An anti-seepage treatment method for construction joints of basement floor slabs

Abstract

The present invention relates to the field of building construction, and specifically to an anti-seepage treatment method for construction joints of basement floors, comprising the following steps: Step 1, preparing the raw materials of anti-seepage cement slurry: the ingredients of the anti-seepage cement slurry are calculated in parts by weight, including: cement, coarse aggregate, fine aggregate, fly ash, water, polyvinyl alcohol fiber, anti-seepage agent, water reducer and defoaming agent. Step 2, mixing of the anti-seepage cement slurry; Step 3, construction of the anti-seepage cement slurry; Step 4, maintenance of the anti-seepage cement slurry. The present invention uses a cement slurry with excellent anti-seepage ability, high compressive strength and not easy to crack. The present invention is more convenient to operate and does not require the use of a water-stop steel plate. Therefore, the requirements for the terrain are lower. When the water-stop steel plate is inconvenient to lower or the construction conditions are limited, the construction joints of the basement slab can also be well filled and reinforced, and a very good anti-seepage effect can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of building construction, and particularly relates to a method for anti-seepage treatment of construction joints of basement floors. Background Art

[0002] A construction joint refers to a joint formed between the previously and subsequently cast concrete during the concrete pouring process due to design requirements or construction needs for segmented pouring. A construction joint is not a real "joint". It is just that there is a bonding surface between the previously cast concrete that has exceeded the initial setting time or is of a different type from the subsequently cast concrete, and this bonding surface is called a construction joint.

[0003] According to the relevant regulations for the construction of building basements in China, it is not allowed to leave construction joints during the construction of basement floors. During construction, corresponding measures must be taken to ensure continuous pouring of the concrete for the basement floor of the building. However, in actual construction, due to reasons such as power outages during construction and failures of concrete delivery pumps, continuous pouring of concrete cannot be achieved during pouring, resulting in the appearance of construction joints. Moreover, due to construction requirements for some building basements, the horizontal and vertical components in the basement cannot be poured in one go. Therefore, construction joints are inevitably formed during the actual construction of basement floors.

[0004] Due to its own reasons and external environmental influences in the basement of a building, the basement floor is prone to moisture and water seepage due to the existence of construction joints. Currently, traditional methods for dealing with leakage problems at construction joints use waterstop steel plates. After adding the waterstop steel plate, when water seeps along the gap at the joint position between the new and old concrete and encounters the waterstop steel plate, it can no longer seep inwards, and the waterstop steel plate plays the role of cutting off the water seepage path. At the same time, when water seeps along the gap between the waterstop steel plate and the concrete, the waterstop steel plate has a certain length, which also extends the water seepage path and can also play a waterproofing role. However, for construction joints or construction cold joints where waterstop steel plates are not set or cannot be set due to construction conditions, the conventional method is to simply clean the leakage surface and apply cement slurry for treatment, but ordinary cement slurries cannot solve the problem of internal water seepage. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the purpose of the present invention is to provide a method for anti-seepage treatment of construction joints of basement floors.

[0006] The purpose of the present invention is achieved by the following technical solutions:

[0007] A method for anti-seepage treatment of construction joints of basement floors includes the following steps:

[0008] Step 1, configure the raw materials for the anti-seepage cement slurry:

[0009] The ingredients of the anti-permeability cement slurry are calculated by weight and include:

[0010] 130-180 parts of cement, 378-426 parts of coarse aggregate, 212-267 parts of fine aggregate, 35-50 parts of fly ash, 100-140 parts of water, 5.2-7.6 parts of polyvinyl alcohol fiber, 3.6-5.5 parts of anti-penetration agent, 1.2-3 parts of water reducer and 0.15-0.5 parts of defoaming agent.

[0011] Step 2, mixing of anti-seepage cement slurry:

[0012] Weigh each component of the anti-permeability cement slurry in step 1 according to parts by weight, then put each component into a mixer, and fully mix them under the operation of the mixer to form an anti-permeability cement slurry;

[0013] Step 3, construction of anti-seepage cement slurry:

[0014] Clean the construction joint of the basement floor to be constructed and its surroundings, rinse with clean water and dry, and then apply the anti-seepage cement slurry obtained in step 2 to the construction joint according to a pre-set range;

[0015] Step 4, maintenance of anti-seepage cement slurry:

[0016] After step 3 is completed, the construction site is covered and protected, and watered periodically for maintenance.

