Basalt fiber reinforced anti-crack road concrete and preparation method thereof

Abstract

The invention discloses basalt fiber reinforced anti-crack road concrete and a preparation method thereof, and belongs to the technical field of concrete preparation, and the preparation method specifically comprises the following steps: transferring a concrete precursor into a mold, transferring the mold to a vibration table, vibrating for 1-2 minutes, scraping the raised part of the surface by using a scraper, covering the surface of the material with a preservative film, and drying to obtain the basalt fiber reinforced anti-crack road concrete. Performing post-treatment to obtain the anti-crack concrete. The preparation method comprises the following steps: cleaning basalt fibers, activating, carrying out surface modification, curing to obtain composite basalt fibers, hydrolyzing a borosilicate monomer to prepare modified borosilane with a double-bond structure, converting the double-bond structure into an epoxy group through an epoxidation reaction to obtain a modified curing agent, and preparing the composite basalt fibers by using the modified curing agent and the modified borosilane as additives. And mixing with cement and other materials to obtain the wear-resistant, fracture-resistant and corrosion-resistant anti-crack concrete.

Description

Technical Field

[0001] The present invention relates to the technical field of concrete preparation, and particularly relates to a basalt fiber-reinforced crack-resistant road concrete and a preparation method thereof. Background Art

[0002] In recent years, significant progress has been made in the wear resistance and crack resistance of basalt fiber-reinforced crack-resistant road concrete. Traditional concrete is prone to cracking under high traffic loads and harsh environments, affecting the service life of roads. To solve this problem, researchers have begun to try adding basalt fiber. This natural high-strength material can effectively enhance the crack resistance and wear resistance of concrete. Basalt fiber has excellent properties such as high temperature resistance and corrosion resistance, enabling concrete to maintain good performance in extreme environments. Research shows that basalt fiber can significantly reduce crack generation and improve the wear resistance of roads. Especially under high-intensity traffic impacts, it can effectively extend the service life of road surfaces. Nowadays, basalt fiber-reinforced concrete is widely used in infrastructure such as roads and bridges that require high crack resistance and wear resistance, becoming an important material for improving road quality.

[0003] In the prior art CN114656218B, a crack-resistant concrete with a low shrinkage rate and a preparation method thereof are disclosed, including the following raw materials in parts by weight: 100 - 150 parts of water, 80 - 120 parts of cement, 50 - 90 parts of silica sand, 40 - 80 parts of fly ash, 50 - 80 parts of limestone, 20 - 40 parts of reinforcing fiber, and 5 - 8 parts of water reducing agent. The reinforcing fiber includes modified basalt fiber, and the preparation method of the modified basalt fiber includes the following steps: 1): Immerse the basalt fiber in acid solution, take it out, wash it until neutral, and dry it to obtain pretreated fiber; 2): Take a rare earth solution, place the pretreated fiber prepared in step 1) in the rare earth solution, soak it for 2 - 3 h, take it out and dry it to obtain the modified basalt fiber, which has the performance characteristic of crack resistance.

[0004] However, in the above patent content, the basalt fiber is acid-leached and then soaked in a rare earth solution to obtain modified basalt fiber. However, the active sites exposed after acid leaching are limited, and it is difficult to form a stable cross-linked structure between the effective components in the rare earth solution and the basalt fiber by simple room-temperature soaking and drying. Moreover, the concrete lacks a curing agent that can stably disperse the modified basalt fiber, resulting in the need to further improve the crack resistance and wear resistance of the concrete material. Summary of the Invention

[0005] The purpose of the present invention is to provide a basalt fiber-reinforced crack-resistant road concrete and a preparation method thereof, which are used to solve the technical problem that the crack resistance and wear resistance of road concrete in the prior art need to be further improved.

[0006] The object of the present invention can be achieved by the following technical solutions: A crack-resistant road concrete reinforced with basalt fibers, comprising raw materials in the following parts by weight: 25 - 30 parts of cement, 6 - 8 parts of composite basalt fibers, 8 - 12 parts of modified curing agent, 100 - 120 parts of coarse aggregate, 60 - 70 parts of fine aggregate, 10 - 14 parts of fly ash, and 8 - 12 parts of auxiliary additive;

[0007] Among them, the auxiliary additive is obtained by mixing deionized water, polycarboxylate water reducer, sodium dodecyl sulfate, hydroxypropyl methyl cellulose ether, and polydimethylsiloxane in a dosage ratio of 280 - 300 g: 10 - 12 g: 80 - 100 g: 4 - 5 g: 0.1 - 0.3 g.

[0008] Among them, the fine aggregate is obtained by passing natural river sand through a 40 - 60 mesh sieve; the coarse aggregate comprises raw materials in the following parts by weight: 1 - 2 parts of construction gravel with a particle size of 4.5 - 5.0 mm and 2 - 3 parts of basalt slag with a particle size of 5.4 - 9.6 mm.

[0009] Furthermore, the preparation method of the composite basalt fiber comprises the following steps:

[0010] A1. Add tetramethyl orthosilicate, deionized water, and absolute ethanol into a reaction kettle and stir. After the temperature of the reaction kettle rises to 30 - 50 °C, use saturated sodium hydroxide aqueous solution to adjust the pH of the reaction system to 8 - 10. After heat-preserving and stirring for 12 - 16 h, add activated basalt fibers into the reaction kettle, heat-preserve and stir for 1 - 2 h, and then perform post-treatment to obtain a composite basalt fiber precursor;

[0011] A2. Add hydroxyl silicone oil and ethanol into the reaction kettle. The temperature of the reaction kettle is steadily raised to 40 - 50 °C. After heat-preserving and stirring for 10 - 15 min, add the composite basalt fiber precursor into the reaction kettle and soak for 40 - 60 min, and then perform post-treatment to obtain the composite basalt fiber.

