A cement mortar for road repair and its preparation method

Abstract

The present invention discloses a cement mortar for road repair and a preparation method thereof, and relates to the technical field of cement mortar preparation. When preparing the cement mortar for road repair, the present invention first prepares a multi-hydrogen bond chain extender, and then prepares an aqueous polyurethane emulsion and an aqueous epoxy emulsion; the aqueous polyurethane emulsion and the aqueous epoxy emulsion are mixed, and then nano titanium dioxide and a silane coupling agent are added to prepare a polymer reinforced emulsion; silicate cement, fast-hardening sulphoaluminate cement, fly ash, polymer reinforced emulsion, curing agent, water, defoaming agent, and water reducing agent are mixed and stirred to prepare cement mortar for road repair. The cement mortar for road repair prepared by the present invention has the advantages of fast solidification speed, high early strength, short construction time, and self-repairing performance.

Description

Technical Field

[0001] The invention relates to the technical field of cement mortar preparation, in particular to cement mortar for road repair and a preparation method thereof. Background Art

[0002] Cement concrete pavement is widely used in highways of all levels due to its advantages of high strength, strong bearing capacity and good durability. However, due to improper construction and overloading, cement concrete pavement has been seriously damaged, hindering normal traffic. On the one hand, traditional cement-based repair materials have a long curing period, which seriously affects the time of opening traffic; on the other hand, due to low bonding strength and poor durability, the repaired cement concrete pavement is destroyed in a short time.

[0003] Compared with ordinary concrete materials, organic-inorganic composite repair materials have the advantages of good flexibility, strong adhesion, good durability, and compact structure. The addition of polymers improves the performance of traditional cement-based materials, and since most of the composite material is still cement, it ensures compatibility with the cement concrete matrix, so it has been widely used in engineering.

[0004] Waterborne polyurethane is a hydrophilic organic resin with good flexibility, good durability and stable comprehensive performance. By introducing waterborne polyurethane into the cement concrete system, a composite effect of synergistic polymerization and curing of waterborne polyurethane and hydration and hardening of cement can be constructed. Epoxy emulsion modified cement mortar has excellent mechanical properties, chemical stability and bonding properties. However, if waterborne polyurethane or waterborne epoxy is used alone, each has its own advantages and disadvantages: waterborne polyurethane is characterized by good flexibility and good radiation resistance, but insufficient bonding; waterborne epoxy resin has excellent bonding, but the solid body is relatively brittle and hard, and has poor radiation resistance. Summary of the invention

[0005] The object of the present invention is to provide a cement mortar for road repair and a preparation method thereof, so as to solve the problems existing in the prior art.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A cement mortar for road repair, wherein the cement mortar for road repair is prepared by first preparing a multi-hydrogen bond chain extender, then preparing an aqueous polyurethane emulsion and an aqueous epoxy emulsion; mixing the aqueous polyurethane emulsion and the aqueous epoxy emulsion, then adding nano titanium dioxide and a silane coupling agent to prepare a polymer reinforced emulsion; and mixing and stirring silicate cement, fast-hardening sulphoaluminate cement, fly ash, a polymer reinforced emulsion, a curing agent, water, a defoamer, and a water reducing agent to prepare the cement mortar for road repair;

[0008] The multi-hydrogen bond chain extender is prepared by first reacting 2,4-diamino-6-methyl-1,3,5-triazine with diisocyanate, and then reacting with 2-amino-2-methyl-1,3-propanediol and ethanol;

[0009] The waterborne polyurethane emulsion is prepared by reacting isophorone diisocyanate with polycarbonate diol, 3-dimethylamino-1,2-propylene glycol, 2, 4-pentanedione dioxime, a multi-hydrogen bond chain extender, and a haloalkane, and then emulsifying with water.

[0010] The water-based epoxy emulsion is prepared by reacting epoxy resin with 2-aminoethylphosphonic acid and diethylamine, and then adding water for emulsification.

[0011] As an optimization, the cement mortar for road repair includes the following components in parts by mass: 20~80 parts of silicate cement, 10~70 parts of fast-hardening sulphoaluminate cement, 5~20 parts of fly ash, 250~400 parts of sand, 30~50 parts of polymer enhanced emulsion, 1~5 parts of curing agent, 2~15 parts of water, 0.1~1 parts of defoaming agent, and 0.1~1 parts of water reducing agent.

[0012] As an optimization, the diisocyanate is one of m-phenylene diisocyanate, p-phenylene diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

[0013] As an optimization, the alkyl halide is one of methyl iodide, methyl bromide and methyl chloride.

[0014] As an optimization, the epoxy resin is bisphenol A type epoxy resin.

[0015] A method for preparing cement mortar for road repairing comprises the following preparation steps:

[0016] (1) According to the mass percentage, weigh 15-20 parts of polycarbonate diol and 25-30 parts of N,N-dimethylformamide and mix them evenly. In a nitrogen atmosphere, heat to 70-75°C, evenly add 16.6-23.7 parts of isophorone diisocyanate dropwise over 40-50 minutes, add 0.33-0.47 parts of dibutyltin dilaurate, and react at 250-350 r / min for 1.5-2 hours. After sampling to confirm the complete reaction, cool to 50-55°C, add 2.23-3.81 parts of 3-dimethylamino-1,2-propylene glycol, and react for 1.5-2 hours. After sampling to confirm the complete reaction, add 1.46-2.34 parts of 2, 4-pentanedione dioxime, react at 70-80°C, 300-400 r / min for 2-3 hours, take a sample to confirm the complete reaction, add 4.6-9.8 parts of multi-hydrogen bond chain extender, react at 60-70°C, 300-400 r / min for 2-3 hours, add 3.2-5.3 parts of alkyl halide, react at 25-30°C, 300-400 r / min for 1.5-2 hours, remove N,N-dimethylformamide by vacuum distillation, add 85-130 parts of pure water, stir at 1500-2000 r / min for 40-50 minutes, and prepare waterborne polyurethane emulsion;

[0017] (2) By weight, 10-15 parts of epoxy resin and 20-30 parts of propylene glycol monomethyl ether were mixed evenly, stirred at 70-80°C and 200-300 r / min for 30-40 min, after the epoxy resin was completely dissolved, 0.79-0.93 parts of 2-aminoethylphosphonic acid were added, reacted at 80-90°C and 300-400 r / min for 2-3 h, 2.86-4.45 parts of 20 wt% ethylenediamine solution in propylene glycol monomethyl ether were added dropwise at 2-3 drops per second, reacted at 15-25°C and 200-300 r / min for 1-2 h, 27-40 parts of pure water were added at 55°C and 2000-2400 r / min at 2-3 drops per second, stirred for 30-40 min after the addition was completed, and propylene glycol monomethyl ether was removed by vacuum distillation to obtain a waterborne epoxy emulsion;

[0018] (3) Mix the aqueous polyurethane emulsion and the aqueous epoxy emulsion in a mass ratio of (2.5-3):1, stir at 100-150 r / min for 20-30 min, add 1-1.5% of the mass of the aqueous epoxy emulsion nano-titanium dioxide and 3-4% of the mass of the aqueous epoxy emulsion silane coupling agent, stir at 100-150 r / min for 15-20 min, and then ultrasonicate for 1-1.5 h to obtain a polymer reinforced emulsion;

[0019] (4) By weight, mix 20-80 parts of Portland cement, 10-70 parts of rapid-hardening sulphoaluminate cement, 5-20 parts of fly ash, 250-400 parts of sand, and 0.1-1 part of water reducer evenly, stir in a pot for 1-2 min, add 30-50 parts of polymer reinforced emulsion, 1-5 parts of curing agent, 2-15 parts of water, and 0.1-1 part of defoaming agent, and stir for another 3 min to prepare cement mortar for road repair.

