A basalt fiber reinforced anti-cracking road concrete and a preparation method thereof

Abstract

The application discloses a basalt fiber reinforced anti-cracking road concrete and a preparation method thereof, and belongs to the technical field of concrete preparation, and specifically comprises the following steps: transferring a concrete precursor into a mold, transferring the mold to a vibration table, scraping the surface protrusions flat with a scraper after vibration for 1-2 minutes, covering the material surface with a preservative film, and obtaining the anti-cracking concrete through post-processing; the application is to activate the basalt fiber after cleaning, then to solidify the composite basalt fiber after surface modification, to prepare modified borosilane with a double bond structure by hydrolysis of borosil monomer, to convert the double bond structure into an epoxy group through an epoxidation reaction, to obtain a modified curing agent, and to obtain a wear-resistant, anti-bending and corrosion-resistant anti-cracking concrete by taking the two as additives and mixing with cement and other materials.

Description

Technical Field

[0001] This invention relates to the field of concrete preparation technology, specifically to a basalt fiber reinforced crack-resistant road concrete and its preparation method. Background Technology

[0002] In recent years, basalt fiber-reinforced crack-resistant road concrete has made significant progress in terms of wear resistance and crack resistance. Traditional concrete is prone to cracking under high traffic loads and harsh environments, affecting the service life of roads. To solve this problem, researchers began to try adding basalt fibers. This natural high-strength material can effectively enhance the crack resistance and wear resistance of concrete. Basalt fibers have excellent high-temperature resistance and corrosion resistance, which allows concrete to maintain good performance even in extreme environments. Studies have shown that basalt fibers can significantly reduce crack formation and improve the wear resistance of roads. Especially under high-intensity traffic impact, it can effectively extend the service life of road surfaces. Today, 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] The prior art CN114656218B discloses a low-shrinkage, crack-resistant concrete and its preparation method, comprising the following raw materials in parts by weight: 100-150 parts water, 80-120 parts cement, 50-90 parts silica sand, 40-80 parts fly ash, 50-80 parts limestone, 20-40 parts reinforcing fiber, and 5-8 parts water-reducing agent. The reinforcing fiber includes modified basalt fiber. The preparation method of modified basalt fiber includes the following steps: 1) Immersing basalt fiber in acid solution, removing it, washing it until neutral, and drying it to obtain pretreated fiber; 2) Taking a rare earth solution, placing the pretreated fiber prepared in step 1) in the rare earth solution, soaking it for 2-3 hours, removing it, and drying it to obtain the crack-resistant concrete.

[0004] However, the aforementioned patent describes a modified basalt fiber obtained by acid leaching followed by soaking in a rare earth solution. However, the number of active sites exposed after acid leaching is limited, and simple room temperature soaking and drying is insufficient to allow the effective components in the rare earth solution to form a stable cross-linked structure with the basalt fiber. Furthermore, the concrete lacks a curing agent that can stably disperse the modified basalt fiber, resulting in the need for further improvement in the crack resistance and wear resistance of this concrete material. Summary of the Invention

[0005] The purpose of this invention is to provide a basalt fiber reinforced crack-resistant road concrete and its preparation method, in order 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 objective of this invention can be achieved through the following technical solution: a basalt fiber reinforced crack-resistant road concrete, comprising the following raw material components by weight: 25-30 parts cement, 6-8 parts composite basalt fiber, 8-12 parts modified curing agent, 100-120 parts coarse aggregate, 60-70 parts fine aggregate, 10-14 parts fly ash and 8-12 parts auxiliary additives.

[0007] The auxiliary additive is prepared by mixing deionized water, polycarboxylate superplasticizer, sodium dodecyl sulfate, hydroxypropyl methylcellulose ether and polydimethylsiloxane in a ratio of 280-300g:10-12g:80-100g:4-5g:0.1-0.3g.

[0008] The fine aggregate is obtained by passing natural river sand through a 40-60 mesh sieve; the coarse aggregate consists of the following raw materials by weight: 1-2 parts of building crushed stone with a particle size of 4.5-5.0 mm and 2-3 parts of basalt fragments with a particle size of 5.4-9.6 mm.

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

[0010] A1. Tetramethyl silicate, deionized water and anhydrous ethanol are added to the reaction vessel and stirred. After the temperature of the reaction vessel is raised to 30-50℃, the pH of the reaction system is adjusted to 8-10 using saturated sodium hydroxide aqueous solution. After stirring and maintaining the temperature for 12-16h, activated basalt fiber is added to the reaction vessel and stirred and maintained for 1-2h. The composite basalt fiber precursor is obtained by post-treatment.

[0011] A2. Add hydroxyl silicone oil and ethanol to the reactor. Raise the temperature of the reactor to 40-50°C and stir for 10-15 minutes. Then add the composite basalt fiber precursor to the reactor and impregnate for 40-60 minutes. After post-treatment, the composite basalt fiber is obtained.