[0012] The reaction principle for preparing the composite basalt fiber is as follows: Under alkaline and heating conditions, tetramethyl orthosilicate undergoes hydrolysis. Through long-term stirring, silicon dioxide particles are generated in the reaction system. After adding activated basalt fibers, the active reaction sites on the surface of the activated basalt fibers will attract the silicon dioxide particles to adhere to the surface of the activated basalt fibers, thereby repairing the defects on the surface of the activated basalt fibers, and then obtaining the composite basalt fiber precursor. The silicon dioxide particles on the surface of the composite basalt fiber precursor further increase the surface roughness of the fiber. Through physical adhesion and chemical group reactions, the hydroxyl silicone oil is evenly adhered to the surface of the composite basalt fiber precursor, and finally, the composite basalt fiber is obtained after curing.

[0013] Further, in step A1, the dosage ratio of tetramethyl orthosilicate, deionized water, absolute ethanol and activated basalt fiber is 3-4 g: 20-30 mL: 40-60 mL: 10-12 g. The post-treatment includes: after the reaction is completed, when the temperature of the reaction kettle drops to room temperature, filter the reaction solution to collect the filter cake. After washing the filter cake 3-5 times with absolute ethanol and deionized water, transfer the filter cake to a reaction kettle at a temperature of 60-80 °C and vacuum dry it to constant weight to obtain the composite basalt fiber precursor;

[0014] Further, in step A2, the dosage ratio of hydroxy silicone oil, ethanol and the composite basalt fiber precursor is 4-6 g: 100-120 mL: 10-12 g. The post-treatment includes: after infiltration is completed, take out the composite basalt fiber precursor, transfer the composite basalt fiber precursor to a muffle furnace, and the muffle furnace is heated to 240-250 °C at a heating rate of 8-10 °C / min, keep it warm for 2-3 h, and wait for the temperature of the muffle furnace to cool naturally to room temperature to obtain the composite basalt fiber.

[0015] Further, the preparation method of the activated basalt fiber includes the following steps:

[0016] B1. Disperse the basalt fiber into an ultrasonic generator filled with 3-5 wt% sodium hydroxide aqueous solution, raise the temperature of the ultrasonic generator to 40-50 °C, keep it warm and ultrasonic for 40-60 min, and obtain the modified basalt fiber through post-treatment;

[0017] B2. Perform plasma activation on the modified basalt fiber to obtain the activated basalt fiber.

[0018] The reaction principle for preparing the activated basalt fiber is: by adding and ultrasonic cleaning with acetone, the impurities on the surface of the basalt fiber are removed to obtain the modified basalt fiber, and through the activation of the plasma gas, the reaction activity of the modified basalt fiber is enhanced, and finally the activated basalt fiber is prepared.

[0019] Further, in step B1, the dosage ratio of the basalt fiber and the 3-5 wt% sodium hydroxide aqueous solution is 2-3 g: 30-36 mL, the ultrasonic frequency is 20-40 kHz, and the post-treatment includes: after the reaction is completed, when the temperature of the reaction kettle drops to room temperature, filter the reaction solution to collect the filter cake. After washing the filter cake 3-5 times with absolute ethanol and deionized water, transfer the filter cake to a reaction kettle at a temperature of 60-80 °C and vacuum dry it to constant weight to obtain the modified basalt fiber;

[0020] Further, in step B2, the plasma activation operation is as follows: Place the modified basalt fiber in a quartz tube. After measuring the airtightness of the quartz tube, evacuate the air. After controlling the internal pressure of the quartz tube to be 30 - 40 Pa, adjust the rotation speed of the quartz tube to 15 - 20 r / min. After rotating for 2 - 3 min, control the frequency of the low-temperature plasma generator to be 13.56 MHz and the power to be 100 - 120 W. Open the gate to introduce oxygen, with an oxygen introduction rate of 20 mL / min. Discharge for 270 - 320 s. After the discharge is completed, stop vacuum pumping. After the internal pressure of the quartz tube returns to atmospheric pressure, take out the fiber and vacuum package it to obtain activated basalt fiber.

[0021] Further, the preparation method of the modified curing agent includes the following steps:

[0022] C1. Add vinyltrichlorosilane, vinyldichloroborane, N,N-dimethylformamide, and deionized water to a reaction kettle and stir. After the temperature of the reaction kettle rises to 40 - 60 °C, use a saturated sodium hydroxide aqueous solution to adjust the pH of the reaction system to 8 - 10, keep stirring for 2 - 3 h, and perform post-treatment to obtain modified borosilane;

[0023] C2. Add the modified borosilane, benzoic acid, aluminum chloride, and N,N-dimethylformamide to a low-temperature reaction kettle and stir. Lower the temperature of the reaction kettle to 0 - 5 °C. While keeping stirring, add a saturated hydrogen peroxide aqueous solution dropwise to the reaction kettle. The dropping operation lasts for 3 - 4 h. After the dropping is completed, keep stirring for 40 - 60 min, and perform post-treatment to obtain the modified curing agent.

[0024] The reaction equation for preparing the modified curing agent is:

[0025]

[0026] The reaction principle for preparing the modified activator is: Under alkaline conditions, the chlorine groups on vinyltrichlorosilane and vinyldichloroborane undergo hydrolysis, causing the silicon group and the boron group to form a modified borosilane with a spatial cross-linked structure. And through low-temperature oxidation with peroxyacid, the double-bond structure on the modified borosilane is converted into an epoxy group, and finally the modified curing agent is prepared.

[0027] Further, in step C1, the dosage ratio of vinyltrichlorosilane, vinyldichloroborane, N,N-dimethylformamide, and deionized water is 4 - 6 g: 2 - 3 g: 20 - 30 mL: 10 - 12 mL. The post-treatment includes: After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, transfer the reaction solution to a rotary evaporator, raise the temperature of the rotary evaporator to 60 - 80 °C, and perform vacuum distillation until no liquid is collected to obtain the modified borosilane;

[0028] Further, in step C2, the dosage ratio of the modified borosilane, benzoic acid, aluminum chloride, N,N-dimethylformamide and saturated aqueous hydrogen peroxide solution is 16-18 g: 5-7 g: 0.6-0.8 g: 80-90 mL: 10-12 mL. The post-treatment includes: after the reaction is completed, when the temperature of the reaction kettle drops to room temperature, transfer the reaction solution to a rotary evaporator, raise the temperature of the rotary evaporator to 60-80 °C, and distill under reduced pressure until no liquid is collected, then a modified curing agent is obtained.

