Special single-component waterproof mortar for concrete downstream face and preparation process of special single-component waterproof mortar

Abstract

The invention provides special single-component waterproof mortar for a concrete downstream face and a preparation process thereof, and relates to the field of building waterproofing, and the single-component waterproof mortar comprises the following components: cement, magnesium acrylate, active nano silicon dioxide, a modifier, a rapid hardening agent, tartaric acid, a dry film mildew preventive, metakaolin and quartz sand. A preparation method of the modifier A comprises the following steps: dissolving sodium hydroxypropyl methyl cellulose and potassium persulfate in water, then adding a PVA solution, uniformly stirring, drying and grinding to 200 meshes. A preparation method of the modifier B comprises the following steps: dissolving sodium hydroxypropyl methyl cellulose and sodium sulfite in water, then adding a PVA solution, uniformly stirring, drying and grinding to 200 meshes. Maintenance and leaking stoppage can be conducted on the downstream face of a concrete structure, good waterproof and leaking stoppage effects can be achieved under the condition that open water and seepage water pressure exist on the downstream face, and the self-repairing function is achieved.

Description

Technical Field

[0001] The invention relates to the field of building waterproofing, and in particular to a single-component waterproof mortar specially used for a concrete back water surface and a preparation process thereof. Background Art

[0002] At present, in order to make full use of space resources, there are more and more underground projects such as underground pipe galleries, subways, and underground garage storage rooms. However, leakage problems in underground projects occur frequently. According to relevant statistics, the leakage rate of residential underground garages can reach 92.68%. The surface in direct contact with water in a building is called the water-facing surface, and the surface corresponding to the water-facing surface is called the back-facing surface. Once the waterproof layer on the water-facing surface fails, the building will leak. When repairing and plugging underground projects, if the water-facing surface is difficult to manage for a while or the cost of waterproofing on the water-facing surface is too high, you can only choose to waterproof and plug leaks on the back-facing surface.

[0003] Flexible materials in the prior art, such as waterproof coils, polymer waterproof coatings, JS waterproof coatings and other materials, have a certain ability to resist water pressure, but when used on the back water surface, they are prone to bulging, peeling and base layer shedding. At present, the mainstream cement-based penetrating crystallization waterproof materials and ordinary polymer waterproof mortars used on the back water surface can only play an auxiliary role in plugging leaks or moisture-proofing on base surfaces without water seepage pressure and obvious water. The objects of repair are generally old residential areas. The concrete has no free calcium ions after years of erosion. The repair of cement-based penetrating crystallization coatings depends on free calcium ions. Only a thin layer of calcium ions in the coating may achieve a one-time repair effect. In a humid environment, the free calcium of cement in the cement-based penetrating crystallization coating will be consumed by carbon dioxide in the air in a short time, and the self-repair function will be lost. At the same time, in the low temperature environment in winter or when construction is carried out in cold areas, the existing flexible materials have poor frost resistance and cannot achieve the corresponding waterproof effect.

[0004] After arduous exploration, our team of inventors has solved the following problems existing in the prior art: the waterproof materials in the prior art have low bonding strength with concrete in a water environment; the waterproof and leak-proof effect is poor and the anti-seepage performance is poor when there is open water and seepage pressure on the back of the concrete structure; the self-repair function is poor; and the frost resistance is poor. Summary of the invention

[0005] In order to solve the above-mentioned problems existing in the prior art, the present invention provides a one-component waterproof mortar specially used for the back water surface of concrete and its preparation process, and achieves the following invention objectives: improving the bonding strength between the one-component waterproof mortar and concrete in a water environment, improving the anti-seepage and anti-freeze properties of the waterproof mortar, achieving better waterproof and leak-proof effects in construction in a water and low-temperature environment, and having a self-repairing function for a long time.

[0006] To achieve the above purpose, the technical solutions adopted are as follows: A one-component waterproof mortar specially used for the back water surface of concrete comprises the following components: cement, magnesium acrylate, active nano-silicon dioxide, a modifier, a quick-hardening agent, tartaric acid, a dry film mildew preventer, metakaolin and quartz sand.

