Fiber reinforced geopolymer and a drainage pipe prepared therefrom

Abstract

The present application relates to the technical field of fiber reinforced geopolymer, and particularly discloses a fiber reinforced geopolymer and a drainage pipeline prepared from the same. The fiber reinforced geopolymer comprises mineral powder, fly ash, quartz sand, alkali activator, fiber, latex powder and rubber powder. The mineral powder and the fly ash are sequentially added, stirred at low speed, and mixed uniformly. While stirring, the fiber is slowly added and dry-stirred, then the quartz sand and the rubber powder are added, and water is added to stir uniformly. The latex powder is dissolved in water after being added, forms a coating layer to wrap the surface of the fiber or the geopolymer raw material, changes the interface characteristics of the fiber and the geopolymer matrix, slows down the occurrence of the polymerization reaction, makes the mechanical properties of the EGC material decrease, improves the interface bonding between the fiber and the geopolymer matrix, forms a structure of the synergistic effect of the fiber-latex powder-geopolymer matrix, increases the fracture energy of the fiber reinforced geopolymer, and improves the bending toughness of the fiber reinforced geopolymer.

Description

Technical Field

[0001] This invention belongs to the field of fiber-reinforced geopolymer technology, specifically relating to a fiber-reinforced geopolymer and drainage pipes made therefrom. Background Technology

[0002] Today, the demand for cement is increasing across various sectors, including residential, commercial, and industrial construction. 50% of the carbon dioxide emissions from the cement industry come from the limestone calcination process, and the remaining 50% from fuel combustion in kilns, transportation, and the electricity used in manufacturing operations. The type of fuel used in cement production affects carbon dioxide emissions. Measures should be taken to reduce air pollution and global warming. Using cement alternatives in concrete production is a fair starting point for reducing concrete carbon dioxide emissions. Cement alternatives can be diverse, including fly ash, blast furnace slag (GGBS), rice husk ash, metakaolin, etc., and alternatives to industrial waste should be considered.

[0003] Replacing 100% of cement with these industrial byproducts will help leverage the growing waste stream and achieve carbon reduction targets more quickly. Fiber-reinforced geopolymers (EGC) are produced using industrial waste / byproducts (fly ash, mineral powder). EGC is produced using materials containing high silicon and high aluminum. Single materials or combinations of two or more materials are used. Fine and coarse aggregates are selected as required. Geopolymer concrete is mixed with an alkaline solution. An alkaline solution is prepared by adding sodium or potassium silicate and sodium or potassium hydroxide. Suitable organic fibers are then added. Currently, for problems such as shrinkage and cracking in EGC, adhesive powder can be added to alleviate these issues. Finally, all components are mixed according to the mixing design. The geopolymer concrete is then cured using thermosetting or environmental curing methods. The hardening mechanism of geopolymers is the condensation of potassium oligomers (silicate-siloxane) into a potassium polymer (silicate-siloxane) crosslinked network.

[0004] The carbon emissions during the preparation of 1 kg of geopolymer cement are only 0.18 kg, which is only 24% of that of ordinary Portland cement. At the same time, the energy consumption during production is lower, accounting for only 30% of the energy consumption of cement production. If the activity of solid waste is increased, its energy consumption can be reduced to 10% of that of cement production. Studies have shown that EGC possesses excellent mechanical properties, fire resistance, high-temperature resistance, erosion resistance, and good impermeability, making it highly favored by researchers and considered a potential substitute for cement or a supplementary cement material in certain fields.

[0005] With the continuous advancement of urban underground integrated pipe gallery systems, higher standards are being set for underground pipeline construction, making the selection of suitable pipe gallery materials paramount. Currently, the main types of underground pipelines in my country are concrete pipes and plastic pipes. Concrete pipes, when used as drainage pipes, are easily corroded by sewage, causing leaks and seepage, thus often resulting in insufficient service life. Furthermore, concrete pipes are heavy, have poor wear resistance, high roughness, a high breakage rate, and weak water flow capacity. Plastic pipes have higher manufacturing costs, and inconsistent quality is common during manufacturing. They are also relatively lightweight, with insufficient ring stiffness, making them prone to damage or even collapse under excessive external pressure. During use, plastic drainage pipes may be affected by chemicals in sewage, leading to aging, hardening, brittleness, and even cracking. Therefore, plastic pipes require regular inspection and maintenance, increasing labor costs.

[0006] How to utilize EGC to manufacture small-diameter drainage pipes is a technical problem that researchers urgently need to solve. Using EGC to manufacture small-diameter drainage pipes is not only cheaper than using ordinary cement, but also causes less environmental pollution, utilizes solid waste, and promotes green production. However, the performance of existing EGC materials is not very stable due to the inconsistent activity of the supplied raw materials. Summary of the Invention

[0007] The purpose of this invention is to address the aforementioned shortcomings of the prior art by providing a fiber-reinforced geopolymer and a drainage pipe made therefrom. The invention utilizes latex powder, which dissolves in water after being incorporated, to form a coating layer that wraps around the surface of the fiber or geopolymer raw material. This alters the interfacial properties of the fiber and geopolymer matrix, slows down the polymerization reaction, and reduces the mechanical properties of the EGC material. Simultaneously, it improves the interfacial adhesion between the fiber and the geopolymer matrix, forming a synergistic structure of fiber, latex powder, and geopolymer matrix. This increases the fracture energy of the fiber-reinforced geopolymer, thereby enhancing its flexural toughness.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] The first objective of this invention is to provide a fiber-reinforced geopolymer comprising the following components in parts by weight: 250-300 parts mineral powder, 200-220 parts fly ash, 670-730 parts quartz sand, 120-150 parts alkali activator, 7.6-24 parts fiber, 3.5-34.9 parts latex powder, and 20.9-41.9 parts rubber powder. The invention also includes the following preparation steps: adding mineral powder and fly ash sequentially to a cement mortar mixer, stirring at low speed until uniformly mixed; slowly adding fiber while stirring and dry-mixing for a first preset time; then adding quartz sand, latex powder, and rubber powder, and adding water while stirring until uniformly mixed to obtain the fiber-reinforced geopolymer.

[0010] Furthermore, the fiber is at least one of polyvinyl alcohol fiber, polypropylene fiber, and polyoxymethylene fiber.