[0029] The present invention also provides a preparation method of basalt fiber-reinforced crack-resistant road concrete, comprising the following steps:

[0030] S1. Place the composite basalt fiber, fine aggregate, fly ash and cement in a stirring kettle, mix evenly, add the coarse aggregate, stir for 1-3 min, then add the modified curing agent and auxiliary additives, and stir for 3-5 min to obtain a concrete precursor.

[0031] S2. Transfer the concrete precursor to a mold, transfer the mold to a vibrating table, vibrate for 1-2 min, then use a spatula to scrape the bulges on the surface and cover the surface of the material with a plastic wrap, and perform post-treatment to obtain crack-resistant concrete.

[0032] Further, in step S2, the post-treatment includes: transfer the mold to a standard curing box at a temperature of 25 °C and a humidity of 95%, cure at constant temperature and humidity for 24-36 h, then demold, soak in water at room temperature for 20-24 h, and dry to obtain crack-resistant concrete.

[0033] The present invention has the following beneficial effects:

[0034] 1. Through the synergistic effect of the composite basalt fiber and the modified curing agent, the present invention significantly improves the compressive strength and wear resistance of the concrete. After the basalt fiber is cleaned and surface-activated, it is modified with silica particles and infiltrated with silicone oil to form a structure with both a rough surface and a flexible transition layer, enabling the fiber to not only be closely embedded in the cement matrix but also disperse stress through elastic buffering to prevent crack propagation. Moreover, the modified curing agent forms a stable cross-linked network during the hydration process, and its epoxy groups chemically bond with the cement components, effectively filling the pores and enhancing the matrix densification, reducing the generation of internal micro-cracks. The curing agent inhibits crack initiation through the densified structure, while the fiber prevents crack propagation through physical bridging. At the same time, the silica on the fiber surface chemically bonds with the silicon component in the curing agent to form a continuous reinforcement system. The combination of the two makes the internal structure of the concrete more uniform and compact, and slows down surface wear, thus synchronously solving the problems of large brittleness and easy cracking of traditional concrete.

[0035] 2. The present invention effectively improves the flexural and tensile strengths of concrete by improving the combination mode of basalt fiber and curing agent. After the basalt fiber is chemically cleaned to remove surface impurities, a micro-concave and convex structure is formed on its surface through activation treatment. Subsequently, silicon dioxide particles are covered and silicone oil is infiltrated. After high-temperature curing, there is a rough particle layer on the fiber surface to enhance the mechanical bonding with the concrete, and the flexible silicone oil layer buffers the stress to prevent the fiber from detaching from the concrete. The treated fiber forms a three-dimensional network structure in the concrete, which can effectively hold the cracks and disperse the stress. At the same time, the modified curing agent reduces the generation of micro-cracks inside the concrete by combining with the materials, and the fiber prevents the propagation of existing cracks through physical bridging. Meanwhile, the silicon dioxide on the fiber surface and the silicon component in the curing agent form a continuous reinforcement system through chemical bonding. When the concrete is subjected to bending or tension, the fiber network disperses the external stress, and the curing agent strengthens the internal structure. The two jointly control the generation and propagation path of cracks through material modification and chemical reaction, jointly delaying the crack development and improving the bearing capacity.

[0036] 3. In the present invention, after the surface of the basalt fiber is cleaned and activated, a layer of tiny silicon dioxide particles is covered and a silicone oil protective layer is applied. The silicon dioxide particles are tightly combined with the fiber to form an acid and alkali resistant protective layer, which cooperates with the silicone oil to prevent corrosive liquids from penetrating into the joint between the fiber and the concrete. Moreover, the silicon dioxide on the fiber surface and the silicon component in the curing agent are chemically bonded, making the fiber adhere more firmly to the concrete, avoiding the generation of corrosion notches due to insufficient bonding. The modified curing agent undergoes a chemical reaction during the solidification of the concrete to form a stable network structure, thereby filling the tiny pores inside the concrete, reducing the generation of cracks. At the same time, it is connected to the cement component through chemical bonds, making the concrete more compact and strong, reducing the possibility of corrosive gases or liquids diffusing inside. By reducing the internal pores and cracks of the concrete with the curing agent and blocking the intrusion of corrosive media from the outside with the fiber, the corrosion resistance of the concrete is greatly improved. Specific embodiments

[0037] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0038] The fly ash used in the present invention is purchased from Wuhan Jiyesheng Chemical Co., Ltd., and the product number is A01085;

[0039] The hydroxyl silicone oil used in the present invention is purchased from Zhejiang Zhenghe Silicon Materials Co., Ltd., and the brand number is 207-35;

[0040] The bisphenol A epoxy resin used in the present invention was purchased from Shandong Qiansheng Chemical Co., Ltd., with the brand number E51;

[0041] The cement used in the present invention was purchased from Jiaozuo Qianye Cement Co., Ltd., with the model of P.O42.5 Portland cement;

[0042] The polydimethylsiloxane used in the present invention was purchased from Shanghai Dingfen Technology Co., Ltd., with the product number P06715;

[0043] The polycarboxylate superplasticizer used in the present invention was purchased from Guangdong Wengjiang Chemical Reagent Co., Ltd., with the product number PA96208;

[0044] The hydroxypropyl methyl cellulose ether used in the present invention was purchased from Shanghai Yuanye Biotechnology Co., Ltd., with the product number S25213-250g;

[0045] The basalt fiber used in the present invention was purchased from Jiangsu Jumo New Material Technology Co., Ltd., with the product name of basalt fiber special for asphalt mixture.