[0007] The mass proportion of the components is: 550-600 parts of cement, 100-120 parts of magnesium acrylate, 8-10 parts of active nano-silicon dioxide, 12-15 parts of modifier A, 5-8 parts of modifier B, 0.3-0.5 parts of quick-hardening agent, 0.5-0.8 parts of tartaric acid, 0.2-0.25 parts of dry film mildew inhibitor, 40-50 parts of metakaolin, and 340-380 parts of quartz sand.

[0008] The preparation method of the modifier A is as follows: sodium hydroxypropyl methylcellulose and potassium persulfate are dissolved in water, and then a PVA solution is added, stirred evenly, and ground to 200 meshes after drying; the PVA solution is a polyvinyl alcohol solution with a mass fraction of 10% that has undergone a freeze-thaw cycle; the mass ratio of the sodium hydroxypropyl methylcellulose: potassium persulfate: water: PVA solution is 1:1.5:40:100.

[0009] The preparation method of the modifier B is as follows: sodium hydroxypropyl methylcellulose and sodium sulfite are dissolved in water, and then a PVA solution is added, stirred evenly, and ground to 200 meshes after drying; the PVA solution is a polyvinyl alcohol solution with a mass fraction of 10% that has undergone a freeze-thaw cycle; the mass ratio of the sodium hydroxypropyl methylcellulose: sodium sulfite: water: PVA solution is 1:0.5:20:100.

[0010] The dry film mildew preventer includes, but is not limited to, any one or more of tetrachloroisophthalonitrile, salicylanilide, and aminobenzenesulfonamide.

[0011] The quartz sand is prepared by mixing 70-140 mesh quartz sand and 40-60 mesh quartz sand in a mass ratio of 8-9:9-10.

[0012] The cement is 425 white Portland cement; The active nano silicon dioxide has a purity of 99% and a fineness of 0.5 nanometers; The quick-hardening agent: the model is electrochemical BEFORM; The metakaolin: model is Henan Yukun Y-110 type.

[0013] The preparation process of the special single-component waterproof mortar for concrete back water surface includes the steps of preparing modifier A, preparing modifier B, preparing raw materials, premixing and preparing finished products.

[0014] The premixing comprises mixing active nano silicon dioxide and metakaolin to obtain a premix.

[0015] The finished product is obtained by adding half of the mass of cement into a zero-gravity mixing tank, and then adding magnesium acrylate, modifier A, modifier B, quick-hardening agent, tartaric acid, dry film mildew inhibitor, premix, remaining cement, and quartz sand, starting stirring and mixing evenly; discharging and packaging to prepare a special single-component waterproof mortar for concrete back water surface.

[0016] The single-component waterproof mortar specially used for the back water surface of concrete has a water-cement ratio of (20-25) parts: 100 parts when used.

[0017] The beneficial effects of the present invention are as follows: (1) The waterproof mortar of the present invention has high water resistance and can survive in a long-term water environment without failure. It also has the characteristics of rapid strength growth and strong water holding capacity. It can quickly combine with the base layer in a water environment to form a waterproof layer. The waterproof mortar of the present invention adopts inorganic and organic dual permeability, which works in coordination and can seal concrete leaks in the presence of open water and seepage pressure on the back surface, achieving a waterproof and anti-seepage effect; (2) The waterproof mortar of the present invention has good adhesion to concrete, reaching a wet base surface bonding strength (3 days) of 1.0-1.5 MPa and a wet base surface bonding strength (28 days) of 1.8-2.3 MPa; the waterproof mortar can form a whole with the base layer without peeling or falling off; (3) The waterproof mortar of the present invention has excellent anti-seepage performance and can resist the erosion of water pressure. The anti-seepage performance of mortar (3 days) is 225-250MPa, the anti-seepage performance of mortar (7 days) is 300-375MPa, and the anti-seepage performance of mortar (28 days) is 400-475MPa; the anti-seepage performance of concrete (second anti-seepage pressure, 56 days) is 0.8-1.0MPa, and the anti-seepage performance of concrete (third anti-seepage pressure, 84 days) is 0.8-0.9MPa; (4) The addition of a specific modifier to the waterproof mortar of the present invention greatly improves the anti-freeze-thaw effect of the product and improves the cold resistance of the product. The antifreeze property is 95-98%, which is suitable for use in cold areas and low temperature environments. (5) In the present invention, magnesium acrylate will wrap a part of cement during the polymerization process. If it cracks later, it will be released to provide free calcium ions. Compared with conventional permeable crystallization waterproof materials, the present invention has strong self-repairing ability, more self-repairing times, and greatly improved waterproof life. Compared with other cement materials, it is more suitable for repairing and plugging old concrete in old communities; (6) The present invention has good flexibility, and the flexibility (lateral deformation) is 1.1-1.4 mm; (7) The waterproof mortar of the present invention is mildew-resistant and white in color. It can be used as a decorative layer and applied to the back surface of concrete. It can be waterproof and eliminate the latex paint process. (8) The waterproof mortar of the present invention is a single component and is easy to store, transport and use. DETAILED DESCRIPTION

