Cement-based material doped with waste ceramic powder and preparation process of cement-based material

Abstract

The invention discloses a cement-based material doped with waste ceramic powder. The cement-based material is prepared from P.O 42.5 R Portland cement, modified waste ceramic powder, first / second modified powder, modified nano calcium carbonate, polyepoxysuccinic acid grafted graphene oxide, modified composite aggregate and water, the modified waste ceramic powder is prepared by carrying out composite modification on waste ceramic powder through KH-560 and polyethylene glycol 400; the first modified powder is prepared by mixing vanadium titano-magnetite tailing nanowires and fly ash microspheres; the second modified powder is obtained by performing KH-550 pretreatment on polylactic acid microspheres, mixing the pretreated polylactic acid microspheres with hydroxypropyl methyl cellulose phosphate, performing jet milling, and performing coating modification with polyglycerol fatty acid ester; the modified composite aggregate is modified by KH-570 after blast furnace slag and waste ceramic powder are mixed; the modified nano calcium carbonate is obtained by sequentially modifying nano calcium carbonate with casein phosphopeptides and chitosan quaternary ammonium salt. The material can solve the problems of heavy load shearing, mountain torrent erosion, temperature difference freeze thawing and the like of deep canyon roads, and is adaptive to canyon service environments.

Description

Technical Field

[0001] This invention belongs to the field of cement-based materials technology, specifically a cement-based material doped with waste ceramic powder and its preparation process. Background Technology

[0002] In the deep canyon areas of the transition zone between the western Sichuan Plateau and the Sichuan Basin, the hardening of village roads is a crucial project for ensuring smooth rural logistics and supporting agricultural production. Constrained by the canyon terrain, these roads are mostly carved along the bottom or sides of the canyons, resulting in narrow and winding routes with a significant proportion of sections accessible from overhead views. They primarily connect villages and terraced fields on both sides of the canyons, serving the functions of transporting agricultural products, facilitating agricultural machinery access, and providing daily transportation for villagers. Locally in Sichuan, ceramic enterprises generate a large amount of waste ceramics annually. The ceramic powder obtained after grinding this waste mainly consists of SiO2 and Al2O3, possessing certain pozzolanic activity, and can be used as an auxiliary cementitious material in cement-based materials. Currently, the recycling rate of this ceramic powder is low, with most disposal through landfill, which occupies land resources and easily causes environmental pollution. While applying this ceramic powder to cement-based materials for roads in the aforementioned canyon areas can meet the needs of solid waste resource utilization and low-cost construction, the existing technology still faces some technical challenges in practical application due to the combined effects of the special working conditions of canyon sections and the inherent limitations of ceramic powder itself. These challenges are specifically reflected in the following aspects: First, there is the uneven shear stress caused by heavy-duty agricultural machinery turning and the uneven load-bearing capacity of the roadbed. The narrow, winding sections of highways in deep canyons require heavy-duty agricultural machinery to repeatedly turn and brake at low speeds, resulting in significant shear-compaction combined effects on the road surface and wheel tracks. Simultaneously, the compaction quality of the roadbed is difficult to guarantee uniformity due to terrain constraints, leading to areas with weak load-bearing capacity, further exacerbating stress concentration on the road surface. This necessitates cement-based materials possessing both high shear strength and good stress diffusion capabilities. However, in practical applications, the addition of ceramic powder reduces the early shear strength of the material, and the interfacial bonding between ceramic powder and cement paste is poor, making it prone to cracking under combined stress, ultimately leading to road surface defects such as sandblasting and subsidence.

[0003] Secondly, there is the erosion caused by flash floods and gravel. Due to the canyon narrowing effect, short-term heavy rainfall during the rainy season (June-September) can easily converge and form flash floods. The water flow carries gravel and sand from the canyon, and the high flow velocity exerts a combined effect of impact, frictional wear, and erosion on the road surface. In addition, the limited drainage space on both sides of the highway means that flash floods can easily overflow the road surface, causing widespread erosion and further aggravating the road surface damage. This places high demands on the wear resistance, impact resistance, and erosion resistance of cement-based materials. However, simply grinding ceramic powder makes it difficult to make the internal structure of the material dense. Not only is the impact toughness insufficient, making it prone to surface peeling, but the interface bonding with the aggregate is also relatively loose, making it easy for water flow to erode and form pores.