[0020] As an optimization, the multi-hydrogen bond chain extender in step (1) includes the following preparation steps:

[0021] (A) Under nitrogen atmosphere, 2,4-diamino-6-methyl-1,3,5-triazine, hexamethylene diisocyanate and 1-methyl-2-pyrrolidone were mixed uniformly in a mass ratio of 1:(9.4-10.7):(0.3-0.4), reacted at 100-110°C and 200-300 r / min for 16-20 h, cooled naturally to room temperature, added anhydrous chloroform (0.3-0.35 times the mass of hexamethylene diisocyanate), continued stirring for 1.5-2 h, slowly poured into the washing solution within 10 min, continued stirring for 40-50 min, filtered, washed with the washing solution for 3-5 times, and vacuum dried at 50-60°C for 16-20 h to obtain a multi-hydrogen bond monomer;

[0022] (B) Under nitrogen atmosphere, a multi-hydrogen bond monomer, 2-amino-2-methyl-1,3-propanediol and anhydrous chloroform are mixed uniformly in a mass ratio of 1:(0.24-0.26):(8-9), and refluxed at 60°C and 200-300 r / min for 10-12 h. Anhydrous ethanol in an amount of 0.15 times the mass of the multi-hydrogen bond monomer is added, and the reaction is continued for 8-10 h. The mixture is naturally cooled to room temperature and filtered. The precipitated solid is dissolved with 2 times the mass of N,N-dimethylformamide, and then centrifuged at 10000-12000 rpm for 15-20 min. The supernatant is separated by filtration. Diethyl ether in an amount of 2 times the mass of N,N-dimethylformamide is added to the supernatant, and the mixture is stirred at 150-200 r / min for 15-20 min. The mixture is allowed to stand for 4-6 h, filtered, washed with acetone for 3-4 times, and vacuum dried at 40-50°C for 10-12 h to prepare a multi-hydrogen bond chain extender.

[0023] As an optimization, the multi-hydrogen bond monomer reaction process in step (A) is as follows:

[0024] .

[0025] As an optimization, the reaction process of the multi-hydrogen bond chain extender in step (B) is as follows:

[0026] .

[0027] As an optimization, the reaction process of the aqueous polyurethane emulsion in step (1) is as follows:

[0028] ;

[0029] ;

[0030] ;

[0031] .

[0032] As an optimization, the reaction process of the waterborne epoxy emulsion in step (2) is as follows:

[0033] ;

[0034] .

[0035] As an optimization, the silane coupling agent in step (3) is one of KH550 and KH792.

[0036] As an optimization, the washing solution in step (A) is prepared by mixing n-heptane and isopropyl ether in a volume ratio of 6:1.

[0037] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0038] In the preparation of cement mortar for road repair, 2,4-diamino-6-methyl-1,3,5-triazine is firstly reacted with diisocyanate, and then with 2-amino-2-methyl-1,3-propanediol and ethanol to obtain a multi-hydrogen bond chain extender; isophorone diisocyanate is reacted with polycarbonate diol, 3-dimethylamino-1,2-propanediol, 2, 4-pentanedione dioxime, multi-hydrogen bond chain extender and alkyl halide are reacted, and then water is added for emulsification to obtain waterborne polyurethane emulsion; epoxy resin is reacted with 2-aminoethylphosphonic acid and diethylamine, and then water is added for emulsification to obtain waterborne epoxy emulsion; waterborne polyurethane emulsion and waterborne epoxy emulsion are mixed, and then nano-titanium dioxide and silane coupling agent are added to obtain polymer reinforced emulsion; silicate cement, fast-hardening sulphoaluminate cement, fly ash, polymer reinforced emulsion, curing agent, water, defoaming agent and water reducing agent are mixed and stirred to obtain cement mortar for road repair.

[0039] First, 2,4-diamino-6-methyl-1,3,5-triazine reacts with diisocyanate to obtain a molecule with urea and triazine structure, which can form quadruple hydrogen bonds. Then, it reacts with 2-amino-2-methyl-1,3-propanediol to introduce diols for subsequent chain extenders, and then uses ethanol to cap the end. In this method, the multiple hydrogen bond structure is no longer located on the main chain, but is designed on the side chain, so that it can rotate and move more freely, which promotes the formation of multiple hydrogen bonds and improves the self-healing effect. 3-dimethylamino-1,2-propanediol is introduced into the waterborne polyurethane, and then quaternized with halogenated alkanes to obtain hydrophilic quaternary ammonium cations. The quaternary ammonium ion liquid does not exist directly on the main chain, but is located on the short side chain, and its hydrophilicity is improved. The formed waterborne polyurethane emulsion has better stability and can be stable for more than six months. 2, 4-Pentanedione dioxime reacts to obtain an oxime-carbamate self-healing structure. At the same time, the nitrogen and oxygen elements in this structure can form coordination bonds with metal ions such as calcium ions in cement mortar, which not only improves the bonding strength between the organic polymer and the inorganic cement mortar, but also drives the calcium ions to repair microcracks as the chain segments move.

[0040] Secondly, the epoxy resin reacts with 2-aminoethylphosphonic acid. While introducing anionic groups to form ionic bonds with cations on the polyurethane segments, the phosphate groups also have good complexing properties, which can improve the strength and reduce water, thereby reducing the amount of water reducer or even eliminating the need for water reducer. The aqueous epoxy emulsion is mixed with the aqueous polyurethane emulsion, and nano-titanium dioxide and a silane coupling agent are added. The silane coupling agent improves the dispersibility of the nano-titanium dioxide while also improving the bonding between the polymer-enhanced emulsion and the inorganic material, thereby improving the bonding strength. In addition to the strength improvement brought about by doping, nano-titanium dioxide also has a photothermal effect, which can effectively convert photothermal energy into the self-healing structure, and can achieve the ability to repair at room temperature. At the same time, the repair ability increases with rising temperature.

[0041] Finally, silicate cement, fast-hardening sulphoaluminate cement, fly ash and sand are mixed, and polymer-reinforced emulsion, curing agent, water, defoaming agent, water-reducing agent and the like are added and stirred evenly to obtain cement mortar for road repair. The polymer-reinforced emulsion greatly accelerates the curing and film-forming speed when compounded with water-based polyurethane emulsion and water-based epoxy emulsion, and can be cured into a film within 5 to 6 hours. The polymer curing process proceeds together with the cement hydration process to form a three-dimensional interpenetrating network of polymer-inorganic cement, which effectively improves the strength after solidification. As for cement, ordinary cement is compounded with fast-hardening sulphoaluminate cement to greatly improve its setting time, and higher early strength can be obtained under simple maintenance, shortening the time of road closure and reducing the economic losses caused by traffic inconvenience. Fly ash is also added to the formula, which can promote the self-repairing effect of microcracks and reduce the porosity of cement after solidification, thereby improving the overall strength. DETAILED DESCRIPTION

[0042] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] The raw material model information used in all the following examples and comparative examples is as follows:

[0044] Polycarbonate diol: model UH-50, molecular weight 500;

[0045] Epoxy resin: E44 epoxy resin, brand name Xingchen, item number 8989, purchased from Nantong Xingchen Synthetic Materials Co., Ltd.

