A kind of anti-seepage and anti-cracking reinforced concrete pipe and preparation method thereof

Abstract

The present invention relates to the technical field of concrete pipes, and specifically discloses an anti-seepage and anti-cracking reinforced concrete pipe and a preparation method thereof. The method comprises: 1) building a mold; 2) placing a steel cage in the mold; 3) preparing a concrete mixture: 3-1) mixing cement, fly ash, sand, stone, water reducer, and calcium carbonate whisker uniformly to obtain a premix; 3-2) adding water to the premix and mixing uniformly to obtain a concrete mixture; 4) injecting the concrete mixture into a mold, curing, and demoulding to obtain an anti-seepage and anti-cracking reinforced concrete pipe. The present invention has the advantage of improving the anti-seepage performance of reinforced concrete pipes.

Description

Technical Field

[0001] The invention relates to the field of concrete pipes, and in particular to an anti-seepage and anti-cracking reinforced concrete pipe and a preparation method thereof. Background Art

[0002] Reinforced concrete pipes are pipes made of reinforced concrete, mainly used to transport fluid substances such as water, oil, and gas.

[0003] Compared with steel pipes, concrete pipes can save a lot of steel and have lower production costs. They are widely used in factories, mines, oil fields, ports, urban construction, etc.

[0004] Concrete is a composite material formed by a combination of cementitious materials and aggregates. Concrete uses cementitious materials to bond aggregates to form a whole. During the solidification process, hydration heat is generated, which causes the concrete to expand and contract with heat, resulting in capillary pores and fine cracks in general concrete after solidification. Therefore, although concrete pipes have high strength characteristics, especially when combined with steel bars, their tensile and compressive strengths are high, but concrete pipes usually have capillary pores and fine cracks on the pipe wall, which makes the concrete pipe prone to leakage when transporting high-pressure fluids. Therefore, there is still room for improvement. Summary of the invention

[0005] In order to improve the anti-seepage performance of reinforced concrete pipes, the present application provides an anti-seepage and crack-resistant reinforced concrete pipe and a preparation method thereof.

[0006] In a first aspect, the present application provides a method for preparing an anti-seepage and anti-cracking reinforced concrete pipe, which adopts the following technical solution:

[0007] A method for preparing an anti-seepage and anti-cracking reinforced concrete pipe comprises the following steps:

[0008] Step 1), building a mold;

[0009] Step 2), placing a steel cage in the mold;

[0010] Step 3), preparing a concrete mixture, specifically as follows:

[0011] Step 3-1), cement, fly ash, sand, stone, water reducing agent and calcium carbonate whisker are mixed uniformly to obtain a premix;

[0012] Step 3-2), adding water to the premix and mixing evenly to obtain a concrete mixture;

[0013] Step 4), injecting the concrete mixture into the mold, curing, and demoulding to obtain an impermeable and crack-resistant reinforced concrete pipe;

[0014] In the step 3-1), the preparation method of calcium carbonate whiskers is as follows:

[0015] Step 01), mixing calcium hydroxide with water to prepare a calcium hydroxide suspension;

[0016] Step 02), mixing a water-soluble magnesium salt, a water-soluble zinc salt, lactic acid, malic acid, pyruvic acid, and water to prepare a crystal form control solution;

[0017] Step 03), adding the crystal form control liquid to the calcium hydroxide suspension, mixing evenly, to obtain a reaction liquid;

[0018] Step 04), carbon dioxide is introduced into the reaction solution to react, and after a precipitate is generated, the precipitate is filtered and taken to obtain calcium carbonate whiskers.

[0019] By adopting the above technical scheme, by adding calcium carbonate whiskers prepared by a special process when preparing a concrete mixture, the concrete mixture will be restricted by the calcium carbonate whiskers when it expands and contracts during the solidification process, so that it is not easy to produce capillaries and fine cracks after the concrete mixture is solidified, so that the prepared reinforced concrete pipe has higher anti-seepage performance, and is not prone to leakage when transporting high-pressure fluids. Moreover, under the action of calcium carbonate whiskers, the concrete far away from the steel bars can be well reinforced, so that when transporting high-pressure fluids, the concrete structure far away from the steel bars is not prone to cracking, and the prepared reinforced concrete pipe has good anti-cracking performance.

[0020] By combining water-soluble magnesium salt, water-soluble zinc salt, lactic acid, malic acid and pyruvic acid to form a crystal control liquid, the effect of inducing calcium carbonate crystal deformation is better, and calcium carbonate whiskers with a special structure can be formed. The calcium carbonate whiskers are filled into the concrete mixture, which can significantly improve the modification effect on the anti-permeability performance of the concrete, thereby greatly improving the anti-permeability grade of the concrete structure, so that the reinforced concrete pipe can transport higher-pressure fluids and is better suitable for special application scenarios. The application range of reinforced concrete pipes is wide and they have high economic value.

[0021] Preferably, in step 3), the mass ratios of cement, fly ash, sand, stone, water reducing agent, calcium carbonate whisker and water are: 380-385: 45-48: 750-760: 1000-1010: 6.4-6.5: 24-26: 158-162.

[0022] By adopting the above technical scheme and specifically selecting the mass proportions of cement, fly ash, sand, stone, water reducer, calcium carbonate whisker and water, the concrete mixture has higher strength after solidification, and the obtained reinforced concrete pipe has higher strength and can be applied to various complex application scenarios. The reinforced concrete pipe is not easily damaged due to pressure and has a longer service life.

[0023] Preferably, in step 02), the mass ratio of water-soluble magnesium salt, water-soluble zinc salt, lactic acid, malic acid, pyruvic acid and water is 1-2:1-2:3-4:1-2:2-3:100.