[0011] Furthermore, the latex powder is PVA latex powder or VAE latex powder.

[0012] Furthermore, the mineral powder is selected as S95 grade ground slag powder with a density of 2.88 g / cm³. 3 Specific surface area is 440m² 2 / kg.

[0013] Furthermore, the fly ash is selected as Grade II fly ash with a density of 2.24 g / cm³. 3 Specific surface area is 400m² 2 / kg.

[0014] Furthermore, the fiber content is an external addition based on wet bulk volume, and the fiber is polyvinyl alcohol fiber.

[0015] Furthermore, the mass concentration ratio of the VAE latex powder and the rubber powder is (3-5):3, wherein the VAE latex powder is added based on the total mass of mineral powder and fly ash, and the rubber powder is added based on the mass of quartz sand.

[0016] Furthermore, the particle size of the quartz sand is 20-40 mesh.

[0017] A second objective of this invention is to provide the application of the aforementioned fiber-reinforced geopolymer in the preparation of building materials.

[0018] The third objective of this invention is to provide a drainage pipe by pouring the aforementioned fiber-reinforced geopolymer into a prefabricated pipe mold, removing air bubbles, and then demolding and curing for 7 to 28 days to obtain the drainage pipe.

[0019] Compared with the prior art, the beneficial effects of the technical solution provided by the present invention are as follows:

[0020] (1) Compared with other fiber-reinforced geopolymers, this invention adds latex powder and rubber powder to modify the engineered geopolymer composite material, which effectively improves the problem of poor fiber dispersion in geopolymer when the fiber content is large, and improves the toughness and deformation capacity of fiber-reinforced geopolymer. Compared with the group without rubber powder, the fracture energy of the group with rubber powder is increased by more than 50%. After being added, the latex powder dissolves in water and forms a coating layer on the surface of the fiber or geopolymer raw material, which changes the interfacial characteristics of the fiber and geopolymer matrix, slows down the occurrence of geopolymerization reaction, and reduces the mechanical properties of EGC material. At the same time, it improves the interfacial bonding between the fiber and the geopolymer matrix, forming a synergistic structure of fiber-latex powder-geopolymer matrix, which increases the fracture energy of fiber-reinforced geopolymer and improves the bending toughness of fiber-reinforced geopolymer.

[0021] (2) The fiber-reinforced geopolymer provided by this invention uses industrial wastes / byproducts such as fly ash and mineral powder, providing a new solution to solid waste accumulation. The carbon emissions during the production of 1 kg of geopolymer cement are 0.18 kg, which is only 24% of that of ordinary silicate cement; at the same time, the energy consumption during the production process is lower, accounting for only 30% of the energy consumption of cement production, which responds to the national energy conservation and emission reduction policy.

[0022] (3) Fiber-reinforced geopolymers are cheaper, denser, and have double the impermeability compared to other small-diameter drainage pipe materials. They also enhance the pipe's ability to resist long-term corrosion. Attached Figure Description

[0023] Figure 1a This is a comparison chart of the setting time of single-component rubber powder provided by the present invention;

[0024] Figure 1b A comparison chart of setting time for VAE-blended latex powder mortar provided by this invention;

[0025] Figure 1c A comparison chart of setting times for mortar with PVA latex powder alone, provided by this invention;

[0026] Figure 2 A comparison chart of the setting times of VAE latex powder and rubber powder provided by the present invention;

[0027] Figure 3 A comparison chart of the setting times of mixed PVA latex powder and rubber powder provided by the present invention;

[0028] Figure 4 A comparison chart of the flowability of mortars containing mixed VAE latex powder and rubber powder provided by the present invention;

[0029] Figure 5 A comparison chart of the flowability of mixed PVA latex powder and rubber powder provided by the present invention;

[0030] Figure 6 Comparison chart of 28-day compressive strength of mortars containing VAE latex powder and rubber powder in different proportions provided by the present invention;

[0031] Figure 7 Comparison of 28-day flexural strength of mortars containing VAE latex powder and rubber powder in different proportions provided by the present invention;

[0032] Figure 8 A comparison chart of the 28-day compression-flexural ratio of mortars containing VAE latex powder and rubber powder, provided by the present invention;

[0033] Figure 9 Comparison chart of 28-day compressive strength of mortars with different proportions of mixed PVA latex powder and rubber powder provided by the present invention;

[0034] Figure 10 Comparison of 28-day flexural strength of mortars containing different proportions of PVA latex powder and rubber powder provided by the present invention;

[0035] Figure 11 A comparison chart of the compression-flexural ratio of mortars containing mixed PVA latex powder and rubber powder at 28 days, provided by the present invention.

[0036] Figure 12a Load-deflection curves of mortars containing 3% VAE latex powder and 3% rubber powder at different proportions for 28 days provided by the present invention;

[0037] Figure 12b Load-deflection curves of mortars containing 5% VAE latex powder and 3% rubber powder at different proportions for 28 days provided by the present invention;

[0038] Figure 13a Load-deflection curves of mortars containing 1% PVA latex powder and 3% rubber powder at different proportions for 28 days provided by the present invention.

[0039] Figure 13b The load-deflection curves of mortars containing 2% PVA latex powder and 3% rubber powder provided by this invention after 28 days.

[0040] Figure 14a The SEM images of PVA1 group without adhesive powder provided by this invention;

[0041] Figure 14b SEM images of the PVA1 group after 7 days with 3% VAE latex powder added, provided for the present invention;

[0042] Figure 14c SEM images of the PVA1 group after 7 days with 1% PVA latex powder added, provided for the present invention;

[0043] Figure 15A cross-sectional view of a small-diameter drainage pipe provided by the present invention;

[0044] Figure 16 A longitudinal section view of a small-diameter drainage pipe provided for this invention;

[0045] Figure 17 The overall structure diagram of the small-diameter drainage pipe provided by the present invention. Detailed Implementation

[0046] To make the present invention easier to understand, specific embodiments are described below to further illustrate the invention. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. 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. Unless otherwise defined, the technical terms used below have the same meaning as understood by those skilled in the art; unless otherwise specified, the raw materials and reagents involved herein can be purchased commercially or obtained by known methods.