[0046] Nano titanium dioxide: item number 100360, brand name Xianfeng Nano, particle size 20-40 nm, purchased from Jiangsu Xianfeng Nanomaterials Technology Co., Ltd.;

[0047] Silane coupling agent: model KH550;

[0048] Portland cement: 52.5 grade Portland cement, purchased from Hunan Ningxiang Nanfang Cement Co., Ltd.;

[0049] Rapid hardening sulphoaluminate cement: selected from 42.5 grade rapid hardening sulphoaluminate cement produced by Hubei Xiaogan Anda Special Cement Co., Ltd.;

[0050] Fly ash: first-grade ash, purchased from Jining Hengzhi New Building Materials Co., Ltd.;

[0051] Sand: quartz sand, particle size 10~20 mesh, mud content 0.4%;

[0052] Curing agent: CYDHD-200 curing agent;

[0053] Defoamer: Zhonglian B-367 cement defoamer;

[0054] Water reducing agent: CP1801X polycarboxylic acid water reducing agent.

[0055] Embodiment 1: A method for preparing cement mortar for road repair, the method for preparing cement mortar for road repair comprising the following preparation steps:

[0056] (1) Under nitrogen atmosphere, 2,4-diamino-6-methyl-1,3,5-triazine, hexamethylene diisocyanate, and 1-methyl-2-pyrrolidone were mixed uniformly in a mass ratio of 1:9.4:0.3, reacted at 100°C and 200 r / min for 20 h, naturally cooled to room temperature, added anhydrous chloroform (0.3 times the mass of hexamethylene diisocyanate), continued stirring for 1.5 h, slowly poured into the washing solution within 10 min, continued stirring for 40 min, filtered, washed with the washing solution for 3 times, and vacuum dried at 50°C for 20 h to obtain a multi-hydrogen bond monomer;

[0057] (2) Under nitrogen atmosphere, a multi-hydrogen bond monomer, 2-amino-2-methyl-1,3-propanediol and anhydrous chloroform were mixed uniformly in a mass ratio of 1:0.24:8, and refluxed at 60°C and 200 r / min for 10 h. Anhydrous ethanol 0.15 times the mass of the multi-hydrogen bond monomer was added, and the reaction was continued for 8 h. The mixture was naturally cooled to room temperature, filtered, and the precipitated solid was dissolved with 2 times the mass of N,N-dimethylformamide. The mixture was then centrifuged at 10,000 rpm for 20 min, and the supernatant was separated by filtration. Diethyl ether 2 times the mass of N,N-dimethylformamide was added to the supernatant, and the mixture was stirred at 150 r / min for 20 min. The mixture was allowed to stand for 4 h, filtered, washed with acetone 3 times, and dried in vacuo at 40°C for 12 h to obtain a multi-hydrogen bond chain extender.

[0058] (3) By mass, weigh 15 parts of polycarbonate diol and 25 parts of N,N-dimethylformamide and mix them evenly. In a nitrogen atmosphere, heat to 70°C, evenly add 16.6 parts of isophorone diisocyanate dropwise over 40 minutes, add 0.33 parts of dibutyltin dilaurate, react at 250 r / min for 1.5 hours, take samples to confirm complete reaction, cool to 50°C, add 2.23 parts of 3-dimethylamino-1,2-propylene glycol, react for 1.5 hours, take samples to confirm complete reaction, add 1.46 parts of 2, 4-pentanedione dioxime, react at 70°C, 300 r / min for 3 hours, take a sample to confirm the complete reaction, add 4.6 parts of multi-hydrogen bond chain extender, react at 60°C, 300 r / min for 3 hours, add 3.2 parts of iodomethane, react at 25°C, 300 r / min for 2 hours, remove N,N-dimethylformamide by vacuum distillation, add 85 parts of pure water, stir at 1500 r / min for 40 minutes, and prepare waterborne polyurethane emulsion;

[0059] (4) By weight, 10 parts of epoxy resin and 20 parts of propylene glycol monomethyl ether were mixed evenly, stirred at 70°C and 200 r / min for 40 min, after the epoxy resin was completely dissolved, 0.79 parts of 2-aminoethylphosphonic acid were added, reacted at 80°C and 300 r / min for 3 h, 2.86 parts of 20 wt% ethylenediamine propylene glycol monomethyl ether solution were added dropwise at 2 drops per second, reacted at 15°C and 200 r / min for 2 h, 27 parts of pure water were added at 55°C and 2000 r / min at 2 drops per second, stirred for 30 min after the addition was completed, and propylene glycol monomethyl ether was removed by vacuum distillation to obtain a water-based epoxy emulsion;

[0060] (5) Mix the waterborne polyurethane emulsion and the waterborne epoxy emulsion in a mass ratio of 2.5:1, stir at 100 r / min for 30 min, add 1% of nano-titanium dioxide by mass of the waterborne epoxy emulsion and 3% of silane coupling agent by mass of the waterborne epoxy emulsion, stir at 100 r / min for 20 min, and then ultrasonicate for 1 h to obtain a polymer reinforced emulsion;

[0061] (6) By weight, 64 parts of Portland cement, 28 parts of rapid hardening sulphoaluminate cement, 8 parts of fly ash, 250 parts of sand, and 0.15 parts of water reducer were mixed evenly and stirred in a pot for 1 min. Then 33.8 parts of polymer reinforced emulsion, 2.5 parts of curing agent, 13.4 parts of water, and 0.1 part of defoaming agent were added and stirred for another 3 min to prepare cement mortar for road repair.

[0062] Embodiment 2: A method for preparing cement mortar for road repair, the method for preparing cement mortar for road repair comprising the following preparation steps:

[0063] (1) Under nitrogen atmosphere, 2,4-diamino-6-methyl-1,3,5-triazine, hexamethylene diisocyanate, and 1-methyl-2-pyrrolidone were mixed uniformly in a mass ratio of 1:10.1:0.35, reacted at 105°C and 250 r / min for 18 h, naturally cooled to room temperature, added with anhydrous chloroform (0.32 times the mass of hexamethylene diisocyanate), continued stirring for 1.8 h, slowly poured into the washing solution within 10 min, continued stirring for 45 min, filtered, washed with the washing solution for 4 times, and vacuum dried at 55°C for 18 h to obtain a multi-hydrogen bond monomer;

[0064] (2) Under nitrogen atmosphere, a multi-hydrogen bond monomer, 2-amino-2-methyl-1,3-propanediol and anhydrous chloroform were mixed in a mass ratio of 1:0.25:8.5, and refluxed at 60°C and 250 r / min for 11 h. Anhydrous ethanol (0.15 times the mass of the multi-hydrogen bond monomer) was added, and the reaction was continued for 9 h. The mixture was naturally cooled to room temperature and filtered. The precipitated solid was dissolved with 2 times the mass of N,N-dimethylformamide, and then centrifuged at 11000 rpm for 18 min. The supernatant was separated by filtration. Diethyl ether (2 times the mass of N,N-dimethylformamide) was added to the supernatant, stirred at 175 r / min for 18 min, allowed to stand for 5 h, filtered, washed with acetone 3 times, and vacuum dried at 45°C for 11 h to obtain a multi-hydrogen bond chain extender.

