A method for preparing high-strength concrete

Abstract

The present invention relates to the technical field of concrete, and discloses a method for preparing high-strength concrete, wherein epoxy resin emulsion, cationic emulsified asphalt, aminopropyl acrylamide cardanol polystyrene, etc. are added to water, sheared and dispersed, cement, sand, fly ash, etc. are then added, stirred and mixed, vibrated and degassed, and cured and maintained to obtain high-strength concrete. The aminopropyl acrylamide cardanol polystyrene of the present invention contains an active imine group, which can undergo a curing and cross-linking reaction with epoxy resin, and has a good reinforcing and reinforcing effect, and contains an alkenyl group at the same time, which can undergo a cross-linking reaction with the unsaturated double bonds of asphalt at high temperature, so that the aminopropyl acrylamide cardanol polystyrene improves the compatibility between epoxy resin and cationic emulsified asphalt, improves the mechanical properties of epoxy asphalt concrete, and shows higher axial compressive strength and compressive elastic modulus.

Description

Technical Field

[0001] The invention relates to the technical field of concrete, in particular to a method for preparing high-strength concrete. Background Art

[0002] With the rapid development of my country's transportation infrastructure construction, the demand for concrete is getting higher and higher, and higher requirements are also put forward for the performance of concrete. Adding admixtures such as epoxy resin, asphalt, rubber powder, steel fiber, inorganic nanofiller, etc. to concrete can obtain epoxy asphalt concrete, rubber concrete, etc. with better performance.

[0003] Epoxy asphalt has high mechanical strength, durability, wear resistance, anti-corrosion and waterproof properties, and is widely used in concrete binders, roads, bridges, tunnels and other construction fields. The patent with announcement number CN111825388B discloses that modified asphalt, bisphenol A epoxy resin, curing agent, polyurethane prepolymer, and compatibilizer are reacted to make modified epoxy asphalt, and then the modified epoxy asphalt concrete made with sand, cement, lignin and other raw materials has the advantages of high flexibility and low pollution, but the patent requires the additional addition of curing agent and compatibilizer, and does not improve the compressive strength and modulus of epoxy asphalt concrete. Summary of the invention

[0004] (I) Technical problem to be solved: The present invention provides an epoxy asphalt concrete with high compressive strength and high modulus.

[0005] (II) Technical solution: A method for preparing high-strength concrete:

[0006] Step (1), adding chloromethyl polystyrene to N,N-dimethylformamide, adding cardanol and a catalyst after stirring, pouring the solution into ethanol after the reaction, filtering, washing with ethanol and water in sequence, and drying to obtain cardanol-based polystyrene.

[0007] Step (2), add cardanol polystyrene to dichloromethane, add m-chloroperbenzoic acid after stirring, distill under reduced pressure after the reaction, wash with ethanol and water in turn, and dry to obtain epoxy cardanol polystyrene. The reaction formula is:

[0008] .

[0009] Step (3), add epoxy cardanol polystyrene, N-(3-aminopropyl) methacrylamide hydrochloride, and triethylamine to N,N-dimethylformamide, pour the solution into ethanol after the reaction, filter, wash with water and ethanol in turn, and dry to obtain aminopropyl acrylamide cardanol polystyrene. The reaction formula is:

[0010] .

[0011] Step (4), adding 26-40 parts by weight of epoxy resin emulsion, 60-110 parts by weight of cationic emulsified asphalt, 4.5-13.2 parts by weight of aminopropyl acrylamide cardanol polystyrene, and 0.1-0.3 parts by weight of silicone defoamer to 180-200 parts by weight of water, shearing and dispersing, then adding 230-290 parts by weight of cement, 730-800 parts by weight of sand, 1000 parts by weight of gravel, 44-54 parts by weight of fly ash, 60-76 parts by weight of slag powder, and 4.5-5.2 parts by weight of polycarboxylate water reducer, stirring and mixing, vibrating and degassing, first curing at 80-90° C. for 2-3 hours, then curing at 120-130° C. for 4-6 hours, and curing to obtain high-strength concrete.