[0018] To make the purpose, technical solution and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0019] Example 1 A special single-component waterproof mortar for concrete back water surface and its preparation process

[0020] Step 1: Preparation of Modifier A Sodium hydroxypropyl methylcellulose and potassium persulfate were dissolved in water, and then a 10% by mass PVA solution that had undergone a freeze-thaw cycle was added, stirred evenly, dried, and ground into 200 meshes to obtain modifier A.

[0021] The mass ratio of the sodium hydroxypropyl methylcellulose: potassium persulfate: water: PVA solution is 1:1.5:40:100.

[0022] Step 2: Preparation of Modifier B Sodium hydroxypropyl methylcellulose and sodium sulfite were dissolved in water, and then a 10% by mass PVA solution that had undergone a freeze-thaw cycle was added, stirred evenly, dried, and ground into 200 meshes to obtain modifier B.

[0023] The mass ratio of the hydroxypropylmethylcellulose sodium: sodium sulfite: water: PVA solution is 1:0.5:20:100.

[0024] Step 3: Raw material preparation Prepare the raw material components according to the following mass ratio: 550 parts of cement, 100 parts of magnesium acrylate, 8 parts of active nano-silica, 12 parts of modifier A, 5 parts of modifier B, 0.4 parts of quick hardening agent, 0.5 parts of tartaric acid, 0.2 parts of dry film mildew inhibitor, 50 parts of metakaolin, and 380 parts of quartz sand.

[0025] The cement is 425 white Portland cement; The active nano silicon dioxide has a purity of 99% and a fineness of 0.5 nanometers; The quick-hardening agent: the model is electrochemical BEFORM; The dry film mildew preventer is tetrachloroisophthalonitrile; The metakaolin: model is Henan Yukun Y-110; The quartz sand is prepared by mixing 70-140 mesh quartz sand and 40-60 mesh quartz sand in a mass ratio of 9:10.

[0026] Step 4: Premix First, active nano-silicon dioxide and metakaolin are added into a three-dimensional mixing motion machine and stirred for 30 minutes for premixing to obtain a premix.

[0027] Step 5: Obtain the finished product Add half of the mass of cement into a zero-gravity mixing tank, and then add magnesium acrylate, modifier A, modifier B, quick-hardening agent, tartaric acid, dry film mildew inhibitor, premix, remaining cement, and quartz sand, and start stirring for 30 minutes to mix evenly; discharge the material, package it, and make a special single-component waterproof mortar for concrete back water surface.

[0028] When using a special single-component waterproof mortar for the back surface of concrete, the water-cement ratio of the mortar is 20 parts: 100 parts; The above-mentioned parts are all parts by mass.

[0029] Example 2 A one-component waterproof mortar specially used for concrete back water surface and its preparation process

[0030] Step 1: Preparation of Modifier A Sodium hydroxypropyl methylcellulose and potassium persulfate were dissolved in water, and then a 10% by mass PVA solution that had undergone a freeze-thaw cycle was added, stirred evenly, dried, and ground into 200 meshes to obtain modifier A.

[0031] The mass ratio of the sodium hydroxypropyl methylcellulose: potassium persulfate: water: PVA solution is 1:1.5:40:100.

[0032] Step 2: Preparation of Modifier B Sodium hydroxypropyl methylcellulose and sodium sulfite were dissolved in water, and then a 10% by mass PVA solution that had undergone a freeze-thaw cycle was added, stirred evenly, dried, and ground into 200 meshes to obtain modifier B.