[0024] By adopting the above technical scheme and specifically selecting the mass ratio of water-soluble magnesium salt, water-soluble zinc salt, lactic acid, malic acid, pyruvic acid and water, the crystal control liquid has a better inducing effect on the deformation of calcium carbonate crystals, and a better formation of a special calcium carbonate whisker structure, and a more significant effect on the modification of the anti-permeability performance of concrete, and the quality of the obtained reinforced concrete pipe is better.

[0025] Preferably, in step 01), the mass ratio of calcium hydroxide to water is 7-8:100.

[0026] By adopting the above technical solution and specifically selecting the mass ratio of calcium hydroxide and water, the concentration of the calcium hydroxide suspension is made just right, which is more conducive to the subsequent reaction to generate calcium carbonate whiskers.

[0027] Preferably, in step 03), the mass ratio of the crystal form control liquid to the calcium hydroxide suspension is 1-2:1.

[0028] By adopting the above technical scheme and specifically selecting the mass ratio of the crystal form control liquid and the calcium hydroxide suspension, the crystal form control liquid can better induce the deformation of calcium carbonate crystals, better form calcium carbonate whiskers with special structures, and improve the anti-permeability performance of concrete modified by calcium carbonate whiskers.

[0029] Preferably, in step 04), the flow rate of carbon dioxide is 50-60 ml / min.

[0030] By adopting the above technical solution and controlling the flow rate of carbon dioxide, the crystal form control liquid can be better matched, the calcium carbonate crystal deformation can be better induced, the calcium carbonate whiskers can be better formed, and the quality of the prepared calcium carbonate whiskers can be better.

[0031] Preferably, in step 04), the reaction solution is firstly kept at a constant temperature of 80-90° C., and then carbon dioxide is introduced.

[0032] By adopting the above technical solution and keeping the temperature at 80-90° C., the efficiency of generating calcium carbonate whiskers is higher and has higher economic value.

[0033] In a second aspect, the present application provides an anti-seepage and anti-cracking reinforced concrete pipe, which adopts the following technical solution:

[0034] A seepage-proof and crack-proof reinforced concrete pipe is prepared by the above-mentioned method for preparing the seepage-proof and crack-proof reinforced concrete pipe.

[0035] By adopting the above technical scheme, the reinforced concrete pipe produced has high strength, is not easy to be damaged, and has high anti-seepage and anti-cracking performance. It is not easy to leak, crack and the like when transporting high-pressure fluid, so that the reinforced concrete pipe has a long service life, a wide range of applications, and high economic value.

[0036] In summary, this application has the following beneficial effects:

[0037] 1. Since the present application adds calcium carbonate whiskers produced by a special process when preparing the concrete mixture, the concrete mixture will be restricted by the calcium carbonate whiskers when it expands and contracts during the solidification process, so that the concrete mixture is not prone to produce capillaries and fine cracks after solidification, so that the prepared reinforced concrete pipe has higher anti-seepage performance, and is not prone to leakage when transporting high-pressure fluids. Moreover, under the action of calcium carbonate whiskers, the concrete far away from the steel bar part can be well reinforced, so that when transporting high-pressure fluids, the concrete structure far away from the steel bar part is not prone to cracking, and the prepared reinforced concrete pipe has good anti-cracking performance.

[0038] 2. In the present application, it is preferred to form a crystal control liquid by combining water-soluble magnesium salt, water-soluble zinc salt, lactic acid, malic acid and pyruvic acid, so that the effect of inducing calcium carbonate crystal distortion is better, and calcium carbonate whiskers with a special structure can be formed, so that the calcium carbonate whiskers are filled into the concrete mixture, which can significantly improve the modification effect on the anti-permeability performance of the concrete, thereby greatly improving the anti-permeability grade of the concrete structure, so that the reinforced concrete pipe can transport higher-pressure fluids, and is better suitable for special application scenarios. The application range of reinforced concrete pipes is wide and has high economic value.

[0039] 3. In the present application, it is preferred that the mass ratio of cement, fly ash, sand, stone, water reducing agent, calcium carbonate whisker and water be specifically selected, so that the concrete mixture has high strength after curing. The obtained reinforced concrete pipe has high strength and can be applied to various complex application scenarios. The reinforced concrete pipe is not easily damaged due to pressure and has a long service life. DETAILED DESCRIPTION

[0040] The present application is further described in detail below with reference to the embodiments.

[0041] Example 1

[0042] A method for preparing an anti-seepage and anti-cracking reinforced concrete pipe, characterized in that it comprises the following steps:

[0043] Step 1), build the mold using wooden boards according to design requirements.

[0044] Step 2), place the bundled steel cage in the mold, position the steel cage so that its axis coincides with the mold axis, and fix the steel cage to complete the installation of the steel cage.

[0045] Step 3), preparing a concrete mixture, specifically as follows:

[0046] Step 3-1), 380kg cement, 45kg fly ash, 750kg sand, 1000kg stone, 6.4kg water reducer, 24kg calcium carbonate whisker are put into a stirring kettle, the speed is 60r / min, stirring for 5min, mixing evenly, and obtaining a premix.

[0047] Step 3-2), add 158 kg of water to the premix, rotate at 60 r / min, stir for 3 min, mix evenly, and obtain a concrete mixture.

[0048] Step 4), inject the concrete mixture into the mold, tap the mold lightly to make the concrete mixture fill the mold, after the concrete pouring is completed, cover it with plastic film and cure for 3 days, demould it, and let it stand and cure for 28 days to obtain an impermeable and crack-resistant reinforced concrete pipe.

[0049] Among them, cement is silicate cement, standard: P.O42.5R.

[0050] Among them, the fly ash is first-grade fly ash.