[0012] Preferably, in step (1), the amount of chloromethyl polystyrene is 100 parts by weight, the amount of cardanol is 60-76 parts by weight, and the amount of the catalyst is 18-22 parts by weight. The catalyst is sodium hydroxide or potassium hydroxide.

[0013] Preferably, the reaction in step (1) is carried out at 70-100° C. for 12-18 h.

[0014] Preferably, in step (2), the amount of cardanol-based polystyrene used is 100 parts by weight, and the amount of m-chloroperbenzoic acid used is 20-24 parts by weight.

[0015] Preferably, the reaction in step (2) is carried out at 0-5°C for 5-7h.

[0016] Preferably, in step (3), the amount of epoxy cardanol polystyrene used is 100 parts by weight, the amount of N-(3-aminopropyl) methacrylamide hydrochloride used is 35-42 parts by weight, and the amount of triethylamine used is 21-26 parts by weight.

[0017] Preferably, the reaction in step (3) is carried out at 40-50° C. for 6-10 h.

[0018] (III) Technical effect: The present invention reacts chloromethyl polystyrene with the phenolic hydroxyl group of cardanol to obtain cardanol-based polystyrene, and then uses meta-chloroperbenzoic acid as an oxidant to oxidize the unsaturated olefin group of cardanol into an epoxy group, which is then subjected to a ring-opening reaction with the imino group of N-(3-aminopropyl) methacrylamide hydrochloride to obtain aminopropyl acrylamide cardanol-based polystyrene containing an imino group and an alkenyl group.

[0019] The present invention uses cement, sand, slag powder, fly ash, epoxy resin, cationic emulsified asphalt and the like as main raw materials of concrete, and uses aminopropyl acrylamide cardanol-based polystyrene as a curing agent for the epoxy resin. The aminopropyl acrylamide cardanol-based polystyrene contains an active imine group and can undergo a curing and cross-linking reaction with the epoxy resin, thereby bonding the rigid polystyrene molecular chain and the flexible alkyl long chain of cardanol to the epoxy resin molecular chain, thus playing a good reinforcing and strengthening role. The present invention also contains an alkenyl group and can undergo a cross-linking reaction with the unsaturated double bonds of asphalt at high temperature to generate a strong covalent bond, so that the aminopropyl acrylamide cardanol-based polystyrene can play the role of a bridging agent and a compatibilizer, thereby improving the compatibility between the epoxy resin and the cationic emulsified asphalt, further improving the mechanical properties of the epoxy asphalt concrete, and showing higher axial compressive strength and compressive elastic modulus. DETAILED DESCRIPTION

[0020] The following examples are only used to illustrate the embodiments of the present invention and do not constitute any limitation to the present invention. Those skilled in the art will appreciate that various modifications may be made without departing from the spirit and scope of the present invention, and these modifications all fall within the scope of protection of the present invention.

[0021] The epoxy resin emulsion of the present invention, model EP355, Jining Sunbright Biotechnology Co., Ltd. Cationic emulsified asphalt, model 90#, Hebei Dezhishan Petrochemical Co., Ltd. Chloromethyl polystyrene, CAS registration number 55844-94-5, Hubei Yunmei Technology Co., Ltd. Polycarboxylic acid water reducer, model Sika 540P, Shanghai Hengchuang Chemical Co., Ltd. Cement is 42.5 silicate cement. The average particle size of sand is 70 mesh, and the stone is crushed stone with an average particle size of 30 mm. The average particle size of fly ash is 200 mesh. Slag powder is S95 grade slag powder.

[0022] Example 1: (1) Add 50 g of chloromethyl polystyrene to 700 mL of N,N-dimethylformamide, stir, then add 33 g of cardanol and 9.6 g of potassium hydroxide as a catalyst, stir and react at 90°C for 12 h, pour the solution into ethanol, filter, wash with ethanol and water in turn, and dry to obtain cardanol-based polystyrene.