[0017] Preferably, in step 1, the cement is PO42.5 ordinary Portland cement.

[0018] Preferably, in step 1, the coarse aggregate is selected from crushed stone with a fineness of 5-10 mm; and the fine aggregate is selected from fine sand with a fineness of 0.2-5 mm.

[0019] Preferably, in step 1, the fly ash is Class F low-calcium fly ash, with a calcium oxide content of less than 10% and a fineness requirement of no more than 12% on a 45 μm square hole sieve.

[0020] Preferably, in step 1, the polyvinyl alcohol fiber has a fineness of 50-100 dtex, a strength of 8-10 cN / dtex, and a length of 5-10 mm.

[0021] Preferably, the anti-permeation agent is modified polyetherimide composite microspheres with a particle size of 60-100 μm.

[0022] Preferably, the water reducer is a polycarboxylic acid water reducer, including methacrylic acid / methyl acrylate copolymer or allyl ether copolymer.

[0023] Preferably, the defoaming agent is polydimethylsiloxane or polyether-modified polysiloxane.

[0024] Preferably, the preparation method of the modified polyetherimide composite microspheres includes:

[0025] (1) Preparation of the activated polyetherimide solution:

[0026] Under the protection of nitrogen, bisphenol A diether dianhydride and 4,4'-diaminodiphenyl ether are blended in N,N-dimethylformamide, and stirred at 25 - 30 °C for 8 - 12 h. Then 4-ethynylphthalic anhydride is added, and stirring continues at 25 - 30 °C for 5 - 10 h. Subsequently, triethylamine and acetic anhydride are added in sequence, and stirring continues at 25 - 30 °C for 1 - 2 h to obtain the activated polyetherimide solution;

[0027] Among them, the mass ratio of bisphenol A diether dianhydride, 4,4'-diaminodiphenyl ether, 4-ethynylphthalic anhydride, triethylamine, acetic anhydride to N,N-dimethylformamide is 2.2:5.2:0.5:3.4:3.2:50;

[0028] (2) Preparation of the disulfide-based polysiloxane copolymer:

[0029] Vinyl polysiloxane and allyl methyl disulfide are blended in N,N-dimethylformamide, sodium persulfate is added, the temperature is raised to 75 - 85 °C, and stirring reaction is carried out for 3 - 5 h. Then it is naturally cooled to room temperature. After removing impurities and drying, the disulfide-based polysiloxane copolymer is obtained;

[0030] Among them, the vinyl polysiloxane is divinyl-terminated polydimethylsilane with an average molecular weight of 5000; the mass ratio of vinyl polysiloxane, allyl methyl disulfide to N,N-dimethylformamide is 1:0.2 - 0.4:10, and the addition amount of sodium persulfate is 2% - 6% of the mass of vinyl polysiloxane.

[0031] (3) Preparation of the modified polyetherimide composite microspheres:

[0032] The disulfide-based polysiloxane copolymer and the activated polyetherimide solution are mixed. After sufficient stirring, it is poured into a high-pressure homogenizer and stirred at high speed. At the same time, an aqueous solution of polyvinylpyrrolidone is added dropwise. After gradually forming a microsphere suspension, the solvent is removed to obtain the modified polyetherimide composite microspheres;

[0033] Among them, the mass ratio of the disulfide-based polysiloxane copolymer to the activated polyetherimide solution is 1:100 - 200; the mass fraction of the aqueous solution of polyvinylpyrrolidone is 3% - 8%, and the mass ratio of the activated polyetherimide solution to the aqueous solution of polyvinylpyrrolidone is 1:4.5 - 5.5.

[0034] Preferably, in the step 2, during the mixing process of the anti-seepage cement slurry, first put cement, coarse aggregate, fine aggregate, coal ash, water reducing agent and water into the mixer, stir evenly, then put polyvinyl alcohol fiber and anti-seepage agent, stir evenly, and finally put defoaming agent and stir evenly.

[0035] Preferably, in the step 4, the curing standards are: temperature 20 - 25 °C, humidity 85% - 95%, and time 7 - 28 days.

[0036] The beneficial effects of the present invention are as follows:

[0037] 1. The present invention discloses an anti-seepage treatment method for construction joints of basement floors, mainly using a cement slurry with excellent anti-seepage ability, high compressive strength, and not easy to crack. Compared with traditional anti-seepage treatment methods, the operation of the present invention is more convenient, does not require the use of water stop steel plates, so the requirements for the terrain are lower. In the case where it is inconvenient to place the water stop steel plate or restricted by construction conditions, it can also better fill and reinforce the construction joints of the basement floor, and can achieve very good anti-seepage effects.