[0012] The reaction principle for preparing composite basalt fibers is as follows: under alkaline and heated conditions, tetramethyl silicate undergoes hydrolysis. After prolonged stirring, silica particles are generated in the reaction system, followed by the addition of activated basalt fibers. The active reaction sites on the surface of the activated basalt fibers attract silica particles to adhere to the surface of the activated basalt fibers, thereby repairing the defects on the surface of the activated basalt fibers and obtaining a composite basalt fiber precursor. The silica particles on the surface of the composite basalt fiber precursor further improve the surface roughness of the fiber. Through physical adhesion and chemical group reaction, hydroxyl silicone oil is uniformly adhered to the surface of the composite basalt fiber precursor. Finally, after curing, composite basalt fibers are obtained.

[0013] Further, in step A1, the ratio of tetramethyl silicate, deionized water, anhydrous ethanol and activated basalt fiber is 3-4g:20-30mL:40-60mL:10-12g. The post-treatment includes: after the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction liquid to collect the filter cake, wash the filter cake 3-5 times with anhydrous ethanol and deionized water, transfer the filter cake to a reaction vessel at a temperature of 60-80℃, and vacuum dry it to constant weight to obtain the composite basalt fiber precursor.

[0014] Further, in step A2, the ratio of hydroxyl silicone oil, ethanol, and composite basalt fiber precursor is 4-6g:100-120mL:10-12g. The post-treatment includes: after impregnation, the composite basalt fiber precursor is removed and transferred to a muffle furnace. The muffle furnace is heated to 240-250℃ at a heating rate of 8-10℃ / min and held at that temperature for 2-3 hours. After the muffle furnace temperature is allowed to cool naturally to room temperature, composite basalt fiber is obtained.

[0015] Furthermore, the preparation method of activated basalt fibers includes the following steps:

[0016] B1. Disperse basalt fibers into an ultrasonic generator containing a 3-5 wt% sodium hydroxide aqueous solution, raise the temperature of the ultrasonic generator to 40-50℃, maintain the temperature and sonicate for 40-60 min, and then process to obtain modified basalt fibers.

[0017] B2. The modified basalt fiber is plasma activated to obtain activated basalt fiber.

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

[0019] Further, in step B1, the ratio of basalt fiber to 3-5wt% sodium hydroxide aqueous solution is 2-3g:30-36mL, the ultrasonic frequency is 20-40kHz, and the post-treatment includes: after the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction solution to collect the filter cake, wash the filter cake 3-5 times with anhydrous ethanol and deionized water, transfer the filter cake to a reaction vessel at a temperature of 60-80℃, and vacuum dry it to constant weight to obtain modified basalt fiber;

[0020] Further, in step B2, the plasma activation operation is as follows: the modified basalt fiber is placed in a quartz tube. After the quartz tube is determined to be airtight, the air is evacuated. The internal air pressure of the quartz tube is controlled to be 30-40 Pa. The rotation speed of the quartz tube is adjusted to 15-20 r / min. After rotating for 2-3 min, the frequency of the low-temperature plasma generator is controlled to be 13.56 MHz and the power to be 100-120 W. The gate is opened to introduce oxygen at a rate of 20 mL / min. The discharge lasts for 270-320 s. After the discharge is completed, the vacuuming is stopped. After the internal air pressure of the quartz tube returns to atmospheric pressure, the fiber is taken out and vacuum-packed to obtain activated basalt fiber.

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

[0022] C1. Vinyltrichlorosilane, vinyldichloroborane, N,N-dimethylformamide and deionized water are added to a reaction vessel and stirred. After the temperature of the reaction vessel is raised to 40-60℃, the pH of the reaction system is adjusted to 8-10 using a saturated sodium hydroxide aqueous solution. The mixture is kept at this temperature and stirred for 2-3 hours. The modified borosilicate is then obtained after post-treatment.

[0023] C2. Modified borosilicate, benzoic acid, aluminum chloride and N,N-dimethylformamide are added to a low-temperature reactor and stirred. The reactor temperature is reduced to 0-5℃. While maintaining the temperature and stirring, saturated hydrogen peroxide aqueous solution is added dropwise to the reactor. The dropwise addition is maintained for 3-4 hours. After the dropwise addition is completed, the reactor is stirred at the temperature for 40-60 minutes. The modified curing agent is then obtained through post-treatment.

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

[0025]

[0026] The reaction principle for preparing the modified activator is as follows: under alkaline conditions, the chlorine groups on vinyltrichlorosilane and vinyldichloroborane undergo hydrolysis, causing the silicon and boron groups to form a spatially cross-linked modified borosilicate. The double bond structure on the modified borosilicate is then converted into epoxy groups through low-temperature oxidation with peroxy acid, ultimately yielding the modified curing agent.

[0027] Further, in step C1, the ratio of vinyltrichlorosilane, vinyldichloroborane, N,N-dimethylformamide and deionized water is 4-6g:2-3g:20-30mL:10-12mL. The post-treatment includes: after the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, transfer the reaction solution to a rotary evaporator, raise the temperature of the rotary evaporator to 60-80℃, and distill under reduced pressure until no liquid is collected to obtain modified borosilicate.