[0004] Thirdly, extreme temperature differences and alternating freeze-thaw cycles, icing and melting occur. Deep canyon sections have elevation differences of 1500-3000m, with extreme diurnal temperature variations reaching 20-28℃. These drastic temperature differences between the surface and interior of the road surface easily trigger deep shrinkage cracks. High-altitude mountain passes are also prone to alternating freeze-thaw cycles in winter, where repeated expansion and contraction of moisture causes damage due to expansion, infiltration, and re-expansion. Simultaneously, strong winds and high humidity within the canyons slow down moisture evaporation from the road surface, further exacerbating freeze-thaw damage. Furthermore, poor maintenance conditions in mountainous areas make timely insulation and moisture retention difficult, leading to uncontrolled early damage. This necessitates cement-based materials with excellent volume stability, frost resistance, and early crack resistance. However, ceramic powder slows down the hydration process of cement, resulting in slow early strength development, poor volume stability, and a tendency to crack. Moreover, ceramic powder has limited effect on optimizing pore structure; the repeated expansion and contraction of pore water during freeze-thaw cycles disrupts the interface structure, exacerbating road damage.

[0005] Therefore, it is of great significance to develop a cement-based material doped with waste ceramic powder that can adapt to the combined working conditions of shear-rolling stress, mountain torrents and gravel erosion, and extreme temperature freeze-thaw cycles on the aforementioned mountain roads in deep canyons. Summary of the Invention

[0006] The purpose of this invention is to provide a cement-based material doped with waste ceramic powder and its preparation process, so as to effectively improve the problems of insufficient early shear strength, poor resistance to mountain torrents and gravel erosion, and poor resistance to temperature difference freeze-thaw in traditional cement-based materials with ceramic powder doping in mountainous roads with deep canyons.

[0007] The objective of this invention is achieved through the following technical solution: A cement-based material doped with waste ceramic powder, comprising the following components in parts by weight: 320-360 parts of P・O 42.5R grade ordinary Portland cement, 90-120 parts of modified waste ceramic powder, 0.7-1.1 parts of first modified powder, 28-38 parts of second modified powder, 1.8-2.8 parts of modified nano calcium carbonate, 6-8 parts of polyepoxysuccinic acid grafted graphene oxide, 1680-1780 parts of modified composite aggregate, and 155-165 parts of water; The modified waste ceramic powder is obtained by modifying waste ceramic powder with silane coupling agent KH-560 and polyethylene glycol 400. The first modified powder is made by mixing vanadium-titanium magnetite tailings nanowires and fly ash microspheres, followed by ultrasonic dispersion, spray drying, and inert atmosphere calcination. The second modified powder is obtained by pretreating polylactic acid microspheres with KH-550, mixing them with hydroxypropyl methylcellulose phosphate, grinding them by air jet milling, and then coating them with polyglycerol fatty acid esters for modification. The modified composite aggregate is obtained by mixing blast furnace slag and waste ceramic powder and then modifying it with silane coupling agent KH-570; The modified nano-calcium carbonate is obtained by first modifying nano-calcium carbonate with casein phosphopeptide, and then modifying it with chitosan quaternary ammonium salt.

[0008] As one possible implementation of this application, in the first modified powder, the mass ratio of vanadium-titanium magnetite tailings nanowires to fly ash microspheres is 1:(7-10).

[0009] As some possible implementations of this application, the preparation conditions of the first modified powder are: ultrasonic dispersion in anhydrous ethanol for 20-60 min, spray drying, and calcination at 550-650℃ for 1-2 h under a nitrogen inert atmosphere.

[0010] As one possible implementation of this application, the mass ratio of blast furnace slag to waste ceramic powder in the modified composite aggregate is (5-7):(3-5).

[0011] As one possible implementation of this application, in the modified nano-calcium carbonate, the mass ratio of nano-calcium carbonate to casein phosphopeptide is (6-10):1.

[0012] As one possible implementation of this application, in the second modified powder, the mass ratio of hydroxypropyl methylcellulose phosphate to polylactic acid microspheres is (2-4):1.