[0065] (3) By mass, weigh 18 parts of polycarbonate diol and 27 parts of N,N-dimethylformamide and mix them evenly. In a nitrogen atmosphere, heat to 70°C, evenly add 22.86 parts of isophorone diisocyanate and 0.45 parts of dibutyltin dilaurate in 45 minutes, and react at 300r / min for 1.5 hours. After sampling to confirm the complete reaction, cool to 50°C, add 3.37 parts of 3-dimethylamino-1,2-propylene glycol, and react for 1.5 hours. After sampling to confirm the complete reaction, add 2.34 parts of 2, 4-pentanedione dioxime, react at 75°C, 350r / min for 2.5h, take a sample to confirm the complete reaction, add 6.3 parts of multi-hydrogen bond chain extender, react at 65°C, 350r / min for 2.5h, add 4.4 parts of iodomethane, react at 25°C, 350r / min for 1.5h, remove N,N-dimethylformamide by vacuum distillation, add 115 parts of pure water, stir at 1800r / min for 45min, and obtain waterborne polyurethane emulsion;

[0066] (4) By weight, 12 parts of epoxy resin and 25 parts of propylene glycol monomethyl ether were mixed evenly, stirred at 75°C and 250 r / min for 35 min, after the epoxy resin was completely dissolved, 0.83 parts of 2-aminoethylphosphonic acid were added, reacted at 85°C and 350 r / min for 2.5 h, 3.6 parts of 20 wt% ethylenediamine solution in propylene glycol monomethyl ether were added dropwise at 2 drops per second, reacted at 20°C and 250 r / min for 1.5 h, 32 parts of pure water were added at 55°C and 2200 r / min at 2 drops per second, stirred for 35 min after the addition was completed, and propylene glycol monomethyl ether was removed by vacuum distillation to obtain a water-based epoxy emulsion;

[0067] (5) Mix the aqueous polyurethane emulsion and the aqueous epoxy emulsion in a mass ratio of 2.8:1, stir at 150 r / min for 25 min, add 1.2% of the mass of the aqueous epoxy emulsion nano-titanium dioxide and 3.5% of the mass of the aqueous epoxy emulsion silane coupling agent, stir at 125 r / min for 18 min, and then ultrasonicate for 1.2 h to obtain a polymer reinforced emulsion;

[0068] (6) By weight, 54 parts of Portland cement, 36 parts of rapid hardening sulphoaluminate cement, 10 parts of fly ash, 300 parts of sand, and 0.3 parts of water reducer were mixed evenly and stirred in a pot for 1.5 min. Then, 42.6 parts of polymer reinforced emulsion, 3 parts of curing agent, 6.8 parts of water, and 0.2 parts of defoaming agent were added and stirred for another 4 min to prepare cement mortar for road repair.

[0069] Embodiment 3: A method for preparing cement mortar for road repair, the method for preparing cement mortar for road repair comprising the following preparation steps:

[0070] (1) Under nitrogen atmosphere, 2,4-diamino-6-methyl-1,3,5-triazine, hexamethylene diisocyanate and 1-methyl-2-pyrrolidone were mixed uniformly in a mass ratio of 1:10.7:0.4, reacted at 110°C and 300 r / min for 16 h, cooled naturally to room temperature, added with anhydrous chloroform (0.35 times the mass of hexamethylene diisocyanate), continued stirring for 2 h, slowly poured into the washing solution within 10 min, continued stirring for 50 min, filtered, washed with the washing solution for 5 times, and dried in vacuum at 60°C for 16 h to obtain a multi-hydrogen bond monomer;

[0071] (2) Under nitrogen atmosphere, a multi-hydrogen bond monomer, 2-amino-2-methyl-1,3-propanediol and anhydrous chloroform were mixed uniformly in a mass ratio of 1:0.26:9, and refluxed at 60°C and 300 r / min for 10 h. Anhydrous ethanol 0.15 times the mass of the multi-hydrogen bond monomer was added, and the reaction was continued for 10 h. The mixture was naturally cooled to room temperature, filtered, and the precipitated solid was dissolved with 2 times the mass of N,N-dimethylformamide. The mixture was then centrifuged at 12000 rpm for 15 min, and the supernatant was separated by filtration. Ether 2 times the mass of N,N-dimethylformamide was added to the supernatant, and the mixture was stirred at 200 r / min for 15 min. The mixture was allowed to stand for 6 h, filtered, washed with acetone 4 times, and dried in vacuo at 50°C for 10 h to obtain a multi-hydrogen bond chain extender.

[0072] (3) According to the mass percentage, 20 parts of polycarbonate diol and 30 parts of N,N-dimethylformamide were weighed and mixed evenly. Under a nitrogen atmosphere, the temperature was raised to 75°C, and 23.7 parts of isophorone diisocyanate were evenly added dropwise within 50 minutes. 0.47 parts of dibutyltin dilaurate were added, and the mixture was reacted at 350 r / min for 1.5 hours. After sampling to confirm the complete reaction, the temperature was lowered to 55°C, 3.81 parts of 3-dimethylamino-1,2-propylene glycol were added, and the mixture was reacted for 2 hours. After sampling to confirm the complete reaction, 1.73 parts of 2, 4-pentanedione dioxime, react at 80°C, 400r / min for 2h, take a sample to confirm the complete reaction, add 9.8 parts of multi-hydrogen bond chain extender, react at 70°C, 400r / min for 2h, add 5.3 parts of iodomethane, react at 30°C, 400r / min for 1.5h, remove N,N-dimethylformamide by vacuum distillation, add 130 parts of pure water, stir at 2000r / min for 40min, and obtain waterborne polyurethane emulsion;

[0073] (4) 15 parts of epoxy resin and 30 parts of propylene glycol monomethyl ether were mixed uniformly by weight, stirred at 80°C and 300 r / min for 30 min, and after the epoxy resin was completely dissolved, 0.93 parts of 2-aminoethylphosphonic acid were added, and the mixture was reacted at 90°C and 400 r / min for 2 h. 4.45 parts of 20 wt% ethylenediamine solution in propylene glycol monomethyl ether were added dropwise at 3 drops per second, and the mixture was reacted at 25°C and 300 r / min for 1 h. 40 parts of pure water were added at 55°C and 2400 r / min at 3 drops per second. After the addition was completed, the mixture was stirred for another 40 min, and the propylene glycol monomethyl ether was removed by vacuum distillation to obtain a waterborne epoxy emulsion.

[0074] (5) Mix the waterborne polyurethane emulsion and the waterborne epoxy emulsion in a mass ratio of 3:1, stir at 150 r / min for 20 min, add 1.5% of nano-titanium dioxide by mass of the waterborne epoxy emulsion and 4% of silane coupling agent by mass of the waterborne epoxy emulsion, stir at 150 r / min for 15 min, and then ultrasonicate for 1.5 h to obtain a polymer reinforced emulsion;

[0075] (6) By weight, 44 parts of Portland cement, 44 parts of rapid hardening sulphoaluminate cement, 12 parts of fly ash, 350 parts of sand, and 0.35 parts of water reducer were mixed evenly and stirred in a pot for 2 min. Then, 46.5 parts of polymer reinforced emulsion, 3.5 parts of curing agent, 3.3 parts of water, and 0.3 parts of defoaming agent were added and stirred for another 5 min to prepare cement mortar for road repair.

