A high-performance modified bamboo residue-rubber-recycled concrete and its preparation method

Abstract

This invention discloses a high-performance modified bamboo residue-rubber-recycled concrete and its preparation method, belonging to the field of building materials technology, and includes the following raw materials: cement 350-380 kg / m³ 3 Coarse aggregate 700-1100 kg / m³ 3 Fine aggregate 800-860 kg / m³ 3 200-210 kg / m³ of recycled aggregate 3 Rubber granules 15-20 kg / m 3 Water 100-110 kg / m³ 3 Water-reducing agent 4-6 kg / m³ 3 The invention relates to modified bamboo slag, wherein the modified bamboo slag is added at a concentration of 0.2-0.8% of the total volume of concrete. This invention enables the modified bamboo slag to effectively function as a fiber reinforcement in concrete, synergistically utilizing recycled aggregates and rubber particles, significantly improving the mechanical properties and crack resistance of concrete, achieving high-value utilization of various solid wastes, and possessing both excellent performance and environmental benefits.

Description

Technical Field

[0001] This invention relates to the field of new materials technology, specifically to a high-performance modified bamboo residue-rubber-recycled concrete and its preparation method. Background Technology

[0002] Traditional concrete primarily relies on raw materials such as cement and natural sand and gravel, consuming significant amounts of natural resources in its production, and the cement production process is accompanied by substantial carbon emissions. Furthermore, the high brittleness and cracking tendency of traditional concrete limit its application in certain engineering fields. Developing resource-saving and high-performance new types of concrete is an important research direction in the field of building materials.

[0003] On the other hand, the construction, transportation, and agricultural sectors generate a large amount of solid waste, such as waste concrete, used tires, and bamboo processing residues. Improper disposal of this waste will cause environmental pollution and resource waste. Utilizing solid waste to produce concrete can solve the disposal problem and reduce dependence on natural resources, making it an important approach to the green development of concrete materials.

[0004] Existing technologies have included research on modifying concrete using single or two types of solid waste. For example, adding recycled aggregates introduces weak interfaces, leading to a decrease in the mechanical properties of concrete; adding rubber particles can improve toughness but severely reduces strength; and adding untreated plant fibers faces problems such as poor fiber-matrix bonding and easy decay. Currently, there is still a lack of solutions that can synergistically utilize multiple solid wastes and effectively solve key technical challenges such as strength loss and interfacial bonding, thereby producing high-performance concrete. Summary of the Invention

[0005] The present invention aims to provide a high-performance modified bamboo residue-rubber-recycled concrete and its preparation method, in order to solve the technical problem that the mechanical properties of concrete decrease significantly when multiple solid wastes are used in combination in the prior art.

[0006] To solve the above-mentioned technical problems, the technical solution proposed in this application is as follows:

[0007] A high-performance modified bamboo residue-rubber-recycled concrete comprises the following raw materials: cement 350-380 kg / m³ 3 Coarse aggregate 700-1100 kg / m³ 3 Fine aggregate 800-860kg / m³ 3 200-210 kg / m³ of recycled aggregate 3 Rubber granules 15-20 kg / m 3 Water 100-110kg / m 3 Water-reducing agent 4-6 kg / m³ 3And improved bamboo slag; the amount of improved bamboo slag added is 0.2-0.8% of the total volume of concrete.

[0008] Furthermore, the fine aggregate is river sand; the coarse aggregate is crushed stone; the volume ratio of fine aggregate to rubber granules is 19:5, and the volume ratio of coarse aggregate to recycled aggregate is 3:1.

[0009] Furthermore, the fineness modulus of the river sand is 2.8, and the fine aggregate is in a dry state.

[0010] Furthermore, the rubber granules have a particle size of less than 1 mm. After being washed with a 1-3% NaOH solution, the rubber granules are rinsed with water and then air-dried.

[0011] Furthermore, the coarse aggregate is continuously graded crushed stone with a particle size of 5-30mm, and the coarse aggregate is in a dry state after being washed with water and naturally air-dried.

[0012] Furthermore, the water-reducing agent is a polycarboxylate high-efficiency water-reducing agent with a water reduction rate of 23-25%.

[0013] Furthermore, the recycled aggregate has a particle size of 5-30mm and is waste concrete with an original strength of C30.

[0014] Furthermore, the improved bamboo residue includes: thin bamboo residue with a diameter of 0.6-1.18 mm and a length of 20-40 mm; medium bamboo residue with a diameter of 1.18-2.36 mm and a length of 20-40 mm; coarse bamboo residue with a diameter of 2.36-4 mm and a length of 20-40 mm; bamboo powder and bamboo residue; bamboo chips and bamboo residue.