[0047] To address the shortcomings of existing small-diameter drainage pipes, such as their heavy weight, poor wear resistance, high roughness, high breakage rate, and weak water flow capacity, this invention provides a stable EGC material specifically designed for small-diameter drainage pipes.

[0048] This invention uses geopolymer raw materials, quartz sand, fiber, latex powder, rubber powder, alkali activator and water to prepare latex powder / rubber powder modified engineering geopolymer composites. At the same time, the working performance of VAE latex powder, PVA latex powder and rubber powder in the engineering geopolymer composites in single or mixed state is studied, and EGC materials suitable for small diameter drainage pipes are developed.

[0049] The EGC powder is made from mineral powder and fly ash. The mineral powder is S95 grade ground slag powder with a density of 2.88 g / cm³. 3 Specific surface area is 440m² 2 / kg. Grade II fly ash with a density of 2.24 g / cm³ is selected. 3 Specific surface area is 400m² 2 / kg, and their chemical composition is shown in Table 1.

[0050] Table 1. Composition of mineral powder and fly ash.

[0051]

[0052] Alkali activators were prepared using water glass (sodium silicate solution) and industrial-grade NaOH particles. The water glass modulus was 3.23, and its main parameters are shown in Table 2. The purity of the industrial-grade NaOH was 99%. The method for preparing the composite alkali activator was as follows: NaOH particles were added to the water glass, and the water glass was prepared into a 1.5 modulus alkali activator by adjusting the amount of NaOH added. The 1.5 modulus composite alkali activator required the addition of 10.58 g of NaOH particles to 100 g of the original sodium water glass solution.

[0053] Table 2. Parameters of sodium silicate (wt.%)

[0054]

[0055] EGC uses polyvinyl alcohol fiber (PVA fiber), and the basic properties of the fiber are shown in Appendix 3. The fiber length is 12 mm.

[0056] Table 3. Basic Properties of PVA Fibers

[0057]

[0058] EGC sand is made from quartz sand, a silicate mineral whose main mineral component is SiO2. Quartz sand is milky white or colorless and translucent, with a hardness of 7 and a density of 2.65. The particle size of the quartz sand used is 20-40 mesh.

[0059] The materials were made using tap water.

[0060] The preparation method of a fiber-reinforced geopolymer provided in this application will be described in detail below with reference to specific embodiments and comparative examples.

[0061] Example 1

[0062] This embodiment provides a fiber-reinforced geopolymer, which is prepared by using a single-component rubber powder and the method described above.

[0063] Rubber powder is used as sand in engineering polymer composites, therefore the amount of rubber powder added is determined by the mass ratio of quartz sand. The rubber powder content is designed at two levels: 3% and 6%. Mortar mix proportions with rubber powder as the sole additive are shown in Table 4.

[0064] Table 4. Mix proportions of mortar with rubber powder as the sole additive (unit: g)

[0065]

[0066] It should be noted that the fiber content is an external addition by volume, and the rubber powder is added externally according to the mass ratio of the quartz sand.

[0067] Experiment 1-1: The added rubber powder was 3% rubber powder; the added fiber was 1% PVA fiber.

[0068] Experiment 1-2: The added rubber powder was 3% rubber powder; the added fiber was 2% PVA fiber.

[0069] Experiments 1-3: The added rubber powder was 3% rubber powder; the added fibers were 1% PP fiber and 1% PVA fiber.

[0070] Experiments 1-4: The added rubber powder was 3% rubber powder; the added fibers were 1% POM fiber and 1% PVA fiber.

[0071] Experiments 1-5: The added rubber powder was 6% rubber powder; the added fiber was 1% PVA fiber.

[0072] Experiments 1-6: The added rubber powder was 6% rubber powder; the added fiber was 2% PVA fiber.

[0073] Experiments 1-7: The added rubber powder was 6% rubber powder; the added fibers were 1% PP fiber and 1% PVA fiber.

[0074] Experiments 1-8: The added rubber powder was 6% rubber powder; the added fibers were 1% POM fiber and 1% PVA fiber.

[0075] Example 2

[0076] This embodiment provides a fiber-reinforced geopolymer, which is prepared by using VAE-doped latex powder and the method described above.

[0077] Based on the inventors' previous design of the composition of engineered geopolymer composites, two levels of VAE latex powder content were designed: 3% and 5%, to analyze and determine the impact of VAE latex powder incorporation on engineered geopolymer composites. Mortar mix proportions with different VAE latex powder contents are shown in Table 5.

[0078] Table 5. Mix proportions of mortar with VAE latex powder alone (unit: g)

[0079]

[0080] It should be noted that the fiber content is an external addition by volume, and the VAE latex powder is an external addition by mass ratio of mineral powder and fly ash.

[0081] Experiment 2-1: No VAE latex powder was added, and the added fiber was 1% PVA fiber.

[0082] Experiment 2-2: No VAE latex powder was added; the added fiber was 2% PVA fiber.

[0083] Experiment 2-3: No VAE latex powder was added; the added fibers were 1% PP fiber and 1% PVA fiber.

[0084] Experiment 2-4: No VAE latex powder was added; the added fibers were 1% POM fiber and 1% PVA fiber.

[0085] Experiment 2-5: The added adhesive powder was 3% VAE latex powder; the added fiber was 1% PVA fiber.

[0086] Experiment 2-6: The added adhesive powder was 3% VAE latex powder; the added fiber was 2% PVA fiber.

[0087] Experiment 2-7: The added rubber powder was 3% VAE latex powder; the added fibers were 1% PP fiber and 1% PVA fiber.

[0088] Experiment 2-8: The added adhesive powder was 3% VAE latex powder; the added fibers were 1% POM fiber and 1% PVA fiber.

[0089] Experiment 2-9: The added adhesive powder was 5% VAE latex powder; the added fiber was 1% PVA fiber.

[0090] Experiment 2-10: The added adhesive powder was 5% VAE latex powder; the added fiber was 2% PVA fiber.

[0091] Experiment 2-11: The added rubber powder was 5% VAE latex powder; the added fibers were 1% PP fiber and 1% PVA fiber.

[0092] Experiment 2-12: The added rubber powder was 5% VAE latex powder; the added fibers were 1% POM fiber and 1% PVA fiber.

[0093] Example 3

[0094] This embodiment provides a fiber-reinforced geopolymer, which is prepared by using PAE latex powder as a single component and the method described above.