[0028] Further, in step C2, the ratio of modified borosilicate, 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. The post-treatment includes: after the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, transfer the reaction solution to a rotary evaporator, raise the temperature of the rotary evaporator to 60-80℃, and distill under reduced pressure until no liquid is collected to obtain the modified curing agent.

[0029] This invention also proposes a method for preparing basalt fiber-reinforced crack-resistant road concrete, comprising the following steps:

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

[0031] S2. Transfer the concrete precursor to the mold, transfer the mold to the vibrating table, vibrate for 1-2 minutes, use a scraper to smooth the raised parts of the surface and cover the material surface with plastic wrap. The post-treatment yields crack-resistant concrete.

[0032] Furthermore, in step S2, the post-treatment includes: transferring the mold to a standard curing chamber at a temperature of 25°C and a humidity of 95%, curing it at constant temperature and humidity for 24-36 hours, demolding it, immersing it in room temperature water for 20-24 hours, and then air-drying it to obtain crack-resistant concrete.

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

[0034] 1. This invention significantly improves the compressive strength and wear resistance of concrete through the synergistic effect of composite basalt fibers and modified curing agents. After cleaning and surface activation, the basalt fibers are modified with silica particles and impregnated with silicone oil to form a structure that combines a rough surface with a flexible transition layer. This allows the fibers to be tightly embedded in the cement matrix and to disperse stress through elastic buffering, preventing crack propagation. During hydration, the modified curing agent forms a stable cross-linked network, and its epoxy groups form chemical bonds with the cement components, effectively filling pores and improving the density of the matrix, reducing the generation of internal microcracks. The curing agent inhibits crack initiation through densification, while the fibers prevent crack propagation through physical bridging. At the same time, the silica on the fiber surface forms chemical bonds with the silicon components 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, thereby simultaneously solving the problems of high brittleness and easy cracking of traditional concrete.

[0035] 2. This invention improves the flexural and tensile strength of concrete by modifying the combination of basalt fiber and curing agent. After chemical cleaning to remove surface impurities, the basalt fiber is activated to form a micro-uneven structure on its surface. Subsequently, it is covered with silica particles and impregnated with silicone oil. After high-temperature curing, the rough particle layer on the fiber surface enhances the mechanical bond with the concrete, while the flexible silicone oil layer buffers stress and prevents the fiber from separating from the concrete. The treated fiber forms a three-dimensional network structure in the concrete, which can effectively hold cracks and disperse stress. At the same time, the modified curing agent reduces the generation of micro-cracks inside the concrete by combining with the material, while the fiber prevents the propagation of existing cracks through physical bridging. Simultaneously, the silica 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 external stress, and the curing agent strengthens the internal structure. Through material modification and chemical reaction, the two work together to control the crack generation and propagation path, jointly delaying crack development and improving load-bearing capacity.

[0036] 3. In this invention, after the basalt fiber is first surface-cleaned and activated, it is covered with a layer of silica microparticles and coated with a silicone oil protective layer. The silica particles are tightly bonded to the fiber, forming an acid and alkali resistant protective layer. This layer works synergistically with the silicone oil to prevent corrosive liquids from penetrating into the bond between the fiber and the concrete. Furthermore, the silica on the fiber surface and the silicon component in the curing agent chemically bond together, making the fiber and concrete adhere more firmly and preventing corrosion gaps caused by poor bonding. The modified curing agent undergoes a chemical reaction when the concrete solidifies, forming a stable network structure that fills the tiny pores inside the concrete, reducing the formation of cracks. At the same time, it connects with the cement components through chemical bonds, making the concrete more compact and solid, reducing the possibility of corrosive gases or liquids diffusing inside. By reducing the internal pores and cracks of the concrete through the curing agent, and by blocking the intrusion of corrosive media from the outside, the corrosion resistance of the concrete is significantly improved. Detailed Implementation

[0037] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The fly ash used in this invention was purchased from Wuhan Jiyesheng Chemical Co., Ltd., with product number A01085.

[0039] The hydroxyl silicone oil used in this invention was purchased from Zhejiang Zhenghe Silicon Materials Co., Ltd., and its grade is 207-35.

[0040] The bisphenol A type epoxy resin used in this invention was purchased from Shandong Qiansheng Chemical Co., Ltd., and its grade is E51.

[0041] The cement used in this invention was purchased from Jiaozuo Qianye Cement Co., Ltd., and the type is P.O42.5 silicate cement;

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

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

[0044] The hydroxypropyl methylcellulose ether used in this invention was purchased from Shanghai Yuanye Biotechnology Co., Ltd., with product number S25213-250g.

[0045] The basalt fiber used in this invention was purchased from Jiangsu Jumao New Material Technology Co., Ltd., and its product name is Basalt Fiber for Asphalt Mixture.

[0046] Example 1

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

[0048] Step ①: Preparation of modified borosilicate

[0049] Weigh out 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 a reaction vessel. Stir the mixture and raise the temperature of the reaction vessel to 40°C. Adjust the pH of the reaction system to 8 using a saturated sodium hydroxide aqueous solution. Keep the mixture warm and stir for 2 hours. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature and transfer the reaction solution to a rotary evaporator. Raise the temperature of the rotary evaporator to 60°C and distill under reduced pressure until no liquid is collected to obtain modified borosilicate.