[0033] The mass ratio of the hydroxypropylmethylcellulose sodium: sodium sulfite: water: PVA solution is 1:0.5:20:100.

[0034] Step 3: Raw material preparation Prepare the raw material components according to the following mass ratio: 600 parts of cement, 100 parts of magnesium acrylate, 10 parts of active nano-silica, 12 parts of modifier A, 5 parts of modifier B, 0.5 parts of quick hardening agent, 0.8 parts of tartaric acid, 0.2 parts of dry film mildew inhibitor, 40 parts of metakaolin, and 340 parts of quartz sand.

[0035] The cement is 425 white Portland cement; The active nano silicon dioxide has a purity of 99% and a fineness of 0.5 nanometers; The quick-hardening agent: the model is electrochemical BEFORM; The dry film mildew inhibitor is aminobenzenesulfonamide; The metakaolin: model is Henan Yukun Y-110; The quartz sand is prepared by mixing 70-140 mesh quartz sand and 40-60 mesh quartz sand in a mass ratio of 8:9.

[0036] Step 4: Premix First, active nano-silicon dioxide and metakaolin are added into a three-dimensional mixing motion machine and stirred for 30 minutes for premixing to obtain a premix.

[0037] Step 5: Obtain the finished product Add half of the mass of cement into a zero-gravity mixing tank, and then add magnesium acrylate, modifier A, modifier B, quick-hardening agent, tartaric acid, dry film mildew inhibitor, premix, remaining cement, and quartz sand, and start stirring for 30 minutes to mix evenly; discharge the material, package it, and make a special single-component waterproof mortar for concrete back water surface.

[0038] When using a special single-component waterproof mortar for the back surface of concrete, the water-cement ratio of the mortar is 25 parts:100 parts; The above-mentioned parts are all parts by mass.

[0039] Example 3 A one-component waterproof mortar specially used for concrete back water surface and its preparation process

[0040] Step 1: Preparation of Modifier A Sodium hydroxypropyl methylcellulose and potassium persulfate were dissolved in water, and then a 10% by mass PVA solution that had undergone a freeze-thaw cycle was added, stirred evenly, dried, and ground into 200 meshes to obtain modifier A.

[0041] The mass ratio of the sodium hydroxypropyl methylcellulose: potassium persulfate: water: PVA solution is 1:1.5:40:100.

[0042] Step 2: Preparation of Modifier B Sodium hydroxypropyl methylcellulose and sodium sulfite were dissolved in water, and then a 10% by mass PVA solution that had undergone a freeze-thaw cycle was added, stirred evenly, dried, and ground into 200 meshes to obtain modifier B.

[0043] The mass ratio of the hydroxypropylmethylcellulose sodium: sodium sulfite: water: PVA solution is 1:0.5:20:100.

[0044] Step 3: Raw material preparation Prepare the raw material components according to the following mass ratio: 600 parts of cement, 120 parts of magnesium acrylate, 10 parts of active nano-silica, 15 parts of modifier A, 8 parts of modifier B, 0.5 parts of quick hardening agent, 0.8 parts of tartaric acid, 0.2 parts of dry film mildew inhibitor, 40 parts of metakaolin, and 340 parts of quartz sand.

[0045] The cement is 425 white Portland cement; The active nano silicon dioxide has a purity of 99% and a fineness of 0.5 nanometers; The quick-hardening agent: the model is electrochemical BEFORM; The dry film mildew inhibitor is salicylic anilide; The metakaolin: model is Henan Yukun Y-110; The quartz sand is prepared by mixing 70-140 mesh quartz sand and 40-60 mesh quartz sand in a mass ratio of 8:9.

[0046] Step 4: Premix First, active nano-silicon dioxide and metakaolin are added into a three-dimensional mixing motion machine and stirred for 30 minutes for premixing to obtain a premix.

[0047] Step 5: Obtain the finished product Add half of the mass of cement into a zero-gravity mixing tank, and then add magnesium acrylate, modifier A, modifier B, quick-hardening agent, tartaric acid, dry film mildew inhibitor, premix, remaining cement, and quartz sand, and start stirring for 30 minutes to mix evenly; discharge the material, package it, and make a special single-component waterproof mortar for concrete back water surface.