[0076] Comparative Example 1

[0077] A method for preparing cement mortar for road repair, the method comprising the following preparation steps:

[0078] (1) Under nitrogen atmosphere, 2,4-diamino-6-methyl-1,3,5-triazine, hexamethylene diisocyanate, and 1-methyl-2-pyrrolidone were mixed uniformly in a mass ratio of 1:10.1:0.35, reacted at 105°C and 250 r / min for 18 h, naturally cooled to room temperature, added with anhydrous chloroform (0.32 times the mass of hexamethylene diisocyanate), continued stirring for 1.8 h, slowly poured into the washing solution within 10 min, continued stirring for 45 min, filtered, washed with the washing solution for 4 times, and vacuum dried at 55°C for 18 h to obtain a multi-hydrogen bond monomer;

[0079] (2) Under nitrogen atmosphere, a multi-hydrogen bond monomer, 2-amino-2-methyl-1,3-propanediol and anhydrous chloroform were mixed in a mass ratio of 1:0.25:8.5, and refluxed at 60°C and 250 r / min for 11 h. Anhydrous ethanol (0.15 times the mass of the multi-hydrogen bond monomer) was added, and the reaction was continued for 9 h. The mixture was naturally cooled to room temperature and filtered. The precipitated solid was dissolved with 2 times the mass of N,N-dimethylformamide, and then centrifuged at 11000 rpm for 18 min. The supernatant was separated by filtration. Diethyl ether (2 times the mass of N,N-dimethylformamide) was added to the supernatant, stirred at 175 r / min for 18 min, allowed to stand for 5 h, filtered, washed with acetone 3 times, and vacuum dried at 45°C for 11 h to obtain a multi-hydrogen bond chain extender.

[0080] (3) By weight, 18 parts of polycarbonate diol and 27 parts of N,N-dimethylformamide were weighed and mixed evenly. Under a nitrogen atmosphere, the temperature was raised to 70°C, and 20.01 parts of isophorone diisocyanate were evenly added dropwise over 45 minutes. 0.4 parts of dibutyltin dilaurate were added, and the reaction was carried out at 300 r / min for 1.5 hours. After sampling to confirm the complete reaction, the temperature was lowered to 50°C, and 3.22 parts of 3-dimethylamino-1-butyltin dilaurate were added. ,2-propylene glycol, react for 1.5 hours, take a sample to confirm the complete reaction, add 11.03 parts of multi-hydrogen bond chain extender, react at 65°C, 350r / min for 2.5 hours, add 4.15 parts of iodomethane, react at 25°C, 350r / min for 1.5 hours, remove N,N-dimethylformamide by vacuum distillation, add 113 parts of pure water, stir at 1800r / min for 45 minutes, and obtain a waterborne polyurethane emulsion;

[0081] (4) By weight, 12 parts of epoxy resin and 25 parts of propylene glycol monomethyl ether were mixed evenly, stirred at 75°C and 250 r / min for 35 min, after the epoxy resin was completely dissolved, 0.83 parts of 2-aminoethylphosphonic acid were added, reacted at 85°C and 350 r / min for 2.5 h, 3.6 parts of 20 wt% ethylenediamine solution in propylene glycol monomethyl ether were added dropwise at 2 drops per second, reacted at 20°C and 250 r / min for 1.5 h, 32 parts of pure water were added at 55°C and 2200 r / min at 2 drops per second, stirred for 35 min after the addition was completed, and propylene glycol monomethyl ether was removed by vacuum distillation to obtain a water-based epoxy emulsion;

[0082] (5) Mix the aqueous polyurethane emulsion and the aqueous epoxy emulsion in a mass ratio of 2.8:1, stir at 150 r / min for 25 min, add 1.2% of the mass of the aqueous epoxy emulsion nano-titanium dioxide and 3.5% of the mass of the aqueous epoxy emulsion silane coupling agent, stir at 125 r / min for 18 min, and then ultrasonicate for 1.2 h to obtain a polymer reinforced emulsion;

[0083] (6) By weight, 54 parts of Portland cement, 36 parts of rapid hardening sulphoaluminate cement, 10 parts of fly ash, 300 parts of sand, and 0.3 parts of water reducer were mixed evenly and stirred in a pot for 1.5 min. Then, 42.6 parts of polymer reinforced emulsion, 3 parts of curing agent, 6.8 parts of water, and 0.2 parts of defoaming agent were added and stirred for another 4 min to prepare cement mortar for road repair.

[0084] Comparative Example 2

[0085] A method for preparing cement mortar for road repair, the method comprising the following preparation steps:

[0086] (1) By mass, weigh 18 parts of polycarbonate diol and 27 parts of N,N-dimethylformamide and mix them evenly. In a nitrogen atmosphere, heat to 70°C, evenly add 20.01 parts of isophorone diisocyanate and 0.4 parts of dibutyltin dilaurate in 45 minutes, and react at 300r / min for 1.5 hours. After sampling to confirm the complete reaction, cool to 50°C, add 3.49 parts of 3-dimethylamino-1,2-propylene glycol, and react for 1.5 hours. After sampling to confirm the complete reaction, add 2.64 parts of 2, 4-Pentanedione dioxime, react at 75°C, 350r / min for 2.5h, take a sample to confirm the complete reaction, add 4.47 parts of methyl iodide, react at 25°C, 350r / min for 1.5h, remove N,N-dimethylformamide by vacuum distillation, add 98 parts of pure water, stir at 1800r / min for 45min, and obtain a waterborne polyurethane emulsion;

[0087] (2) By weight, 12 parts of epoxy resin and 25 parts of propylene glycol monomethyl ether were mixed evenly, stirred at 75°C and 250 r / min for 35 min, after the epoxy resin was completely dissolved, 0.83 parts of 2-aminoethylphosphonic acid were added, reacted at 85°C and 350 r / min for 2.5 h, 3.6 parts of 20 wt% ethylenediamine solution of propylene glycol monomethyl ether were added dropwise at 2 drops per second, reacted at 20°C and 250 r / min for 1.5 h, 32 parts of pure water were added at 55°C and 2200 r / min at 2 drops per second, stirred for 35 min after the addition was completed, and propylene glycol monomethyl ether was removed by vacuum distillation to obtain a water-based epoxy emulsion;

[0088] (3) Mix the aqueous polyurethane emulsion and the aqueous epoxy emulsion in a mass ratio of 2.8:1, stir at 150 r / min for 25 min, add 1.2% of the mass of the aqueous epoxy emulsion nano-titanium dioxide and 3.5% of the mass of the aqueous epoxy emulsion silane coupling agent, stir at 125 r / min for 18 min, and then ultrasonicate for 1.2 h to obtain a polymer reinforced emulsion;

[0089] (4) By weight, 54 parts of Portland cement, 36 parts of rapid-hardening sulphoaluminate cement, 10 parts of fly ash, 300 parts of sand, and 0.3 parts of water reducer were mixed evenly and stirred in a pot for 1.5 min. Then, 42.6 parts of polymer reinforced emulsion, 3 parts of curing agent, 6.8 parts of water, and 0.2 parts of defoaming agent were added and stirred for another 4 min to prepare cement mortar for road repair.

