Impact-resistant concrete synergistically toughened by PVA (polyvinyl alcohol) fiber and waste glass powder

Abstract

The invention relates to the technical field of special low-carbon concrete, and discloses PVA fiber and waste glass powder synergistically toughened impact-resistant concrete. The PVA fiber and waste glass powder synergistically toughened impact-resistant concrete is prepared from the following raw materials in parts by mass: 280 to 360 parts of cement, 40 to 120 parts of modified waste glass powder, 700 to 800 parts of medium sand, 900 to 1000 parts of gravel, 10 to 20 parts of modified PVA fiber, 6 to 7 parts of water reducing agent, 1 to 3 parts of defoaming agent, 0.5 to 1 part of composite hydration accelerant and 160 to 220 parts of water. According to the impact-resistant concrete synergistically toughened by the PVA fibers and the waste glass powder, provided by the invention, the 28-day compressive strength can reach 61.2 MPa, the 28-day breaking strength can reach 10.8 MPa, the final crack impact frequency can reach 136, and the impact-resistant concrete has good mechanical properties and impact resistance.

Description

Technical Field

[0001] This invention relates to the field of special low-carbon concrete technology, and more specifically, to an impact-resistant concrete synergistically toughened with PVA fiber and waste glass powder. Background Technology

[0002] Concrete, as the world's most widely used building material, is extensively applied in various engineering projects such as buildings, bridges, tunnels, and military defense. However, the inherent disadvantages of traditional concrete, such as high brittleness, low tensile strength, easy cracking, and poor impact resistance, severely limit its application in important engineering structures that need to withstand dynamic loads, explosive impacts, or fatigue stress.

[0003] To improve the toughness and impact resistance of concrete, the most common method used in engineering is to incorporate various fibers into the concrete, such as steel fibers, polypropylene fibers, and polyvinyl alcohol (PVA) fibers. Among these, PVA fibers have attracted widespread attention due to their high tensile strength, high elastic modulus, excellent alkali resistance, and affinity with the cement matrix. PVA fibers can form a three-dimensional randomized support system within the concrete, effectively bridging microcracks and preventing crack propagation, thereby significantly improving the toughness and impact resistance of the concrete.

[0004] However, the application of PVA fibers still faces challenges. First, the smooth surface of PVA fibers results in weak chemical bonding with the cement matrix, relying mainly on mechanical anchoring force. Under long-term loads or repeated impacts, fiber pull-out can easily occur, leading to a decrease in toughening effect. Second, uneven fiber dispersion can easily create weak points in concrete, negatively impacting mechanical properties.

[0005] On the other hand, with increasing global emphasis on sustainable development and the resource utilization of solid waste, the application of industrial waste in concrete has become a research hotspot. Waste glass, as a massive source of solid waste, not only occupies land but also poses environmental problems when disposed of and landfilled. Grinding waste glass into powder and using it as a mineral admixture to partially replace cement can not only consume solid waste and reduce the carbon footprint of concrete, but its active silica can also react with cement hydration products to produce pozzolanic material, improving the later-stage strength and durability of concrete.

[0006] However, there are obvious drawbacks to using waste glass powder directly in concrete: the active silica in waste glass may react harmfully with the alkali in cement, causing the concrete to expand and crack; the pozzolanic reaction of waste glass powder is slow, which will result in slow early strength development of concrete; and the interfacial bond between untreated waste glass powder and cement paste is weak, which may become a weak link inside the concrete.

[0007] Currently, although some studies have attempted to use fibers and waste glass powder together, these are often simple physical mixtures that fail to address the fundamental problems mentioned above, such as weak adhesion between fibers and the matrix, low activity of glass powder, and potential risks. The failure to form a strong, synergistic interfacial transition zone between fibers, glass powder, and the cement matrix results in limited performance improvement of the composite material, particularly in impact resistance, which is insufficient to meet the requirements of high-end applications.

[0008] Therefore, developing a high-impact concrete that can fully utilize the toughening effect of PVA fibers and the volcanic ash activity of waste glass powder, and achieve synergistic effects between the two through modification technology, not only has important scientific value, but also has broad application prospects and significant environmental and economic benefits. Summary of the Invention

[0009] The purpose of this invention is to provide impact-resistant concrete that is synergistically toughened by PVA fiber and waste glass powder.

[0010] To achieve the above objectives, the present invention provides the following technical solution: One of the technical solutions of this invention: An impact-resistant concrete synergistically toughened with PVA fiber and waste glass powder comprises the following raw materials in parts by weight: 280-360 parts cement, 40-120 parts modified waste glass powder, 700-800 parts medium sand, 900-1000 parts crushed stone, 10-20 parts modified PVA fiber, 6-7 parts water-reducing agent, 1-3 parts defoamer, 0.5-1 part composite hydration accelerator, and 160-220 parts water.