[0046] Example 1

[0047] This example provides a preparation method of a modified curing agent for preparing basalt fiber-reinforced crack-resistant road concrete, including the following steps:

[0048] Step ①, prepare modified borosilane

[0049] Weigh: 40.0 g of vinyltrichlorosilane, 20.0 g of vinyldichloroborane, 200.0 mL of N,N-dimethylformamide and 100.0 mL of deionized water and add them to the reaction kettle for stirring. After the temperature of the reaction kettle rises to 40 °C, use saturated sodium hydroxide aqueous solution to adjust the pH of the reaction system to 8, keep stirring for 2 h. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, transfer the reaction solution to the rotary evaporator, raise the temperature of the rotary evaporator to 60 °C, and distill under reduced pressure until no liquid is collected, then obtain the modified borosilane.

[0050] Step ②, prepare modified curing agent

[0051] Weigh: 48.0 g of modified borosilane, 15.0 g of benzoic acid, 1.8 g of aluminum chloride and 240.0 mL of N,N-dimethylformamide and add them to the low-temperature reaction kettle for stirring. Lower the temperature of the reaction kettle to 5 °C. Under the state of keeping stirring, add 30.0 mL of saturated hydrogen peroxide aqueous solution dropwise to the reaction kettle, and maintain the dropping operation for 3 h. After the dropping is completed, keep stirring for 40 min. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, transfer the reaction solution to the rotary evaporator, raise the temperature of the rotary evaporator to 60 °C, and distill under reduced pressure until no liquid is collected, then obtain the modified curing agent.

[0052] Example 2

[0053] This embodiment provides a preparation method of a modified curing agent for preparing basalt fiber-reinforced crack-resistant road concrete, including the following steps:

[0054] Step ①, preparing modified borosilane

[0055] Weigh: 60.0 g of vinyltrichlorosilane, 30.0 g of vinyldichloroborane, 300.0 mL of N,N-dimethylformamide and 120.0 mL of deionized water and add them to a reaction kettle for stirring. After the temperature of the reaction kettle rises to 60 °C, use saturated sodium hydroxide aqueous solution to adjust the pH of the reaction system to 10, keep stirring for 3 h. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, transfer the reaction solution to a rotary evaporator, raise the temperature of the rotary evaporator to 80 °C, and perform vacuum distillation until no liquid is collected, then obtain modified borosilane.

[0056] Step ②, preparing modified curing agent

[0057] Weigh: 54.0 g of modified borosilane, 21.0 g of benzoic acid, 2.4 g of aluminum chloride and 270.0 mL of N,N-dimethylformamide and add them to a low-temperature reaction kettle for stirring. Lower the temperature of the reaction kettle to 0 °C. While maintaining the state of stirring and keeping warm, add 36.0 mL of saturated hydrogen peroxide aqueous solution dropwise to the reaction kettle. The dropping operation lasts for 4 h. After the dropping is completed, keep stirring for 60 min. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, transfer the reaction solution to a rotary evaporator, raise the temperature of the rotary evaporator to 80 °C, and perform vacuum distillation until no liquid is collected, then obtain modified curing agent.

[0058] Example 3

[0059] This embodiment provides a preparation method of a modified curing agent for preparing basalt fiber-reinforced crack-resistant road concrete, including the following steps:

[0060] Step ①, preparing modified borosilane

[0061] Weigh: 50.0 g of vinyltrichlorosilane, 25.0 g of vinyldichloroborane, 250.0 mL of N,N-dimethylformamide and 120.0 mL of deionized water and add them to a reaction kettle for stirring. After the temperature of the reaction kettle rises to 50 °C, use saturated sodium hydroxide aqueous solution to adjust the pH of the reaction system to 9, keep stirring for 3 h. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, transfer the reaction solution to a rotary evaporator, raise the temperature of the rotary evaporator to 70 °C, and perform vacuum distillation until no liquid is collected, then obtain modified borosilane.

[0062] Step ②, preparing modified curing agent

[0063] Weigh: 51.0 g of modified borosilane, 18.0 g of benzoic acid, 2.1 g of aluminum chloride and 250.0 mL of N,N-dimethylformamide and add them to a low-temperature reaction kettle for stirring. The temperature of the reaction kettle is reduced to 3 °C. Under the state of heat preservation and stirring, 36.0 mL of saturated hydrogen peroxide aqueous solution is added dropwise to the reaction kettle. The dropping operation is maintained for 4 h. After the dropping is completed, heat preservation and stirring are carried out for 50 min. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, transfer the reaction solution to a rotary evaporator, raise the temperature of the rotary evaporator to 70 °C, and carry out vacuum distillation until no liquid is produced, and then a modified curing agent is obtained.

[0064] Example 4

[0065] This example provides a preparation method of activated basalt fibers for preparing basalt fiber-reinforced crack-resistant road concrete, including the following steps:

[0066] Step I. Prepare modified basalt fibers

[0067] Weigh: 20.0 g of basalt fibers are dispersed into an ultrasonic generator containing 300.0 mL of 3 wt% sodium hydroxide aqueous solution. The temperature of the ultrasonic generator is raised to 40 °C, the ultrasonic frequency is 20 kHz, and heat preservation and ultrasonic treatment are carried out for 40 min. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, filter the reaction solution by suction to collect the filter cake, wash the filter cake 3 times with absolute ethanol and deionized water, and then transfer the filter cake to a reaction kettle at 60 °C and vacuum dry it to constant weight to obtain modified basalt fibers.

[0068] Step II. Prepare activated basalt fibers

[0069] Weigh: 20.0 g of modified basalt fibers are placed in a quartz tube. After measuring that the quartz tube reaches airtightness, evacuate the air. After controlling the internal pressure of the quartz tube to be 30 Pa, adjust the rotation speed of the quartz tube to 15 r / min. After rotating for 2 min, control the frequency of the low-temperature plasma generator to be 13.56 MHz and the power to be 100 W. Open the gate to introduce oxygen, and the oxygen introduction rate is 20 mL / min. Discharge for 270 s. After the discharge is completed, stop vacuum pumping. After the internal pressure of the quartz tube returns to atmospheric pressure, take out the fibers and vacuum package them to obtain activated basalt fibers.