[0095] Four design levels of PVA latex powder were selected: 0.5%, 1%, 1.5%, and 2%, to analyze and determine the impact of PVA latex powder incorporation on engineered polymer composites. Mortar mix proportions with different PVA latex powder incorporations are shown in Table 6.

[0096] Table 6. Mix proportions of mortar with PVA latex powder alone (unit: g)

[0097]

[0098] It should be noted that the fiber content is an external addition by volume, and the PVA latex powder is an external addition by mass ratio of mineral powder and fly ash.

[0099] Experiment 3-1: The added adhesive powder was 0.5% PVA latex powder; the added fiber was 1% PVA fiber.

[0100] Experiment 3-2: The added adhesive powder was 0.5% PVA latex powder; the added fiber was 2% PVA fiber.

[0101] Experiment 3-3: The added adhesive powder was 0.5% PVA latex powder; the added fibers were 1% PP fiber and 1% PVA fiber.

[0102] Experiments 3-4: The added adhesive powder was 0.5% PVA latex powder; the added fibers were 1% POM fiber and 1% PVA fiber.

[0103] Experiment 3-5: The added adhesive powder was 1% PVA latex powder; the added fiber was 1% PVA fiber.

[0104] Experiment 3-6: The added adhesive powder was 1% PVA latex powder; the added fiber was 2% PVA fiber.

[0105] Experiment 3-7: The added adhesive powder was 1% PVA latex powder; the added fibers were 1% PP fiber and 1% PVA fiber.

[0106] Experiment 3-8: The added adhesive powder was 1% PVA latex powder; the added fibers were 1% POM fiber and 1% PVA fiber.

[0107] Experiment 3-9: The added adhesive powder was 1.5% PVA latex powder; the added fiber was 1% PVA fiber.

[0108] Experiment 3-10: The added adhesive powder was 1.5% PVA latex powder; the added fiber was 2% PVA fiber.

[0109] Experiment 3-11: The added adhesive powder was 1.5% PVA latex powder; the added fibers were 1% PP fiber and 1% PVA fiber.

[0110] Experiment 3-12: The added adhesive powder was 1.5% PVA latex powder; the added fibers were 1% POM fiber and 1% PVA fiber.

[0111] Experiment 3-13: The added adhesive powder was 2% PVA latex powder; the added fiber was 1% PVA fiber.

[0112] Experiment 3-14: The added adhesive powder was 2% PVA latex powder; the added fiber was 2% PVA fiber.

[0113] Experiment 3-15: The added adhesive powder was 2% PVA latex powder; the added fibers were 1% PP fiber and 1% PVA fiber.

[0114] Experiment 3-16: The added rubber powder was 2% PVA latex powder; the added fibers were 1% POM fiber and 1% PVA fiber.

[0115] Example 4

[0116] This embodiment provides a fiber-reinforced geopolymer, which is prepared by mixing VAE latex powder and rubber powder using the method described above.

[0117] Based on relevant literature and previous experimental results, the inventors selected two dosages of VAE latex powder: 3% and 5%, while the dosage of rubber powder was selected as 3%. At the same time, the selected fiber ratios were four previously optimized ratios: PVA 1 vol%, PVA 2 vol%, PP 1 vol% plus PVA 1 vol%, and POM 1 vol% plus PVA 1 vol%. Therefore, the mortar mix ratios of VAE latex powder and rubber powder are shown in Table 7.

[0118] Table 7.

[0119]

[0120] It should be noted that the fiber content is an external addition by volume, and the adhesive powder is an external addition based on the mass ratio of mineral powder and fly ash.

[0121] Experiment 4-1: The mixed rubber powder incorporated: 3% VAE latex powder and 3% rubber powder; the incorporated fiber is 1% PVA fiber.

[0122] Experiment 4-2: The mixed rubber powder incorporated: 3% VAE latex powder and 3% rubber powder; the incorporated fiber was 2% PVA fiber.

[0123] Experiment 4-3: The mixed rubber powder incorporated: 3% VAE latex powder and 3% rubber powder; the incorporated fibers were 1% PP fiber and 1% PVA fiber.

[0124] Experiment 4-4: The mixed rubber powder incorporated was 3% VAE latex powder and 3% rubber powder; the incorporated fibers were 1% POM fiber and 1% PVA fiber.

[0125] Experiment 4-5: The mixed rubber powder incorporated was 5% VAE latex powder and 3% rubber powder; the incorporated fiber was 1% PVA fiber.

[0126] Experiment 4-6: The mixed rubber powder incorporated was 5% VAE latex powder and 3% rubber powder; the incorporated fiber was 2% PVA fiber.

[0127] Experiment 4-7: The mixed rubber powder incorporated was 5% VAE latex powder and 3% rubber powder; the incorporated fibers were 1% PP fiber and 1% PVA fiber.

[0128] Experiment 4-8: The mixed rubber powder incorporated was 5% VAE latex powder and 3% rubber powder; the incorporated fibers were 1% POM fiber and 1% PVA fiber.

[0129] Example 5

[0130] This embodiment provides a fiber-reinforced geopolymer, prepared by blending PAE latex powder and rubber powder using the method described above. The mortar mix proportions of the PAE latex powder and rubber powder blend are shown in Table 8.

[0131] Table 8.

[0132]

[0133] It should be noted that the fiber content is an external addition by volume, the PVA latex powder is calculated based on the total mass of mineral powder and fly ash, and the rubber powder is calculated based on the mass of quartz sand.

[0134] Experiment 5-1: The mixed rubber powder incorporated was 1% PAE latex powder and 3% rubber powder; the incorporated fiber was 1% PVA fiber.

[0135] Experiment 5-2: The mixed rubber powder incorporated was 1% PAE latex powder and 3% rubber powder; the incorporated fiber was 2% PVA fiber.

[0136] Experiment 5-3: The mixed rubber powder incorporated was 1% PAE latex powder and 3% rubber powder; the incorporated fibers were 1% PP fiber and 1% PVA fiber.

[0137] Experiment 5-4: The mixed rubber powder incorporated was 1% PAE latex powder and 3% rubber powder; the incorporated fibers were 1% POM fiber and 1% PVA fiber.