[0011] Furthermore, the method for preparing the modified waste glass powder includes the following steps: The waste glass powder was subjected to thermal activation treatment, alkali activation treatment, and silica coating in sequence to obtain the modified waste glass powder.

[0012] Furthermore, the thermal activation treatment specifically involves: controlling the heating rate at 5°C / min to heat the waste glass powder to 300-400°C, and then controlling the cooling rate at 15°C / min to rapidly cool the heated waste glass powder to room temperature, thereby obtaining thermally activated waste glass powder.

[0013] Furthermore, the alkaline activation treatment specifically involves: using ethylene glycol as a grinding aid, controlling the ball-to-powder ratio at 10:1, and ball-milling the thermally activated waste glass powder obtained from the thermal activation treatment until the specific surface area is greater than 800 m². 2 / kg, and then the ball-milled waste glass powder was immersed in a 1mol / L NaOH solution and activated at room temperature for 10-30 minutes to obtain alkali-activated waste glass powder.

[0014] Furthermore, the silica coating specifically involves: dispersing alkali-activated waste glass powder obtained from alkali activation treatment in deionized water to obtain an alkali-activated waste glass powder dispersion; then, according to a mass ratio of tetraethyl orthosilicate to alkali-activated waste glass powder of 1:(50-100), adding dropwise an ethanol solution of tetraethyl orthosilicate with an effective concentration of 10% (v:v) to the alkali-activated waste glass powder dispersion; reacting at 60°C for 2-4 hours; filtering; and drying at 45°C until the water content is below 10% to obtain silica-coated waste glass powder.

[0015] Furthermore, the method for preparing the modified PVA fiber includes the following steps: The modified PVA fibers were obtained by sequentially subjecting the PVA fibers to ultraviolet irradiation treatment and silane coupling agent modification.

[0016] Furthermore, the ultraviolet irradiation treatment specifically involves controlling the ozone concentration to 300 ppm, the ultraviolet wavelength to 185 nm, and the irradiation intensity to 15 mW / cm². 2 PVA fibers were subjected to ultraviolet irradiation treatment, with continuous irradiation for the first 20-30 minutes and intermittent irradiation for the next 30-40 minutes to obtain etched PVA fibers. Specifically, the intermittent irradiation is defined as: irradiation for 1 minute followed by a 10-second pause.

[0017] Furthermore, the silane coupling agent modification specifically involves immersing the etched PVA fiber obtained by ultraviolet irradiation treatment in an aqueous solution of silane coupling agent with an effective concentration of 5% (v / v), activating it at room temperature for 30–90 min, and then drying it at room temperature until the water content is less than 10%, thereby obtaining silane coupling agent modified PVA fiber.

[0018] Furthermore, the preparation method of the composite hydration accelerator includes the following steps: Sodium sulfate, sodium gluconate, and nano-silica are mixed to obtain the composite hydration accelerator.

[0019] Furthermore, the mass ratio of sodium sulfate, sodium gluconate and nano silica is (4-6):1:(0.05-0.1).

[0020] The second technical solution of this invention: The above-mentioned method for preparing impact-resistant concrete synergistically toughened by PVA fiber and waste glass powder includes the following steps: 1) Cement, modified waste glass powder and composite hydration accelerator are mixed to obtain an active cementitious material. Then, medium sand, crushed stone and modified PVA fiber are added to the active cementitious material and dry-mixed to obtain a premix. 2) Add water-reducing agent and defoamer to water to obtain a mixture, then add the premix obtained in step 1) to the mixture and mix to obtain the impact-resistant concrete.

[0021] Further, in step 1), the dry mixing specifically involves controlling the stirring speed to 400 r / min and dry mixing for 5 to 15 minutes.

[0022] Further, in step 2), the mixing specifically involves controlling the stirring speed to 200 r / min and stirring for 3 to 5 hours.

[0023] The third technical solution of this invention: The aforementioned impact-resistant concrete, synergistically toughened with PVA fiber and waste glass powder, is used as a special low-carbon concrete in transportation infrastructure protection and military and security engineering.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides an impact-resistant concrete with synergistic toughening of PVA fiber and waste glass powder, which has a 28-day compressive strength of up to 61.2 MPa, a 28-day flexural strength of up to 10.8 MPa, and a final crack impact count of up to 136, exhibiting good mechanical properties and impact resistance.