[0013] In addition, to achieve the above objectives, this application also provides a preparation process for cement-based materials doped with waste ceramic powder, comprising the following steps: (1) Premixing: P·O 42.5R grade ordinary silicate cement, modified waste ceramic powder, second modified powder, and modified nano calcium carbonate are thoroughly stirred to obtain premixed powder; the first modified powder is dispersed in water, polyepoxysuccinic acid grafted graphene oxide is added, and stirred until completely dissolved to obtain functional aqueous solution; (2) Mixing and molding: The modified composite aggregate is put into the mixer, the functional aqueous solution is poured in, and after mixing thoroughly, the premixed powder is added. After mixing thoroughly, a mixture with a slump of 80-120mm is obtained. (3) Curing: The mixture is poured and then immediately covered with a moisturizing film. After curing, the cement-based material is obtained.

[0014] Compared with the prior art, the beneficial effects of the present invention are: The cement-based material doped with waste ceramic powder provided by this invention can effectively improve the problems of insufficient early shear strength, poor resistance to mountain torrents and gravel erosion, and poor resistance to temperature difference freeze-thaw cycles in traditional cement-based materials under the combined working conditions of mountain roads in deep canyons. Specifically: In the benchmark cementitious system: P·O 42.5R grade ordinary Portland cement and modified waste ceramic powder synergistically construct the cementitious system. After the modified waste ceramic powder is modified by a composite of silane coupling agent KH-560 and polyethylene glycol 400, the silane coupling agent can improve the interfacial affinity between ceramic powder and cement paste and reduce interfacial voids, while polyethylene glycol 400 can play a role in dispersing and water retention, improving the problem of uneven dispersion of ceramic powder and early water loss. At the same time, the pozzolanic activity of the modified waste ceramic powder is more easily exerted, and it can undergo a secondary reaction with cement hydration products to generate more calcium silicate hydrate (CSH) gel. The ceramic powder particles can also fill the pores formed by cement hydration. Multiple effects synergistically improve the internal pore structure of the cementitious system, alleviate the problem of loose interfacial transition zone caused by water infiltration in the high humidity environment of the canyon, and improve the density of the system.

[0015] In the first modified powder: the microsphere effect of fly ash microspheres helps to disperse interfacial stress, while tailings nanowires can enhance the interfacial bearing capacity, thereby alleviating the stress concentration problem under the combined action of shearing and rolling of heavy-duty agricultural machinery and reducing the generation of interfacial cracks.

[0016] In the second modified powder: the water-retention properties of hydroxypropyl methylcellulose phosphate can delay the early evaporation of water in cement paste, improving the problem of slow strength development caused by insufficient early curing; polylactic acid microspheres are first pretreated with KH-550 to form an alkali-resistant intermediate layer, and then coated with polyglycerol fatty acid ester to form a hydrophobic protective layer. The double protection can effectively isolate the strong alkaline environment of cement hydration and ensure the long-term stability of the uniform closed microporous structure introduced by the polylactic acid microspheres; these micropores can provide buffer space for the expansion of water in freeze-thaw cycles, relieve freeze-thaw volume expansion stress, and synergistically optimize the pore structure with hydroxypropyl methylcellulose phosphate to improve the freeze-thaw resistance of the material.

[0017] In modified nano-calcium carbonate: after modification with casein phosphopeptides, the cement hydration process can be accelerated, the early formation of CSH gel can be promoted, the early strength of the material can be improved, and the problem of low early strength caused by the addition of ceramic powder can be alleviated. The dense water-resistant film formed by secondary modification with chitosan quaternary ammonium salt can isolate some of the moisture in the high humidity and soaking environment of the canyon, reduce the swelling degree of the bio-based component casein phosphopeptides, ensure the long-term stability of the early strength activation function, and at the same time, the water-resistant film can also enhance the durability of interfacial adhesion.

[0018] In polyepoxysuccinic acid grafted with graphene oxide (as a water-reducing agent): the scale inhibition and dispersion properties of polyepoxysuccinic acid can improve the fluidity of cement paste, making it suitable for on-site mixing and pouring in mountainous areas; the high thermal conductivity of graphene oxide can accelerate heat transfer between the surface and interior of the road surface, reduce temperature gradient, and thus alleviate shrinkage cracks caused by extreme temperature differences; the synergistic effect of the two after grafting can not only ensure the workability of the paste, but also promote the uniform dispersion of each component, and improve the consistency of the overall performance of the material.