[0015] Furthermore, the cement is P·O42.5 silicate cement.

[0016] On the other hand, this application also claims protection for a method for preparing high-performance modified bamboo residue-rubber-recycled concrete, including the following steps:

[0017] (1) Pour the coarse aggregate, fine aggregate, and recycled aggregate into a forced mixer and mix them;

[0018] (2) Pour in cement, rubber granules and modified bamboo residue and mix;

[0019] (3) Pour in some water and stir;

[0020] (4) Pour the remaining water and water-reducing agent into the mixture and stir. After stirring, pour the mixture into a mold and vibrate it to obtain high mechanical properties bamboo residue-rubber-recycled concrete.

[0021] Furthermore, the improved method for preparing bamboo residue includes the following steps:

[0022] (1) Place the raw material bamboo residue in a vibrator to remove the surface soil and some stains to obtain C1;

[0023] (2) Place C1 in a drying oven and bake for 3 hours. The baking time is divided into three steps: the first step is to preheat the oven at 85±2℃ for one hour; the second step is to accelerate the drying at 100±5℃ for one hour; the third step is to adapt the drying at 90±5℃ for one hour; and C2 is obtained.

[0024] (3) The dried C2 was placed in the improvement solution for soaking treatment to obtain C3. The improvement solution was obtained by mixing 40-45% water-soluble phenolic resin and 50-55% melamine-urea-phenolic resin at a mass ratio of 1:1.

[0025] (4) Place C3 in a drying oven and dry it for 2 hours at a temperature of 70±5℃ to obtain C4;

[0026] (5) Place C4 in a dry and ventilated indoor area to allow it to naturally return to room temperature to obtain C5;

[0027] (6) C5 is then screened by a sieve or crushed by a shredder to obtain improved bamboo residue in different forms.

[0028] Furthermore, the independent stirring and mixing time in steps (1), (2), (3), and (4) is 1-2 minutes.

[0029] Furthermore, the vibration is divided into two stages. The mixture is filled halfway into the mold for the first vibration, and then the second vibration is performed. The vibration time for each stage does not exceed 60 seconds.

[0030] Furthermore, the standard curing temperature for concrete is 20±2℃, the curing humidity is >95%, and the curing time is 28-32 days.

[0031] Compared with the prior art, the present invention achieves the following beneficial technical effects:

[0032] This application describes a high-performance concrete prepared by synergistically utilizing three solid wastes: recycled aggregate, rubber granules, and bamboo residue modified with a special resin. This invention effectively solves key technical problems such as reduced concrete strength and poor interfacial bonding caused by the incorporation of multiple solid wastes. The modified bamboo residue exhibits excellent fiber reinforcement and toughening effects, significantly improving the crack resistance and overall mechanical properties of the concrete, while simultaneously achieving resource utilization of waste. Its preparation process is simple and reliable, providing a practical solution for the production of environmentally friendly high-strength concrete. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 To improve the different forms of bamboo residue, from top to bottom and from left to right, they are thin bamboo residue, medium bamboo residue, coarse bamboo residue, bamboo powder residue, and bamboo shavings residue;

[0035] Figure 2 This is the initial morphology of crack development in rubber recycled concrete under axial compressive load in Example 2;

[0036] Figure 3 This represents the final crack development morphology of the rubber recycled concrete under axial compressive load in Example 2.

[0037] Figure 4 The final crack development morphology of high-performance modified bamboo slag-rubber-recycled concrete under axial compressive load in Examples 3-6 is shown in (a)-(d) from left to right; Examples 3-6 are shown in the following order.

[0038] Figure 5 The final crack development morphology of high-performance modified bamboo slag-rubber-recycled concrete under axial compressive load in Examples 7-10 are shown in (a)-(d) from left to right; Examples 7-10 are shown in the following order.

[0039] Figure 6 The final crack development morphology of high-performance modified bamboo slag-rubber-recycled concrete under axial compressive load in Examples 11-14 is shown in (a)-(d) from left to right; Examples 11-14 are shown in the following order.

[0040] Figure 7 The final crack development morphology of high-performance modified bamboo slag-rubber-recycled concrete under axial compressive load in Examples 15-18 is shown in (a)-(d) from left to right; Examples 15-18 are shown in the following order.

[0041] Figure 8 The images show the final crack development morphology of high-performance modified bamboo slag-rubber-recycled concrete under axial compressive load in Examples 19-22, where (a)-(d) are Examples 19-22 from left to right. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1: Ordinary Concrete (NC)

[0044] Ordinary concrete (NC) is prepared from the following raw materials: cement 360 kg / m³ 3 Fine aggregate 855 kg / m 3 Crushed stone 1034.63 kg / m³ 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 .