[0138] Experiment 5-5: The mixed rubber powder incorporated was 2% PAE latex powder and 3% rubber powder; the incorporated fiber was 1% PVA fiber.

[0139] Experiments 5-6: The mixed rubber powder incorporated was 2% PAE latex powder and 3% rubber powder; the incorporated fiber was 2% PVA fiber.

[0140] Experiment 5-7: The mixed rubber powder incorporated was 2% PAE latex powder and 3% rubber powder; the incorporated fibers were 1% PP fiber and 1% PVA fiber.

[0141] Experiment 5-8: The mixed rubber powder incorporated was 2% PAE latex powder and 3% rubber powder; the incorporated fibers were 1% POM fiber and 1% PVA fiber.

[0142] Comparative Example 1

[0143] This comparative example provides a fiber-reinforced geopolymer without adhesive powder.

[0144] It is basically the same as Experiment 1 in Example 1, except that no adhesive powder is added.

[0145] To better illustrate the properties of the fiber-reinforced geopolymer provided by the present invention, the applicant conducted the following studies on Examples 1-4 and the comparative examples:

[0146] (1) Study on condensation time

[0147] The setting time of the composite material was tested using a Vicat apparatus. Timing started from the addition of water. After the composite material was stirred, it was poured into the test mold. When the needle sank to 4±1mm from the bottom plate, the specimen was the initial setting time. The mold was flipped over, and after the needle was replaced, the time when the needle could no longer leave a mark on the composite material was the final setting time.

[0148] refer to Figure 1a The figure shows the setting time of fiber-reinforced geopolymer mortar with rubber powder as a single additive. As can be seen from the figure, compared to the case without rubber powder, the effect of different amounts of rubber powder on the setting time of the fiber-reinforced geopolymer mortar is not significant. When 3% rubber powder is added, the setting time of the fiber-reinforced geopolymer mortar is only slightly extended under the four fiber dosage ratios, with the extension being around 3%. When 6% rubber powder is added, the setting time of the fiber-reinforced geopolymer mortar does not change significantly compared to the case without rubber powder. The PVA1 group and PP1+1 group show an extension of approximately 8%, while the PVA2 group and POM1+1 group show no significant change.

[0149] refer to Figure 1b The setting time of fiber-reinforced geopolymers with VAE latex powder was compared among three formulations: no VAE powder, 3% VAE latex powder, and 5% VAE latex powder. The shortest setting time was observed in the PVA2 group, while the setting times of the other three groups (PVA1, PP1+1, and POM1+1) showed little difference. The setting time gradually increased with increasing VAE latex powder content, with the largest variation observed in the PVA1 group, which increased from 38 minutes without VAE powder to 48 minutes with 5% VAE latex powder.

[0150] refer to Figure 1cThe figure shows the setting time of fiber-reinforced geopolymer mortar with PVA latex powder as the sole additive. As can be seen from the figure, the setting time of all fiber-reinforced geopolymer mortar mixes increases to varying degrees with the increase of PVA latex powder content. The setting time of the PVA1 group of mortars increased from 38 min without adhesive powder to 46 min with 2% PVA latex powder; the setting time of the PVA2 group increased from 33 min without adhesive powder to 41 min with 2% PVA latex powder; the setting time of the PP1+1 group increased from 37 min to 48 min with 2% PVA latex powder; and the setting time of the POM1+1 group increased from 39 min without adhesive powder to 48 min with 2% PVA latex powder. This indicates that the incorporation of PVA latex powder can delay the setting time of the engineered polymer composite mortar to a certain extent. This may be because the incorporation of PVA latex powder changes the rheological properties of the engineered polymer composite mortar, thereby delaying the setting time.

[0151] Will Figure 1a , 1b Compared with 1c, it can be found that the effect of rubber powder alone on the setting time of fiber-reinforced geopolymer is much smaller than that of VAE latex powder alone and PVA latex powder alone.

[0152] refer to Figure 2 The figure represents the setting time of the fiber-reinforced geopolymer when VAE latex powder and rubber powder are mixed. The figure shows that when the rubber powder content is maintained at 3%, the setting time of the fiber-reinforced geopolymer is significantly prolonged with increasing VAE latex powder content. The setting time of the PVA1 group increased from 38 minutes without added rubber powder to 46 minutes with 3% VAE latex powder and 3% rubber powder, and then to 48 minutes with 5% VAE latex powder and 3% rubber powder, an increase of 26%. The setting time of the PP1+1 group increased from 37 minutes without added rubber powder to 47 minutes with 5% VAE latex powder and 3% rubber powder, an increase of 27%. The smallest increase was in the POM group, where the setting time increased from 39 minutes to 45 minutes with 5% VAE latex powder and 3% rubber powder, an increase of only 15%, much smaller than that of the PVA1, PVA2, and PP1+1 groups. This may be because the interaction between VAE latex powder and POM fibers is different from that between PVA and PP fibers.

[0153] from Figure 2It was also found that, compared to fiber-reinforced geopolymers with VAE latex powder alone, the effects of mixing VAE latex powder and rubber powder on the setting time of fiber-reinforced geopolymer mortar were almost identical, with no significant difference. The increase in setting time for each group did not fluctuate significantly, indicating that rubber powder had a relatively small impact on setting time. This may be because rubber powder mainly acts as fine aggregate in fiber-reinforced geopolymer mortar, serving a filling function; while VAE latex powder alters the surface properties of various components in the composite material, thus delaying the setting time of the fiber-reinforced geopolymer.

[0154] refer to Figure 3 The setting time of fiber-reinforced geopolymer mortar with PVA latex powder and rubber powder is denoted as . The setting time varies considerably among the groups. For the PVA1 group, the setting time increased from 38 min without mortar powder to 44 min with 1% PVA latex powder and 3% rubber powder, and then to 48 min with 2% PVA latex powder and 3% rubber powder. For the PVA2 group, the setting time was delayed from 33 min without mortar powder to 42 min with 2% PVA latex powder and 3% rubber powder. For the PP1+1 group, the setting time increased from 37 min initially to 44 min with 1% PVA latex powder and 3% rubber powder, and then to 51 min with 2% PVA latex powder and 3% rubber powder. For the POM1+1 group, the setting time increased from 39 min to 45 min, and finally to 49 min with 2% PVA latex powder and 3% rubber powder. Comparing the setting time of fiber-reinforced geopolymer mortar with mixed PVA latex powder and rubber powder with that with PVA latex powder and rubber powder alone, it can be found that rubber powder has little effect on setting time, while PVA latex powder has a more significant effect on setting time.