[0051] Among them, the sand is river sand, 20-40 mesh.

[0052] Among them, the stone is granite crushed stone with a particle size of 9-12mm.

[0053] Among them, the water reducer is polycarboxylic acid water reducer, which was purchased from Jinan Yanglan New Materials Technology Co., Ltd.

[0054] Among them, calcium carbonate whiskers are homemade.

[0055] The preparation method of calcium carbonate whiskers is as follows:

[0056] Step 01), 70kg of calcium hydroxide and 1000kg of water are put into a stirring tank, heated and kept at 90°C, with a rotation speed of 120r / min, stirred for 120min, and mixed evenly to obtain a calcium hydroxide suspension.

[0057] Step 02), 10 kg of water-soluble magnesium salt, 10 kg of water-soluble zinc salt, 30 kg of lactic acid, 10 kg of malic acid, 20 kg of pyruvic acid, and 1000 kg of water are put into a container, mixed evenly until completely dissolved, to obtain a crystal control solution.

[0058] Step 03), put 1000kg of crystal control liquid and 1000kg of calcium hydroxide suspension into a reactor, rotate at 120r / min, stir continuously, mix evenly, and obtain a reaction solution.

[0059] Step 04), keep stirring at a speed of 120r / min and heat the reaction solution to a constant temperature of 80°C. While keeping stirring, introduce carbon dioxide into the reaction solution at a flow rate of 50-60ml / min to react. After a precipitate is generated and the pH value of the system drops to 6.8, stop introducing carbon dioxide, terminate the reaction, filter through a filter, take the precipitate, and dry it to obtain calcium carbonate whiskers.

[0060] Calcium hydroxide is commercially available, CAS number: 1305-62-0.

[0061] The water-soluble magnesium salt is magnesium chloride, which is commercially available, CAS number: 7786-30-3.

[0062] The water-soluble zinc salt is zinc chloride, which is commercially available with a CAS number of 7646-85-7.

[0063] Lactic acid is commercially available, CAS number: 50-21-5.

[0064] Malic acid is commercially available, CAS number: 636-61-3.

[0065] Pyruvic acid is commercially available, CAS number: 127-17-3.

[0066] Example 2

[0067] A method for preparing an anti-seepage and anti-cracking reinforced concrete pipe, characterized in that it comprises the following steps:

[0068] Step 1), build the mold using wooden boards according to design requirements.

[0069] Step 2), place the bundled steel cage in the mold, position the steel cage so that its axis coincides with the mold axis, and fix the steel cage to complete the installation of the steel cage.

[0070] Step 3), preparing a concrete mixture, specifically as follows:

[0071] Step 3-1), 383kg cement, 46kg fly ash, 755kg sand, 1005kg stone, 6.45kg water reducer, and 25kg calcium carbonate whisker are put into a stirring kettle at a speed of 60r / min, stirred for 5min, and mixed evenly to obtain a premix.

[0072] Step 3-2), add 158 kg of water to the premix, rotate at 60 r / min, stir for 3 min, mix evenly, and obtain a concrete mixture.

[0073] Step 4), inject the concrete mixture into the mold, tap the mold lightly to make the concrete mixture fill the mold, after the concrete pouring is completed, cover it with plastic film and cure for 3 days, demould it, and let it stand and cure for 28 days to obtain an impermeable and crack-resistant reinforced concrete pipe.

[0074] Among them, cement is silicate cement, standard: P.O42.5R.

[0075] Among them, the fly ash is first-grade fly ash.

[0076] Among them, the sand is river sand, 20-40 mesh.

[0077] Among them, the stone is granite crushed stone with a particle size of 9-12mm.

[0078] Among them, the water reducer is polycarboxylic acid water reducer, which was purchased from Jinan Yanglan New Materials Technology Co., Ltd.

[0079] Among them, calcium carbonate whiskers are homemade.

[0080] The preparation method of calcium carbonate whiskers is as follows:

[0081] Step 01), 75kg of calcium hydroxide and 1000kg of water are put into a stirring tank, heated and kept at a constant temperature of 90°C, a rotation speed of 120r / min, stirred for 120min, and mixed evenly to obtain a calcium hydroxide suspension.

[0082] Step 02), 15 kg of water-soluble magnesium salt, 15 kg of water-soluble zinc salt, 35 kg of lactic acid, 15 kg of malic acid, 25 kg of pyruvic acid, and 1000 kg of water are put into a container, mixed evenly until completely dissolved, to obtain a crystal control solution.

[0083] Step 03), put 1500kg of crystal control liquid and 1000kg of calcium hydroxide suspension into a reactor, rotate at 120r / min, stir continuously, mix evenly, and obtain a reaction solution.

[0084] Step 04), keep stirring at a speed of 120r / min and heat the reaction solution to a constant temperature of 85°C. While keeping stirring, introduce carbon dioxide into the reaction solution at a flow rate of 50-60ml / min to react. After a precipitate is generated and the pH value of the system drops to 6.8, stop introducing carbon dioxide, terminate the reaction, filter through a filter, take the precipitate, and dry it to obtain calcium carbonate whiskers.

[0085] Calcium hydroxide is commercially available, CAS number: 1305-62-0.

[0086] The water-soluble magnesium salt is magnesium chloride, which is commercially available, CAS number: 7786-30-3.

[0087] The water-soluble zinc salt is zinc chloride, which is commercially available with a CAS number of 7646-85-7.

[0088] Lactic acid is commercially available, CAS number: 50-21-5.

[0089] Malic acid is commercially available, CAS number: 636-61-3.

[0090] Pyruvic acid is commercially available, CAS number: 127-17-3.