[0025] This invention provides an impact-resistant concrete synergistically toughened with PVA fiber and waste glass powder. Through a specific waste glass powder modification process, a PVA fiber surface treatment process, and the synergistic effect of a composite hydration accelerator, a low-carbon concrete material with excellent comprehensive performance was successfully prepared. Specifically: This invention provides an impact-resistant concrete synergistically toughened with PVA fiber and waste glass powder, exhibiting a 28-day compressive strength of 58.5–61.2 MPa and a 28-day flexural strength of 10.2–10.8 MPa, demonstrating excellent structural load-bearing capacity. This is mainly due to the following: the modified waste glass powder undergoes a three-step treatment process of thermal activation, alkali activation, and silica coating, which significantly increases the surface active sites and enhances the pozzolanic reactivity, enabling it to form a denser microstructure with cement hydration products. Simultaneously, the sodium sulfate, sodium gluconate, and nano-silica in the composite hydration accelerator synergistically regulate the hydration process, ensuring early strength development and promoting continuous enhancement in the later stages, achieving a uniform and dense distribution of hydration products. The present invention provides an impact-resistant concrete with a final cracking impact resistance of up to 120-136 times, synergistically toughened by PVA fiber and waste glass powder, exhibiting excellent impact resistance. This is mainly due to the following: the modified PVA fiber is treated with ultraviolet irradiation etching and silane coupling agent, which increases the surface roughness and introduces functional groups that can form chemical bonds with the cement matrix, significantly improving the interfacial bonding strength between the fiber and the matrix; at the same time, the modified waste glass powder forms a strong interfacial bond with the cement matrix, and the three work synergistically to construct an effective stress transfer and energy dissipation system; when the material is impacted, the fiber can effectively bridge cracks, prevent crack propagation, and consume a large amount of energy through the fiber pull-out process, thereby greatly improving the toughness of the material. The present invention provides an impact-resistant concrete synergistically toughened with PVA fiber and waste glass powder. By using a large amount of waste glass powder to replace part of the cement, it not only realizes the resource utilization of solid waste and reduces cement consumption and carbon emissions, but also controls material costs while ensuring high performance through optimized mix design. It is in line with the development direction of green building materials and has good promotion and application value. Detailed Implementation

[0026] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0027] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included within this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0028] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0029] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0030] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0031] In the following examples, all raw materials used were commercially available, as detailed in Table 1. Table 1 Raw Materials and Specifications

[0032] The following embodiments illustrate a method for preparing impact-resistant concrete synergistically toughened with PVA fibers and waste glass powder, comprising the following steps: 1. Modification of waste glass powder 1) Control the heating rate to 5℃ / min and heat the waste glass powder to 300~400℃. Then control the cooling rate to 15℃ / min and rapidly cool the heated waste glass powder to room temperature to obtain thermally activated waste glass powder. 2) Using ethylene glycol as a grinding aid, and controlling the ball-to-powder ratio at 10:1, the thermally activated waste glass powder obtained in step 1) is ball-milled until the specific surface area is greater than 800 m². 2 / kg, and then the ball-milled waste glass powder was immersed in a 1mol / L NaOH solution and activated at room temperature for 10-30 minutes to obtain alkali-activated waste glass powder; 3) Disperse the alkali-activated waste glass powder obtained in step 2) in deionized water to obtain an alkali-activated waste glass powder dispersion. Then, according to the mass ratio of tetraethyl orthosilicate to alkali-activated waste glass powder of 1: (50-100), add a 10% (v:v) effective concentration of tetraethyl orthosilicate in ethanol to the alkali-activated waste glass powder dispersion dropwise. React at 60°C for 2-4 hours, filter, and dry at 45°C until the water content is less than 10% to obtain silica-coated waste glass powder, i.e., the modified waste glass powder. 2. Modification of PVA fibers 1) Control ozone concentration to 300 ppm, ultraviolet wavelength to 185 nm, and irradiation intensity to 15 mW / cm². 2 PVA fibers were subjected to ultraviolet irradiation treatment. Continuous irradiation was used for the first 20 to 30 minutes, and intermittent irradiation was used for the next 30 to 40 minutes (irradiation for 1 minute, pause for 10 seconds) to obtain etched PVA fibers. 2) Immerse the etched PVA fiber obtained in step 1) in an aqueous solution of silane coupling agent with an effective concentration of 5% (v / v), activate it at room temperature for 30-90 min, and then dry it at room temperature until the water content is less than 10% to obtain silane coupling agent modified PVA fiber, i.e., the modified PVA fiber. 3. Preparation of composite hydration accelerator Sodium sulfate, sodium gluconate, and nano silica were mixed in a mass ratio of (4-6):1:(0.05-0.1) to obtain the composite hydration accelerator. 4. Preparation of impact-resistant concrete 1) Weigh each raw material according to the following mass proportions: 280-360 parts cement, 40-120 parts modified waste glass powder, 700-800 parts medium sand, 900-1000 parts crushed stone, 10-20 parts modified PVA fiber, 6-7 parts water-reducing agent, 1-3 parts defoamer, 0.5-1 part composite hydration accelerator, and 160-220 parts water; 2) Mix the cement, modified waste glass powder and composite hydration accelerator weighed in step 1) to obtain an active cementitious material. Then add the medium sand, crushed stone and modified PVA fiber weighed in step 1) to the active cementitious material, control the stirring speed to 400 r / min, and dry mix for 5 to 15 minutes to obtain a premix. 3) Add the water-reducing agent and defoamer weighed in step 1) to the water weighed in step 1) to obtain a mixture. Then add the premix obtained in step 2) to the mixture, control the stirring speed to 200 r / min, and stir for 3 to 5 hours to obtain the impact-resistant concrete.