[0023] (2) Add 80 g of cardanol-based polystyrene to 800 mL of dichloromethane, stir, then add 17.4 g of m-chloroperbenzoic acid, stir and react at 0°C for 7 h, distill under reduced pressure, wash with ethanol and water in turn, and dry to obtain epoxy cardanol-based polystyrene.

[0024] (3) Add 100 g of epoxy cardanol polystyrene, 38 g of N-(3-aminopropyl) methacrylamide hydrochloride, and 23 g of triethylamine to 1.2 L of N,N-dimethylformamide, and stir to react at 40 °C for 10 h. Pour the solution into ethanol, filter, wash with water and ethanol in turn, and dry to obtain aminopropyl acrylamide cardanol polystyrene.

[0025] (4) Add 310g of epoxy resin emulsion, 0.75kg of cationic emulsified asphalt, 72g of aminopropyl acrylamide cardanol polystyrene, and 2g of silicone defoamer TEGO810 to 1.8kg of water, shear and disperse, then add 2.3kg of cement, 7.5kg of sand, 10kg of gravel, 480g of fly ash, 750g of slag powder, and 45g of polycarboxylic acid water reducer, stir and mix, vibrate to degas, first cure at 90℃ for 2h, then cure at 120℃ for 6h, and cure at room temperature for 7-21 days to obtain high-strength concrete.

[0026] Example 2: (1) Add 50 g of chloromethyl polystyrene to 800 mL of N,N-dimethylformamide, stir, then add 38 g of cardanol and 11 g of potassium hydroxide catalyst, stir and react at 70°C for 18 h, pour the solution into ethanol, filter, wash with ethanol and water in turn, and dry to obtain cardanol-based polystyrene.

[0027] (2) Add 80 g of cardanol-based polystyrene to 800 mL of dichloromethane, stir, then add 19.2 g of m-chloroperbenzoic acid, stir and react at 5°C for 5 h, distill under reduced pressure, wash with ethanol and water in turn, and dry to obtain epoxy cardanol-based polystyrene.

[0028] (3) Add 100 g of epoxy cardanol polystyrene, 42 g of N-(3-aminopropyl) methacrylamide hydrochloride, and 26 g of triethylamine to 1.5 L of N,N-dimethylformamide, and stir at 50 °C for 6 h. Pour the solution into ethanol, filter, wash with water and ethanol in turn, and dry to obtain aminopropyl acrylamide cardanol polystyrene.

[0029] (4) Add 260g of epoxy resin emulsion, 0.6kg of cationic emulsified asphalt, 45g of aminopropyl acrylamide cardanol polystyrene, and 1g of silicone defoamer TEGO810 to 2kg of water, shear and disperse, then add 2.7kg of cement, 8kg of sand, 10kg of gravel, 540g of fly ash, 660g of slag powder, and 45g of polycarboxylic acid water reducer, stir and mix, vibrate to degas, first cure at 90℃ for 2h, then cure at 130℃ for 4h, and cure at room temperature for 7-21 days to obtain high-strength concrete.

[0030] Example 3: (1) Add 50 g of chloromethyl polystyrene to 600 mL of N,N-dimethylformamide, stir, add 30 g of cardanol and 9 g of catalyst sodium hydroxide, stir and react at 100°C for 12 h, pour the solution into ethanol, filter, wash with ethanol and water in turn, and dry to obtain cardanol-based polystyrene.

[0031] (2) Add 80 g of cardanol-based polystyrene to 800 mL of dichloromethane, stir, then add 16 g of m-chloroperbenzoic acid, stir and react at 0°C for 5 h, distill under reduced pressure, wash with ethanol and water in turn, and dry to obtain epoxy cardanol-based polystyrene.