[0070] Example 5

[0071] This example provides a preparation method of activated basalt fibers for preparing basalt fiber-reinforced crack-resistant road concrete, including the following steps:

[0072] Step I. Prepare modified basalt fibers

[0073] Weigh: Disperse 30.0 g of basalt fibers into an ultrasonic generator containing 360.0 mL of 5 wt% aqueous sodium hydroxide solution. Raise the temperature of the ultrasonic generator to 50 °C, with an ultrasonic frequency of 40 kHz. Keep the temperature for ultrasonic treatment for 60 min. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature. Filter the reaction solution by suction to collect the filter cake. Wash the filter cake 5 times with absolute ethanol and deionized water. Then transfer the filter cake to a reaction kettle at 80 °C and vacuum dry it to constant weight to obtain modified basalt fibers.

[0074] Step II. Prepare activated basalt fibers

[0075] Weigh: Place 30.0 g of modified basalt fibers in a quartz tube. After measuring that the quartz tube has achieved airtightness, evacuate the air. After controlling the internal pressure of the quartz tube to be 40 Pa, adjust the rotation speed of the quartz tube to 20 r / min. After rotating for 3 min, control the frequency of the low-temperature plasma generator to be 13.56 MHz and the power to be 120 W. Open the gate to introduce oxygen with an oxygen introduction rate of 20 mL / min. Discharge for 320 s. After the discharge is completed, stop vacuum pumping. After the internal pressure of the quartz tube returns to atmospheric pressure, take out the fibers and vacuum package them to obtain activated basalt fibers.

[0076] Example 6

[0077] This example provides a preparation method of activated basalt fibers for preparing crack-resistant road concrete reinforced with basalt fibers, including the following steps:

[0078] Step I. Prepare modified basalt fibers

[0079] Weigh: Disperse 24.0 g of basalt fibers into an ultrasonic generator containing 320.0 mL of 4 wt% aqueous sodium hydroxide solution. Raise the temperature of the ultrasonic generator to 50 °C, with an ultrasonic frequency of 36 kHz. Keep the temperature for ultrasonic treatment for 50 min. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature. Filter the reaction solution by suction to collect the filter cake. Wash the filter cake 4 times with absolute ethanol and deionized water. Then transfer the filter cake to a reaction kettle at 80 °C and vacuum dry it to constant weight to obtain modified basalt fibers.

[0080] Step II. Prepare activated basalt fibers

[0081] Weigh: Place 24.0 g of modified basalt fibers in a quartz tube. After measuring that the quartz tube has achieved airtightness, evacuate the air. After controlling the internal pressure of the quartz tube to be 36 Pa, adjust the rotation speed of the quartz tube to 18 r / min. After rotating for 3 min, control the frequency of the low-temperature plasma generator to be 13.56 MHz and the power to be 120 W. Open the gate to introduce oxygen with an oxygen introduction rate of 20 mL / min. Discharge for 300 s. After the discharge is completed, stop vacuum pumping. After the internal pressure of the quartz tube returns to atmospheric pressure, take out the fibers and vacuum package them to obtain activated basalt fibers.

[0082] Example 7

[0083] This example provides a preparation method of composite basalt fiber for preparing basalt fiber-reinforced crack-resistant road concrete, including the following steps:

[0084] Step (i), preparing a composite basalt fiber precursor

[0085] Weigh: Add 6.0 g of tetramethyl orthosilicate, 40.0 mL of deionized water and 80.0 mL of absolute ethanol into a reaction kettle and stir. After the temperature of the reaction kettle rises to 30 °C, use a saturated sodium hydroxide aqueous solution to adjust the pH of the reaction system to 8. After keeping the temperature and stirring for 12 h, add 20.0 g of the activated basalt fiber prepared in Step 4 into the reaction kettle, keep the temperature and stir for 1 h. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, filter the reaction solution by suction to collect the filter cake, wash the filter cake 3 times with absolute ethanol and deionized water, then transfer the filter cake to a reaction kettle at 60 °C, and vacuum dry it to constant weight to obtain the composite basalt fiber precursor.

[0086] Step (ii), preparing the composite basalt fiber

[0087] Weigh: Add 8.0 g of hydroxy silicone oil and 200.0 mL of ethanol into a reaction kettle. The temperature of the reaction kettle is steadily raised to 40 °C. After keeping the temperature and stirring for 10 min, add 20.0 g of the composite basalt fiber precursor into the reaction kettle and soak it for 40 min. After the soaking is completed, take out the composite basalt fiber precursor, transfer the composite basalt fiber precursor to a muffle furnace, and the muffle furnace is heated to 240 °C at a heating rate of 8 °C / min, keep the temperature for 2 h, and wait for the temperature of the muffle furnace to cool naturally to room temperature to obtain the composite basalt fiber.

[0088] Example 8

[0089] This example provides a preparation method of composite basalt fiber for preparing basalt fiber-reinforced crack-resistant road concrete, including the following steps:

[0090] Step (i), preparing a composite basalt fiber precursor

[0091] Weigh: Add 8.0 g of tetramethyl orthosilicate, 60.0 mL of deionized water and 120.0 mL of absolute ethanol into a reaction kettle and stir. After the temperature of the reaction kettle rises to 50 °C, use a saturated sodium hydroxide aqueous solution to adjust the pH of the reaction system to 10. After keeping the temperature and stirring for 16 h, add 24.0 g of the activated basalt fiber prepared in Step 5 into the reaction kettle, keep the temperature and stir for 1 h. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, filter the reaction solution by suction to collect the filter cake, wash the filter cake 5 times with absolute ethanol and deionized water, then transfer the filter cake to a reaction kettle at 80 °C, and vacuum dry it to constant weight to obtain the composite basalt fiber precursor.

[0092] Step (ii), preparing composite basalt fibers

[0093] Weigh: Add 12.0 g of hydroxyl silicone oil and 240.0 mL of ethanol into a reaction kettle. The temperature of the reaction kettle is steadily raised to 50 °C. After heat preservation and stirring for 15 min, add 24.0 g of composite basalt fiber precursor into the reaction kettle and soak for 60 min. After the soaking is completed, take out the composite basalt fiber precursor, transfer the composite basalt fiber precursor to a muffle furnace, and the muffle furnace is heated to 250 °C at a heating rate of 10 °C / min, and heat-treated for 3 h. Wait for the temperature of the muffle furnace to cool naturally to room temperature to obtain composite basalt fibers.