[0091] Example 3

[0092] A method for preparing an anti-seepage and anti-cracking reinforced concrete pipe, characterized in that it comprises the following steps:

[0093] Step 1), build the mold using wooden boards according to design requirements.

[0094] Step 2), place the bundled steel cage in the mold, position the steel cage so that its axis coincides with the mold axis, and fix the steel cage to complete the installation of the steel cage.

[0095] Step 3), preparing a concrete mixture, specifically as follows:

[0096] Step 3-1), 385kg cement, 48kg fly ash, 760kg sand, 1010kg stone, 6.5kg water reducer, 26kg calcium carbonate whisker are put into a stirring kettle, the speed is 60r / min, stirring for 5min, mixing evenly, and obtaining a premix.

[0097] Step 3-2), add 162kg water to the premix, rotate at 60r / min, stir for 3min, mix evenly, and obtain a concrete mixture.

[0098] Step 4), inject the concrete mixture into the mold, tap the mold lightly to make the concrete mixture fill the mold, after the concrete pouring is completed, cover it with plastic film and cure for 3 days, demould it, and let it stand and cure for 28 days to obtain an impermeable and crack-resistant reinforced concrete pipe.

[0099] Among them, cement is silicate cement, standard: P.O42.5R.

[0100] Among them, the fly ash is first-grade fly ash.

[0101] Among them, the sand is river sand, 20-40 mesh.

[0102] Among them, the stone is granite crushed stone with a particle size of 9-12mm.

[0103] Among them, the water reducer is polycarboxylic acid water reducer, which was purchased from Jinan Yanglan New Materials Technology Co., Ltd.

[0104] Among them, calcium carbonate whiskers are homemade.

[0105] The preparation method of calcium carbonate whiskers is as follows:

[0106] Step 01), put 80kg of calcium hydroxide and 1000kg of water into a stirring tank, heat and keep the temperature at 90°C, rotate at 120r / min, stir for 120min, mix evenly, and prepare a calcium hydroxide suspension.

[0107] Step 02), 20 kg of water-soluble magnesium salt, 20 kg of water-soluble zinc salt, 40 kg of lactic acid, 20 kg of malic acid, 30 kg of pyruvic acid, and 1000 kg of water are put into a container, mixed evenly until completely dissolved, to obtain a crystal control solution.

[0108] Step 03), put 2000kg of crystal control liquid and 1000kg of calcium hydroxide suspension into a reactor, rotate at 120r / min, stir continuously, mix evenly, and obtain a reaction solution.

[0109] Step 04), keep the rotation speed at 120r / min and continue stirring, and heat the reaction solution to a constant temperature of 90°C. While keeping the stirring state, introduce carbon dioxide into the reaction solution at a flow rate of 50-60ml / min to react. After a precipitate is generated and the pH value of the system drops to 6.8, stop introducing carbon dioxide, terminate the reaction, filter through a filter, take the precipitate, and dry it to obtain calcium carbonate whiskers.

[0110] Calcium hydroxide is commercially available, CAS number: 1305-62-0.

[0111] The water-soluble magnesium salt is magnesium chloride, which is commercially available, CAS number: 7786-30-3.

[0112] The water-soluble zinc salt is zinc chloride, which is commercially available with a CAS number of 7646-85-7.

[0113] Lactic acid is commercially available, CAS number: 50-21-5.

[0114] Malic acid is commercially available, CAS number: 636-61-3.

[0115] Pyruvic acid is commercially available, CAS number: 127-17-3.

[0116] Example 4

[0117] A method for preparing an anti-seepage and anti-cracking reinforced concrete pipe, characterized in that it comprises the following steps:

[0118] Step 1), build the mold using wooden boards according to design requirements.

[0119] Step 2), place the bundled steel cage in the mold, position the steel cage so that its axis coincides with the mold axis, and fix the steel cage to complete the installation of the steel cage.

[0120] Step 3), preparing a concrete mixture, specifically as follows:

[0121] Step 3-1), 383kg cement, 46kg fly ash, 755kg sand, 1005kg stone, 6.45kg water reducer, and 25kg calcium carbonate whisker are put into a stirring kettle at a speed of 60r / min, stirred for 5min, and mixed evenly to obtain a premix.

[0122] Step 3-2), add 158 kg of water to the premix, rotate at 60 r / min, stir for 3 min, mix evenly, and obtain a concrete mixture.

[0123] Step 4), inject the concrete mixture into the mold, tap the mold lightly to make the concrete mixture fill the mold, after the concrete pouring is completed, cover it with plastic film and cure for 3 days, demould it, and let it stand and cure for 28 days to obtain an impermeable and crack-resistant reinforced concrete pipe.

[0124] Among them, cement is silicate cement, standard: P.O42.5R.

[0125] Among them, the fly ash is first-grade fly ash.

[0126] Among them, the sand is river sand, 20-40 mesh.

[0127] Among them, the stone is granite crushed stone with a particle size of 9-12mm.

[0128] Among them, the water reducer is polycarboxylic acid water reducer, which was purchased from Jinan Yanglan New Materials Technology Co., Ltd.

[0129] Among them, calcium carbonate whiskers are homemade.

[0130] The preparation method of calcium carbonate whiskers is as follows:

[0131] Step 01), 75kg of calcium hydroxide and 1000kg of water are put into a stirring tank, heated and kept at a constant temperature of 90°C, a rotation speed of 120r / min, stirred for 120min, and mixed evenly to obtain a calcium hydroxide suspension.

[0132] Step 02), 15 kg of water-soluble magnesium salt, 15 kg of water-soluble zinc salt, 35 kg of lactic acid, 15 kg of malic acid, 25 kg of pyruvic acid, and 1000 kg of water are put into a container, mixed evenly until completely dissolved, to obtain a crystal control solution.