[0045] Preparation method: Pour fine aggregate (river sand) and crushed stone into a forced mixer and dry mix for 1 minute; then add cement and continue mixing for 1 minute; next, pour in water and mix for 1 minute; finally, add water-reducing agent and mix for 2 minutes, for a total mixing time of 5 minutes. Pour the mixture into a mold, compact it, and then cure it for 28 days under standard curing conditions (temperature 20±2℃, humidity >95%).

[0046] Example 2: Rubber Recycled Concrete (RZC)

[0047] Rubber recycled concrete (RZC) is prepared from the following raw materials: 360 kg / m³ of cement. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 .

[0048] The volume ratio of fine aggregate to rubber granules is 19:5, and the volume ratio of coarse aggregate to recycled aggregate is 3:1. The rubber granules have a particle size of less than 1 mm. After being washed with a 2% NaOH solution for 30 minutes, they are rinsed with clean water until neutral and then air-dried before use. The recycled aggregate is made from crushed waste concrete with an original strength of C30, and has a particle size of 5-30 mm.

[0049] Preparation method: Follow the same steps as in Example 1 for ingredient preparation, stirring, vibration and curing.

[0050] Example 3 High-performance modified bamboo residue-rubber-recycled concrete (BRC1-0.2)

[0051] A high-performance modified bamboo residue-rubber-recycled concrete (BRC1-0.2) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 Fine bamboo residue 1.8 kg / m 3 The modified bamboo residue dosage is 0.2% of the total concrete volume.

[0052] The volume ratio of fine aggregate to rubber granules is 19:5, and the volume ratio of coarse aggregate to recycled aggregate is 3:1. Fine bamboo residue (see...) Figure 1 The preparation methods of (a)-(e) are as follows:

[0053] (1) Place the raw material bamboo residue in a vibrator and vibrate for 5 minutes to remove the surface dirt and some stains to obtain C1;

[0054] (2) Place C1 in a drying oven and bake for 3 hours: First step: preheating, set the temperature to 85℃ and dry for 1 hour; Second step: accelerated drying, set the temperature to 100℃ and dry for 1 hour; Third step: adaptation treatment, set the temperature to 90℃ and dry for 1 hour; to obtain C2;

[0055] (3) The dried C2 was placed in the improvement solution for 2 hours to obtain C3; the improvement solution was obtained by mixing 42% water-soluble phenolic resin and 52% melamine-urea-phenolic resin at a mass ratio of 1:1.

[0056] (4) Place C3 in a drying oven and dry it for 2 hours at a temperature of 70°C to obtain C4;

[0057] (5) Place C4 in a dry and ventilated indoor place to allow it to naturally return to room temperature (about 25°C) to obtain C5;

[0058] (6) C5 is screened by a screening machine to obtain fine bamboo residue with a diameter of 0.6-1.18 mm and a length of 20-40 mm.

[0059] Preparation method of high-performance modified bamboo residue-rubber-recycled concrete (BRC1-0.2):

[0060] (1) Pour coarse aggregate (crushed stone), fine aggregate (river sand), and recycled aggregate into a forced mixer and dry mix for 1.5 min;

[0061] (2) Pour cement, rubber granules and modified bamboo residue (fine bamboo residue) into the mixer and continue to dry mix for 1.5 min;

[0062] (3) Pour in 70% water and stir for 1.5 minutes;

[0063] (4) Mix the remaining 30% water and water-reducing agent evenly and pour them into the mixer. Mix for 2 minutes, for a total mixing time of 6.5 minutes.

[0064] (5) Put the mixture into the mold, first fill half of it and vibrate for the first time for 45 seconds; then fill the remaining mixture and vibrate for the second time for 45 seconds.

[0065] (6) The molded specimens were cured for 28 days under standard curing conditions (temperature 20±2℃, humidity >95%).

[0066] (In the formulation descriptions of subsequent Examples 4-22, the volume ratios of fine aggregate, rubber granules, coarse aggregate, and recycled aggregate are consistent with those of Examples 2 and 3, i.e., the volume ratio of fine aggregate to rubber granules is 19:5, and the volume ratio of coarse aggregate to recycled aggregate is 3:1. For the sake of brevity, this description will not be repeated in the following examples, but this ratio applies to all examples.)