[0048] When using a special single-component waterproof mortar for the back surface of concrete, the water-cement ratio of the mortar is 25 parts:100 parts; The above-mentioned parts are all parts by mass.

[0049] Example 4 Performance Testing

[0050] The performance indicators of the one-component waterproof mortar for concrete back water surface prepared in Examples 1-3 were tested, and compared with the typical values ​​of conventional cement-based penetrating crystalline waterproof coating (CCCW C) and polymer cement waterproof mortar (JF II) purchased on the market: The one-component waterproof mortar for concrete back water surface prepared in Examples 1-3 and cement-based penetrating crystalline waterproof coating (CCCW C) and polymer cement waterproof mortar (JF II) were prepared and tested according to the following method: Specimen curing environment: Considering that the repair environment of the seepage project is relatively humid and the humidity is relatively high, the specimen curing conditions of this experiment are implemented in accordance with GB 18445-2012 "Cement-based penetrating crystalline waterproof material", with a temperature of (20±2)℃ and a relative humidity of 95%.

[0051] (1) Prepare and cure the specimens according to the method in 7.2.7 of GB 18445-2012 “Cement-based penetrating crystalline waterproof materials”, and test the wet surface bonding strength at 3 days and 28 days.

[0052] (2) Prepare and maintain the specimens according to the method in 7.2.8 of GB 18445-2012 “Cement-based penetrating crystalline waterproof materials”, and test the impermeability of the mortar at 3 days, 7 days, and 28 days, i.e. the impermeability pressure ratio of the coating.

[0053] (3) According to the method in 7.2.8 of GB 18445-2012 "Cement-based penetrating crystalline waterproof material", the specimens were cured for 28 days and then taken out. The specimens were divided into two groups. One group of specimens was subjected to freeze-thaw cycle treatment: according to the method in Chapter 4 of GB / T50082-2009, air-frozen at -15℃ for 4 hours, thawed in a (20±2)℃ curing pool for 4 hours, and subjected to 25 cycles; the other group of specimens was not subjected to freeze-thaw cycle treatment. According to the method in 7.2.8 of GB 18445-2012 "Cement-based penetrating crystalline waterproof material", the anti-seepage pressure test was carried out. The anti-seepage pressure after freeze-thaw cycle was divided by the anti-seepage pressure without freeze-thaw cycle to obtain the anti-seepage pressure retention rate, which is the frost resistance.

[0054] (4) Prepare and cure the specimens in accordance with Appendix B of JC / T1004-2006, and test the lateral deformation, i.e. flexibility.

[0055] (5) Prepare and cure the test specimens in accordance with 7.2.9 of GB 18445-2012 “Cement-based penetrating crystalline waterproof materials” and conduct a concrete impermeability test; after curing for 56 days, test the second impermeability pressure; after curing for 84 days, test the third impermeability pressure.

[0056] The waterproof performance test results of the waterproof mortar of Examples 1-3, cement-based penetrating crystalline waterproof coating (CCCW C), and polymer cement waterproof mortar (JF II) are shown in Table 1: Table 1 Waterproof performance test results

[0057] According to Table 1, the wet base surface bonding strength (3 days) of the waterproof mortar of the present invention is 1.0-1.5 MPa, the wet base surface bonding strength (28 days) is 1.8-2.3 MPa, the mortar impermeability (3 days) is 225-250 MPa, the mortar impermeability (7 days) is 300-375 MPa, the mortar impermeability (28 days) is 400-475 MPa, the frost resistance is 95-98%, the flexibility (lateral deformation) is 1.1-1.4 mm, the concrete impermeability (second impermeability pressure, 56 days) is 0.8-1.0 MPa, and the concrete impermeability (third impermeability pressure, 84 days) is 0.8-0.9 MPa.