[0033] Example 1 A type of impact-resistant concrete 1. Modification of waste glass powder 1) Control the heating rate to 5℃ / min, heat the waste glass powder to 300℃, and then control the cooling rate to 15℃ / min, rapidly cool the heated waste glass powder to room temperature to obtain thermally activated waste glass powder. 2) Using ethylene glycol as a grinding aid, and controlling the ball-to-powder ratio at 10:1, the thermally activated waste glass powder obtained in step 1) is ball-milled until the specific surface area is greater than 800 m². 2 / kg, and then the ball-milled waste glass powder was immersed in a 1mol / L NaOH solution and activated at room temperature for 10min to obtain alkali-activated waste glass powder; 3) Disperse the alkali-activated waste glass powder obtained in step 2) in deionized water to obtain an alkali-activated waste glass powder dispersion. Then, according to the mass ratio of tetraethyl orthosilicate to alkali-activated waste glass powder of 1:50, add an ethanol solution of tetraethyl orthosilicate with an effective concentration of 10% (v:v) to the alkali-activated waste glass powder dispersion dropwise. React at 60°C for 2 hours, filter, and dry at 45°C until the water content is less than 10% to obtain silica-coated waste glass powder, i.e., the modified waste glass powder. 2. Modification of PVA fibers 1) Control ozone concentration to 300 ppm, ultraviolet wavelength to 185 nm, and irradiation intensity to 15 mW / cm². 2 PVA fibers were subjected to ultraviolet irradiation treatment. Continuous irradiation was used for the first 20 minutes, and intermittent irradiation was used for the next 30 minutes (irradiation for 1 minute, pause for 10 seconds) to obtain etched PVA fibers. 2) The etched PVA fiber obtained in step 1) is immersed in an aqueous solution of silane coupling agent with an effective concentration of 5% (v / v), and activated at room temperature for 30 min. Then it is dried at room temperature until the water content is less than 10% to obtain silane coupling agent modified PVA fiber, i.e., the modified PVA fiber. 3. Preparation of composite hydration accelerator Sodium sulfate, sodium gluconate, and nano silica were mixed in a mass ratio of 4:1:0.05 to obtain the composite hydration accelerator. 4. Preparation of impact-resistant concrete 1) Weigh each raw material according to the following mass proportions: 280 parts cement, 40 parts modified waste glass powder, 700 parts medium sand, 900 parts crushed stone, 10 parts modified PVA fiber, 6 parts water-reducing agent, 1 part defoamer, 0.5 parts composite hydration accelerator, and 160 parts water. 2) Mix the cement, modified waste glass powder and composite hydration accelerator weighed in step 1) to obtain an active cementitious material. Then add the medium sand, crushed stone and modified PVA fiber weighed in step 1) to the active cementitious material, control the stirring speed to 400 r / min, dry mix for 5 min to obtain a premix. 3) Add the water-reducing agent and defoamer weighed in step 1) to the water weighed in step 1) to obtain a mixture. Then add the premix obtained in step 2) to the mixture, control the stirring speed to 200 r / min, and stir for 3 hours to obtain the impact-resistant concrete.