[0038] 2. In the present invention, the anti-seepage cement slurry on the market is analyzed and re-proportioned. In addition to the conventional cement, fly ash and aggregates to be added, polyvinyl alcohol fiber is added to the present invention. Polyvinyl alcohol fiber is a high-toughness fiber. After it is added to the cement, it can form a three-dimensional support network structure in the concrete to prevent the generation of cracks during the vibration molding process of the concrete.

[0039] 3. An anti-seepage agent is also added to the anti-seepage cement slurry of the present invention. Most of the traditional anti-seepage agents on the market are organosiloxanes, which utilize the waterproof property of organosiloxanes. Although it can indeed play a certain anti-seepage effect, the effect is not ideal. The anti-seepage agent of the present invention is obtained by improving the traditional organosiloxane. It utilizes the reaction of allyl methyl disulfide with vinyl-containing polysiloxane (organosiloxane). This combination process makes the polysiloxane contain both disulfide groups and organosilicon groups at the same time, enhancing its waterproof property and also strengthening its crosslinking property. Then, by combining with active polyetherimide, a modified polyetherimide composite microsphere is formed as the anti-seepage agent. The anti-seepage agent prepared by this method, compared with the traditional organosiloxane, not only has better compatibility with cement, but also makes the cured cement have better waterproof performance, stronger mechanical properties, less likely to crack, and more durable. Detailed Embodiments

[0040] In order to more clearly illustrate the present invention and have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solutions of the present invention are described in detail below, but it cannot be understood as a limitation on the feasible scope of the present invention.

[0041] For easier understanding, the process analysis of the anti-permeation agent synthesized by the present invention is as follows:

[0042] (1) The activation of polyetherimide is completed at room temperature. The synthesized activated polyetherimide contains a large number of phenylacetylene groups. The introduction of phenylacetylene groups as end-capping agents can construct a network cross-linked structure, thereby improving the dimensional stability and high temperature resistance of polyetherimide, and also preparing for the subsequent further cross-linking with copolymers to form microspheres.

[0043] (2) Disulfide-based polysiloxane copolymers are obtained by reacting vinyl polysiloxane containing olefin groups with allyl methyl disulfide containing both disulfide and olefin groups. The product is a polysiloxane polymer containing disulfide.

[0044] (3) The polysiloxane polymer containing disulfide is dissolved in the activated polyetherimide solution, and then microspheres are formed by emulsification-chemical crosslinking method, polyvinyl pyrrolidone is used as a dispersant, and water is used as a precipitant to finally obtain modified polyetherimide composite microspheres.

[0045] The present invention will be further described below with reference to the following examples.

[0046] Example 1

[0047] A method for preventing penetration of a basement floor construction joint comprises the following steps:

[0048] Step 1: Prepare the raw materials for the anti-seepage cement slurry:

[0049] The ingredients of the anti-permeability cement slurry are calculated by weight and include:

[0050] 150 parts of cement, 394 parts of coarse aggregate, 236 parts of fine aggregate, 45 parts of fly ash, 120 parts of water, 6.4 parts of polyvinyl alcohol fiber, 4.8 parts of anti-penetration agent, 1.8 parts of water reducer and 0.33 parts of defoaming agent.

[0051] Step 2, mixing of anti-seepage cement slurry:

[0052] Weigh the components of the anti-seepage cement slurry in step 1 in parts by weight, first add cement, coarse aggregate, fine aggregate, fly ash, water reducer and water into a mixer, stir evenly, then add polyvinyl alcohol fiber and anti-seepage agent, stir evenly, and finally add defoamer, stir evenly, and fully mix under the operation of the mixer to form an anti-seepage cement slurry;

[0053] Step 3, construction of anti-seepage cement slurry:

[0054] Clean the construction joint and its surrounding area of the basement floor to be constructed. After rinsing with clean water and drying, apply the anti-seepage cement slurry obtained in Step 2 to the construction joint within the preset range.

[0055] Step 4, curing of the anti-seepage cement slurry:

[0056] After the construction in Step 3 is completed, cover and protect the construction site and sprinkle water for curing at irregular intervals. The curing standards are: temperature 20 - 25°C, humidity 85% - 95%, and time 7 - 28 days.