[0050] Step 2: Preparation of modified curing agent

[0051] Weigh out 48.0 g of modified borosilicate, 15.0 g of benzoic acid, 1.8 g of aluminum chloride, and 240.0 mL of N,N-dimethylformamide and add them to a low-temperature reactor. Stir the reactor until the temperature drops to 5°C. While maintaining the temperature and stirring, add 30.0 mL of saturated hydrogen peroxide aqueous solution dropwise to the reactor. Continue the dropwise addition for 3 hours. After the addition is complete, stir the reactor for 40 minutes. Once the reaction is complete, let the temperature of the reactor drop to room temperature. Transfer the reaction solution to a rotary evaporator. Raise the temperature of the rotary evaporator to 60°C and distill under reduced pressure until no liquid is collected to obtain the modified curing agent.

[0052] Example 2

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

[0054] Step ①: Preparation of modified borosilicate

[0055] Weigh out 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 vessel. Stir the mixture and raise the temperature of the reaction vessel to 60°C. Adjust the pH of the reaction system to 10 using a saturated sodium hydroxide aqueous solution. Keep the mixture warm and stir for 3 hours. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature and transfer the reaction solution to a rotary evaporator. Raise the temperature of the rotary evaporator to 80°C and distill under reduced pressure until no liquid is collected to obtain modified borosilicate.

[0056] Step 2: Preparation of modified curing agent

[0057] Weigh out 54.0 g of modified borosilicate, 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 reactor. Stir the reactor until the temperature drops to 0°C. While maintaining the temperature and stirring, add 36.0 mL of saturated hydrogen peroxide aqueous solution dropwise to the reactor. Continue the dropwise addition for 4 hours. After the addition is complete, stir the reactor for 60 minutes. Once the reaction is complete, let the temperature of the reactor drop to room temperature. Transfer the reaction solution to a rotary evaporator. Raise the temperature of the rotary evaporator to 80°C and distill under reduced pressure until no liquid is collected to obtain the modified curing agent.

[0058] Example 3

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

[0060] Step ①: Preparation of modified borosilicate

[0061] Weigh out 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 vessel. Stir the mixture and raise the temperature of the reaction vessel to 50°C. Adjust the pH of the reaction system to 9 using a saturated sodium hydroxide aqueous solution. Keep the mixture warm and stir for 3 hours. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature and transfer the reaction solution to a rotary evaporator. Raise the temperature of the rotary evaporator to 70°C and distill under reduced pressure until no liquid is collected to obtain modified borosilicate.

[0062] Step 2: Preparation of modified curing agent

[0063] Weigh out 51.0 g of modified borosilicate, 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 reactor. Stir the reactor until the temperature drops to 3°C. While maintaining the temperature and stirring, add 36.0 mL of saturated hydrogen peroxide aqueous solution dropwise to the reactor. Continue the dropwise addition for 4 hours. After the addition is complete, stir the reactor for 50 minutes. Once the reaction is complete, let the temperature of the reactor drop to room temperature. Transfer the reaction solution to a rotary evaporator and raise the temperature of the rotary evaporator to 70°C. Distill under reduced pressure until no liquid is collected to obtain the modified curing agent.

[0064] Example 4

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

[0066] Step I: Preparation of modified basalt fibers

[0067] Weigh 20.0g of basalt fiber and disperse it in an ultrasonic generator containing 300.0mL of 3wt% sodium hydroxide aqueous solution. Raise the temperature of the ultrasonic generator to 40℃, set the ultrasonic frequency to 20kHz, and maintain the temperature for 40min. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction liquid and collect the filter cake. Wash the filter cake three times with anhydrous ethanol and deionized water, then transfer the filter cake to a reaction vessel at 60℃ and vacuum dry it to constant weight to obtain modified basalt fiber.

[0068] Step II: Preparation of activated basalt fibers

[0069] Weigh 20.0g of modified basalt fiber and place it in a quartz tube. After the quartz tube is determined to be airtight, evacuate the air and control the internal air pressure of the quartz tube to 30Pa. Then, adjust the rotation speed of the quartz tube to 15r / min and rotate for 2min. Control the frequency of the low-temperature plasma generator to 13.56MHz and the power to 100W, open the gate to introduce oxygen at a rate of 20mL / min, and discharge for 270s. After the discharge is completed, stop evacuating the vacuum. After the internal air pressure of the quartz tube returns to atmospheric pressure, take out the fiber and vacuum package it to obtain activated basalt fiber.

[0070] Example 5

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

[0072] Step I: Preparation of modified basalt fibers

[0073] Weigh out 30.0g of basalt fiber and disperse it in an ultrasonic generator containing 360.0mL of 5wt% sodium hydroxide aqueous solution. Raise the temperature of the ultrasonic generator to 50℃, set the ultrasonic frequency to 40kHz, and maintain the temperature for 60min. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction liquid and collect the filter cake. Wash the filter cake 5 times with anhydrous ethanol and deionized water, then transfer the filter cake to a reaction vessel at 80℃ and vacuum dry it to constant weight to obtain modified basalt fiber.