[0034] Example 2 A type of impact-resistant concrete 1. Modification of waste glass powder 1) Control the heating rate to 5℃ / min, heat the waste glass powder to 350℃, and then control the cooling rate to 15℃ / min, rapidly cool the heated waste glass powder to room temperature to obtain thermally activated waste glass powder. 2) Using ethylene glycol as a grinding aid, and controlling the ball-to-powder ratio at 10:1, the thermally activated waste glass powder obtained in step 1) is ball-milled until the specific surface area is greater than 800 m². 2 / kg, and then the ball-milled waste glass powder was immersed in a 1mol / L NaOH solution and activated at room temperature for 20min to obtain alkali-activated waste glass powder; 3) Disperse the alkali-activated waste glass powder obtained in step 2) in deionized water to obtain an alkali-activated waste glass powder dispersion. Then, according to the mass ratio of tetraethyl orthosilicate to alkali-activated waste glass powder of 1:80, add an ethanol solution of tetraethyl orthosilicate with an effective concentration of 10% (v:v) to the alkali-activated waste glass powder dispersion dropwise. React at 60°C for 3 hours, filter, and dry at 45°C until the water content is less than 10% to obtain silica-coated waste glass powder, i.e., the modified waste glass powder. 2. Modification of PVA fibers 1) Control ozone concentration to 300 ppm, ultraviolet wavelength to 185 nm, and irradiation intensity to 15 mW / cm². 2 PVA fibers were subjected to ultraviolet irradiation treatment. The first 25 minutes were continuous irradiation, and the next 35 minutes were intermittent irradiation (1 minute of irradiation followed by a 10-second pause) to obtain etched PVA fibers. 2) The etched PVA fiber obtained in step 1) is immersed in an aqueous solution of silane coupling agent with an effective concentration of 5% (v / v), and activated at room temperature for 60 min. Then it is dried at room temperature until the water content is less than 10% to obtain silane coupling agent modified PVA fiber, i.e., the modified PVA fiber. 3. Preparation of composite hydration accelerator The composite hydration accelerator was obtained by mixing sodium sulfate, sodium gluconate, and nano silica in a mass ratio of 5:1:0.05. 4. Preparation of impact-resistant concrete 1) Weigh each raw material according to the following mass proportions: 300 parts cement, 50 parts modified waste glass powder, 750 parts medium sand, 950 parts crushed stone, 15 parts modified PVA fiber, 6 parts water-reducing agent, 2 parts defoamer, 0.8 parts composite hydration accelerator, and 200 parts water. 2) Mix the cement, modified waste glass powder and composite hydration accelerator weighed in step 1) to obtain an active cementitious material. Then add the medium sand, crushed stone and modified PVA fiber weighed in step 1) to the active cementitious material, control the stirring speed to 400 r / min, dry mix for 10 min to obtain a premix. 3) Add the water-reducing agent and defoamer weighed in step 1) to the water weighed in step 1) to obtain a mixture. Then add the premix obtained in step 2) to the mixture, control the stirring speed to 200 r / min, and stir for 5 hours to obtain the impact-resistant concrete.

[0035] Example 3 A type of impact-resistant concrete 1. Modification of waste glass powder 1) Control the heating rate to 5℃ / min, heat the waste glass powder to 400℃, and then control the cooling rate to 15℃ / min, rapidly cool the heated waste glass powder to room temperature to obtain thermally activated waste glass powder. 2) Using ethylene glycol as a grinding aid, and controlling the ball-to-powder ratio at 10:1, the thermally activated waste glass powder obtained in step 1) is ball-milled until the specific surface area is greater than 800 m². 2 / kg, and then the ball-milled waste glass powder was immersed in a 1mol / L NaOH solution and activated at room temperature for 30 minutes to obtain alkali-activated waste glass powder; 3) Disperse the alkali-activated waste glass powder obtained in step 2) in deionized water to obtain an alkali-activated waste glass powder dispersion. Then, according to the mass ratio of tetraethyl orthosilicate to alkali-activated waste glass powder of 1:100, add an ethanol solution of tetraethyl orthosilicate with an effective concentration of 10% (v:v) to the alkali-activated waste glass powder dispersion dropwise. React at 60°C for 4 hours, filter, and dry at 45°C until the water content is less than 10% to obtain silica-coated waste glass powder, i.e., the modified waste glass powder. 2. Modification of PVA fibers 1) Control ozone concentration to 300 ppm, ultraviolet wavelength to 185 nm, and irradiation intensity to 15 mW / cm². 2 PVA fibers were subjected to ultraviolet irradiation treatment. The first 30 minutes were continuous irradiation, and the next 40 minutes were intermittent irradiation (1 minute of irradiation followed by a 10-second pause) to obtain etched PVA fibers. 2) The etched PVA fiber obtained in step 1) is immersed in an aqueous solution of silane coupling agent with an effective concentration of 5% (v / v), and activated at room temperature for 90 min. Then it is dried at room temperature until the water content is less than 10% to obtain silane coupling agent modified PVA fiber, i.e., the modified PVA fiber. 3. Preparation of composite hydration accelerator Sodium sulfate, sodium gluconate, and nano silica were mixed in a mass ratio of 6:1:0.1 to obtain the composite hydration accelerator. 4. Preparation of impact-resistant concrete 1) Weigh each raw material according to the following mass proportions: 360 parts cement, 120 parts modified waste glass powder, 800 parts medium sand, 1000 parts crushed stone, 20 parts modified PVA fiber, 7 parts water-reducing agent, 3 parts defoamer, 1 part composite hydration accelerator, and 220 parts water. 2) Mix the cement, modified waste glass powder and composite hydration accelerator weighed in step 1) to obtain an active cementitious material. Then add the medium sand, crushed stone and modified PVA fiber weighed in step 1) to the active cementitious material, control the stirring speed to 400 r / min, and dry mix for 15 min to obtain a premix. 3) Add the water-reducing agent and defoamer weighed in step 1) to the water weighed in step 1) to obtain a mixture. Then add the premix obtained in step 2) to the mixture, control the stirring speed to 200 r / min, and stir for 5 hours to obtain the impact-resistant concrete.