[0133] Step 03), put 1500kg of crystal control liquid and 1000kg of calcium hydroxide suspension into a reactor, rotate at 120r / min, stir continuously, mix evenly, and obtain a reaction liquid.

[0134] Step 04), keep stirring at a speed of 120r / min and heat the reaction solution to a constant temperature of 85°C. While keeping stirring, introduce carbon dioxide into the reaction solution at a flow rate of 50-60ml / min to react. After a precipitate is generated and the pH value of the system drops to 6.8, stop introducing carbon dioxide, terminate the reaction, filter through a filter, take the precipitate, and dry it to obtain calcium carbonate whiskers.

[0135] Calcium hydroxide is commercially available, CAS number: 1305-62-0.

[0136] The water-soluble magnesium salt is magnesium sulfate, which is commercially available, CAS number: 7487-88-9.

[0137] The water-soluble zinc salt is zinc sulfate, which is commercially available with a CAS number of 7733-02-0.

[0138] Lactic acid is commercially available, CAS number: 50-21-5.

[0139] Malic acid is commercially available, CAS number: 636-61-3.

[0140] Pyruvic acid is commercially available, CAS number: 127-17-3.

[0141] Comparative Example 1

[0142] A method for preparing an anti-seepage and anti-cracking reinforced concrete pipe, characterized in that it comprises the following steps:

[0143] Step 1), build the mold using wooden boards according to design requirements.

[0144] Step 2), place the bundled steel cage in the mold, position the steel cage so that its axis coincides with the mold axis, and fix the steel cage to complete the installation of the steel cage.

[0145] Step 3), preparing a concrete mixture, specifically as follows:

[0146] Step 3-1), 383kg cement, 46kg fly ash, 755kg sand, 1005kg stone, 6.45kg water reducer, and 25kg calcium carbonate whisker are put into a stirring kettle at a speed of 60r / min, stirred for 5min, and mixed evenly to obtain a premix.

[0147] Step 3-2), add 158 kg of water to the premix, rotate at 60 r / min, stir for 3 min, mix evenly, and obtain a concrete mixture.

[0148] Step 4), inject the concrete mixture into the mold, tap the mold lightly to make the concrete mixture fill the mold, after the concrete pouring is completed, cover it with plastic film and cure for 3 days, demould it, and let it stand and cure for 28 days to obtain an impermeable and crack-resistant reinforced concrete pipe.

[0149] Among them, cement is silicate cement, standard: P.O42.5R.

[0150] Among them, the fly ash is first-grade fly ash.

[0151] Among them, the sand is river sand, 20-40 mesh.

[0152] Among them, the stone is granite crushed stone with a particle size of 9-12mm.

[0153] Among them, the water reducer is polycarboxylic acid water reducer, which was purchased from Jinan Yanglan New Materials Technology Co., Ltd.

[0154] Among them, calcium carbonate whiskers are homemade.

[0155] The preparation method of calcium carbonate whiskers is as follows:

[0156] Step 01), 75kg of calcium hydroxide and 1000kg of water are put into a stirring tank, heated and kept at a constant temperature of 90°C, a rotation speed of 120r / min, stirred for 120min, and mixed evenly to obtain a calcium hydroxide suspension.

[0157] Step 02), 15 kg of water-soluble barium salt, 15 kg of water-soluble zinc salt, 35 kg of lactic acid, 15 kg of malic acid, 25 kg of pyruvic acid, and 1000 kg of water are put into a container, mixed evenly until completely dissolved, to obtain a crystal control solution.

[0158] Step 03), put 1500kg of crystal control liquid and 1000kg of calcium hydroxide suspension into a reactor, rotate at 120r / min, stir continuously, mix evenly, and obtain a reaction liquid.

[0159] Step 04), keep stirring at a speed of 120r / min and heat the reaction solution to a constant temperature of 85°C. While keeping stirring, introduce carbon dioxide into the reaction solution at a flow rate of 50-60ml / min to react. After a precipitate is generated and the pH value of the system drops to 6.8, stop introducing carbon dioxide, terminate the reaction, filter through a filter, take the precipitate, and dry it to obtain calcium carbonate whiskers.

[0160] Calcium hydroxide is commercially available, CAS number: 1305-62-0.

[0161] The water-soluble barium salt is barium chloride, which is commercially available with a CAS number of 10361-37-2.

[0162] The water-soluble zinc salt is zinc chloride, which is commercially available with a CAS number of 7646-85-7.

[0163] Lactic acid is commercially available, CAS number: 50-21-5.

[0164] Malic acid is commercially available, CAS number: 636-61-3.

[0165] Pyruvic acid is commercially available, CAS number: 127-17-3.

[0166] Comparative Example 2

[0167] A method for preparing an anti-seepage and anti-cracking reinforced concrete pipe, characterized in that it comprises the following steps:

[0168] Step 1), build the mold using wooden boards according to design requirements.

[0169] Step 2), place the bundled steel cage in the mold, position the steel cage so that its axis coincides with the mold axis, and fix the steel cage to complete the installation of the steel cage.

[0170] Step 3), preparing a concrete mixture, specifically as follows:

[0171] Step 3-1), 383kg cement, 46kg fly ash, 755kg sand, 1005kg stone, 6.45kg water reducer, and 25kg calcium carbonate whisker are put into a stirring kettle at a speed of 60r / min, stirred for 5min, and mixed evenly to obtain a premix.

[0172] Step 3-2), add 158 kg of water to the premix, rotate at 60 r / min, stir for 3 min, mix evenly, and obtain a concrete mixture.