[0057] Among them, in Step 1, the cement is PO42.5 ordinary Portland cement; the coarse aggregate is selected from crushed stones with a fineness of 5 - 10 mm; the fine aggregate is selected from fine sand with a fineness of 0.2 - 5 mm; the fly ash is F-class low-calcium fly ash with a calcium oxide content of less than 10%, and the fineness requirement is that the residue on a 45μm square-hole sieve is not more than 12%; the fineness of the polyvinyl alcohol fiber is 50 - 100 dtex, the strength is 8 - 10 cN / dtex, and the length is 5 - 10 mm; the water reducing agent is a polycarboxylate-based water reducing agent, which is a methyl methacrylate-methylacrylic acid copolymer; the defoaming agent is polydimethylsiloxane.

[0058] The anti-seepage agent is a modified polyetherimide composite microsphere with a particle size of 60 - 100μm. The preparation method of the modified polyetherimide composite microsphere includes:

[0059] (1) Preparation of the activated polyetherimide solution:

[0060] Under the protection of nitrogen, blend bisphenol A diether dianhydride and 4,4'-diaminodiphenyl ether in N,N-dimethylformamide, and stir at 25 - 30°C for 10 h. Add 4-ethynylphthalic anhydride and continue to stir at 25 - 30°C for 8 h. Then add triethylamine and acetic anhydride in sequence and continue to stir at 25 - 30°C for 2 h to obtain the activated polyetherimide solution.

[0061] Among them, the mass ratio of bisphenol A diether dianhydride, 4,4'-diaminodiphenyl ether, 4-ethynylphthalic anhydride, triethylamine, acetic anhydride to N,N-dimethylformamide is 2.2:5.2:0.5:3.4:3.2:50;

[0062] (2) Preparation of the disulfide-based polysiloxane copolymer:

[0063] Blend vinyl polysiloxane and allyl methyl disulfide in N,N-dimethylformamide, add sodium persulfate, heat up to 80°C, stir and react for 4 h, then naturally cool to room temperature. After removing impurities and drying, obtain the disulfide-based polysiloxane copolymer.

[0064] The vinyl polysiloxane is a divinyl-terminated polydimethylsilane with an average molecular weight of 5000; the mass ratio of vinyl polysiloxane, allyl methyl disulfide and N,N-dimethylformamide is 1:0.3:10, and the amount of sodium persulfate added is 4% of the mass of the vinyl polysiloxane.

[0065] (3) Preparation of modified polyetherimide composite microspheres:

[0066] The disulfide-based polysiloxane copolymer and the activated polyetherimide solution are mixed, stirred thoroughly, poured into a high-pressure homogenizer, stirred at high speed, and an aqueous solution of polyvinyl pyrrolidone is added dropwise to gradually form a microsphere suspension. The solvent is then removed to obtain modified polyetherimide composite microspheres;

[0067] The mass ratio of the disulfide-based polysiloxane copolymer to the activated polyetherimide solution is 1:150; the mass fraction of the polyvinyl pyrrolidone aqueous solution is 5%, and the mass ratio of the activated polyetherimide solution to the polyvinyl pyrrolidone aqueous solution is 1:5.

[0068] Example 2

[0069] A method for preventing penetration of a basement floor construction joint comprises the following steps:

[0070] Step 1: Prepare the raw materials for the anti-seepage cement slurry:

[0071] The ingredients of the anti-permeability cement slurry are calculated by weight and include:

[0072] 130 parts cement, 378 parts coarse aggregate, 212 parts fine aggregate, 35 parts fly ash, 100 parts water, 5.2 parts polyvinyl alcohol fiber, 3.6 parts anti-penetration agent, 1.2 parts water reducer and 0.15 parts defoaming agent.

[0073] Step 2, mixing of anti-seepage cement slurry:

[0074] Weigh the components of the anti-seepage cement slurry in step 1 in parts by weight, first add cement, coarse aggregate, fine aggregate, fly ash, water reducer and water into a mixer, stir evenly, then add polyvinyl alcohol fiber and anti-seepage agent, stir evenly, and finally add defoamer, stir evenly, and fully mix under the operation of the mixer to form an anti-seepage cement slurry;

[0075] Step 3, construction of anti-seepage cement slurry:

[0076] Clean the construction joint of the basement floor to be constructed and its surroundings, rinse with clean water and dry, and then apply the anti-seepage cement slurry obtained in step 2 to the construction joint according to a pre-set range;

[0077] Step 4, curing of the anti-seepage cement slurry:

[0078] After the construction in Step 3 is completed, cover and protect the construction site and sprinkle water for curing at irregular intervals. The curing standards are: temperature 20 - 25°C, humidity 85% - 95%, and time 7 - 28 days.