[0094] Example 9

[0095] This example provides a preparation method of composite basalt fibers for preparing basalt fiber-reinforced crack-resistant road concrete, including the following steps:

[0096] Step (i), preparing composite basalt fiber precursor

[0097] Weigh: Add 7.2 g of tetramethyl orthosilicate, 54.0 mL of deionized water and 100.0 mL of absolute ethanol into a reaction kettle and stir. After the temperature of the reaction kettle rises to 40 °C, use saturated sodium hydroxide aqueous solution to adjust the pH of the reaction system to 9. After heat preservation and stirring for 16 h, add 24.0 g of the activated basalt fibers prepared in step 6 into the reaction kettle, and heat preservation and stirring for 2 h. After the reaction is completed, wait for the temperature of the reaction kettle to drop to room temperature, filter the reaction solution by suction to collect the filter cake, wash the filter cake 4 times with absolute ethanol and deionized water, then transfer the filter cake to a reaction kettle at a temperature of 80 °C, and vacuum dry to constant weight to obtain the composite basalt fiber precursor.

[0098] Step (ii), preparing composite basalt fibers

[0099] Weigh: Add 10.0 g of hydroxyl silicone oil and 210.0 mL of ethanol into a reaction kettle. The temperature of the reaction kettle is steadily raised to 50 °C. After heat preservation and stirring for 15 min, add 24.0 g of composite basalt fiber precursor into the reaction kettle and soak for 54 min. After the soaking is completed, take out the composite basalt fiber precursor, transfer the composite basalt fiber precursor to a muffle furnace, and the muffle furnace is heated to 240 °C at a heating rate of 9 °C / min, and heat-treated for 3 h. Wait for the temperature of the muffle furnace to cool naturally to room temperature to obtain composite basalt fibers.

[0100] Example 10

[0101] This example provides a preparation method of basalt fiber-reinforced crack-resistant road concrete, including the following steps:

[0102] Step one, preparing concrete precursor

[0103] Weigh: 280 parts of deionized water, 10 parts of polycarboxylate water reducer, 80 parts of sodium dodecyl sulfate, 4 parts of hydroxypropyl methyl cellulose ether and 0.1 part of polydimethylsiloxane, and mix them to obtain an auxiliary additive;

[0104] Weigh: 1 part of construction gravel with a particle size of 4.5 mm and 2 parts of basalt slag with a particle size of 5.4 mm, and mix them to obtain coarse aggregate;

[0105] Pass the natural river sand through a 40-mesh sieve to obtain fine aggregate;

[0106] Weigh: 6 parts of the composite basalt fiber prepared in Example 7, 60 parts of fine aggregate, 10 parts of fly ash and 25 parts of cement, place them in a stirring kettle, mix evenly, add 100 parts of coarse aggregate, stir for 1 min, then add 8 parts of the modified curing agent prepared in Example 1 and 8 parts of the auxiliary additive, and stir for 3 min to obtain a concrete precursor.

[0107] Step Two: Prepare crack-resistant concrete

[0108] Transfer the concrete precursor to a mold, transfer the mold to a vibrating table, vibrate for 1 min, then use a spatula to scrape the bulges on the surface flat and cover the surface of the material with plastic wrap, and transfer the mold to a standard curing box at a temperature of 25°C and a humidity of 95%, cure it under constant temperature and humidity for 24 h, then demold it, soak it in room-temperature water for 20 h, and dry it to obtain crack-resistant concrete.

[0109] Example 11

[0110] This example provides a preparation method of basalt fiber-reinforced crack-resistant road concrete, which includes the following steps:

[0111] Step One: Prepare a concrete precursor

[0112] Weigh: 300 parts of deionized water, 12 parts of polycarboxylate water reducer, 100 parts of sodium dodecyl sulfate, 5 parts of hydroxypropyl methyl cellulose ether and 0.3 part of polydimethylsiloxane, and mix them to obtain an auxiliary additive;

[0113] Weigh: 2 parts of construction gravel with a particle size of 5.0 mm and 3 parts of basalt slag with a particle size of 6.4 mm, and mix them to obtain coarse aggregate;

[0114] Pass the natural river sand through a 60-mesh sieve to obtain fine aggregate;

[0115] Weigh: 8 parts of the composite basalt fiber prepared in Example 8, 70 parts of fine aggregate, 14 parts of fly ash, and 30 parts of cement, place them in a stirring kettle, mix evenly, add 120 parts of coarse aggregate, stir for 3 minutes, then add 12 parts of the modified curing agent prepared in Example 2 and 12 parts of auxiliary additive, stir for 5 minutes to obtain a concrete precursor.

[0116] Step 2: Prepare crack-resistant concrete

[0117] Transfer the concrete precursor to a mold, transfer the mold to a vibrating table, vibrate for 2 minutes, use a spatula to scrape the bulges on the surface and cover the material surface with plastic wrap, and transfer the mold to a standard curing box at a temperature of 25°C and a humidity of 95%, cure at constant temperature and humidity for 36 hours, then demold, soak in room-temperature water for 24 hours, and air dry to obtain crack-resistant concrete.

[0118] Example 12

[0119] This example provides a preparation method of basalt fiber-reinforced crack-resistant road concrete, including the following steps:

[0120] Step 1: Prepare a concrete precursor

[0121] Weigh 288 parts of deionized water, 12 parts of polycarboxylate water reducer, 96 parts of sodium dodecyl sulfate, 5 parts of hydroxypropyl methylcellulose ether, and 0.2 parts of polydimethylsiloxane and mix them to obtain an auxiliary additive;

[0122] Weigh: 1 part of building gravel with a particle size of 4.8 mm and 1 part of basalt slag with a particle size of 7.2 mm and mix them to obtain coarse aggregate;

[0123] Pass the natural river sand through a 50-mesh sieve to obtain fine aggregate;

[0124] Weigh: 7 parts of the composite basalt fiber prepared in Example 9, 64 parts of fine aggregate, 12 parts of fly ash, and 28 parts of cement, place them in a stirring kettle, mix evenly, add 120 parts of coarse aggregate, stir for 2 minutes, then add 10 parts of the modified curing agent prepared in Example 3 and 10 parts of auxiliary additive, stir for 4 minutes to obtain a concrete precursor.