[0019] In modified composite aggregates: blast furnace slag and waste ceramic powder are mixed and modified with silane coupling agent KH-570. The silane coupling agent can improve the interfacial affinity between the composite aggregate and cement paste through bridging, reduce interfacial voids, and reduce the risk of water seepage and erosion from the interface. At the same time, the high strength and wear resistance of blast furnace slag itself can improve the impact resistance and wear resistance of the aggregate itself. It can also synergistically optimize the aggregate performance with waste ceramic powder, enhance the overall resistance to mountain torrent sand and gravel erosion and the load-bearing capacity of the material, and meet the working conditions of frequent mountain torrents in canyon sections.

[0020] In summary, this invention improves the interfacial transition zone performance of cement-based materials under complex working conditions in deep canyon sections by rationally combining and complementing the functions of each component, optimizes the internal pore structure, and enhances the early strength and long-term stability of the material. The final cement-based material prepared can meet the construction and use requirements of mountain roads in deep canyon sections. Detailed Implementation

[0021] The present invention will be further described in detail below with reference to specific embodiments and comparative examples. Components for which preparation methods are not mentioned in the embodiments and comparative examples are all commercially available conventional products (such as P·O 42.5R grade ordinary Portland cement, etc.). All "parts" refer to parts by mass. In industrial production, "kg" can be used as the unit of mass.

[0022] Example 1 1. Preparation of some non-commercially available components.

[0023] (1) Preparation of modified waste ceramic powder: ① Take waste building ceramic fragments (mainly composed of SiO2 and Al2O3) from industrial ceramic production waste, remove glaze fragments, metal impurities and non-metallic impurities such as soil, plastic fragments and wood chips, then crush them with a jaw crusher, ball mill them and pass them through a 200-mesh sieve. Place them in a 105℃ oven to dry for 6 hours to remove moisture and obtain pretreated waste ceramic powder. Separately, a composite modifier solution was obtained by mixing 10% silane coupling agent KH-560, 5% polyethylene glycol 400, and 85% anhydrous ethanol by mass fraction and ultrasonically dispersing for 30 minutes (power 300W, frequency 20kHz). ② Take 100 parts of pretreated waste ceramic powder, add 30 parts of the above composite modifier solution, and soak at 25℃ with constant temperature stirring at 400r / min for 2h; then place in an oven at 105℃ to dry for 4h, grind through a 200-mesh sieve to obtain modified waste ceramic powder.

[0024] (2) Preparation of the first modified powder: ① Take vanadium-titanium magnetite tailings (vanadium-titanium magnetite smelting tailings from metallurgical enterprises, mainly containing TiO2 and Fe2O3, after removing impurities such as soil and unsorted ore fragments), pulverize them by air jet mill, and prepare nanowires by hydrothermal method using deionized water as solvent (hydrothermal conditions: 200℃, 5h). After filtration and drying, vanadium-titanium magnetite tailings nanowires are obtained; take fly ash (coal ash from thermal power plants), first separate the fly ash microspheres with a particle size of 50-100μm by air jet classification screening, then remove the attached carbon slag, metal fragments and soil impurities, and dry at 105℃ for 4h for later use to obtain refined fly ash microspheres; ② Take vanadium-titanium magnetite tailings nanowires and fly ash microspheres at a mass ratio of 1:9, add anhydrous ethanol (the amount of which is 3 times the total mass of vanadium-titanium magnetite tailings nanowires and fly ash microspheres), and ultrasonically disperse for 40 min (power 300W, frequency 20kHz); then spray dry the dispersion (inlet air temperature 180℃, outlet air temperature 80℃), and then calcine it in a nitrogen inert atmosphere furnace at 600℃ for 1.5 h. After cooling, grind it through a 300-mesh sieve to obtain the first modified powder.

[0025] (3) Preparation of the second modified powder: ① Hydroxypropyl methylcellulose phosphate and polylactic acid microspheres (particle size 1-5μm) were taken at a mass ratio of 3:1. The polylactic acid microspheres were first pretreated with KH-550: 1% KH-550 ethanol solution (5% of the mass of polylactic acid microspheres) was added, stirred at 25℃ for 1h, and vacuum dried (60℃, 2h). Then, it was mixed with hydroxypropyl methylcellulose phosphate and fed into an air jet mill for pulverization (pulverization pressure 0.7MPa, feed rate 5kg / h). The specific surface area of ​​the product was controlled to be 600-700m² / g to obtain composite micro powder. ② Polyglycerol fatty acid ester and the above composite micro powder were taken at a mass ratio of 1:10. Anhydrous ethanol (4 times the total mass of polyglycerol fatty acid ester and composite micro powder) was added and ultrasonically dispersed for 30min (power 300W, frequency 20kHz). Then, it was spray dried (inlet air temperature 160℃, outlet air temperature 70℃) to obtain the second modified powder.