[0074] Step II: Preparation of activated basalt fibers

[0075] Weigh 30.0g of modified basalt fiber and place it in a quartz tube. After the quartz tube is determined to be airtight, evacuate the air and control the internal air pressure of the quartz tube to 40Pa. Then, adjust the rotation speed of the quartz tube to 20r / min and rotate for 3min. Control the frequency of the low-temperature plasma generator to 13.56MHz and the power to 120W, open the gate to introduce oxygen at a rate of 20mL / min, and discharge for 320s. After the discharge is completed, stop evacuating the vacuum. After the internal air pressure of the quartz tube returns to atmospheric pressure, remove the fiber and vacuum package it to obtain activated basalt fiber.

[0076] Example 6

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

[0078] Step I: Preparation of modified basalt fibers

[0079] Weigh out 24.0g of basalt fiber and disperse it in an ultrasonic generator containing 320.0mL of 4wt% sodium hydroxide aqueous solution. Raise the temperature of the ultrasonic generator to 50℃, set the ultrasonic frequency to 36kHz, and maintain the temperature for 50min. After the reaction is complete, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction liquid and collect the filter cake. Wash the filter cake four times with anhydrous ethanol and deionized water, then transfer the filter cake to a reaction vessel at 80℃ and vacuum dry it to constant weight to obtain modified basalt fiber.

[0080] Step II: Preparation of activated basalt fibers

[0081] Weigh 24.0g of modified basalt fiber and place it in a quartz tube. After the quartz tube is determined to be airtight, evacuate the air and control the internal air pressure of the quartz tube to 36Pa. Then, adjust the rotation speed of the quartz tube to 18r / min and rotate for 3min. Control the frequency of the low-temperature plasma generator to 13.56MHz and the power to 120W. Open the gate to introduce oxygen at a rate of 20mL / min. Discharge for 300s. After the discharge is completed, stop evacuating the vacuum. After the internal air pressure of the quartz tube returns to atmospheric pressure, take out the fiber and vacuum package it to obtain activated basalt fiber.

[0082] Example 7

[0083] This embodiment provides a method for preparing composite basalt fibers for use in the preparation of crack-resistant road concrete reinforced with basalt fibers, including the following steps:

[0084] Step 1: Preparation of composite basalt fiber precursor

[0085] Weigh out 6.0 g of tetramethyl silicate, 40.0 mL of deionized water and 80.0 mL of anhydrous ethanol and add them to the reaction vessel. Stir the mixture. After the temperature of the reaction vessel is raised to 30°C, adjust the pH of the reaction system to 8 using saturated sodium hydroxide aqueous solution. After stirring for 12 h, add 20.0 g of the activated basalt fiber prepared in step 4 to the reaction vessel and stir for 1 h. After the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction liquid and collect the filter cake. Wash the filter cake three times with anhydrous ethanol and deionized water. Transfer the filter cake to the reaction vessel at 60°C and vacuum dry it to constant weight to obtain the composite basalt fiber precursor.

[0086] Step 2: Preparation of composite basalt fibers

[0087] Weigh out: Add 8.0g of hydroxyl silicone oil and 200.0mL of ethanol to the reaction vessel. Raise the temperature of the reaction vessel to 40℃ and stir for 10min. Then add 20.0g of composite basalt fiber precursor to the reaction vessel and impregnate for 40min. After impregnation, remove the composite basalt fiber precursor and transfer it to a muffle furnace. Heat the muffle furnace to 240℃ at a heating rate of 8℃ / min and hold for 2h. Allow the muffle furnace to cool naturally to room temperature to obtain composite basalt fiber.

[0088] Example 8

[0089] This embodiment provides a method for preparing composite basalt fibers for use in the preparation of crack-resistant road concrete reinforced with basalt fibers, including the following steps:

[0090] Step 1: Preparation of composite basalt fiber precursor

[0091] Weigh out 8.0 g of tetramethyl silicate, 60.0 mL of deionized water, and 120.0 mL of anhydrous ethanol and add them to the reaction vessel. Stir the mixture. After the temperature of the reaction vessel is raised to 50°C, adjust the pH of the reaction system to 10 using a saturated sodium hydroxide aqueous solution. After stirring for 16 h, add 24.0 g of the activated basalt fiber prepared in step 5 to the reaction vessel and stir for 1 h. After the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction liquid and collect the filter cake. Wash the filter cake 5 times with anhydrous ethanol and deionized water, and then transfer the filter cake to the reaction vessel at 80°C. Vacuum dry to constant weight to obtain the composite basalt fiber precursor.

[0092] Step 2: Preparation of composite basalt fibers

[0093] Weigh out: Add 12.0g of hydroxyl silicone oil and 240.0mL of ethanol to the reaction vessel. Raise the temperature of the reaction vessel to 50℃ and stir for 15min. Then add 24.0g of composite basalt fiber precursor to the reaction vessel and impregnate for 60min. After impregnation, remove the composite basalt fiber precursor and transfer it to a muffle furnace. Raise the temperature of the muffle furnace to 250℃ at a heating rate of 10℃ / min and hold for 3h. Allow the temperature of the muffle furnace to cool naturally to room temperature to obtain composite basalt fiber.