[0036] Comparative Example 1 A type of concrete Same as Example 2, except that the modification of the waste glass powder in step 1 is as follows: 1) Using ethylene glycol as a grinding aid, and controlling the ball-to-powder ratio at 10:1, the waste glass powder was ball-milled to a specific surface area greater than 800 m². 2 / kg, and then the ball-milled waste glass powder was immersed in a 1mol / L NaOH solution and activated at room temperature for 10min to obtain alkali-activated waste glass powder; 2) Disperse the alkali-activated waste glass powder obtained in step 1) in deionized water to obtain an alkali-activated waste glass powder dispersion. Then, according to the mass ratio of tetraethyl orthosilicate to alkali-activated waste glass powder of 1:50, add an ethanol solution of tetraethyl orthosilicate with an effective concentration of 10% (v:v) to the alkali-activated waste glass powder dispersion dropwise. React at 60°C for 2 hours, filter, and dry at 45°C until the water content is less than 10% to obtain silica-coated waste glass powder, i.e., the modified waste glass powder.

[0037] Comparative Example 2 A type of concrete Same as Example 2, except that the modification of the waste glass powder in step 1 is as follows: 1) Control the heating rate to 5℃ / min, heat the waste glass powder to 350℃, and then control the cooling rate to 5℃ / min, cool the heated waste glass powder to room temperature to obtain thermally activated waste glass powder. 2) Using ethylene glycol as a grinding aid, and controlling the ball-to-powder ratio at 10:1, the thermally activated waste glass powder obtained in step 1) is ball-milled until the specific surface area is greater than 800 m². 2 / kg, and then the ball-milled waste glass powder was immersed in a 1mol / L NaOH solution and activated at room temperature for 10min to obtain alkali-activated waste glass powder; 3) Disperse the alkali-activated waste glass powder obtained in step 2) in deionized water to obtain an alkali-activated waste glass powder dispersion. Then, according to the mass ratio of tetraethyl orthosilicate to alkali-activated waste glass powder of 1:50, add an ethanol solution of tetraethyl orthosilicate with an effective concentration of 10% (v:v) to the alkali-activated waste glass powder dispersion dropwise. React at 60°C for 2 hours, filter, and dry at 45°C until the water content is less than 10% to obtain silica-coated waste glass powder, i.e., the modified waste glass powder.

[0038] Comparative Example 3 A type of concrete Same as Example 2, except that the modification of the waste glass powder in step 1 is as follows: 1) Control the heating rate to 5℃ / min, heat the waste glass powder to 350℃, and then control the cooling rate to 20℃ / min, cool the heated waste glass powder to room temperature to obtain thermally activated waste glass powder. 2) Using ethylene glycol as a grinding aid, and controlling the ball-to-powder ratio at 10:1, the thermally activated waste glass powder obtained in step 1) is ball-milled until the specific surface area is greater than 800 m². 2 / kg, and then the ball-milled waste glass powder was immersed in a 1mol / L NaOH solution and activated at room temperature for 10min to obtain alkali-activated waste glass powder; 3) Disperse the alkali-activated waste glass powder obtained in step 2) in deionized water to obtain an alkali-activated waste glass powder dispersion. Then, according to the mass ratio of tetraethyl orthosilicate to alkali-activated waste glass powder of 1:50, add an ethanol solution of tetraethyl orthosilicate with an effective concentration of 10% (v:v) to the alkali-activated waste glass powder dispersion dropwise. React at 60°C for 2 hours, filter, and dry at 45°C until the water content is less than 10% to obtain silica-coated waste glass powder, i.e., the modified waste glass powder.

[0039] Comparative Example 4 A type of concrete Same as Example 2, except that the modification of the waste glass powder in step 1 is as follows: 1) Control the heating rate to 5℃ / min, heat the waste glass powder to 300℃, and then control the cooling rate to 15℃ / min, rapidly cool the heated waste glass powder to room temperature to obtain thermally activated waste glass powder. 3) Disperse the thermally activated waste glass powder obtained in step 1) in deionized water to obtain a thermally activated waste glass powder dispersion. Then, according to the mass ratio of tetraethyl orthosilicate to thermally activated waste glass powder of 1:50, add a 10% (v:v) effective concentration of tetraethyl orthosilicate in ethanol to the thermally activated waste glass powder dispersion dropwise. React at 60°C for 2 hours, filter, and dry at 45°C until the water content is less than 10% to obtain silica-coated waste glass powder, i.e., the modified waste glass powder.