[0125] Step 2: Prepare crack-resistant concrete

[0126] Transfer the concrete precursor to a mold, transfer the mold to a vibrating table, vibrate for 2 minutes, use a spatula to scrape the bulges on the surface and cover the material surface with plastic wrap, and transfer the mold to a standard curing box at a temperature of 25°C and a humidity of 95%, cure at constant temperature and humidity for 32 hours, then demold, soak in room-temperature water for 21 hours, and air dry to obtain crack-resistant concrete.

[0127] Comparative Example 1

[0128] The difference between this comparative example and Example 12 is that in the process of preparing the composite basalt fiber used, step ㈠ is cancelled, and activated basalt fiber is used in step ㈡ to equivalently replace the composite basalt fiber precursor.

[0129] Comparative Example 2

[0130] The difference between this comparative example and Example 12 is that in step ① of the preparation process of the modified adhesive used, the use of vinyl dichloroborane is cancelled, and vinyl trichlorosilane is used to equivalently replace vinyl dichloroborane.

[0131] Comparative Example 3

[0132] The difference between this comparative example and Example 12 is that bisphenol A epoxy resin is used to equivalently replace the modified adhesive.

[0133] Performance test:

[0134] Referring to the standard GB / T 50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete", the flexural strength, compressive strength, splitting tensile strength and abrasion resistance of the crack-resistant concrete prepared in Examples 10-12 and Comparative Examples 1-3 were tested after 28 days of solidification;

[0135] Referring to the standard GB / T 50082-2024 "Standard for Test Methods of Long-Term Performance and Durability of Concrete", the sulfate erosion resistance of the crack-resistant concrete prepared in Examples 10-12 and Comparative Examples 1-3 after 28 days of solidification was tested. The specific data are shown in Table 1.

[0136] Table 1 - Performance test data table of each specimen

[0137]

[0138] Data analysis:

[0139] By comparing and analyzing the data in Table 1 above, it can be found that the flexural strength of the crack-resistant concrete prepared by the present invention is 13.54 MPa, the compressive strength is 64.17 MPa, the splitting tensile strength is 6.71 MPa, and the wear loss after 45 cycles is 1.24 kg·m 2 while the sulfate resistance grade is KS150, and all data are better than those of the comparative examples;

[0140] It is noted that in the present invention, through the synergistic effect of composite basalt fiber and modified curing agent, the compressive strength and wear resistance of concrete are significantly improved. After being cleaned and surface-activated, the basalt fiber is modified with silica particles and infiltrated with silicone oil to form a structure with both a rough surface and a flexible transition layer. This enables the fiber to be closely embedded in the cement matrix and, through elastic buffering, disperse stress and prevent crack propagation. Moreover, during the hydration process, the modified curing agent forms a stable cross-linked network, and its epoxy groups chemically bond with the cement components, effectively filling the pores and enhancing the matrix density, reducing the generation of internal micro-cracks. The curing agent inhibits crack initiation through densification of the structure, while the fiber prevents crack propagation through physical bridging. At the same time, the silica on the fiber surface chemically bonds with the silicon component in the curing agent to form a continuous reinforcement system. The combination of the two makes the internal structure of the concrete more uniform and compact, and slows down surface wear, thus synchronously solving the problems of high brittleness and easy cracking of traditional concrete.

[0141] It is noted that in the present invention, by improving the combination mode of basalt fiber and curing agent, the flexural and tensile strengths of concrete are effectively enhanced. After chemically cleaning the basalt fiber to remove surface impurities, an activation treatment is carried out to form a micro-convex and concave structure on its surface. Subsequently, silica particles are covered and silicone oil is infiltrated. After high-temperature curing, the fiber surface has both a rough particle layer to enhance the mechanical bonding with the concrete and a flexible silicone oil layer to buffer stress and prevent the fiber from detaching from the concrete. The treated fiber forms a three-dimensional network structure in the concrete, which can effectively hold the cracks and disperse the stress. At the same time, the modified curing agent reduces the generation of internal micro-cracks by combining with the material, and the fiber prevents the propagation of existing cracks through physical bridging. Moreover, the silica on the fiber surface chemically combines with the silicon component in the curing agent to form a continuous reinforcement system. When the concrete is subjected to bending or tension, the fiber network disperses the external stress, and the curing agent strengthens the internal structure. The two jointly control the generation and propagation path of cracks through material modification and chemical reactions, jointly delaying crack development and enhancing the load-bearing capacity.

[0142] It is noted that in the present invention, first, the basalt fiber is surface-cleaned and activated, then covered with a layer of tiny silica particles and coated with a silicone oil protective layer. The silica particles are tightly combined with the fiber to form an acid- and alkali-resistant protective layer, which cooperates with the silicone oil to prevent corrosive liquids from penetrating into the joint between the fiber and the concrete. Moreover, the silica on the fiber surface chemically combines with the silicon component in the curing agent, making the fiber adhere more firmly to the concrete, avoiding corrosion notches caused by loose bonding. The modified curing agent undergoes a chemical reaction during the solidification of the concrete to form a stable network structure, thereby filling the tiny pores inside the concrete, reducing crack generation, and at the same time connecting with the cement component through chemical bonds, making the concrete more compact and solid, reducing the possibility of the diffusion of corrosive gases or liquids inside. By reducing the internal pores and cracks of the concrete with the curing agent and blocking the intrusion of corrosive media from the outside with the fiber, the corrosion resistance of the concrete is significantly improved;

[0143] Specifically, the basalt fiber is cleaned and activated, then surface-modified and cured to obtain composite basalt fiber. A modified borosilane with a double-bond structure is prepared by hydrolyzing borosilane monomers. Through an epoxidation reaction, the double-bond structure is converted into epoxy groups to obtain a modified curing agent. Using these two as additives and mixing them with materials such as cement, an anti-cracking concrete with wear resistance, flexural strength, and corrosion resistance is obtained.