[0094] Example 9

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

[0096] Step 1: Preparation of composite basalt fiber precursor

[0097] Weigh out 7.2 g of tetramethyl silicate, 54.0 mL of deionized water and 100.0 mL of anhydrous ethanol and add them to the reaction vessel. Stir the mixture. After the temperature of the reaction vessel is raised to 40°C, adjust the pH of the reaction system to 9 using saturated sodium hydroxide aqueous solution. After stirring for 16 h, add 24.0 g of the activated basalt fiber prepared in step 6 to the reaction vessel and stir for 2 h. After the reaction is completed, wait for the temperature of the reaction vessel to drop to room temperature, filter the reaction liquid and collect the filter cake. Wash the filter cake 4 times with anhydrous ethanol and deionized water. Transfer the filter cake to the reaction vessel at 80°C and vacuum dry it to constant weight to obtain the composite basalt fiber precursor.

[0098] Step 2: Preparation of composite basalt fibers

[0099] Weigh out: Add 10.0g of hydroxyl silicone oil and 210.0mL of ethanol to the reaction vessel. The reaction vessel is heated to 50℃ and stirred for 15min. Then, add 24.0g of composite basalt fiber precursor to the reaction vessel and impregnate for 54min. After impregnation, remove the composite basalt fiber precursor and transfer it to a muffle furnace. The muffle furnace is heated to 240℃ at a heating rate of 9℃ / min and held for 3h. After the muffle furnace temperature is allowed to cool naturally to room temperature, composite basalt fiber is obtained.

[0100] Example 10

[0101] This embodiment provides a method for preparing basalt fiber-reinforced crack-resistant road concrete, including the following steps:

[0102] Step 1: Preparation of concrete precursor

[0103] Weigh out 280 parts of deionized water, 10 parts of polycarboxylate superplasticizer, 80 parts of sodium dodecyl sulfate, 4 parts of hydroxypropyl methylcellulose ether, and 0.1 parts of polydimethylsiloxane and mix them to obtain the auxiliary additive;

[0104] Weigh out 1 part of 4.5mm building crushed stone and 2 parts of 5.4mm basalt slag and mix them to obtain coarse aggregate;

[0105] Natural river sand is passed through a 40-mesh sieve to obtain fine aggregate;

[0106] Weigh out 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 and place them in a mixing tank. Mix them evenly, add 100 parts of coarse aggregate, stir for 1 minute, then add 8 parts of the modified curing agent prepared in Example 1 and 8 parts of auxiliary additives, stir for 3 minutes to obtain the concrete precursor.

[0107] Step 2: Preparation of crack-resistant concrete

[0108] The concrete precursor is transferred to a mold, which is then placed on a vibrating table. After vibrating for 1 minute, the raised areas on the surface are smoothed with a scraper, and the material surface is covered with plastic wrap. The mold is then transferred to a standard curing chamber at 25°C and 95% humidity. After curing at constant temperature and humidity for 24 hours, the mold is demolded, immersed in room temperature water for 20 hours, and then dried to obtain crack-resistant concrete.

[0109] Example 11

[0110] This embodiment provides a method for preparing basalt fiber-reinforced crack-resistant road concrete, including the following steps:

[0111] Step 1: Preparation of concrete precursor

[0112] Weigh out 300 parts of deionized water, 12 parts of polycarboxylate superplasticizer, 100 parts of sodium dodecyl sulfate, 5 parts of hydroxypropyl methylcellulose ether and 0.3 parts of polydimethylsiloxane and mix them to obtain auxiliary additives;

[0113] Weigh out 2 parts of 5.0mm building crushed stone and 3 parts of 6.4mm basalt slag and mix them to obtain coarse aggregate;

[0114] Natural river sand is passed through a 60-mesh sieve to obtain fine aggregate;

[0115] Weigh out 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 and place them in a mixing tank. Mix them 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 additives, stir for 5 minutes to obtain the concrete precursor.

[0116] Step 2: Preparation of crack-resistant concrete

[0117] The concrete precursor is transferred to a mold, which is then placed on a vibrating table. After vibrating for 2 minutes, the raised areas on the surface are smoothed with a scraper, and the material surface is covered with plastic wrap. The mold is then transferred to a standard curing chamber at 25°C and 95% humidity. After curing at constant temperature and humidity for 36 hours, the mold is removed, and the material is soaked in room temperature water for 24 hours and then dried to obtain crack-resistant concrete.

[0118] Example 12

[0119] This embodiment provides a method for preparing basalt fiber-reinforced crack-resistant road concrete, including the following steps:

[0120] Step 1: Preparation of concrete precursor

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

[0122] Weigh out 1 part of building crushed stone 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] Natural river sand is passed through a 50-mesh sieve to obtain fine aggregate;

[0124] Weigh out 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 and place them in a mixing tank. Mix them 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 additives, stir for 4 minutes to obtain the concrete precursor.