[0155] (2) Study on fluidity

[0156] The flowability of polymer composite paste and mortar in engineering applications was tested using a truncated conical mold. For paste, a truncated conical mold with an upper diameter of 36 mm, a lower diameter of 60 mm, and a height of 60 mm was used; for mortar, a truncated conical mold with an upper diameter of 60 mm, a lower diameter of 100 mm, and a height of 60 mm was used. The mixed composite material was poured into the truncated conical mold, the upper surface was smoothed, and the mold was lifted vertically. The diameters in two perpendicular directions were measured with a steel ruler, and the average value was taken as the flowability of the composite material.

[0157] refer to Figure 4The figure shows the flowability of fiber-reinforced geopolymer mortar with VAE latex powder and rubber powder. As can be seen from the figure, the flowability of the composite material decreases significantly with the addition of rubber powder. Specifically, the flowability of the PVA1 group decreased from 194 mm to 180 mm and then to 173 mm, a reduction of 10.84%. The flowability of the PVA2 group decreased directly from 127 mm to loss of flowability. The flowability of the PP1+1 group decreased from 231 mm without rubber powder to 215 mm with 5% VAE latex powder and 3% rubber powder, a reduction of 6.93%. The flowability of the POM1+1 group (220 mm) decreased only slightly more than that of the PP1+1 group, by 9.87%. Analysis of the flowability data for each fiber ratio shows that the blending of VAE latex powder and rubber powder has a significant impact on flowability. A comparison of the flowability results with those of blending VAE latex powder and rubber powder with those of blending VAE latex powder and rubber powder alone reveals that for fiber-reinforced geopolymer mortar, the decrease in flowability is primarily due to the influence of VAE latex powder. This is likely because, compared to rubber powder, VAE latex powder dissolves in water and then bonds with the mortar material, increasing the overall viscosity of the composite mortar. Rubber powder, on the other hand, only slightly increases the water requirement of the composite material and does not alter the rheological properties of the mortar.

[0158] refer to Figure 5 The figure shows the flowability of fiber-reinforced geopolymer mortar containing PVA latex powder and rubber powder. As can be seen from the figure, the flowability of the composite mortar gradually decreases with the addition of PVA latex powder and rubber powder. Among the four fiber ratios, the largest decrease is observed in the PVA2 group, reaching 17.32%, while the smallest decrease is in the PP1+1 group, at only 6.06%. The flowability decreases in the PVA1 and POM1+1 groups are both between 9% and 10%. Comparing the flowability with the composite mortar containing VAE latex powder and rubber powder reveals that, except for the POM1+1 group, the flowability decreases for the other three fiber ratios are smaller than those of the group containing VAE latex powder and rubber powder. This indicates that the decrease in flowability when 2% PVA latex powder and 3% rubber powder are added is less than that when 5% VAE latex powder and 3% rubber powder are added. The influence of mixing PVA latex powder and rubber powder on flowability indicates that PVA latex powder has a greater impact on the flowability of composite mortar. This may be because PVA latex powder can be dissolved in water and adsorbed on the surface of mineral powder, fly ash or fibers, thereby hindering the sliding between the components in the slurry and thus affecting the flowability of composite mortar.

[0159] (3) Study on compressive strength

[0160] Six specimens were taken after the flexural strength test for compressive strength testing. The compressive strength test was also conducted using an integrated flexural and compressive strength testing machine, with a load application rate of 1000 N / s ± 100 N / s. The average of the six compressive strength measurements was taken as the experimental result.

[0161] refer to Figure 6 The figure shows the compressive strength of each fiber ratio at 28 days when VAE latex powder and rubber powder are mixed. As can be seen from the figure, among the four fiber ratios, the PP1+1 group has the highest strength at 66.2 MPa and 61.7 MPa, respectively, when mixed with different rubber powders. When 3% VAE latex powder and 3% rubber powder are mixed, the largest decrease in compressive strength at 28 days is in the PP1+1 group (11.26%), and the smallest decrease is in the PVA1 group (9.45%). When 5% VAE latex powder and 3% rubber powder are mixed, the largest decrease in compressive strength at 28 days is in the POM1+1 group.

[0162] refer to Figure 9 The figure shows the 28-day compressive strength of four fiber formulations with different proportions of PVA latex powder and rubber powder. As can be seen from the figure, when different amounts of PVA latex powder and rubber powder are added, the highest compressive strength is for the PP1+1 group, at 66.3 MPa and 62.1 MPa respectively. When 1% PVA latex powder and 3% rubber powder are added, the PP1+1 group shows the largest decrease in 28-day compressive strength, with a decrease of 11.13%, while the decreases for the other three fibers are between 9% and 10%. When 2% PVA latex powder and 3% rubber powder are added, the POM1+1 group shows the largest decrease in compressive strength.

[0163] (4) Study on flexural strength

[0164] Prismatic specimens (40mm×40mm×160mm) cured to the appropriate age were removed from the constant temperature and humidity curing chamber and subjected to flexural strength testing using an integrated flexural and compressive strength testing machine. The loading speed for the flexural test was 50N / s ± 5N / s. The average flexural strength of a set of three prism specimens was taken as the experimental result. If the strength of any of the three prism specimens was outside the range of ±15% of the average, this data was discarded and the average was recalculated. If the strength of two of the three prism specimens was outside the range of ±15% of the average, this set of data was invalidated, and a new set of specimens with the same mix ratio should be tested.

[0165] refer to Figure 7The figure shows the flexural strength after 28 days when VAE latex powder and rubber powder are mixed. The figure reveals that the decrease in flexural strength of composites with different fiber ratios varies depending on the amount of rubber powder added. When 3% VAE latex powder and 3% rubber powder are added, the decrease in flexural strength of PVA1 and PVA2 groups is relatively small, ranging from 3% to 3.2%, while the decrease in POM1+1 group reaches 7.61%. When 5% VAE latex powder and 3% rubber powder are added, the largest decrease is observed in PVA2 group, at 13.40%.