[0173] Step 4), inject the concrete mixture into the mold, tap the mold lightly to make the concrete mixture fill the mold, after the concrete pouring is completed, cover it with plastic film and cure for 3 days, demould it, and let it stand and cure for 28 days to obtain an impermeable and crack-resistant reinforced concrete pipe.

[0174] Among them, cement is silicate cement, standard: P.O42.5R.

[0175] Among them, the fly ash is first-grade fly ash.

[0176] Among them, the sand is river sand, 20-40 mesh.

[0177] Among them, the stone is granite crushed stone with a particle size of 9-12mm.

[0178] Among them, the water reducer is polycarboxylic acid water reducer, which was purchased from Jinan Yanglan New Materials Technology Co., Ltd.

[0179] Among them, calcium carbonate whiskers are homemade.

[0180] The preparation method of calcium carbonate whiskers is as follows:

[0181] Step 01), 75kg of calcium hydroxide and 1000kg of water are put into a stirring tank, heated and kept at a constant temperature of 90°C, a rotation speed of 120r / min, stirred for 120min, and mixed evenly to obtain a calcium hydroxide suspension.

[0182] Step 02), 15 kg of water-soluble magnesium salt, 15 kg of water-soluble barium salt, 35 kg of lactic acid, 15 kg of malic acid, 25 kg of pyruvic acid, and 1000 kg of water are put into a container, mixed evenly until completely dissolved, to obtain a crystal control solution.

[0183] Step 03), put 1500kg of crystal control liquid and 1000kg of calcium hydroxide suspension into a reactor, rotate at 120r / min, stir continuously, mix evenly, and obtain a reaction solution.

[0184] Step 04), keep stirring at a speed of 120r / min and heat the reaction solution to a constant temperature of 85°C. While keeping stirring, introduce carbon dioxide into the reaction solution at a flow rate of 50-60ml / min to react. After a precipitate is generated and the pH value of the system drops to 6.8, stop introducing carbon dioxide, terminate the reaction, filter through a filter, take the precipitate, and dry it to obtain calcium carbonate whiskers.

[0185] Calcium hydroxide is commercially available, CAS number: 1305-62-0.

[0186] The water-soluble magnesium salt is magnesium chloride, which is commercially available, CAS number: 7786-30-3.

[0187] The water-soluble barium salt is barium chloride, which is commercially available with a CAS number of 10361-37-2.

[0188] Lactic acid is commercially available, CAS number: 50-21-5.

[0189] Malic acid is commercially available, CAS number: 636-61-3.

[0190] Pyruvic acid is commercially available, CAS number: 127-17-3.

[0191] Comparative Example 3

[0192] A method for preparing an anti-seepage and anti-cracking reinforced concrete pipe, characterized in that it comprises the following steps:

[0193] Step 1), build the mold using wooden boards according to design requirements.

[0194] Step 2), place the bundled steel cage in the mold, position the steel cage so that its axis coincides with the mold axis, and fix the steel cage to complete the installation of the steel cage.

[0195] Step 3), preparing a concrete mixture, specifically as follows:

[0196] Step 3-1), 383kg cement, 46kg fly ash, 755kg sand, 1005kg stone, 6.45kg water reducer, and 25kg calcium carbonate whisker are put into a stirring kettle at a speed of 60r / min, stirred for 5min, and mixed evenly to obtain a premix.

[0197] Step 3-2), add 158 kg of water to the premix, rotate at 60 r / min, stir for 3 min, mix evenly, and obtain a concrete mixture.

[0198] Step 4), inject the concrete mixture into the mold, tap the mold lightly to make the concrete mixture fill the mold, after the concrete pouring is completed, cover it with plastic film and cure for 3 days, demould it, and let it stand and cure for 28 days to obtain an impermeable and crack-resistant reinforced concrete pipe.

[0199] Among them, cement is silicate cement, standard: P.O42.5R.

[0200] Among them, the fly ash is first-grade fly ash.

[0201] Among them, the sand is river sand, 20-40 mesh.

[0202] Among them, the stone is granite crushed stone with a particle size of 9-12mm.

[0203] Among them, the water reducer is polycarboxylic acid water reducer, which was purchased from Jinan Yanglan New Materials Technology Co., Ltd.

[0204] Among them, calcium carbonate whiskers are homemade.

[0205] The preparation method of calcium carbonate whiskers is as follows:

[0206] Step 01), 75kg of calcium hydroxide and 1000kg of water are put into a stirring tank, heated and kept at a constant temperature of 90°C, a rotation speed of 120r / min, stirred for 120min, and mixed evenly to obtain a calcium hydroxide suspension.

[0207] Step 02), 15 kg of water-soluble magnesium salt, 15 kg of water-soluble zinc salt, 35 kg of nitric acid, 15 kg of malic acid, 25 kg of pyruvic acid, and 1000 kg of water are put into a container, mixed evenly until completely dissolved, to obtain a crystal control solution.

[0208] Step 03), put 1500kg of crystal control liquid and 1000kg of calcium hydroxide suspension into a reactor, rotate at 120r / min, stir continuously, mix evenly, and obtain a reaction solution.

[0209] Step 04), keep stirring at a speed of 120r / min and heat the reaction solution to a constant temperature of 85°C. While keeping stirring, introduce carbon dioxide into the reaction solution at a flow rate of 50-60ml / min to react. After a precipitate is generated and the pH value of the system drops to 6.8, stop introducing carbon dioxide, terminate the reaction, filter through a filter, take the precipitate, and dry it to obtain calcium carbonate whiskers.

[0210] Calcium hydroxide is commercially available, CAS number: 1305-62-0.

[0211] The water-soluble magnesium salt is magnesium chloride, which is commercially available, CAS number: 7786-30-3.

