 kg.

[0079] Performance detection

[0080] Detection 1

[0081] According to GB / T50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete", the concrete of each example and comparative example is made into a 100mm×100mm×100mm cube test piece, and after standard curing for 28 days, the 28d compressive strength (Mpa) of each test piece is detected and recorded in Table 2.

[0082] Detection 2

[0083] According to the slow freezing method of GB / T50082-2009 "Standard for testing durability and long-term performance of ordinary concrete", the concrete of each example and comparative example was made into a 100mmx100mmx100mm cube freezing and thawing test piece, the compressive strength loss rate (%) of each cube freezing and thawing test piece after 100 freeze-thaw cycles was detected and recorded in Table 2.

[0084] Detection 3

[0085] The pore structure of the hardened concrete block of each example and comparative example was analyzed by mercury intrusion method (MIP), the cube freezing and thawing test piece was prepared according to the method of detection 2, and the pore distribution ratio of the cube freezing and thawing test piece at 0 freeze-thaw cycles and 100 freeze-thaw cycles was detected, the specific operation was as follows: the freezing and thawing test piece was placed in an oven and dried to constant weight, then the test piece was knocked into a granular sample of about 5mm, 3.5-4g of test sample was weighed from the sample for mercury intrusion method detection analysis, the pore structure was divided into three categories according to size: micropore (pore size <100nm), mesopore (pore size 100-1000nm), macropore (pore size >1000nm), the detection results of the distribution ratio (%) of pore volume in different diameter regions at 0 freeze-thaw cycles and 100 freeze-thaw cycles were shown in Table 2.

[0086] Table 2:

[0087]

[0088]

[0089] According to the combination of examples 1-8, comparative examples 1-5 and Table 2, it can be analyzed that the concrete of examples 1-8 has good frost resistance.

[0090] Specifically, in combination with Example 1 and Comparative Examples 1-3, the difference between Comparative Example 1, Comparative Example 2 and Comparative Example 3 and Example 1 is that Comparative Example 1 does not contain sodium dodecyl benzene sulfonate, Comparative Example 2 does not contain triphenyl styryl phenol polyoxyethylene ether, and Comparative Example 3 does not contain polyglycerol fatty acid ester. As can be seen from Table 2, the standard compressive strength and frost resistance of Example 1 are better, and thus the applicant analyzes that by adding sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether and polyglycerol fatty acid ester in the concrete, the formation of large ice crystals can be significantly inhibited, the ice crystals with loose structure and low strength are formed, the expansion pressure of the ice crystals is significantly reduced, the internal microcosmic phenomenon is that the proportion of the pores with a pore size of less than 100 nm is still good after 100 freeze-thaw cycles, the external phenomenon is that the loss rate of the compressive strength after 100 freeze-thaw cycles is low, and the frost resistance is good. At the same time, due to the use of sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether and polycarboxylic acid water reducing agent together, stable micro-bubbles can be formed in the concrete mixture, so that the concrete block can form more pores with a pore size of less than 100 nm, and the frost resistance and compressive strength of the concrete are further improved.

[0091] In combination with Example 1 and Comparative Examples 4-5, it can be seen that only sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether and polyglycerol fatty acid ester in the dosage range of the application can achieve the effect of inhibiting the formation of large ice crystals, forming ice crystals with loose structure and low strength, and significantly reducing the expansion pressure of the ice crystals.

[0092] In combination with Example 4 and Examples 5-6, Examples 5-6 add polyacrylamide compared with Example 4, and Examples 5-6 have better frost resistance. Thus, the applicant analyzes that by adding polyacrylamide in the concrete, polyacrylamide has strong adsorption, and cooperates with sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether and polyglycerol fatty acid ester to stably adsorb on the surface of the micro-crystal nucleus formed by sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether and polyglycerol fatty acid ester, the further growth of the crystal nucleus is obviously inhibited, the formation of large ice crystals is further inhibited, the ice crystal structure with loose texture is further promoted, the expansion pressure of the ice crystals is further reduced, and the frost resistance of the concrete is significantly improved.

[0093] Specifically, combined with the analysis of embodiments 5 and 7-8, compared with embodiment 4, the cellulose fiber is added in embodiments 7-8, and embodiments 7-8 have better frost resistance, and thus the applicant analyzes that by adding the cellulose fiber in the concrete, the cellulose fiber not only can promote the full hydration of the concrete, but also can form a three-dimensional structure in the concrete, effectively inhibit the expansion of the cracks in the concrete in the repeated freezing and thawing process, and at the same time, part of the cellulose fiber is inserted into the micro pores formed by the cooperation of sodium dodecyl benzene sulfonate, triphenyl styryl phenol polyoxyethylene ether and polycarboxylic acid water reducing agent, which can not only absorb more free water in the micro pores, but also further inhibit the water molecules to form large ice crystals, avoid the damage of the large ice crystals to the internal structure of the concrete, and significantly improve the frost resistance of the concrete.

[0094] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application, and those skilled in the art can make modifications to the embodiments without creative contribution according to the needs after reading the present specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. An anti-freeze concrete, characterized in that, The anti-freezing concrete comprises the following components in the following mass fractions: 150-180 parts of cement, 65-78 parts of fly ash, 370-430 parts of sand, 560-720 parts of gravel, 1.5-2 parts of polycarboxylate superplasticizer, 1.2-1.5 parts of sodium dodecyl benzene sulfonate, 1.7-2.1 parts of tristyrylphenol polyoxyethylene ether, 1.6-1.9 parts of polyglycerol fatty acid ester, and 75-90 parts of water; The anti-freezing concrete further comprises 1.2-1.5 parts of polyacrylamide. The mass ratio of the sodium dodecyl benzene sulfonate, the tristyrylphenol polyoxyethylene ether, the polyglycerol fatty acid ester, and the polyacrylamide is 1.4:1.8:1.7:1.

2.

2. The frost-resistant concrete according to claim 1, characterized in that The anti-freezing concrete further comprises 6-7.5 parts of cellulose fiber.

3. The frost-resistant concrete according to claim 2, characterized in that The cellulose fiber has a length of 3-5 mm and a diameter of 30-50 μm.

4. A method of producing the freeze-resistant concrete according to claim 1, characterized by, The method comprises the following steps: Step 1: mixing and stirring the water, the polycarboxylate superplasticizer, the sodium dodecyl benzene sulfonate, the tristyrylphenol polyoxyethylene ether, the polyglycerol fatty acid ester, and the polyacrylamide until they are uniformly mixed, and then adding the cement and the fly ash and stirring until they are uniformly mixed to obtain a slurry; Step 2: adding the sand and the gravel to the slurry obtained in step 1 and stirring until the anti-freezing concrete is obtained.

5. A method of producing the freeze-resistant concrete as claimed in claim 2, characterized in that, The method comprises the following steps: Step 1: mixing and stirring the water, the polycarboxylate superplasticizer, the sodium dodecyl benzene sulfonate, the tristyrylphenol polyoxyethylene ether, the polyglycerol fatty acid ester, the polyacrylamide, and the cellulose fiber until they are uniformly mixed, and then adding the cement and the fly ash and stirring until they are uniformly mixed to obtain a slurry; Step 2: adding the sand and the gravel to the slurry obtained in step 1 and stirring until the anti-freezing concrete is obtained.

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