[0026] (4) Preparation of modified nano-calcium carbonate: ① Take nano-calcium carbonate (particle size 50-100nm) and casein phosphopeptide at a mass ratio of 8:1, add deionized water (solid-liquid ratio 1:10, g:ml), stir at 350r / min at 45℃ for 1.5h; filter to collect the precipitate, dry at 105℃ for 3h to obtain the initially modified nano-calcium carbonate. ② Take chitosan quaternary ammonium salt and prepare an aqueous solution with a mass fraction of 5%; add the pre-modified nano calcium carbonate to the aqueous solution at a solid-liquid ratio of 1:8 (g:ml), and ultrasonically disperse for 20 min (power 300W, frequency 20kHz); after vacuum drying (60℃, 0.08MPa) for 4 h, grind it through a 300-mesh sieve to obtain modified nano calcium carbonate.

[0027] (5) Preparation of modified composite aggregate: ① Take blast furnace slag (waste slag from blast furnace smelting in iron and steel enterprises, mainly composed of CaO, SiO2, and Al2O3, and remove unmelted slag blocks, metal fragments, and soil impurities), and crush and screen it to obtain 4.75-19mm aggregate; separately take waste building ceramic fragments (mainly composed of SiO2 and Al2O3) recovered from industrial ceramic production waste, remove glaze fragments, metal impurities, and non-metallic impurities such as soil, plastic fragments, and wood chips, and then ball mill them to a particle size ≤44μm, and dry them at 105℃ for 4h to obtain waste ceramic powder fines; ② Take blast furnace slag aggregate and waste ceramic powder at a mass ratio of 6:4, dry mix for 3 min (200 r / min); spray with 2.0% KH-570 ethanol solution of silane coupling agent (5% of the total mass of aggregate), continue to dry mix for 5 min (200 r / min); dry at 105℃ for 3 h to obtain modified composite aggregate.

[0028] (6) Preparation of polyepoxysuccinic acid grafted graphene oxide: ① Take 10 parts of graphene oxide (purity ≥99%, sheet diameter 0.5-3μm), add 1000 parts of deionized water, add 0.5 parts of sodium dodecylbenzenesulfonate, ultrasonically disperse for 40 min (power 300W, frequency 20kHz), centrifuge (speed 8000r / min, time 10 min), collect the precipitate, wash with deionized water until the filtrate is free of foam, vacuum dry at 60℃ (0.08MPa) for 2 h, and stir intermittently during the drying process (stir once every 30 min, 5 min each time) to prevent agglomeration and obtain modified graphene oxide dry powder; ② Take 100 parts of polyepoxysuccinic acid (molecular weight 2000-3000), add 500 parts of deionized water, and stir at 350 r / min at 60℃ to dissolve; add 5 parts of the above modified graphene oxide dry powder, stir and disperse for 10 min; add 1.5 parts of ammonium persulfate initiator, heat to 70℃, and stir at 450 r / min for 4 h under nitrogen protection; after the reaction is completed, cool to room temperature, adjust the pH to 7-8 with 10% sodium hydroxide solution, and concentrate under reduced pressure (60℃, 0.07 MPa) to a solid content of 40% to obtain polyepoxysuccinic acid grafted graphene oxide.

[0029] 2. Preparation process of cement-based materials doped with waste ceramic powder.