[0125] Step 2: Preparation of crack-resistant concrete

[0126] The concrete precursor is transferred to a mold, which is then placed on a vibrating table. After vibrating for 2 minutes, the raised areas on the surface are smoothed with a scraper, and the material surface is covered with plastic wrap. The mold is then transferred to a standard curing chamber at 25°C and 95% humidity. After curing at constant temperature and humidity for 32 hours, the material is demolded, soaked in room temperature water for 21 hours, and then dried to obtain crack-resistant concrete.

[0127] Comparative Example 1

[0128] The difference between this comparative example and Example 12 is that, in the preparation process of the composite basalt fiber, step (i) is omitted, and in step (ii), activated basalt fiber is used to replace the composite basalt fiber precursor in an equal amount.

[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, vinyl dichloroborane was omitted and replaced with an equal amount of vinyl trichlorosilane.

[0131] Comparative Example 3

[0132] The difference between this comparative example and Example 12 is that an equal amount of bisphenol A type epoxy resin was used to replace the modified adhesive.

[0133] Performance testing:

[0134] 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 curing, in accordance with the standard GB / T 50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete".

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

[0136] Table 1 - Performance Test Data for Each Sample

[0137]

[0138] Data Analysis:

[0139] A comparative analysis of the data in Table 1 above reveals that the crack-resistant concrete prepared by this invention has a flexural strength of 13.54 MPa, a compressive strength of 64.17 MPa, a splitting tensile strength of 6.71 MPa, and an abrasion loss of 1.24 kg·m² after 45 cycles. 2 At the same time, its sulfate resistance grade is KS150, and all data are better than the comparative example;

[0140] This invention significantly improves the compressive strength and wear resistance of concrete through the synergistic effect of composite basalt fibers and modified curing agents. After cleaning and surface activation, the basalt fibers are modified with silica particles and impregnated with silicone oil to form a structure that combines a rough surface with a flexible transition layer. This allows the fibers to be tightly embedded in the cement matrix and to disperse stress through elastic buffering, preventing crack propagation. During hydration, the modified curing agent forms a stable cross-linked network, and its epoxy groups form chemical bonds with the cement components, effectively filling pores and improving the density of the matrix, reducing the generation of internal microcracks. The curing agent inhibits crack initiation through densification, while the fibers prevent crack propagation through physical bridging. At the same time, the silica on the fiber surface forms chemical bonds with the silicon components in the curing agent, forming 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 simultaneously solving the problems of high brittleness and easy cracking of traditional concrete.

[0141] This invention improves the flexural and tensile strength of concrete by modifying the combination of basalt fiber and curing agent. After chemical cleaning to remove surface impurities, the basalt fiber is activated to form a micro-uneven structure on its surface. It is then covered with silica particles and impregnated with silicone oil. After high-temperature curing, the rough particle layer on the fiber surface strengthens the mechanical bond with the concrete, while the flexible silicone oil layer buffers stress and prevents the fiber from separating from the concrete. The treated fiber forms a three-dimensional network structure in the concrete, which can effectively hold cracks and disperse stress. At the same time, the modified curing agent reduces the generation of micro-cracks inside the concrete by combining with the material, while the fiber prevents the propagation of existing cracks through physical bridging. Simultaneously, the silica 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 external stress, and the curing agent strengthens the internal structure. Through material modification and chemical reaction, the two work together to control the crack generation and propagation path, delaying crack development and improving load-bearing capacity.

[0142] In this invention, basalt fibers are first surface-cleaned and activated, then covered with a layer of silica microparticles and coated with a silicone oil protective layer. The silica particles are tightly bonded to the fibers, forming an acid and alkali resistant protective layer. This layer works synergistically with the silicone oil to prevent corrosive liquids from penetrating the bond between the fibers and concrete. Furthermore, the silica on the fiber surface and the silicon component in the curing agent chemically bond together, making the fibers and concrete adhere more firmly and preventing corrosion gaps caused by weak bonding. The modified curing agent undergoes a chemical reaction during concrete solidification, forming a stable network structure that fills the tiny pores inside the concrete, reducing crack formation. Simultaneously, it connects with the cement components through chemical bonds, making the concrete more compact and solid, reducing the possibility of corrosive gases or liquids diffusing inside. By reducing internal pores and cracks in the concrete through the curing agent, and by blocking the intrusion of corrosive media from the outside, the corrosion resistance of the concrete is significantly improved.

[0143] The process involves cleaning and activating basalt fibers, then surface-modifying and curing them to obtain composite basalt fibers. Modified borosilicates with double bond structures are prepared by hydrolyzing borosilicate monomers. Through an epoxidation reaction, the double bond structure is converted into epoxy groups to obtain a modified curing agent. These two are then used as additives and mixed with cement and other materials to obtain a wear-resistant, flexurally resistant, corrosion-resistant, and crack-resistant concrete.