[0212] The water-soluble zinc salt is zinc chloride, which is commercially available with a CAS number of 7646-85-7.

[0213] Nitric acid is commercially available, CAS number: 7697-37-2.

[0214] Malic acid is commercially available, CAS number: 636-61-3.

[0215] Pyruvic acid is commercially available, CAS number: 127-17-3.

[0216] Comparative Example 4

[0217] A method for preparing an anti-seepage and anti-cracking reinforced concrete pipe, characterized in that it comprises the following steps:

[0218] Step 1), build the mold using wooden boards according to design requirements.

[0219] Step 2), place the bundled steel cage in the mold, position the steel cage so that its axis coincides with the mold axis, and fix the steel cage to complete the installation of the steel cage.

[0220] Step 3), preparing a concrete mixture, specifically as follows:

[0221] Step 3-1), 383kg cement, 46kg fly ash, 755kg sand, 1005kg stone, 6.45kg water reducer, and 25kg calcium carbonate whisker are put into a stirring kettle at a speed of 60r / min, stirred for 5min, and mixed evenly to obtain a premix.

[0222] Step 3-2), add 158 kg of water to the premix, rotate at 60 r / min, stir for 3 min, mix evenly, and obtain a concrete mixture.

[0223] Step 4), inject the concrete mixture into the mold, tap the mold lightly to make the concrete mixture fill the mold, after the concrete pouring is completed, cover it with plastic film and cure for 3 days, demould it, and let it stand and cure for 28 days to obtain an impermeable and crack-resistant reinforced concrete pipe.

[0224] Among them, cement is silicate cement, standard: P.O42.5R.

[0225] Among them, the fly ash is first-grade fly ash.

[0226] Among them, the sand is river sand, 20-40 mesh.

[0227] Among them, the stone is granite crushed stone with a particle size of 9-12mm.

[0228] Among them, the water reducer is polycarboxylic acid water reducer, which was purchased from Jinan Yanglan New Materials Technology Co., Ltd.

[0229] Among them, calcium carbonate whiskers are homemade.

[0230] The preparation method of calcium carbonate whiskers is as follows:

[0231] Step 01), 75kg of calcium hydroxide and 1000kg of water are put into a stirring tank, heated and kept at a constant temperature of 90°C, a rotation speed of 120r / min, stirred for 120min, and mixed evenly to obtain a calcium hydroxide suspension.

[0232] Step 02), 15kg of water-soluble magnesium salt, 15kg of water-soluble zinc salt, 35kg of lactic acid, 15kg of phosphoric acid, 25kg of pyruvic acid, and 1000kg of water are put into a container, mixed evenly until completely dissolved, to obtain a crystal form control solution.

[0233] Step 03), put 1500kg of crystal control liquid and 1000kg of calcium hydroxide suspension into a reactor, rotate at 120r / min, stir continuously, mix evenly, and obtain a reaction solution.

[0234] Step 04), keep stirring at a speed of 120r / min and heat the reaction solution to a constant temperature of 85°C. While keeping stirring, introduce carbon dioxide into the reaction solution at a flow rate of 50-60ml / min to react. After a precipitate is generated and the pH value of the system drops to 6.8, stop introducing carbon dioxide, terminate the reaction, filter through a filter, take the precipitate, and dry it to obtain calcium carbonate whiskers.

[0235] Calcium hydroxide is commercially available, CAS number: 1305-62-0.

[0236] The water-soluble magnesium salt is magnesium chloride, which is commercially available, CAS number: 7786-30-3.

[0237] The water-soluble zinc salt is zinc chloride, which is commercially available with a CAS number of 7646-85-7.

[0238] Lactic acid is commercially available, CAS number: 50-21-5.

[0239] Phosphoric acid is commercially available, CAS number: 7664-38-2.

[0240] Pyruvic acid is commercially available, CAS number: 127-17-3.

[0241] Comparative Example 5

[0242] A method for preparing an anti-seepage and anti-cracking reinforced concrete pipe, characterized in that it comprises the following steps:

[0243] Step 1), build the mold using wooden boards according to design requirements.

[0244] Step 2), place the bundled steel cage in the mold, position the steel cage so that its axis coincides with the mold axis, and fix the steel cage to complete the installation of the steel cage.

[0245] Step 3), preparing a concrete mixture, specifically as follows:

[0246] Step 3-1), 383kg cement, 46kg fly ash, 755kg sand, 1005kg stone, 6.45kg water reducer, and 25kg calcium carbonate whisker are put into a stirring kettle at a speed of 60r / min, stirred for 5min, and mixed evenly to obtain a premix.

[0247] Step 3-2), add 158 kg of water to the premix, rotate at 60 r / min, stir for 3 min, mix evenly, and obtain a concrete mixture.

[0248] Step 4), inject the concrete mixture into the mold, tap the mold lightly to make the concrete mixture fill the mold, after the concrete pouring is completed, cover it with plastic film and cure for 3 days, demould it, and let it stand and cure for 28 days to obtain an impermeable and crack-resistant reinforced concrete pipe.

[0249] Among them, cement is silicate cement, standard: P.O42.5R.

[0250] Among them, the fly ash is first-grade fly ash.

[0251] Among them, the sand is river sand, 20-40 mesh.

[0252] Among them, the stone is granite crushed stone with a particle size of 9-12mm.

[0253] Among them, the water reducer is polycarboxylic acid water reducer, which was purchased from Jinan Yanglan New Materials Technology Co., Ltd.

[0254] Among them, calcium carbonate whiskers are homemade.

[0255] The preparation method of calcium carbonate whiskers is as follows:

[0256] Step 01), 75kg of calcium hydroxide and 1000kg of water are put into a stirring tank, heated and kept at a constant temperature of 90°C, a rotation speed of 120r / min, stirred for 120min, and mixed evenly to obtain a calcium hydroxide suspension.