[0040] Comparative Example 5 A type of concrete Same as Example 2, except that the modification of the waste glass powder in step 1 is as follows: 1) Control the heating rate to 5℃ / min, heat the waste glass powder to 300℃, and then control the cooling rate to 15℃ / min, rapidly cool the heated waste glass powder to room temperature to obtain thermally activated waste glass powder. 2) Using ethylene glycol as a grinding aid, and controlling the ball-to-powder ratio at 10:1, the thermally activated waste glass powder obtained in step 1) is ball-milled until the specific surface area is greater than 800 m². 2 / kg, and then the ball-milled waste glass powder was immersed in a 1mol / L NaOH solution and activated at room temperature for 10 minutes to obtain alkali-activated waste glass powder, namely the modified waste glass powder.

[0041] Comparative Example 6 A type of concrete Same as Example 2, except that the modification of the PVA fibers in step 2 is as follows: PVA fibers were immersed in an aqueous solution of silane coupling agent with an effective concentration of 5% (v / v), and activated at room temperature for 30 min. Then, they were dried at room temperature until the moisture content was less than 10% to obtain silane coupling agent modified PVA fibers, namely the modified PVA fibers.

[0042] Comparative Example 7 A type of concrete Same as Example 2, except that the modification of the PVA fibers in step 2 is as follows: 1) Control ozone concentration to 300 ppm, ultraviolet wavelength to 185 nm, and irradiation intensity to 15 mW / cm². 2 PVA fibers were subjected to ultraviolet irradiation for 60 minutes to obtain etched PVA fibers. 2) Immerse the etched PVA fiber obtained in step 1) in an aqueous solution of silane coupling agent with an effective concentration of 5% (v / v), activate it at room temperature for 30 min, and then dry it at room temperature until the water content is less than 10% to obtain silane coupling agent modified PVA fiber, i.e., the modified PVA fiber.

[0043] Comparative Example 8 A type of concrete Same as Example 2, except that the modification of the PVA fibers in step 2 is as follows: 1) Control ozone concentration to 300 ppm, ultraviolet wavelength to 185 nm, and irradiation intensity to 15 mW / cm². 2 PVA fibers were subjected to ultraviolet irradiation treatment, with intermittent irradiation for 60 minutes (1 minute of irradiation followed by a 10-second pause) to obtain etched PVA fibers. 2) Immerse the etched PVA fiber obtained in step 1) in an aqueous solution of silane coupling agent with an effective concentration of 5% (v / v), activate it at room temperature for 30 min, and then dry it at room temperature until the water content is less than 10% to obtain silane coupling agent modified PVA fiber, i.e., the modified PVA fiber.

[0044] Comparative Example 9 A type of concrete Same as Example 2, except that the modification of the PVA fibers in step 2 is as follows: The ozone concentration was controlled at 300 ppm, the ultraviolet wavelength at 185 nm, and the irradiation intensity at 15 mW / cm². 2 The PVA fibers were subjected to ultraviolet irradiation treatment. The first 20 minutes were continuous irradiation, and the next 30 minutes were intermittent irradiation (irradiation for 1 minute and pause for 10 seconds) to obtain etched PVA fibers, namely the modified PVA fibers.

[0045] Comparative Example 10 A type of concrete Same as Example 2, except that the preparation of the composite hydration accelerator in step 3 is as follows: The composite hydration accelerator was obtained by mixing sodium gluconate and nano silica at a mass ratio of 1:0.05.

[0046] Comparative Example 11 A type of concrete Same as Example 2, except that the preparation of the composite hydration accelerator in step 3 is as follows: The composite hydration accelerator was obtained by mixing sodium sulfate and nano silica at a mass ratio of 5:0.05.

[0047] Comparative Example 12 A type of concrete Same as Example 2, except that the preparation of the composite hydration accelerator in step 3 is as follows: Sodium sulfate and sodium gluconate were mixed in a mass ratio of 5:1 to obtain the composite hydration accelerator.