[0079] Among them, in Step 1, the cement is PO42.5 ordinary Portland cement; the coarse aggregate is selected from crushed stones with a fineness of 5 - 10 mm; the fine aggregate is selected from fine sand with a fineness of 0.2 - 5 mm; the fly ash is F-class low-calcium fly ash with a calcium oxide content of less than 10% and a fineness requirement that the residue on a 45μm square hole sieve is not more than 12%; the fineness of the polyvinyl alcohol fiber is 50 - 100 dtex, the strength is 8 - 10 cN / dtex, and the length is 5 - 10 mm; the water reducing agent is a polycarboxylate-based water reducing agent, which is an allyl ether copolymer; the defoaming agent is a polyether-modified polysiloxane.

[0080] The anti-seepage agent is a modified polyetherimide composite microsphere with a particle size of 60 - 100μm. The preparation method of the modified polyetherimide composite microsphere includes:

[0081] (1) Preparation of the activated polyetherimide solution:

[0082] Under the protection of nitrogen, blend bisphenol A diether dianhydride and 4,4'-diaminodiphenyl ether in N,N-dimethylformamide, stir at 25 - 30°C for 8 h, add 4-ethynylphthalic anhydride, continue to stir at 25 - 30°C for 5 h, then successively add triethylamine and acetic anhydride, and continue to stir at 25 - 30°C for 1 h to obtain the activated polyetherimide solution;

[0083] Among them, the mass ratio of bisphenol A diether dianhydride, 4,4'-diaminodiphenyl ether, 4-ethynylphthalic anhydride, triethylamine, acetic anhydride to N,N-dimethylformamide is 2.2:5.2:0.5:3.4:3.2:50;

[0084] (2) Preparation of the disulfide-based polysiloxane copolymer:

[0085] Blend vinyl polysiloxane and allyl methyl disulfide in N,N-dimethylformamide, add sodium persulfate, heat to 75°C, stir and react for 3 h, then naturally cool to room temperature, remove impurities and dry to obtain the disulfide-based polysiloxane copolymer;

[0086] Among them, the vinyl polysiloxane is bis-vinyl-terminated polydimethylsilane with an average molecular weight of 5000; the mass ratio of vinyl polysiloxane, allyl methyl disulfide to N,N-dimethylformamide is 1:0.2:10, and the addition amount of sodium persulfate is 2% of the mass of vinyl polysiloxane.

[0087] (3) Preparation of modified polyetherimide composite microspheres:

[0088] The disulfide-based polysiloxane copolymer and the activated polyetherimide solution are mixed, stirred thoroughly, poured into a high-pressure homogenizer, stirred at high speed, and an aqueous solution of polyvinyl pyrrolidone is added dropwise to gradually form a microsphere suspension. The solvent is then removed to obtain modified polyetherimide composite microspheres;

[0089] The mass ratio of the disulfide-based polysiloxane copolymer to the activated polyetherimide solution is 1:100; the mass fraction of the polyvinyl pyrrolidone aqueous solution is 3%, and the mass ratio of the activated polyetherimide solution to the polyvinyl pyrrolidone aqueous solution is 1:4.5.

[0090] Example 3

[0091] A method for preventing penetration of a basement floor construction joint comprises the following steps:

[0092] Step 1: Prepare the raw materials for the anti-seepage cement slurry:

[0093] The ingredients of the anti-permeability cement slurry are calculated by weight and include:

[0094] 180 parts of cement, 426 parts of coarse aggregate, 267 parts of fine aggregate, 50 parts of fly ash, 140 parts of water, 7.6 parts of polyvinyl alcohol fiber, 5.5 parts of anti-penetration agent, 3 parts of water reducer and 0.5 parts of defoaming agent.