[0257] Step 02), 15 kg of water-soluble magnesium salt, 15 kg of water-soluble zinc salt, 35 kg of lactic acid, 15 kg of malic acid, 25 kg of acetic acid, and 1000 kg of water are put into a container, mixed evenly until completely dissolved, to obtain a crystal control liquid.

[0258] Step 03), put 1500kg of crystal control liquid and 1000kg of calcium hydroxide suspension into a reactor, rotate at 120r / min, stir continuously, mix evenly, and obtain a reaction liquid.

[0259] Step 04), keep stirring at a speed of 120r / min and heat the reaction solution to a constant temperature of 85°C. While keeping stirring, introduce carbon dioxide into the reaction solution at a flow rate of 50-60ml / min to react. After a precipitate is generated and the pH value of the system drops to 6.8, stop introducing carbon dioxide, terminate the reaction, filter through a filter, take the precipitate, and dry it to obtain calcium carbonate whiskers.

[0260] Calcium hydroxide is commercially available, CAS number: 1305-62-0.

[0261] The water-soluble magnesium salt is magnesium chloride, which is commercially available, CAS number: 7786-30-3.

[0262] The water-soluble zinc salt is zinc chloride, which is commercially available with a CAS number of 7646-85-7.

[0263] Lactic acid is commercially available, CAS number: 50-21-5.

[0264] Malic acid is commercially available, CAS number: 636-61-3.

[0265] Acetic acid is commercially available, CAS No.: 64-19-7.

[0266] Experiment 1

[0267] According to GB / T50081-2019 “Standard for Test Methods for Physical and Mechanical Properties of Concrete”, the 7d compressive strength, 28d compressive strength and 28d splitting tensile strength of the samples prepared from the concrete mixtures of each embodiment and comparative example were tested.

[0268] Experiment 2

[0269] According to GB / T50082-2009 "Standard for Test Methods for Long-term Performance and Durability of Ordinary Concrete", the step-by-step pressurization method in the water penetration resistance test was used to detect the anti-permeability grade of the samples prepared from the concrete mixtures of each embodiment and comparative example.

[0270] The specific test data of Experiment 1-2 are shown in Table 1.

[0271] Table 1

[0272]

[0273] According to the data comparison between the embodiments and the comparative examples in Table 1, the compressive strength, splitting tensile strength and impermeability grade of the samples prepared from the concrete mixtures of the embodiments are significantly higher than those of the comparative examples. It can be seen that the calcium carbonate whiskers prepared by using the special crystal form controller in the embodiments have a better modification effect on the concrete, especially in terms of impermeability and crack resistance, so that the reinforced concrete pipes prepared in the embodiments have good impermeability and crack resistance.

[0274] Since the ingredients of the crystal form controllers were changed in each comparative example, the coordination system of magnesium ions, zinc ions, lactic acid, malic acid and pyruvic acid was destroyed, the effect of inducing the crystal form of calcium carbonate was changed, and the shape of the calcium carbonate whiskers was changed. Although the concrete can be reinforced, the reinforcement effect is relatively general, and it is difficult to achieve a high anti-seepage and anti-cracking effect.

[0275] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such 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 method for preparing an anti-seepage and anti-cracking reinforced concrete pipe, characterized in that: The following steps are involved: Step 1), build the mold; Step 2), placing a steel cage in the mold; Step 3), prepare the concrete mixture, as follows: Step 3-1), cement, fly ash, sand, stone, water reducing agent and calcium carbonate whisker are mixed evenly to obtain a premix; Step 3-2), adding water to the premix and mixing evenly to obtain a concrete mixture; Step 4), injecting the concrete mixture into the mold, curing and demoulding, and obtaining an impermeable and crack-resistant reinforced concrete pipe; In the step 3-1), the preparation method of calcium carbonate whiskers is as follows: Step 01), mixing calcium hydroxide with water to prepare a calcium hydroxide suspension; Step 02), mixing water-soluble magnesium salt, water-soluble zinc salt, lactic acid, malic acid, pyruvic acid and water to prepare a crystal form control solution; Step 03), adding the crystal form control liquid to the calcium hydroxide suspension, mixing evenly, to obtain a reaction liquid; Step 04), introducing carbon dioxide into the reaction solution to react, generating a precipitate, filtering and taking the precipitate to obtain calcium carbonate whiskers; In the step 3), the mass ratio of cement, fly ash, sand, stone, water reducing agent, calcium carbonate whisker and water is: 380-385: 45-48: 750-760: 1000-1010: 6.4-6.5: 24-26: 158-162; In the step 02), the mass ratio of water-soluble magnesium salt, water-soluble zinc salt, lactic acid, malic acid, pyruvic acid and water is 1-2:1-2:3-4:1-2:2-3:100; In the step 01), the mass ratio of calcium hydroxide to water is 7-8:100; In the step 03), the mass ratio of the crystal form control liquid to the calcium hydroxide suspension is 1-2:

1.

2. The method for preparing a seepage-proof and crack-resistant reinforced concrete pipe according to claim 1, characterized in that: In the step 04), the flow rate of carbon dioxide is 50-60 ml / min.

3. The method for preparing a seepage-proof and crack-resistant reinforced concrete pipe according to claim 2, characterized in that: In the step 04), the reaction solution is first kept at a constant temperature of 80-90° C., and then carbon dioxide is introduced.

4. A seepage-proof and crack-proof reinforced concrete pipe, characterized in that: The pipe is prepared by the method for preparing the anti-seepage and anti-cracking reinforced concrete pipe according to any one of claims 1 to 3.

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