[0030] (1) Premixing: Take 340 parts of P·O 42.5R grade ordinary Portland cement, 105 parts of modified waste ceramic powder, 33 parts of second modified powder, and 2.3 parts of modified nano calcium carbonate, put them into a high-speed mixer, and stir at 1000r / min for 5min to obtain premixed powder; (2) Preparation of functional aqueous solution: Take 0.9 parts of the first modified powder, add 160 parts of deionized water, and then add 6.5 parts of polyepoxysuccinic acid grafted graphene oxide. Stir at 400 r / min for 20 min until completely dissolved to obtain functional aqueous solution. (3) Mixing and molding: 1730 parts of modified composite aggregate were put into the mixer, functional aqueous solution was poured in, and the mixture was stirred at a low speed of 150 r / min for 2 min; premixed powder was added, and the mixture was stirred at a high speed of 900 r / min for 3 min to obtain a mixture with a slump of 90 mm. (4) Casting and curing: Pour the mixture into a 100mm×100mm×100mm mold, place it on a vibrating table (vibration frequency 50Hz, amplitude 0.5mm) and vibrate for 3 minutes to remove air bubbles, and scrape the surface smooth; immediately cover with a moisturizing film and cure for 24 hours at 20℃ and 85% humidity; then use a composite method of "spraying water curing + silane water-repellent agent spraying" to cure for 28 days (specifically: spray water twice a day after curing for 24 hours to keep the surface moist, spray silane water-repellent agent when curing for 7 days (only spray once on the 7th day), the spraying amount is 0.2kg / m² based on the sample surface area, and continue to spray water once a day for curing until 28 days) to obtain the finished cement-based material.

[0031] Example 2 Compared to Example 1, the following adjustments are made (unless otherwise mentioned, they are considered the same as in Example 1): 1. Adjustment of preparation parameters for some non-commercially available components: (1) In the preparation of the first modified powder, the mass ratio of vanadium-titanium magnetite tailings nanowires to fly ash microspheres was adjusted to 1:8, the ultrasonic dispersion time was adjusted to 30 min, and the calcination temperature was adjusted to 580℃. (2) In the preparation of the second modified powder, the mass ratio of hydroxypropyl methylcellulose phosphate to polylactic acid microspheres was adjusted to 3.5:1; (3) In the preparation of modified composite aggregate, the mass ratio of blast furnace slag to waste ceramic powder is adjusted to 7:3, and the mass fraction of silane coupling agent KH-570 ethanol solution is adjusted to 1.8%.

[0032] 2. Adjustment of preparation parameters for cement-based materials: (1) Premixing stage: 350 parts of P·O 42.5R grade ordinary Portland cement, 95 parts of modified waste ceramic powder, 36 parts of second modified powder, 2.6 parts of modified nano calcium carbonate, the stirring speed was adjusted to 1100 r / min, and the time was adjusted to 4 min; (2) Preparation of functional aqueous solution: 1.0 part of the first modified powder, 158 parts of deionized water, 7.0 parts of polyepoxysuccinic acid grafted graphene oxide, and the stirring speed was adjusted to 450 r / min; (3) Mixing and molding process: 1750 parts of modified composite aggregate, the low speed mixing speed was adjusted to 180 r / min and the time was 2 min, and the high speed mixing speed was adjusted to 1000 r / min and the time was 2.5 min; (4) Curing process: The initial curing temperature is adjusted to 22℃ and the humidity to 82%. After curing for 22 hours, the curing process is switched to compound curing.

[0033] Comparative Example 1 Compared to Example 1, the first modified powder in the raw materials was removed, while the remaining raw materials and their amounts, the preparation process of non-commercially available components, and the preparation process steps of cement-based materials were all the same as in Example 1.

[0034] Comparative Example 2 Compared to Example 1, the modified waste ceramic powder was replaced with an equal mass of unmodified waste ceramic powder (which was only crushed, ball-milled, and dried, without being modified by the composite of silane coupling agent KH-560 and polyethylene glycol 400), and all other conditions were the same as in Example 1.

[0035] Comparative Example 3 Compared to Example 1, the second modified powder was not pretreated with KH-550, but was only subjected to air jet milling and polyglycerol fatty acid ester coating, with all other conditions being the same as in Example 1.

[0036] Comparative Example 4 Compared to Example 1, the modified nano-calcium carbonate in the raw materials was removed, while all other conditions were the same as in Example 1.

[0037] Comparative Example 5 Compared to Example 1, the modified composite aggregate was replaced with an equal mass of unmodified blast furnace slag-waste ceramic powder mixture (dry mixing only, without spraying silane coupling agent KH-570 ethanol solution for modification), and all other conditions were the same as in Example 1.