[0090] Comparative Example 3

[0091] A method for preparing cement mortar for road repair, the method comprising the following preparation steps:

[0092] (1) By weight, 12 parts of epoxy resin and 25 parts of propylene glycol monomethyl ether were mixed evenly, stirred at 75°C and 250 r / min for 35 min, after the epoxy resin was completely dissolved, 0.83 parts of 2-aminoethylphosphonic acid were added, reacted at 85°C and 350 r / min for 2.5 h, 3.6 parts of 20wt% ethylenediamine propylene glycol monomethyl ether solution were added dropwise at 2 drops per second, reacted at 20°C and 250 r / min for 1.5 h, 32 parts of pure water were added at 55°C and 2200 r / min at 2 drops per second, stirred for 35 min after the addition was completed, and propylene glycol monomethyl ether was removed by vacuum distillation to obtain a water-based epoxy emulsion;

[0093] (2) The water-based epoxy emulsion, nano-titanium dioxide and silane coupling agent were mixed evenly in a mass ratio of 1:0.012:0.035, stirred at 125 r / min for 18 min at room temperature, and then ultrasonicated for 1.2 h to obtain a polymer-reinforced emulsion;

[0094] (3) By weight, 54 parts of Portland cement, 36 parts of rapid hardening sulphoaluminate cement, 10 parts of fly ash, 300 parts of sand, and 0.3 parts of water reducer were mixed evenly and stirred in a pot for 1.5 min. Then, 42.6 parts of polymer reinforced emulsion, 12.6 parts of curing agent, 6.8 parts of water, and 0.2 parts of defoaming agent were added and stirred for another 4 min to prepare cement mortar for road repair.

[0095] Comparative Example 4

[0096] A method for preparing cement mortar for road repair, the method comprising the following preparation steps:

[0097] (1) Under nitrogen atmosphere, 2,4-diamino-6-methyl-1,3,5-triazine, hexamethylene diisocyanate, and 1-methyl-2-pyrrolidone were mixed uniformly in a mass ratio of 1:10.1:0.35, reacted at 105°C and 250 r / min for 18 h, naturally cooled to room temperature, added with anhydrous chloroform (0.32 times the mass of hexamethylene diisocyanate), continued stirring for 1.8 h, slowly poured into the washing solution within 10 min, continued stirring for 45 min, filtered, washed with the washing solution for 4 times, and vacuum dried at 55°C for 18 h to obtain a multi-hydrogen bond monomer;

[0098] (2) Under nitrogen atmosphere, a multi-hydrogen bond monomer, 2-amino-2-methyl-1,3-propanediol and anhydrous chloroform were mixed in a mass ratio of 1:0.25:8.5, and refluxed at 60°C and 250 r / min for 11 h. Anhydrous ethanol (0.15 times the mass of the multi-hydrogen bond monomer) was added, and the reaction was continued for 9 h. The mixture was naturally cooled to room temperature and filtered. The precipitated solid was dissolved with 2 times the mass of N,N-dimethylformamide, and then centrifuged at 11000 rpm for 18 min. The supernatant was separated by filtration. Diethyl ether (2 times the mass of N,N-dimethylformamide) was added to the supernatant, stirred at 175 r / min for 18 min, allowed to stand for 5 h, filtered, washed with acetone 3 times, and vacuum dried at 45°C for 11 h to obtain a multi-hydrogen bond chain extender.

[0099] (3) By mass, weigh 18 parts of polycarbonate diol and 27 parts of N,N-dimethylformamide and mix them evenly. In a nitrogen atmosphere, heat to 70°C, evenly add 22.86 parts of isophorone diisocyanate and 0.45 parts of dibutyltin dilaurate in 45 minutes, and react at 300r / min for 1.5 hours. After sampling to confirm the complete reaction, cool to 50°C, add 3.37 parts of 3-dimethylamino-1,2-propylene glycol, and react for 1.5 hours. After sampling to confirm the complete reaction, add 2.34 parts of 2, 4-pentanedione dioxime, react at 75°C, 350r / min for 2.5h, take a sample to confirm the complete reaction, add 6.3 parts of multi-hydrogen bond chain extender, react at 65°C, 350r / min for 2.5h, add 4.4 parts of iodomethane, react at 25°C, 350r / min for 1.5h, remove N,N-dimethylformamide by vacuum distillation, add 115 parts of pure water, stir at 1800r / min for 45min, and obtain waterborne polyurethane emulsion;

[0100] (4) The aqueous polyurethane emulsion, nano-titanium dioxide and silane coupling agent were mixed uniformly in a mass ratio of 1:0.008:0.015, stirred at 125 r / min for 18 min at room temperature, and then ultrasonicated for 1.2 h to obtain a polymer-enhanced emulsion;

[0101] (5) By weight, 54 parts of Portland cement, 36 parts of rapid hardening sulphoaluminate cement, 10 parts of fly ash, 300 parts of sand, and 0.3 parts of water reducer were mixed evenly and stirred in a pot for 1.5 min. Then, 42.6 parts of polymer reinforced emulsion, 6.8 parts of water, and 0.2 parts of defoamer were added and stirred for another 4 min to prepare cement mortar for road repair.

[0102] Comparative Example 5

[0103] A method for preparing cement mortar for road repair, the method comprising the following preparation steps:

[0104] (1) Under nitrogen atmosphere, 2,4-diamino-6-methyl-1,3,5-triazine, hexamethylene diisocyanate, and 1-methyl-2-pyrrolidone were mixed uniformly in a mass ratio of 1:10.1:0.35, reacted at 105°C and 250 r / min for 18 h, naturally cooled to room temperature, added with anhydrous chloroform (0.32 times the mass of hexamethylene diisocyanate), continued stirring for 1.8 h, slowly poured into the washing solution within 10 min, continued stirring for 45 min, filtered, washed with the washing solution for 4 times, and vacuum dried at 55°C for 18 h to obtain a multi-hydrogen bond monomer;

[0105] (2) Under nitrogen atmosphere, a multi-hydrogen bond monomer, 2-amino-2-methyl-1,3-propanediol and anhydrous chloroform were mixed in a mass ratio of 1:0.25:8.5, and refluxed at 60°C and 250 r / min for 11 h. Anhydrous ethanol (0.15 times the mass of the multi-hydrogen bond monomer) was added, and the reaction was continued for 9 h. The mixture was naturally cooled to room temperature and filtered. The precipitated solid was dissolved with 2 times the mass of N,N-dimethylformamide, and then centrifuged at 11000 rpm for 18 min. The supernatant was separated by filtration. Diethyl ether (2 times the mass of N,N-dimethylformamide) was added to the supernatant, stirred at 175 r / min for 18 min, allowed to stand for 5 h, filtered, washed with acetone 3 times, and vacuum dried at 45°C for 11 h to obtain a multi-hydrogen bond chain extender.