[0032] (3) Add 100 g of epoxy cardanol polystyrene, 35 g of N-(3-aminopropyl) methacrylamide hydrochloride, and 21 g of triethylamine to 1.2 L of N,N-dimethylformamide, and stir the mixture at 45 °C for 6 h. Pour the solution into ethanol, filter, wash with water and ethanol, and dry to obtain aminopropyl acrylamide cardanol polystyrene.

[0033] (4) Add 400g of epoxy resin emulsion, 1.1kg of cationic emulsified asphalt, 132g of aminopropyl acrylamide cardanol polystyrene, and 3g of silicone defoamer TEGO810 to 2kg of water, shear and disperse, then add 2.9kg of cement, 7.3kg of sand, 10kg of gravel, 440g of fly ash, 600g of slag powder, and 50g of polycarboxylic acid water reducer, stir and mix, vibrate to degas, first cure at 80℃ for 3h, then cure at 130℃ for 5h, and cure at room temperature for 7-21 days to obtain high-strength concrete.

[0034] Embodiment 4:

[0035] (1) Add 360 g of epoxy resin emulsion, 0.9 kg of cationic emulsified asphalt, 98 g of aminopropyl acrylamide cardanol polystyrene (prepared in Example 1), and 2 g of silicone defoamer TEGO810 to 1.8 kg of water, and disperse by shearing. Then add 2.6 kg of cement, 7.8 kg of sand, 10 kg of gravel, 510 g of fly ash, 720 g of slag powder, and 52 g of polycarboxylic acid water reducer, stir and mix, vibrate to degas, first cure at 80 ° C for 3 h, then cure at 120 ° C for 6 h, and cure at room temperature for 7-21 days to obtain high-strength concrete.

[0036] Comparative Example 1: (1) Add 260 g of epoxy resin emulsion, 0.75 kg of cationic emulsified asphalt, 72 g of cardanol-based polystyrene (prepared in Example 1), and 2 g of silicone defoamer TEGO810 to 1.8 kg of water, shear and disperse, then add 2.3 kg of cement, 7.5 kg of sand, 10 kg of gravel, 480 g of fly ash, 750 g of slag powder, and 45 g of polycarboxylic acid water reducer, stir and mix, vibrate to degas, first cure at 90 ° C for 2 h, then cure at 120 ° C for 6 h, and cure at room temperature for 7-21 days to obtain high-strength concrete.

[0037] Comparative Example 2: (1) Add 260 g of epoxy resin emulsion, 0.75 kg of cationic emulsified asphalt, 72 g of epoxy cardanol polystyrene (prepared by Example 1), and 2 g of silicone defoamer TEGO810 to 1.8 kg of water, shear and disperse, then add 2.3 kg of cement, 7.5 kg of sand, 10 kg of gravel, 480 g of fly ash, 750 g of slag powder, and 45 g of polycarboxylic acid water reducer, stir and mix, vibrate to degas, first cure at 90 ° C for 2 h, then cure at 120 ° C for 6 h, and cure at room temperature for 7-21 days to obtain high-strength concrete.

[0038] Comparative Example 3: (1) Add 260 g of epoxy resin emulsion, 0.75 kg of cationic emulsified asphalt, 72 g of polyetheramine D230 curing agent (prepared by Example 1), and 2 g of silicone defoaming agent TEGO810 to 1.8 kg of water, shear and disperse, then add 2.3 kg of cement, 7.5 kg of sand, 10 kg of gravel, 480 g of fly ash, 750 g of slag powder, and 45 g of polycarboxylic acid water reducer, stir and mix, vibrate to degas, first cure at 90°C for 2 h, then cure at 120°C for 6 h, and cure at room temperature for 7-21 days to obtain high-strength concrete.

[0039] The axial compressive strength and compressive elastic modulus of concrete prisms were tested according to JTG E30-2005 method.

[0040] Table 1 Mechanical properties of concrete

[0041]

[0042] After testing, each embodiment uses aminopropyl acrylamide cardanol-based polystyrene as a curing agent for epoxy resin, which also plays a role in increasing the volume of epoxy resin and asphalt. The obtained epoxy resin concrete has higher axial compressive strength and compressive elastic modulus.