[0067] Example 4: High-performance modified bamboo residue-rubber-recycled concrete (BRC1-0.4)

[0068] A high-performance modified bamboo residue-rubber-recycled concrete (BRC1-0.4) is prepared from the following raw materials: cement 360 kg / m³ 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 Fine bamboo residue 3.6 kg / m 3 The modified bamboo residue dosage is 0.4% of the total concrete volume.

[0069] The preparation method of fine bamboo residue is the same as in Example 3.

[0070] The method for preparing recycled concrete is the same as in Example 3.

[0071] Example 5: High-performance modified bamboo residue-rubber-recycled concrete (BRC1-0.6)

[0072] A high-performance modified bamboo residue-rubber-recycled concrete (BRC1-0.6) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 Fine bamboo residue 5.4 kg / m 3 The modified bamboo residue dosage is 0.6% of the total concrete volume.

[0073] The preparation method of fine bamboo residue is the same as in Example 3.

[0074] The method for preparing recycled concrete is the same as in Example 3.

[0075] Example 6 High-performance modified bamboo residue-rubber-recycled concrete (BRC1-0.8)

[0076] A high-performance modified bamboo residue-rubber-recycled concrete (BRC1-0.8) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 Fine bamboo residue 7.2 kg / m 3 The modified bamboo residue dosage is 0.8% of the total concrete volume.

[0077] The preparation method of fine bamboo residue is the same as in Example 3.

[0078] The method for preparing recycled concrete is the same as in Example 3.

[0079] Example 7 High-performance modified bamboo residue-rubber-recycled concrete (BRC2-0.2)

[0080] A high-performance modified bamboo residue-rubber-recycled concrete (BRC2-0.2) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 1.8 kg / m³ of medium-sized bamboo residue 3 The modified bamboo residue dosage is 0.2% of the total concrete volume.

[0081] The preparation method of medium-sized bamboo residue is similar to that of fine bamboo residue. The difference is that the bamboo residue obtained by sieving in step (6) is medium-sized bamboo residue with a diameter of 1.18-2.36 mm and a length of 20-40 mm.

[0082] The method for preparing recycled concrete is the same as in Example 3.

[0083] Example 8 High-performance modified bamboo residue-rubber-recycled concrete (BRC2-0.4)

[0084] A high-performance modified bamboo residue-rubber-recycled concrete (BRC2-0.4) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 3.6 kg / m³ of medium-sized bamboo shavings 3 The modified bamboo residue dosage is 0.4% of the total concrete volume.

[0085] The preparation method of the bamboo residue is the same as in Example 7.

[0086] The method for preparing recycled concrete is the same as in Example 3.

[0087] Example 9 High-performance modified bamboo residue-rubber-recycled concrete (BRC2-0.6)

[0088] A high-performance modified bamboo residue-rubber-recycled concrete (BRC2-0.6) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 5.4 kg / m³ of medium-sized bamboo shavings 3 The modified bamboo residue dosage is 0.6% of the total concrete volume.

[0089] The preparation method of the bamboo residue is the same as in Example 7.

[0090] The method for preparing recycled concrete is the same as in Example 3.

[0091] Example 10 High-performance modified bamboo residue-rubber-recycled concrete (BRC2-0.8)

[0092] A high-performance modified bamboo residue-rubber-recycled concrete (BRC2-0.8) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 7.2 kg / m³ of medium-sized bamboo shavings 3 The modified bamboo residue dosage is 0.8% of the total concrete volume.

[0093] The preparation method of the bamboo residue is the same as in Example 7.

[0094] The method for preparing recycled concrete is the same as in Example 3.

[0095] Example 11 High-performance modified bamboo residue-rubber-recycled concrete (BRC3-0.2)

[0096] A high-performance modified bamboo residue-rubber-recycled concrete (BRC3-0.2) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 1.8 kg / m³ of coarse bamboo shavings 3 The modified bamboo residue dosage is 0.2% of the total concrete volume.

[0097] The preparation method of coarse bamboo residue is similar to that of fine bamboo residue. The difference is that the coarse bamboo residue obtained by sieving in step (6) has a diameter of 2.36-4 mm and a length of 20-40 mm.

[0098] The method for preparing recycled concrete is the same as in Example 3.

[0099] Example 12 High-performance modified bamboo residue-rubber-recycled concrete (BRC3-0.4)

[0100] A high-performance modified bamboo residue-rubber-recycled concrete (BRC3-0.4) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 Coarse bamboo shavings: 3.6 kg / m 3 The modified bamboo residue dosage is 0.4% of the total concrete volume.

[0101] The preparation method for coarse bamboo residue is the same as in Example 11.

[0102] The method for preparing recycled concrete is the same as in Example 3.