[0106] (3) By mass, weigh 18 parts of polycarbonate diol and 27 parts of N,N-dimethylformamide and mix them evenly. In a nitrogen atmosphere, heat to 70°C, evenly add 22.86 parts of isophorone diisocyanate and 0.45 parts of dibutyltin dilaurate in 45 minutes, and react at 300r / min for 1.5 hours. After sampling to confirm the complete reaction, cool to 50°C, add 3.37 parts of 3-dimethylamino-1,2-propylene glycol, and react for 1.5 hours. After sampling to confirm the complete reaction, add 2.34 parts of 2, 4-pentanedione dioxime, react at 75°C, 350r / min for 2.5h, take a sample to confirm the complete reaction, add 6.3 parts of multi-hydrogen bond chain extender, react at 65°C, 350r / min for 2.5h, add 4.4 parts of iodomethane, react at 25°C, 350r / min for 1.5h, remove N,N-dimethylformamide by vacuum distillation, add 115 parts of pure water, stir at 1800r / min for 45min, and obtain waterborne polyurethane emulsion;

[0107] (4) By weight, 12 parts of epoxy resin and 25 parts of propylene glycol monomethyl ether were mixed evenly, stirred at 75°C and 250 r / min for 35 min, after the epoxy resin was completely dissolved, 0.83 parts of 2-aminoethylphosphonic acid were added, reacted at 85°C and 350 r / min for 2.5 h, 3.6 parts of 20 wt% ethylenediamine solution in propylene glycol monomethyl ether were added dropwise at 2 drops per second, reacted at 20°C and 250 r / min for 1.5 h, 32 parts of pure water were added at 55°C and 2200 r / min at 2 drops per second, stirred for 35 min after the addition was completed, and propylene glycol monomethyl ether was removed by vacuum distillation to obtain a water-based epoxy emulsion;

[0108] (5) Mix the aqueous polyurethane emulsion and the aqueous epoxy emulsion in a mass ratio of 2.8:1, stir at 150 r / min for 25 min, add 1.2% of the mass of the aqueous epoxy emulsion nano-titanium dioxide and 3.5% of the mass of the aqueous epoxy emulsion silane coupling agent, stir at 125 r / min for 18 min, and then ultrasonicate for 1.2 h to obtain a polymer reinforced emulsion;

[0109] (6) By weight, 60 parts of Portland cement, 40 parts of rapid-hardening sulphoaluminate cement, 300 parts of sand, and 0.3 parts of a water reducer were mixed evenly and stirred in a pot for 1.5 min. Then, 42.6 parts of a polymer-enhanced emulsion, 3 parts of a curing agent, 6.8 parts of water, and 0.2 parts of a defoaming agent were added and stirred for another 4 min to prepare cement mortar for road repair.

[0110] Test Example 1

[0111] Setting time test: The setting time of the prepared cement mortar is tested according to the setting time test method in DL / T 5126-2021. The mixing of cement mortar is also carried out according to the mixing method in DL / T 5126-2021. The test results are recorded based on the time when the penetration resistance value reaches 0.5MPa.

[0112] The results are shown in Table 1.

[0113] Table 1

[0114]

[0115] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 1, it can be found that the cement mortar for road repair prepared by the present invention has a faster setting speed.

[0116] By comparing the data in the table, it can be seen that the addition of dioxime groups, multiple hydrogen bonds, water-based polyurethane emulsion, water-based epoxy emulsion and fly ash all promotes the shortening of setting time, accelerates the setting of cement and reduces the construction time.

[0117] Test Example 2

[0118] Mechanical properties test: The prepared cement mortar for road repair was formed and cured in accordance with DL / T 5126-2021 to make specimens. The flexural strength, compressive strength and bonding strength of the prepared specimens were tested in accordance with the flexural strength and compressive strength tests and the mortar base bonding tensile strength test in DL / T 5126-2021. The test mold was a triple mold of 40mm×40mm×160mm. The specimens were divided into three groups: cured for 6h, 1 day and 28 days. The specimens for 6h and 1 day were cured with moisture, and the specimens for 28 days were first cured with moisture for 7 days and then dry cured for 21 days. The curing conditions were carried out in accordance with DL / T 5126-2021. Each group of specimens was tested 5 times and the average value was taken. The test results were recorded.

[0119] The results are shown in Table 2.

[0120] Table 2

[0121]

[0122] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 2, it can be found that the cement mortar for road repair prepared by the present invention has good early strength, and the later strength does not shrink but continues to increase.

[0123] By comparing the data in the table, the introduction of dioxime groups and multiple hydrogen bonds has improved the strength. The compounding of waterborne polyurethane emulsion and waterborne epoxy emulsion has also effectively improved the strength. The addition of fly ash has also significantly improved the flexural and compressive strength.

[0124] Test Example 3

[0125] Corrosion resistance test: Prepare the specimens according to the method of Test Example 2 and cure for 28 days. Immerse the specimens in 10% sulfuric acid solution and 10% sodium chloride solution respectively. Change the immersion solution every 7 days. Record the flexural strength of the specimens after immersion for 21 days. Test 5 specimens for each group of specimens and record the average value data.

[0126] The results are shown in Table 3.

[0127] Table 3

[0128]

[0129] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 3, it can be found that the cement mortar for road repair prepared by the present invention has good corrosion resistance.

[0130] By comparing the data in the table, the compounding of waterborne polyurethane emulsion and waterborne epoxy emulsion can effectively resist salt corrosion and improve the resistance to acid corrosion.

[0131] Test Example 4

[0132] Self-repairing performance test: The cracks of the mortar specimens were prefabricated according to the following steps. First, a 200 mm × 200 mm × 5 mm mold was placed on the insulation board, and then the crack induction device was inserted into both sides of the mold. The height of the crack induction device was about 2 / 3 of the height of the mold to make a simple crack induction device. Then the prepared cement mortar for road repair was poured into the mold and smoothed. Finally, a fan was placed near the mold with a wind speed of about 3m / s. After cracks appeared in the mortar, the blowing was stopped. After measuring the initial crack width, the specimen and the mold were placed in a standard curing room for curing. The temperature and relative humidity were controlled at 20±2℃ and 95±5%, respectively. The cracks prefabricated by the flat plate cracking method were surface cracks with a width of about 0.10~0.60mm and a depth of only 3~5mm. Crack measurements were carried out before and after 21 days of curing, and the surface crack width was measured using the Botest PTS-E40 crack comprehensive width gauge. The self-repairing performance of the prepared cement mortar for road repair was evaluated by the change in crack width. The cracks were divided into three groups: 0.1~0.3mm, 0.3~0.5mm, and 0.5~0.6mm, and the remaining widths of the cracks were recorded separately.

[0133] The results are shown in Table 4.

[0134] Table 4

[0135]

[0136] From the comparison of the experimental data of Examples 1 to 3 and Comparative Examples 1 to 5 in Table 4, it can be found that the cement mortar for road repair prepared by the present invention has good self-repairing performance.

[0137] By comparing the data in the table, the introduction of dioxime groups and multiple hydrogen bonds improves the self-healing efficiency. The ionic bonds of waterborne polyurethane emulsion and waterborne epoxy emulsion help the complex migration of calcium ions. The addition of fly ash accelerates this process, making it possible to repair cracks of larger widths in a short time.