[0144] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to specific implementations. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A basalt fiber reinforced anti-cracking road concrete comprising cement, coarse aggregate, fine aggregate, fly ash and auxiliary additives, characterized in that, The composite basalt fiber also includes a modified curing agent; The tetramethyl orthosilicate, deionized water and anhydrous ethanol are stirred and added into a reaction kettle, the temperature of the reaction kettle is raised to 30-50℃, then saturated sodium hydroxide aqueous solution is used to adjust the pH of the reaction system to 8-10, after 12-16h of heat preservation and stirring, the activated basalt fiber is added into the reaction kettle, and after 1-2h of heat preservation and stirring, the composite basalt fiber precursor is obtained after post-treatment; then the hydroxyl silicone oil and ethanol are added into the reaction kettle, the temperature of the reaction kettle is stably raised to 40-50℃, after 10-15min of heat preservation and stirring, the composite basalt fiber precursor is added into the reaction kettle, and soaked for 40-60min, then the composite basalt fiber is obtained after post-treatment, wherein the activated basalt fiber is prepared by plasma activation; The vinyltrichlorosilane, vinyl dichloroborane, N,N-dimethylformamide and deionized water are stirred and added into a reaction kettle, the temperature of the reaction kettle is raised to 40-60℃, then saturated sodium hydroxide aqueous solution is used to adjust the pH of the reaction system to 8-10, after 2-3h of heat preservation and stirring, the modified boron silane is obtained after post-treatment, wherein the amount ratio of the vinyltrichlorosilane, vinyl dichloroborane, N,N-dimethylformamide and deionized water is 4-6g:2-3g:20-30mL:10-12mL; The structural formula of the ethylenedichloroborane is: ; Then the modified boron silane, benzoic acid, aluminum chloride and N,N-dimethylformamide are stirred and added into a low-temperature reaction kettle, the temperature of the reaction kettle is reduced to 0-5℃, then saturated hydrogen peroxide aqueous solution is added dropwise into the reaction kettle under the condition of heat preservation and stirring, the dropwise operation is maintained for 3-4h, after the dropwise operation is completed, the temperature of the reaction kettle is maintained for 40-60min of heat preservation and stirring, then the modified curing agent is obtained after post-treatment, wherein the amount ratio of the modified boron silane, 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; The cement, the composite basalt fiber, the modified curing agent, the coarse aggregate, the fine aggregate, the fly ash and the auxiliary additive are mixed in a weight ratio of 25-30:6-8:8-12:100-120:60-70:10-14:8-12 to prepare the anti-cracking road concrete.

2. A basalt fiber reinforced crack resistant road concrete as claimed in claim 1, wherein, The auxiliary additive is obtained by mixing deionized water, polycarboxylate superplasticizer, sodium dodecyl sulfate, hydroxypropyl methyl cellulose ether and polydimethylsiloxane in an amount ratio of 280-300g:10-12g:80-100g:4-5g:0.1-0.3g.

3. A basalt fiber reinforced crack resistant road concrete as claimed in claim 1, wherein, The amount ratio of the tetramethyl orthosilicate, deionized water, anhydrous ethanol and activated basalt fiber is 3-4g:20-30mL:40-60mL:10-12g; the amount ratio of the hydroxyl silicone oil, ethanol and composite basalt fiber precursor is 4-6g:100-120mL:10-12g.

4. A basalt fiber reinforced crack resistant road concrete as claimed in claim 1, wherein, The preparation method of the activated basalt fiber comprises the following steps: B1, disperse basalt fiber into ultrasonic generator containing 3-5wt% sodium hydroxide solution, the temperature of ultrasonic generator is raised to 40-50℃, ultrasonic treatment for 40-60min, and then obtain modified basalt fiber after post-treatment; B2, plasma activate the modified basalt fiber to obtain activated basalt fiber.

5. A basalt fiber reinforced crack resistant road concrete as claimed in claim 4, wherein, In step B1, the ratio of basalt fiber and 3-5wt% sodium hydroxide solution is 2-3g:30-36mL; in step B2, the plasma activation operation is as follows: place the modified basalt fiber into quartz tube, after the quartz tube reaches airtightness, pump out air, control the internal pressure of quartz tube to be 30-40Pa, adjust the rotation speed of quartz tube to be 15-20r / min, rotate for 2-3min, control the frequency of low-temperature plasma generator to be 13.56MHz, the power to be 100-120W, open the gate to introduce oxygen, the oxygen introduction rate is 20mL / min, discharge for 270-320s, stop pumping out air after the discharge is completed, take out the fiber after the internal pressure of quartz tube returns to atmospheric pressure, and vacuum package to obtain activated basalt fiber.

6. A method of producing a basalt fiber reinforced anti-cracking road concrete according to any one of claims 1 to 5, characterized in that, Comprise the following steps: S1, place composite basalt fiber, fine aggregate, fly ash and cement in a stirred tank, mix uniformly, add coarse aggregate, stir for 3-5min, then add modified curing agent and auxiliary additive, stir for 5-8min, to obtain concrete precursor; S2, transfer the concrete precursor to a mold, transfer the mold to a vibration table, vibrate for 1-2min, use a scraper to scrape the surface protrusions flat and cover the material surface with plastic wrap, to obtain anti-cracking concrete after post-treatment.

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