[0095] Step 2, mixing of anti-seepage cement slurry:

[0096] Weigh the components of the anti-seepage cement slurry in step 1 in parts by weight, first add cement, coarse aggregate, fine aggregate, fly ash, water reducer and water into a mixer, stir evenly, then add polyvinyl alcohol fiber and anti-seepage agent, stir evenly, and finally add defoamer, stir evenly, and fully mix under the operation of the mixer to form an anti-seepage cement slurry;

[0097] Step 3, construction of anti-seepage cement slurry:

[0098] Clean the construction joint of the basement floor to be constructed and its surroundings, rinse with clean water and dry, and then apply the anti-seepage cement slurry obtained in step 2 to the construction joint according to a pre-set range;

[0099] Step 4, maintenance of anti-seepage cement slurry:

[0100] After step 3 is completed, the construction site should be covered and protected, and watered from time to time for maintenance. The maintenance standards are: temperature 20-25℃, humidity 85%-95%, and time 7-28 days.

[0101] Among them, in the step 1, the cement is PO42.5 ordinary Portland cement; the coarse aggregate is selected from crushed stones with a fineness of 5 - 10 mm; the fine aggregate is selected from fine sand with a fineness of 0.2 - 5 mm; the fly ash is F-class low-calcium fly ash with a calcium oxide content of less than 10%, and the fineness requirement is that the residue on a 45μm square hole sieve is not more than 12%; the fineness of the polyvinyl alcohol fiber is 50 - 100 dtex, the strength is 8 - 10 cN / dtex, and the length is 5 - 10 mm; the water reducing agent is a polycarboxylate water reducing agent, which is an allyl ether copolymer; the defoaming agent is polydimethylsiloxane.

[0102] The anti-permeability agent is a modified polyetherimide composite microsphere with a particle size of 60 - 100μm, and the preparation method of the modified polyetherimide composite microsphere includes:

[0103] (1) Preparation of the activated polyetherimide solution:

[0104] Under the protection of nitrogen, bisphenol A diether dianhydride and 4,4'-diaminodiphenyl ether are blended in N,N-dimethylformamide, and stirred at 25 - 30°C for 12 h. Then 4-ethynylphthalic anhydride is added, and stirring continues at 25 - 30°C for 10 h. Subsequently, triethylamine and acetic anhydride are added in sequence, and stirring continues at 25 - 30°C for 2 h to obtain the activated polyetherimide solution;

[0105] Among them, the mass ratio of bisphenol A diether dianhydride, 4,4'-diaminodiphenyl ether, 4-ethynylphthalic anhydride, triethylamine, acetic anhydride to N,N-dimethylformamide is 2.2:5.2:0.5:3.4:3.2:50;

[0106] (2) Preparation of the disulfide group polysiloxane copolymer:

[0107] Vinyl polysiloxane and allyl methyl disulfide are blended in N,N-dimethylformamide, sodium persulfate is added, the temperature is raised to 85°C, and stirring reaction is carried out for 5 h. Then it is naturally cooled to room temperature. After impurity removal and drying, the disulfide group polysiloxane copolymer is obtained;

[0108] Among them, the vinyl polysiloxane is divinyl-terminated polydimethylsilane with an average molecular weight of 5000; the mass ratio of vinyl polysiloxane, allyl methyl disulfide to N,N-dimethylformamide is 1:0.4:10, and the addition amount of sodium persulfate is 6% of the mass of vinyl polysiloxane.

[0109] (3) Preparation of the modified polyetherimide composite microsphere:

[0110] The disulfide-based polysiloxane copolymer and the activated polyetherimide solution are mixed, stirred thoroughly, poured into a high-pressure homogenizer, stirred at high speed, and an aqueous solution of polyvinyl pyrrolidone is added dropwise to gradually form a microsphere suspension. The solvent is then removed to obtain modified polyetherimide composite microspheres;

[0111] The mass ratio of the disulfide-based polysiloxane copolymer to the activated polyetherimide solution is 1:200; the mass fraction of the polyvinyl pyrrolidone aqueous solution is 8%, and the mass ratio of the activated polyetherimide solution to the polyvinyl pyrrolidone aqueous solution is 1:5.5.

[0112] Comparative Example 1

[0113] An anti-permeability cement slurry, the ingredients of which are calculated by weight, including:

[0114] 150 parts of cement, 394 parts of coarse aggregate, 236 parts of fine aggregate, 45 parts of fly ash, 120 parts of water, 6.4 parts of polyvinyl alcohol fiber, 4.8 parts of anti-penetration agent, 1.8 parts of water reducer and 0.33 parts of defoaming agent.

[0115] The difference from Example 1 is that the anti-permeation agent is different.