[0144] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation manners described. Obviously, many modifications and changes can be made according to the content of this specification. These embodiments are selected and specifically described in this specification to better explain the principle and practical application of the present invention, so that those skilled in the art in the relevant technical field can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A crack-resistant road concrete reinforced with basalt fibers, comprising cement, coarse aggregate, fine aggregate, fly ash and auxiliary additives, characterized in that, It also includes composite basalt fibers and modified curing agents; Among them, tetramethyl silicate, deionized water and absolute ethanol are added to a reaction kettle and stirred. After the temperature of the reaction kettle rises to 30-50 °C, the pH of the reaction system is adjusted to 8-10 using a saturated sodium hydroxide aqueous solution, and after heat preservation and stirring for 12-16 h, activated basalt fibers are added to the reaction kettle, followed by heat preservation and stirring for 1-2 h, and then post-treatment to obtain a composite basalt fiber precursor; then, hydroxyl silicone oil and ethanol are added to the reaction kettle, the temperature of the reaction kettle is steadily raised to 40-50 °C, after heat preservation and stirring for 10-15 min, the composite basalt fiber precursor is added to the reaction kettle and infiltrated for 40-60 min, and then post-treatment to obtain composite basalt fibers; Among them, vinyl trichlorosilane, vinyl dichloroborane, N,N-dimethylformamide and deionized water are added to a reaction kettle and stirred. After the temperature of the reaction kettle rises to 40-60 °C, the pH of the reaction system is adjusted to 8-10 using a saturated sodium hydroxide aqueous solution, and after heat preservation and stirring for 2-3 h, post-treatment is carried out to obtain modified borosilane; then, the modified borosilane, benzoic acid, aluminum chloride and N,N-dimethylformamide are added to a low-temperature reaction kettle and stirred. When the temperature of the reaction kettle is lowered to 0-5 °C and under the state of heat preservation and stirring, a saturated hydrogen peroxide aqueous solution is dropped into the reaction kettle, and the dropping operation is maintained for 3-4 h. After the dropping is completed, heat preservation and stirring are carried out for 40-60 min, and then post-treatment to obtain a modified curing agent; By weight, 25-30 parts of cement, 6-8 parts of composite basalt fibers, 8-12 parts of modified curing agents, 100-120 parts of coarse aggregate, 60-70 parts of fine aggregate, 10-14 parts of fly ash and 8-12 parts of auxiliary additives are used to process and prepare the crack-resistant road concrete.

2. A crack-resistant road concrete reinforced with basalt fibers according to claim 1, characterized in that, The auxiliary additive is obtained by mixing deionized water, polycarboxylate water reducer, sodium dodecyl sulfate, hydroxypropyl methyl cellulose ether and polydimethylsiloxane in a dosage ratio of 280-300 g:10-12 g:80-100 g:4-5 g:0.1-0.3 g.

3. A crack-resistant road concrete reinforced with basalt fibers according to claim 1, characterized in that, The dosage ratio of tetramethyl silicate, deionized water, absolute ethanol and activated basalt fibers is 3-4 g:20-30 mL:40-60 mL:10-12 g; the dosage ratio of hydroxyl silicone oil, ethanol and composite basalt fiber precursor is 4-6 g:100-120 mL:10-12 g.

4. A crack-resistant road concrete reinforced with basalt fibers according to claim 1, characterized in that, The preparation method of the activated basalt fibers includes the following steps: B1. Dispersing basalt fibers into an ultrasonic generator containing 3-5 wt% sodium hydroxide aqueous solution, raising the temperature of the ultrasonic generator to 40-50 °C, heat-preserving and ultrasonicating for 40-60 min, and then post-treating to obtain modified basalt fibers; B2. Performing plasma activation on the modified basalt fibers to obtain activated basalt fibers.

5. A crack-resistant road concrete reinforced with basalt fibers according to claim 4, characterized in that, In step B1, the dosage ratio of basalt fiber to 3-5wt% sodium hydroxide aqueous solution is 2-3g:30-36mL; in step B2, the plasma activation operation is as follows: place the modified basalt fiber in a quartz tube. After measuring the airtightness of the quartz tube, evacuate the air. After controlling the internal pressure of the quartz tube to be 30-40Pa, adjust the rotation speed of the quartz tube to 15-20r / min. After rotating for 2-3min, control the frequency of the low-temperature plasma generator to be 13.56MHz and the power to be 100-120W. Open the gate to introduce oxygen, with the oxygen introduction rate being 20mL / min. Discharge for 270-320s. After the discharge is completed, stop vacuum pumping. After the internal pressure of the quartz tube returns to atmospheric pressure, take out the fiber and vacuum package it to obtain activated basalt fiber.

6. A crack-resistant road concrete reinforced with basalt fibers according to claim 1, characterized in that, The dosage ratio of vinyltrichlorosilane, vinyldichloroborane, N,N-dimethylformamide and deionized water is 4-6g:2-3g:20-30mL:10-12mL; the dosage ratio of modified borosilane, benzoic acid, aluminum chloride, N,N-dimethylformamide and saturated hydrogen peroxide aqueous solution is 16-18g:5-7g:0.6-0.8g:80-90mL:10-12mL.

7. A method for preparing basalt fiber-reinforced crack-resistant road concrete according to any one of claims 1-6, characterized in that, It includes the following steps: S1. Place the composite basalt fiber, fine aggregate, fly ash and cement in a stirring kettle, mix them evenly, add the coarse aggregate, stir for 3-5min, then add the modified curing agent and auxiliary additive, and stir for 5-8min to obtain a concrete precursor. S2. Transfer the concrete precursor to a mold, transfer the mold to a vibrating table, vibrate for 1-2min, then use a spatula to scrape the bulges on the surface and cover the surface of the material with a plastic film, and post-treat to obtain crack-resistant concrete.

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