[0166] refer to Figure 10 The figure shows the 28-day flexural strength of composite mortar when PVA latex powder and rubber powder are mixed. It can be seen from the figure that when 1% PVA latex powder and 3% rubber powder are added, the highest flexural strength is in group PVA2, at 9.3 MPa. At this point, the largest decrease in flexural strength among the four fiber ratios is in group PVA1, at 6.38%. When 2% PVA latex powder and 3% rubber powder are added, the highest flexural strength is in group PP1+1, the largest decrease in flexural strength is in group PVA2, and the smallest decrease is in group PP1+1.

[0167] (5) Study on compressive-flexural ratio

[0168] Prismatic specimens (40mm×40mm×160mm) cured to the appropriate age were removed from the constant temperature and humidity curing chamber and subjected to flexural strength testing using an integrated flexural and compressive strength testing machine. The loading speed for the flexural test was 50N / s ± 5N / s. The average flexural strength of a set of three prism specimens was taken as the experimental result. If the strength of any of the three prism specimens was outside the range of ±15% of the average, this data was discarded and the average was recalculated. If the strength of two of the three prism specimens was outside the range of ±15% of the average, this set of data was invalidated, and a new set of specimens with the same mix ratio should be tested.

[0169] refer to Figure 8The figure shows the 28-day compression-flexure ratio of composite mortars containing VAE latex powder and rubber powder at various fiber ratios. It can be observed that the 28-day compression-flexure ratio of the engineered geopolymer composite mortars at various fiber ratios decreases to some extent after the addition of VAE latex powder and rubber powder. This indicates that the toughness of the engineered geopolymer composite is improved with the incorporation of VAE latex powder and rubber powder. The reasons for this phenomenon may be as follows: First, the hydration of VAE latex powder in the slurry forms a flexible network structure, improving the toughness of the composite and reducing the compression-flexure ratio. Second, the elastomer formed by the hardening of rubber powder and the hydration products of the geopolymer composite can absorb and disperse stress, thus reducing the compression-flexure ratio and increasing the toughness of the engineered geopolymer composite. Third, both VAE latex powder and rubber powder can improve the bonding interface between the geopolymer slurry and quartz sand, enhancing the stress transmission of the composite under load, thereby increasing the toughness and reducing the compression-flexure ratio.

[0170] refer to Figure 11 The figure shows the 28-day compression-to-flexural ratio of engineered geopolymer composite mortar with PVA latex powder and rubber powder. As can be seen from the figure, the compression-to-flexural ratio of the composite mortar decreases with the addition of PVA latex powder and rubber powder, but the difference in compression-to-flexural ratio is not significant when the PVA latex powder content is 1% and 2%. This indicates that the toughness of the engineered geopolymer composite mortar is significantly improved with the addition of PVA latex powder and rubber powder. This may be because the combined effect of the water-retaining effect of PVA latex powder and the filling effect of rubber powder optimizes the internal pore structure of the composite material, enhances its toughness, and thus reduces the compression-to-flexural ratio.

[0171] (6) Bending toughness study

[0172] A three-point bending test was used to determine the flexural toughness of engineered polymer composites. The test was conducted on a universal testing machine, with loading performed using a controlled displacement method at a loading rate of 0.5 mm / min. Data were collected by computer, and load-deflection curves were plotted for flexural toughness analysis.

[0173] refer to Figure 12aThe figure shows the load-deflection curves of engineering geopolymer composite mortar samples with 3% VAE latex powder and 3% rubber powder at 28 days. As can be seen from the figure, the peak load is highest for PVA2 group, followed by PVA1 and PP1+1 groups, and finally POM1+1 group. The fracture deflection is highest for PVA2 group and lowest for PVA1 group, with PP1+1 group slightly lower than POM1+1 group. The figure also shows that only PVA1 group failed abruptly after reaching the peak load among the four fiber ratios; the other three groups exhibited a relatively obvious strain hardening stage, and significant ductility during the strain softening stage following the strain hardening stage. This indicates that under this rubber powder mixing ratio, PVA2, PP1+1, and POM1+1 groups all possess good flexural toughness. However, under this rubber powder mixing ratio, the peak load of PVA2 group is only 3200 N, indicating that the mechanical strength of PVA2 group is relatively poor at this point.

[0174] refer to Figure 12b The figure shows the load-deflection curves of the engineering geopolymer composite mortar with 5% VAE latex powder and 3% rubber powder at 28 days. As can be seen from the figure, the peak load and fracture deflection are both highest in group PVA2, while the peak load and fracture deflection are lowest in group PVA1. The peak load and fracture deflection of group PP1+1 are both higher than those of group POM1+1. Among the four fiber ratios, except for group PVA1, groups PVA2, PP1+1, and POM1+1 all exhibit good flexural toughness.

[0175] contrast Figure 12a and Figure 12b It can be observed that when VAE latex powder and rubber powder are mixed into the engineered polymer composite material, all four fiber ratios can clearly show the strain hardening stage, indicating that the flexural toughness of the four fiber ratios is good at this time. However, the PVA1 group will fail rapidly after the peak load and has insufficient ductility, while the other fiber ratios will fluctuate and decrease after the peak load and have good ductility.

[0176] refer to Figure 13a The figure shows the load-deflection curves of engineering polymer composite mortar with 1% PVA latex powder and 3% rubber powder at 28 days. It can be seen from the figure that all four fiber groups have a relatively obvious strain hardening stage, but there are large differences in the fracture deflection of each group. The fracture deflection of PVA1 group is the smallest, the fracture deflection of POM1+1 group is slightly larger than that of PVA1 group, and the fracture deflection of PVA2 group and PP1+1 group is much larger than that of the other two groups, with PVA2 group having the largest fracture deflection.

[0177] refer to Figure 13bThe figure shows the load-deflection curves of mortar samples with different fiber ratios after 28 days when 2% PVA latex powder and 3% rubber powder were mixed. As can be seen from the figure, all four fiber ratios exhibit a relatively obvious strain hardening stage, with the PVA2 group showing the highest peak load and a fracture deflection only greater than the POM1+1 group. Overall, the load-deflection curves of the four groups are relatively uniform, with little difference between them. This indicates that the flexural toughness of the PVA2 group is significantly lower than that of the other rubber powder ratios, while the PVA1, PP1+1, and POM1+1 groups show little change compared to the other groups.