[0116] The anti-permeation agent of this comparative example is organosiloxane, which is a polymer of vinyl polysiloxane, and the vinyl polysiloxane is bisvinyl-terminated polydimethylsilane with an average molecular weight of 5000.

[0117] Comparative Example 2

[0118] An anti-permeability cement slurry, the ingredients of which are calculated by weight, including:

[0119] 150 parts of cement, 394 parts of coarse aggregate, 236 parts of fine aggregate, 45 parts of fly ash, 120 parts of water, 6.4 parts of polyvinyl alcohol fiber, 4.8 parts of anti-penetration agent, 1.8 parts of water reducer and 0.33 parts of defoaming agent.

[0120] The difference from Example 1 is that the anti-permeation agent is different.

[0121] The anti-permeation agent of this comparative example is common polyetherimide microspheres with a particle size of 60-100 μm, which are prepared by using bisphenol A diether dianhydride and 4,4'-diaminodiphenyl ether as reactants.

[0122] Comparative Example 3

[0123] An anti-seepage cement slurry, the ingredients of which are calculated by weight, including:

[0124] 150 parts of cement, 394 parts of coarse aggregate, 236 parts of fine aggregate, 45 parts of fly ash, 120 parts of water, 6.4 parts of polyvinyl alcohol fiber, 4.8 parts of anti-seepage agent, 1.8 parts of water reducer and 0.33 parts of defoamer.

[0125] The difference from Example 1 lies in the different anti-seepage agents.

[0126] The anti-seepage agent of this comparative example is a composite product of a polymer of vinyl polysiloxane and polyetherimide microspheres, that is, polyetherimide microspheres and a polymer of vinyl polysiloxane are mixed at a mass ratio of 4:1.

[0127] In order to more clearly illustrate the content of the present invention, the performances of the anti-seepage cement slurries prepared in Example 1 and Comparative Examples 1-3 of the present invention were compared. The curing temperature was 20-25 °C, the humidity was 85%-95%, and the time was 28 days. The detected data were integrated in a table, as shown in Table 1.

[0128] Flexural strength and compressive strength: Refer to GB / T 50081 "Standard Test Methods for Physical and Mechanical Properties of Concrete";

[0129] Anti-seepage grade: Refer to GB 50164 "Concrete Quality Control Standard", which is divided into six grades: P4, P6, P8, P10, P12, >P12, respectively indicating the ability to resist hydrostatic pressures of 0.4, 0.6, 0.8, 1.0 and 1.2 MPa without water seepage;

[0130] Crack resistance: Refer to GB / T 50081 "Standard Test Methods for Mechanical Properties of Ordinary Concrete". After 24 h of pouring the cement slurry, the number of cracks and the cracking area per unit area were detected.

[0131] Table 1 Performance of different anti-seepage cement slurries

[0132]

[0133] It can be seen from Table 1 that the flexural strength and compressive strength of Example 1 have obvious advantages compared with other comparative examples, and the anti-seepage grade can reach >P12 grade, the number of cracks within 24 h < 5 pieces / m 2 , the cracking area < 100 mm / m 2 , indicating that its anti-seepage and anti-cracking performances are excellent and very suitable for use as an anti-seepage material for the basement floor.