[0038] Experimental Example Using the 28-day standard-cured finished cement-based materials (size: 100mm×100mm×100mm) prepared in Examples 1-2 and Comparative Examples 1-5 as test samples, performance tests were conducted to adapt to the composite working conditions of deeply cut canyon sections. Three parallel samples were set up in each group, and the average value was taken as the final test result. The test results are shown in Table 1. The specific test methods are as follows: 1. Mountain Torrent Simulation Erosion Performance Test: Samples were completely submerged in simulated mountain torrent water (containing 0.1-5mm canyon sand and gravel with a sand-to-water mass ratio of 1:5) at a constant temperature of 25℃. The water flow velocity was 1.5m / s, with the flow direction changed every 2 hours to simulate the turbulent effect of a mountain torrent. This scouring was repeated for 72 hours. After scouring, the following tests were conducted: ① Sample surface spalling: Δm = initial mass - mass after scouring; ② Compressive strength retention rate: Retention rate = (Compressive strength after scouring / Initial compressive strength) × 100%. The compressive strength test was conducted according to the "Standard for Test Methods of Physical and Mechanical Properties of Concrete".

[0039] 2. Impact performance test of canyon gravel: The drop hammer impact method was used. The sample was fixed on the impact test platform and continuously impacted with an impact energy of 0.6 kN·m (simulating the impact of canyon gravel rolling). The number of impacts when the first visible crack appeared in the sample was recorded.

[0040] 3. Abrasion Performance Test of Canyon Sand and Gravel: A rotary abrasion method was used. The sample was fixed in an abrasion testing machine, with the abrasion wheel contacting the sample surface at a pressure of 0.3 MPa. The abrasion medium consisted of simulated flash flood water and dried canyon sand and gravel (particle size 0.1-2 mm) (mass ratio 1:1). Abrasion was performed continuously for 24 hours. The mass loss rate of the sample after abrasion was measured (abrasion mass loss / initial mass × 100%). 4. Extreme Temperature Difference-Freeze-Thaw Cycle Test: The sample was placed in a high and low temperature freeze-thaw chamber. One freeze-thaw cycle consisted of freezing at -20℃ for 4 hours and thawing at 20℃ for 4 hours. Simultaneously, a temperature difference cycle was superimposed (after each freeze-thaw cycle, a rapid temperature difference change of 5℃ → 30℃ → 5℃ was performed, with a heating / cooling rate of 5℃ / min). A total of 100 cycles were completed. After the cycle is completed, the strength retention rate (compressive strength after the cycle / initial compressive strength × 100%) and the volume change rate [(volume after the cycle - initial volume) / initial volume × 100%) under the superimposed working condition are calculated, and the surface cracking of the sample is observed at the same time.

[0041] 5. Shear-compacting composite stress performance test: A triaxial shear tester was used to apply a vertical compaction stress of 0.5 MPa and a horizontal shear stress simultaneously to test the shear strength of the sample; at the same time, the shear displacement when the sample reached the ultimate shear strength was recorded.

[0042] Table 1: As can be seen from Table 1: Examples 1-2 showed excellent results in various performance tests adapted to the complex working conditions of deep canyons, demonstrating their suitability for the actual service requirements of mountain roads in deep canyon sections. Specifically, after simulated flash flood scouring, the surface spalling was controlled within 8.2g, and the compressive strength retention rate remained above 92.7%, indicating good resistance to flash flood scouring and effectively reducing surface damage and strength reduction caused by sand and gravel carried by water flow. The impact resistance reached over 45 cycles, demonstrating strong resistance to the impact of rolling gravel in the canyon, and good adaptability to dynamic impact loads in canyon sections. The abrasion mass loss rate did not exceed 1.8%, indicating excellent wear resistance and the ability to cope with mountain... Under long-term abrasion conditions of sand and gravel in Hongzhong, and under extreme temperature difference-freeze-thaw conditions, the strength retention rate is above 90.1% and the volume change rate is controlled within 0.30%, indicating that it has good resistance to temperature difference and freeze-thaw, and can adapt to the freeze-thaw alternation and severe temperature difference environment in the high-altitude area of ​​the canyon. In the shear-compaction composite stress test, the shear strength is not less than 3.5MPa and the shear displacement reaches more than 1.5mm, which meets the qualification requirements and can effectively alleviate the damage risk caused by the steering shear of heavy-load agricultural machinery and stress concentration of the roadbed.