[0058] According to the test results in Table 1, the curing condition of the test specimens tested by the present invention is wet curing, and the test results show excellent waterproof, bonding, and anti-seepage properties. The bonding strength and anti-seepage pressure of the waterproof mortar of the present invention are significantly higher at 3 days old, so rapid plugging and water stopping can be achieved; the waterproof mortar of the present invention is used for the maintenance of water seepage projects, which has a significant rapid plugging and water stopping effect. The waterproof mortar of the present invention has excellent antifreeze performance, with a frost resistance of 95-98%, and can be used in cold weather and low temperature environments. The waterproof mortar of the present invention has a large three-time anti-seepage pressure, can self-repair multiple times, and has a longer service life. The waterproof mortar of the present invention has good bonding performance, good bonding with the substrate, and does not peel or bulge.

[0059] Unless otherwise specified, the ratios described in the present invention are all mass ratios, and the percentages described are all mass percentages.

[0060] Obviously, under the concept of the present invention, there are many specific implementation methods that can be changed. Here, it should be stated that any changes made under the inventive concept of the present invention will fall within the protection scope of the present invention.

Claims

1. A one-component waterproof mortar specially used for the back surface of concrete, characterized in that: The invention comprises the following components: cement, magnesium acrylate, active nano-silica, modifier, quick-hardening agent, tartaric acid, dry film mildew preventer, metakaolin and quartz sand.

2. The one-component waterproof mortar specially used for concrete backwater surface according to claim 1, characterized in that: The mass proportion of the components is: 550-600 parts of cement, 100-120 parts of magnesium acrylate, 8-10 parts of active nano-silicon dioxide, 12-15 parts of modifier A, 5-8 parts of modifier B, 0.3-0.5 parts of quick-hardening agent, 0.5-0.8 parts of tartaric acid, 0.2-0.25 parts of dry film mildew inhibitor, 40-50 parts of metakaolin, and 340-380 parts of quartz sand.

3. The one-component waterproof mortar specially used for concrete backwater surface according to claim 1, characterized in that: The preparation method of the modifier A is as follows: sodium hydroxypropyl methylcellulose and potassium persulfate are dissolved in water, and then a PVA solution is added, stirred evenly, and ground to 200 meshes after drying; the PVA solution is a polyvinyl alcohol solution with a mass fraction of 10% that has undergone a freeze-thaw cycle.

4. The one-component waterproof mortar specially used for back water surface of concrete according to claim 3, characterized in that: The mass ratio of the sodium hydroxypropyl methylcellulose: potassium persulfate: water: PVA solution is 1:1.5:40:

100.

5. The one-component waterproof mortar specially used for concrete backwater surface according to claim 1, characterized in that: The preparation method of the modifier B is as follows: sodium hydroxypropyl methylcellulose and sodium sulfite are dissolved in water, and then a PVA solution is added, stirred evenly, and ground to 200 meshes after drying; the PVA solution is a polyvinyl alcohol solution with a mass fraction of 10% that has undergone a freeze-thaw cycle.

6. The one-component waterproof mortar specially used for back water surface of concrete according to claim 5, characterized in that: The mass ratio of the hydroxypropylmethylcellulose sodium: sodium sulfite: water: PVA solution is 1:0.5:20:

100.

7. The one-component waterproof mortar specially used for concrete backwater surface according to claim 1, characterized in that: The quartz sand is prepared by mixing 70-140 mesh quartz sand and 40-60 mesh quartz sand in a mass ratio of 8-9:9-10.

8. The one-component waterproof mortar specially used for concrete backwater surface according to claim 1, characterized in that: The dry film mildew preventer includes, but is not limited to, any one or more of tetrachloroisophthalonitrile, salicylanilide, and aminobenzenesulfonamide.

9. The preparation process of a one-component waterproof mortar specially used for concrete backwater surface according to claim 1, characterized in that: The steps of preparing modifier A, preparing modifier B, preparing raw materials, premixing and obtaining finished products; the premixing: mixing active nano silicon dioxide and metakaolin to obtain a premix.

10. The preparation process of a one-component waterproof mortar specially used for concrete back water surface according to claim 9, characterized in that: The finished product is obtained by adding half of the mass of cement into a zero-gravity mixing tank, and then adding magnesium acrylate, modifier A, modifier B, quick-hardening agent, tartaric acid, dry film mildew inhibitor, premix, remaining cement, and quartz sand, starting stirring and mixing evenly; discharging and packaging to prepare a special single-component waterproof mortar for concrete back water surface.

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