[0134] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for anti-seepage treatment of construction joints of basement floor slabs, characterized in that The steps include: Step 1: Prepare the raw materials for the anti-seepage cement slurry: The ingredients of the anti-permeability cement slurry are calculated by weight and include: 130-180 parts cement, 378-426 parts coarse aggregate, 212-267 parts fine aggregate, 35-50 parts fly ash, 100-140 parts water, 5.2-7.6 parts polyvinyl alcohol fiber, 3.6-5.5 parts anti-penetration agent, 1.2-3 parts water reducer and 0.15-0.5 parts defoaming agent; Step 2, mixing of anti-seepage cement slurry: Weigh each component of the anti-permeability cement slurry in step 1 according to parts by weight, then put each component into a mixer, and fully mix them under the operation of the mixer to form an anti-permeability cement slurry; Step 3, construction of anti-seepage cement slurry: Clean the construction joint of the basement floor to be constructed and its surroundings, rinse with clean water and dry, and then apply the anti-seepage cement slurry obtained in step 2 to the construction joint according to a pre-set range; Step 4, maintenance of anti-seepage cement slurry: After step 3 is completed, the construction site is covered and protected, and watered from time to time; The anti-penetration agent is modified polyetherimide composite microspheres; The preparation method of the modified polyetherimide composite microspheres comprises: (1) Preparation of activated polyetherimide solution: Under nitrogen protection, bisphenol A diether dianhydride and 4,4'-diaminodiphenyl ether are mixed in N,N-dimethylformamide, and stirred at 25-30°C for 8-12 hours. 4-ethynylphthalic anhydride is added, and stirring is continued at 25-30°C for 5-10 hours. Triethylamine and acetic anhydride are then added in sequence, and stirring is continued at 25-30°C for 1-2 hours to obtain an activated polyetherimide solution. The mass ratio of bisphenol A diether dianhydride, 4,4'-diaminodiphenyl ether, 4-ethynylphthalic anhydride, triethylamine, acetic anhydride and N,N-dimethylformamide is 2.2:5.2:0.5:3.4:3.2:50; (2) Preparation of disulfide-based polysiloxane copolymers: Vinyl polysiloxane and allyl methyl disulfide are mixed in N,N-dimethylformamide, sodium persulfate is added, the temperature is raised to 75-85°C, and the mixture is stirred for reaction for 3-5 hours, and then naturally cooled to room temperature. After impurities are removed and dried, a disulfide-based polysiloxane copolymer is obtained; The vinyl polysiloxane is a bis-vinyl-terminated polydimethylsilane with an average molecular weight of 5000; the mass ratio of vinyl polysiloxane, allyl methyl disulfide and N,N-dimethylformamide is 1:0.2-0.4:10, and the amount of sodium persulfate added is 2%-6% of the mass of the vinyl polysiloxane; (3) Preparation of modified polyetherimide composite microspheres: The disulfide-based polysiloxane copolymer and the activated polyetherimide solution are mixed, stirred thoroughly, poured into a high-pressure homogenizer, stirred at high speed, and an aqueous solution of polyvinyl pyrrolidone is added dropwise to gradually form a microsphere suspension. The solvent is then removed to obtain modified polyetherimide composite microspheres; Among them, the mass ratio of the disulfide group polysiloxane copolymer to the activated polyetherimide solution is 1:100 - 200; the mass fraction of the aqueous solution of polyvinylpyrrolidone is 3% - 8%, and the mass ratio of the activated polyetherimide solution to the aqueous solution of polyvinylpyrrolidone is 1:4.5 - 5.

5.

2. The anti-seepage treatment method for the construction joint of the basement floor slab according to claim 1, characterized in that, In the said step 1, the cement is PO42.5 ordinary Portland cement.

3. A method for anti-seepage treatment of construction joints of basement floor slabs according to claim 1, characterized in that, In the said step 1, the coarse aggregate is selected from crushed stones with a fineness of 5 - 10 mm; the fine aggregate is selected from fine sands with a fineness of 0.2 - 5 mm.

4. A method for anti-seepage treatment of construction joints of basement floor slabs according to claim 1, characterized in that, In the said step 1, the fly ash is F-class low-calcium fly ash with a calcium oxide content of less than 10%, and the fineness requirement is that the residue on a 45μm square hole sieve is not more than 12%.

5. A method for anti-seepage treatment of construction joints of basement floor slabs according to claim 1, characterized in that, In the said step 1, the fineness of the polyvinyl alcohol fiber is 50 - 100 dtex, the strength is 8 - 10 cN / dtex, and the length is 5 - 10 mm.

6. The anti-seepage treatment method for the construction joint of the basement floor slab according to claim 1, characterized in that, The particle size of the said anti-seepage agent is 60 - 100μm.

7. A method for anti-seepage treatment of construction joints of basement floor slabs according to claim 1, characterized in that, The said water reducer is a polycarboxylate-based water reducer, including methyl methacrylate / methyl acrylate copolymer or allyl ether copolymer.

8. A method for anti-seepage treatment of construction joints of basement floor slabs according to claim 1, characterized in that, The said defoamer is polydimethylsiloxane or polyether-modified polysiloxane.

9. A method for anti-seepage treatment of construction joints of basement floor slabs according to claim 1, characterized in that, In the said step 2, during the mixing process of the anti-seepage cement slurry, first put cement, coarse aggregate, fine aggregate, coal ash, water reducer and water into the mixer, stir evenly, then put in polyvinyl alcohol fiber and anti-seepage agent, stir evenly, and finally put in defoamer and stir evenly.

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