[0043] The cardanol-based polystyrene and epoxy cardanol-based polystyrene of Comparative Examples 1 and 2 do not contain imino groups and alkenyl groups, and cannot be used as curing agents and compatibilizers for epoxy resins. The axial compressive strength and compressive elastic modulus of the obtained concrete are both very low.

[0044] In Comparative Example 3, conventional polyetheramine D230 is used as a curing agent, which is unable to increase the volume of epoxy resin and asphalt, and the axial compressive strength and compressive elastic modulus of the obtained epoxy asphalt concrete are low.

[0045] The present invention is not limited to the above-mentioned embodiments. Without departing from the essential content of the present invention, any deformation, improvement and substitution that can be thought of by those skilled in the art shall fall within the scope of the present invention.

Claims

1. A method for preparing high-strength concrete, characterized in that: The preparation method is: Step (1), adding chloromethyl polystyrene to N,N-dimethylformamide, adding cardanol and a catalyst after stirring, pouring the solution into ethanol after the reaction, filtering, washing, and drying to obtain cardanol-based polystyrene; Step (2), adding cardanol-based polystyrene to dichloromethane, adding m-chloroperbenzoic acid after stirring, distilling under reduced pressure after the reaction, washing, and drying to obtain epoxy cardanol-based polystyrene; Step (3), adding epoxy cardanol polystyrene, N-(3-aminopropyl) methacrylamide hydrochloride, and triethylamine to N,N-dimethylformamide, and after the reaction, pouring the solution into ethanol, filtering, washing, and drying to obtain aminopropyl acrylamide cardanol polystyrene; Step (4), adding 26-40 parts by weight of epoxy resin emulsion, 60-110 parts by weight of cationic emulsified asphalt, 4.5-13.2 parts by weight of aminopropyl acrylamide cardanol polystyrene, and 0.1-0.3 parts by weight of defoamer to 180-200 parts by weight of water, shearing and dispersing, and then adding 230-290 parts by weight of cement, 730-800 parts by weight of sand, 1000 parts by weight of gravel, 44-54 parts by weight of fly ash, 60-76 parts by weight of slag powder, and 4.5-5.2 parts by weight of water reducing agent, stirring and mixing, vibrating to degas, curing after solidification, and obtaining high-strength concrete; In the step (1), the amount of chloromethyl polystyrene used is 100 parts by weight, the amount of cardanol used is 60-76 parts by weight, and the amount of the catalyst used is 18-22 parts by weight; In the step (2), the amount of cardanol-based polystyrene used is 100 parts by weight, and the amount of m-chloroperbenzoic acid used is 20-24 parts by weight; In the step (3), the amount of epoxy cardanol polystyrene used is 100 parts by weight, the amount of N-(3-aminopropyl) methacrylamide hydrochloride is 35-42 parts by weight, and the amount of triethylamine is 21-26 parts by weight.

2. The method for preparing high-strength concrete according to claim 1, characterized in that: The catalyst is sodium hydroxide or potassium hydroxide.

3. The method for preparing high-strength concrete according to claim 1, characterized in that: The reaction in step (1) is carried out at 70-100° C. for 12-18 hours.

4. The method for preparing high-strength concrete according to claim 1, characterized in that: The reaction in step (2) is carried out at 0-5°C for 5-7h.

5. The method for preparing high-strength concrete according to claim 1, characterized in that: The reaction in step (3) is carried out at 40-50° C. for 6-10 hours.

6. The method for preparing high-strength concrete according to claim 1, characterized in that: In step (4), curing is first carried out at 80-90°C for 2-3 hours and then at 120-130°C for 4-6 hours.

7. The method for preparing high-strength concrete according to claim 1, characterized in that: In the step (4), the defoaming agent is an organosilicon defoaming agent, and the water reducing agent is a polycarboxylic acid water reducing agent.

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