[0048] Performance testing The compressive strength of the concrete (cast as 100mm×100mm×100mm cubic specimens) prepared in Examples 1-3 and Comparative Examples 1-12 was tested in accordance with GB / T 50081 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete". The flexural strength of the concrete (cast as 100mm×100mm×400mm prism specimens) prepared in Examples 1-3 and Comparative Examples 1-12 was tested in accordance with GB / T 50081 "Standard for Test Methods of Mechanical Properties of Ordinary Concrete". According to GB / T 37195 "Fiber-reinforced concrete lining segments", the impact resistance of concrete (cast as Φ100mm×50mm cylindrical specimens) prepared in Examples 1-3 and Comparative Examples 1-12 was tested using a drop hammer impact tester. The performance test results are shown in Table 2; Table 2 Performance Test Results

[0049] As shown in Table 2, the impact-resistant concrete synergistically toughened by PVA fiber and waste glass powder provided by this invention has a 28-day compressive strength of 61.2 MPa, a 28-day flexural strength of 10.8 MPa, and a final crack impact count of 136, exhibiting good mechanical properties and impact resistance.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. An impact-resistant concrete synergistically toughened with PVA fiber and waste glass powder, characterized in that, Includes the following quantities of raw materials: 280-360 parts cement, 40-120 parts modified waste glass powder, 700-800 parts medium sand, 900-1000 parts crushed stone, 10-20 parts modified PVA fiber, 6-7 parts water-reducing agent, 1-3 parts defoamer, 0.5-1 part composite hydration accelerator, and 160-220 parts water.

2. The impact-resistant concrete synergistically toughened with PVA fiber and waste glass powder according to claim 1, characterized in that, The method for preparing the modified waste glass powder includes the following steps: The waste glass powder was subjected to thermal activation treatment, alkali activation treatment, and silica coating in sequence to obtain the modified waste glass powder.

3. The impact-resistant concrete synergistically toughened with PVA fiber and waste glass powder according to claim 2, characterized in that, The thermal activation treatment specifically involves: controlling the heating rate at 5°C / min to heat the waste glass powder to 300-400°C, and then controlling the cooling rate at 15°C / min to rapidly cool the heated waste glass powder to room temperature, thereby obtaining thermally activated waste glass powder.

4. The impact-resistant concrete synergistically toughened with PVA fiber and waste glass powder according to claim 2, characterized in that, The alkaline activation treatment specifically involves: using ethylene glycol as a grinding aid, controlling the ball-to-powder ratio at 10:1, and ball-milling the thermally activated waste glass powder obtained from the thermal activation treatment until the specific surface area is greater than 800 m². 2 / kg, and then the ball-milled waste glass powder was immersed in a 1mol / L NaOH solution and activated at room temperature for 10-30 minutes to obtain alkali-activated waste glass powder.

5. The impact-resistant concrete synergistically toughened with PVA fiber and waste glass powder according to claim 2, characterized in that, The silica coating process specifically involves: dispersing alkali-activated waste glass powder obtained from alkali activation treatment in deionized water to obtain an alkali-activated waste glass powder dispersion; then, according to a mass ratio of tetraethyl orthosilicate to alkali-activated waste glass powder of 1:(50-100), adding a 10% (v:v) effective concentration of tetraethyl orthosilicate in ethanol to the alkali-activated waste glass powder dispersion dropwise; reacting at 60°C for 2-4 hours; filtering; and drying at 45°C until the water content is below 10% to obtain silica-coated waste glass powder.

6. The impact-resistant concrete synergistically toughened with PVA fiber and waste glass powder according to claim 1, characterized in that, The method for preparing the modified PVA fiber includes the following steps: The modified PVA fibers were obtained by sequentially subjecting the PVA fibers to ultraviolet irradiation treatment and silane coupling agent modification.

7. The impact-resistant concrete synergistically toughened with PVA fiber and waste glass powder according to claim 6, characterized in that, The ultraviolet irradiation treatment specifically involves controlling the ozone concentration to 300 ppm, the ultraviolet wavelength to 185 nm, and the irradiation intensity to 15 mW / cm². 2 PVA fibers were subjected to ultraviolet irradiation treatment, with continuous irradiation for the first 20-30 minutes and intermittent irradiation for the next 30-40 minutes to obtain etched PVA fibers.

8. The impact-resistant concrete synergistically toughened by PVA fiber and waste glass powder according to claim 6, characterized in that, The silane coupling agent modification is specifically as follows: the etched PVA fiber obtained by ultraviolet irradiation is immersed in an aqueous solution of silane coupling agent with an effective concentration of 5% (v / v), and activated at room temperature for 30-90 minutes. Then, it is dried at room temperature until the water content is less than 10% to obtain silane coupling agent modified PVA fiber.

9. The impact-resistant concrete synergistically toughened by PVA fiber and waste glass powder according to claim 1, characterized in that, The preparation method of the composite hydration accelerator includes the following steps: Sodium sulfate, sodium gluconate, and nano-silica are mixed to obtain the composite hydration accelerator.

10. The impact-resistant concrete synergistically toughened with PVA fiber and waste glass powder according to claim 9, characterized in that, The mass ratio of sodium sulfate, sodium gluconate and nano silica is (4-6):1:(0.05-0.1).

Images