[0043] Comparative Example 1, due to the removal of the first modified powder, showed significant deterioration in shear resistance, impact resistance, and resistance to flash flood erosion. This indicates that the absence of this component significantly affects the material's interfacial bonding and stress bearing capacity, making it unsuitable for the combined working conditions of heavy-duty agricultural machinery shearing and compaction as well as flash flood impact. Comparative Example 2, using unmodified waste ceramic powder, showed varying degrees of deterioration in all properties, particularly a significant decrease in resistance to flash flood erosion and wear resistance. This demonstrates that composite modification of waste ceramic powder is crucial for improving the density and erosion resistance of the cementitious system. Comparative Example 3, due to the lack of KH-550 pretreatment of the second modified powder, showed... Polyglycerol fatty acid ester coating alone cannot completely isolate the cement from the strongly alkaline hydration environment. Partial hydrolysis of polylactic acid microspheres leads to the failure of the closed microporous structure, resulting in a significant decrease in freeze-thaw resistance. In Comparative Example 4, the removal of modified nano-calcium carbonate reduced shear strength, impact resistance, and overall performance stability, indicating that this component makes a significant contribution to the early strength activation and overall performance stability of the material. Comparative Example 5, using unmodified composite aggregate, exhibited relatively poor erosion resistance, demonstrating that modification with silane coupling agent KH-570 can effectively improve the interfacial affinity between aggregate and cementitious system, enhancing the material's resistance to sand and gravel erosion.

Claims

1. A cement-based material doped with waste ceramic powder, characterized in that, Includes the following components by weight: 320-360 parts of P・O 42.5R grade ordinary Portland cement, 90-120 parts of modified waste ceramic powder, 0.7-1.1 parts of first modified powder, 28-38 parts of second modified powder, 1.8-2.8 parts of modified nano calcium carbonate, 6-8 parts of polyepoxysuccinic acid grafted graphene oxide, 1680-1780 parts of modified composite aggregate, and 155-165 parts of water; The modified waste ceramic powder is obtained by modifying waste ceramic powder with silane coupling agent KH-560 and polyethylene glycol 400. The first modified powder is obtained by mixing vanadium-titanium magnetite tailings nanowires with fly ash microspheres. The second modified powder is obtained by pretreating polylactic acid microspheres with KH-550, mixing them with hydroxypropyl methylcellulose phosphate, grinding them by air jet milling, and then coating them with polyglycerol fatty acid esters for modification. The modified composite aggregate is obtained by mixing blast furnace slag and waste ceramic powder and then modifying it with silane coupling agent KH-570. The modified nano-calcium carbonate is obtained by first modifying nano-calcium carbonate with casein phosphopeptide, and then modifying it with chitosan quaternary ammonium salt.

2. The cement-based material doped with waste ceramic powder according to claim 1, characterized in that, In the first modified powder, the mass ratio of vanadium-titanium magnetite tailings nanowires to fly ash microspheres is 1:(7-10).

3. The cement-based material doped with waste ceramic powder according to claim 1, characterized in that, The preparation conditions for the first modified powder are as follows: ultrasonic dispersion in anhydrous ethanol for 20-60 min, spray drying, and calcination at 550-650℃ for 1-2 h under a nitrogen inert atmosphere.

4. The cement-based material doped with waste ceramic powder according to claim 1, characterized in that, In the modified composite aggregate, the mass ratio of blast furnace slag to waste ceramic powder is (5-7):(3-5).

5. The cement-based material doped with waste ceramic powder according to claim 1, characterized in that, In the modified nano-calcium carbonate, the mass ratio of nano-calcium carbonate to casein phosphopeptide is (6-10):

1.

6. The cement-based material doped with waste ceramic powder according to claim 1, characterized in that, In the second modified powder, the mass ratio of hydroxypropyl methylcellulose phosphate to polylactic acid microspheres is (2-4):

1.

7. A preparation process for a cement-based material doped with waste ceramic powder as described in any one of claims 1-6, characterized in that, Includes the following steps: (1) Premixing: P·O 42.5R grade ordinary silicate cement, modified waste ceramic powder, second modified powder, and modified nano calcium carbonate are thoroughly stirred to obtain premixed powder; the first modified powder is dispersed in water, polyepoxysuccinic acid grafted graphene oxide is added, and stirred until completely dissolved to obtain functional aqueous solution; (2) Mixing and molding: The modified composite aggregate is put into the mixer, the functional aqueous solution is poured in, and after mixing, the premixed powder is added. After mixing, the mixture with a slump of 80-120mm is obtained. (3) Curing: The mixture is poured and then immediately covered with a moisturizing film. After curing, the cement-based material is obtained.

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