[0178] contrast Figure 13a and Figure 13b It can be observed that as the amount of PVA latex powder added increases from 1% to 2%, the flexural toughness of each fiber ratio decreases to a certain extent. This may be because the increase in the amount of PVA latex powder leads to an increase in the internal porosity of the mortar samples of each fiber ratio, which in turn leads to a certain decrease in the flexural toughness of each ratio.

[0179] (7) Microstructure study

[0180] Small samples of engineered geopolymer specimens of the appropriate age were taken as test samples. The samples were sealed and stored in anhydrous ethanol to terminate hydration. Before testing, the samples were dried in an oven for 24 hours and then sputtered with gold. The microstructure of the samples was observed using a German ZEISG Gemini SEM 300.

[0181] refer to Figure 14a The image shows a 7-day SEM image of the PVA1 group without added binder powder. It can be seen that the PVA1 group without added binder powder has a similar morphology to the cement paste on the geopolymer matrix, that is, it has some gel-like substances, as well as a small number of pores and cracks. However, the PVA fibers can be seen to be twisted. This may be because the fibers absorb energy and break when the specimen is subjected to external loads, causing the fiber morphology to change.

[0182] refer to Figure 14b The image shows the 7-day SEM images of the PVA1 group after incorporating 3% VAE latex powder. After incorporating the powder, the PVA fibers still have good bonding with the geopolymer matrix, and a large amount of material is attached to the PVA fibers. However, fine pores can be seen on the surface of most of the gels.

[0183] refer to Figure 14c The image shows a 7-day SEM image of PVA1 group with 1% PVA latex powder added. It can be seen from the image that a large amount of substances are adsorbed on the PVA fibers, and there are a large number of grooves along the fiber axis on the surface of the PVA fibers. This may indicate that the surface of the PVA fibers is damaged during the separation process from the geopolymer matrix.

[0184] contrast Figure 14a -c, when latex powder is incorporated, it dissolves in water to form a coating layer that wraps around the surface of the fiber or geopolymer raw material. This alters the interfacial properties of the fiber and geopolymer matrix, slows down the geopolymerization reaction, and reduces the mechanical properties of the EGC material. At the same time, it improves the interfacial adhesion between the fiber and the geopolymer matrix, forming a synergistic structure of fiber, latex powder, and geopolymer matrix. This increases the fracture energy of the EGC material and improves its flexural toughness.

[0185] Example 6

[0186] This embodiment provides a small-diameter drainage pipe made using the fiber-reinforced geopolymer provided by the present invention.

[0187] The dimensions and molds for small-diameter drainage pipes are designed and prepared. The fiber-reinforced geopolymer provided by this invention is poured into the prefabricated pipe mold, air bubbles are removed, and after demolding and curing for 7 to 28 days, small-diameter drainage pipes are obtained.

[0188] refer to Figure 15-16 The figures show the cross-sectional and longitudinal sections of the pipeline, respectively. In the figures, 1 represents the FRP socket and 2 represents the EGC pipeline. The socket between the pipelines is made of fiber reinforced plastic (FRP). Compared with steel sockets, this type of socket can withstand greater strain and has viscoelasticity and good elastic-plasticity. It has a tighter contact with the pipeline, reducing the possibility of water leakage at the pipeline connection and avoiding the risk of corrosion of steel sockets, thus increasing the stability and durability of the overall pipeline structure.

[0189] refer to Figure 17 The small-diameter drainage pipe provided in this embodiment is shown in the overall structural diagram of the pipe. Using EGC material to fabricate the drainage pipe allows for minimal or no reinforcement, reducing construction steps and improving efficiency. Furthermore, the use of FRP sockets enhances the overall stability and durability of the pipe, resulting in a more robust structure.

[0190] Where there is no conflict, the above embodiments and features described herein can be combined with each other.

[0191] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A fiber reinforced geopolymer, characterized in that, The product comprises the following components by weight: 250-300 parts mineral powder, 200-220 parts fly ash, 670-730 parts quartz sand, 120-150 parts alkali activator, 7.6-24 parts fiber, 3.5-34.9 parts latex powder, and 20.9-41.9 parts rubber powder. It also includes the following preparation steps: mineral powder and fly ash are added sequentially to a cement mortar mixer and stirred at low speed until uniformly mixed; while stirring, fiber is slowly added and dry-mixed for a first preset time; then quartz sand, latex powder, and rubber powder are added, and water is added and stirred until uniformly mixed to obtain the fiber-reinforced geopolymer. The fiber is at least one of polyvinyl alcohol fiber, polypropylene fiber and polyoxymethylene fiber; The latex powder is PVA latex powder or VAE latex powder; When the latex powder is PVA latex powder, the mass concentration ratio of the PVA latex powder and the rubber powder is (1~2):3, wherein the PVA latex powder is added based on the total mass of mineral powder and fly ash, and the rubber powder is added based on the mass of quartz sand. When the latex powder is VAE latex powder, the mass concentration ratio of the VAE latex powder and the rubber powder is (3~5):3, wherein the VAE latex powder is added based on the total mass of mineral powder and fly ash, and the rubber powder is added based on the mass of quartz sand. The fiber content is the wet bulk volume content, which is added externally.

2. The fiber reinforced geopolymer of claim 1, wherein, The mineral powder is selected from S95 grade ground slag powder, with a density of 2.88 g / cm 3 and a specific surface area of 440 m 2 / kg.

3. The fiber reinforced geopolymer of claim 1, wherein, The fly ash is selected from Ⅱ grade fly ash, and the density is 2.24 g / cm 3 , and the specific surface area is 400 m 2 / kg.

4. The fiber reinforced geopolymer of claim 1, wherein, The fiber is polyvinyl alcohol fiber.

5. The fiber reinforced geopolymer of claim 1, wherein, The particle size of the quartz sand is 20-40 mesh.

6. The use of the fiber-reinforced geopolymer as described in any one of claims 1-5 in the preparation of building materials.

7. A drain conduit, characterized in that The fiber-reinforced geopolymer of any one of claims 1-5 is poured into a pre-made pipe mold, air bubbles are removed, and the pipe is demolded and cured for 7-28 days to obtain the drainage pipe.

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