[0138] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A cement mortar for road repair, characterized in that: The cement mortar for road repair is prepared by first preparing a multi-hydrogen bond chain extender, then preparing an aqueous polyurethane emulsion and an aqueous epoxy emulsion; mixing the aqueous polyurethane emulsion and the aqueous epoxy emulsion, and then adding nano titanium dioxide and a silane coupling agent to prepare a polymer reinforced emulsion; mixing and stirring silicate cement, fast-hardening sulphoaluminate cement, fly ash, a polymer reinforced emulsion, a curing agent, water, a defoamer, and a water reducing agent to prepare the cement mortar for road repair; The multi-hydrogen bond chain extender is prepared by first reacting 2,4-diamino-6-methyl-1,3,5-triazine with diisocyanate, and then reacting with 2-amino-2-methyl-1,3-propanediol and ethanol; The waterborne polyurethane emulsion is prepared by reacting isophorone diisocyanate with polycarbonate diol, 3-dimethylamino-1,2-propylene glycol, 2, 4-pentanedione dioxime, a multi-hydrogen bond chain extender, and a haloalkane, and then emulsifying with water. The water-based epoxy emulsion is prepared by reacting epoxy resin with 2-aminoethylphosphonic acid and diethylamine, and then adding water for emulsification; The cement mortar for road repair comprises the following components in parts by weight: 20-80 parts of silicate cement, 10-70 parts of rapid hardening sulphoaluminate cement, 5-20 parts of fly ash, 250-400 parts of sand, 30-50 parts of polymer enhanced emulsion, 1-5 parts of curing agent, 2-15 parts of water, 0.1-1 parts of defoaming agent and 0.1-1 parts of water reducing agent.

2. The cement mortar for road repair according to claim 1, characterized in that: The diisocyanate is one of m-phenylene diisocyanate, p-phenylene diisocyanate, toluene diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

3. The cement mortar for road repair according to claim 1, characterized in that: The alkyl halide is one of methyl iodide, methyl bromide and methyl chloride.

4. The cement mortar for road repair according to claim 1, characterized in that: The epoxy resin is bisphenol A type epoxy resin.

5. A method for preparing cement mortar for road repair, characterized in that: The method comprises the following preparation steps: (1) According to the mass percentage, weigh 15-20 parts of polycarbonate diol and 25-30 parts of N,N-dimethylformamide and mix them evenly. In a nitrogen atmosphere, heat to 70-75°C, evenly add 16.6-23.7 parts of isophorone diisocyanate dropwise over 40-50 minutes, add 0.33-0.47 parts of dibutyltin dilaurate, and react at 250-350 r / min for 1.5-2 hours. After sampling to confirm the complete reaction, cool to 50-55°C, add 2.23-3.81 parts of 3-dimethylamino-1,2-propylene glycol, and react for 1.5-2 hours. After sampling to confirm the complete reaction, add 1.46-2.34 parts of 2, 4-pentanedione dioxime, react at 70-80°C, 300-400 r / min for 2-3 hours, take a sample to confirm the complete reaction, add 4.6-9.8 parts of multi-hydrogen bond chain extender, react at 60-70°C, 300-400 r / min for 2-3 hours, add 3.2-5.3 parts of alkyl halide, react at 25-30°C, 300-400 r / min for 1.5-2 hours, remove N,N-dimethylformamide by vacuum distillation, add 85-130 parts of pure water, stir at 1500-2000 r / min for 40-50 minutes, and prepare waterborne polyurethane emulsion; (2) By weight, 10-15 parts of epoxy resin and 20-30 parts of propylene glycol monomethyl ether were mixed evenly, stirred at 70-80°C and 200-300 r / min for 30-40 min, after the epoxy resin was completely dissolved, 0.79-0.93 parts of 2-aminoethylphosphonic acid were added, reacted at 80-90°C and 300-400 r / min for 2-3 h, 2.86-4.45 parts of 20 wt% ethylenediamine solution in propylene glycol monomethyl ether were added dropwise at 2-3 drops per second, reacted at 15-25°C and 200-300 r / min for 1-2 h, 27-40 parts of pure water were added at 55°C and 2000-2400 r / min at 2-3 drops per second, stirred for 30-40 min after the addition was completed, and propylene glycol monomethyl ether was removed by vacuum distillation to obtain a waterborne epoxy emulsion; (3) Mix the aqueous polyurethane emulsion and the aqueous epoxy emulsion in a mass ratio of (2.5-3):1, stir at 100-150 r / min for 20-30 min, add 1-1.5% of the mass of the aqueous epoxy emulsion nano-titanium dioxide and 3-4% of the mass of the aqueous epoxy emulsion silane coupling agent, stir at 100-150 r / min for 15-20 min, and then ultrasonicate for 1-1.5 h to obtain a polymer reinforced emulsion; (4) By weight, 20-80 parts of Portland cement, 10-70 parts of rapid hardening sulphoaluminate cement, 5-20 parts of fly ash, 250-400 parts of sand, and 0.1-1 part of water reducer are mixed evenly, stirred in a pot for 1-2 minutes, 30-50 parts of polymer enhanced emulsion, 1-5 parts of curing agent, 2-15 parts of water, and 0.1-1 part of defoaming agent are added, and stirred for another 3 minutes to prepare cement mortar for road repair; The multi-hydrogen bond chain extender in step (1) comprises the following preparation steps: (A) Under nitrogen atmosphere, 2,4-diamino-6-methyl-1,3,5-triazine, hexamethylene diisocyanate and 1-methyl-2-pyrrolidone were mixed uniformly in a mass ratio of 1:(9.4-10.7):(0.3-0.4), reacted at 100-110°C and 200-300 r / min for 16-20 h, cooled naturally to room temperature, added anhydrous chloroform (0.3-0.35 times the mass of hexamethylene diisocyanate), continued stirring for 1.5-2 h, slowly poured into the washing solution within 10 min, continued stirring for 40-50 min, filtered, washed with the washing solution for 3-5 times, and vacuum dried at 50-60°C for 16-20 h to obtain a multi-hydrogen bond monomer; (B) Under nitrogen atmosphere, a multi-hydrogen bond monomer, 2-amino-2-methyl-1,3-propanediol and anhydrous chloroform are mixed uniformly in a mass ratio of 1:(0.24-0.26):(8-9), and refluxed at 60°C and 200-300 r / min for 10-12 h. Anhydrous ethanol in an amount of 0.15 times the mass of the multi-hydrogen bond monomer is added, and the reaction is continued for 8-10 h. The mixture is naturally cooled to room temperature and filtered. The precipitated solid is dissolved with 2 times the mass of N,N-dimethylformamide, and then centrifuged at 10000-12000 rpm for 15-20 min. The supernatant is separated by filtration. Diethyl ether in an amount of 2 times the mass of N,N-dimethylformamide is added to the supernatant, and the mixture is stirred at 150-200 r / min for 15-20 min. The mixture is allowed to stand for 4-6 h, filtered, washed with acetone for 3-4 times, and vacuum dried at 40-50°C for 10-12 h to prepare a multi-hydrogen bond chain extender.

6. The method for preparing cement mortar for road repair according to claim 5, characterized in that: The silane coupling agent in step (3) is one of KH550 and KH792.

7. The method for preparing cement mortar for road repair according to claim 5, characterized in that: The washing solution in step (A) is prepared by mixing n-heptane and isopropyl ether in a volume ratio of 6:1.

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