[0103] Example 13 High-performance modified bamboo residue-rubber-recycled concrete (BRC3-0.6)

[0104] A high-performance modified bamboo residue-rubber-recycled concrete (BRC3-0.6) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 5.4 kg / m³ of coarse bamboo residue 3 The modified bamboo residue dosage is 0.6% of the total concrete volume.

[0105] The preparation method for coarse bamboo residue is the same as in Example 11.

[0106] The method for preparing recycled concrete is the same as in Example 3.

[0107] Example 14 High-performance modified bamboo residue-rubber-recycled concrete (BRC3-0.8)

[0108] A high-performance modified bamboo residue-rubber-recycled concrete (BRC3-0.8) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 7.2 kg / m³ of coarse bamboo stalk residue 3 The modified bamboo residue dosage is 0.8% of the total concrete volume.

[0109] The preparation method of coarse bamboo residue is the same as in Example 11.

[0110] The method for preparing recycled concrete is the same as in Example 3.

[0111] Example 15 High-performance modified bamboo residue-rubber-recycled concrete (BRC4-0.2)

[0112] A high-performance modified bamboo residue-rubber-recycled concrete (BRC4-0.2) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 Bamboo powder and bamboo residue 1.8 kg / m³ 3 The modified bamboo residue dosage is 0.2% of the total concrete volume.

[0113] The preparation method of bamboo powder and bamboo residue is similar to that of fine bamboo residue, except that bamboo powder and bamboo residue are obtained by crushing in step (6).

[0114] The method for preparing recycled concrete is the same as in Example 3.

[0115] Example 16 High-performance modified bamboo residue-rubber-recycled concrete (BRC4-0.4)

[0116] A high-performance modified bamboo residue-rubber-recycled concrete (BRC4-0.4) is prepared from the following raw materials: cement 360kg / m³.3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 Bamboo powder and bamboo residue 3.6 kg / m³ 3 The modified bamboo residue dosage is 0.4% of the total concrete volume.

[0117] The preparation method of bamboo powder and bamboo residue is the same as in Example 15.

[0118] The method for preparing recycled concrete is the same as in Example 3.

[0119] Example 17 High-performance modified bamboo residue-rubber-recycled concrete (BRC4-0.6)

[0120] A high-performance modified bamboo residue-rubber-recycled concrete (BRC4-0.6) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 Bamboo powder and bamboo residue 5.4 kg / m³ 3 The modified bamboo residue dosage is 0.6% of the total concrete volume.

[0121] The preparation method of bamboo powder and bamboo residue is the same as in Example 15.

[0122] The method for preparing recycled concrete is the same as in Example 3.

[0123] Example 18 High-performance modified bamboo residue-rubber-recycled concrete (BRC4-0.8)

[0124] A high-performance modified bamboo residue-rubber-recycled concrete (BRC4-0.8) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m3 Rubber granules 19.36 kg / m 3 Bamboo powder and bamboo residue: 7.2 kg / m³ 3 The modified bamboo residue dosage is 0.8% of the total concrete volume.

[0125] The preparation method of bamboo powder and bamboo residue is the same as in Example 15.

[0126] The method for preparing recycled concrete is the same as in Example 3.

[0127] Example 19 High-performance modified bamboo residue-rubber-recycled concrete (BRC5-0.2)

[0128] A high-performance modified bamboo residue-rubber-recycled concrete (BRC5-0.2) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 Bamboo chips and residue 1.8 kg / m³ 3 The modified bamboo residue dosage is 0.2% of the total concrete volume.

[0129] The preparation method of bamboo chips and bamboo residue is similar to that of fine bamboo residue. The difference is that in step (6), bamboo chips and bamboo residue are obtained by crushing with a pulverizer, and their shape is slightly coarser than that of bamboo powder and bamboo residue.

[0130] The method for preparing recycled concrete is the same as in Example 3.

[0131] Example 20 High-performance modified bamboo residue-rubber-recycled concrete (BRC5-0.4)

[0132] A high-performance modified bamboo residue-rubber-recycled concrete (BRC5-0.4) is prepared from the following raw materials: cement 360 kg / m³ 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 Bamboo chips and bamboo residue: 3.6 kg / m³ 3 The modified bamboo residue dosage is 0.4% of the total concrete volume.

[0133] The method for preparing bamboo chips and bamboo residue is the same as in Example 19.

[0134] The method for preparing recycled concrete is the same as in Example 3.

[0135] Example 21 High-performance modified bamboo residue-rubber-recycled concrete (BRC5-0.6)

[0136] A high-performance modified bamboo residue-rubber-recycled concrete (BRC5-0.6) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 Bamboo chips and residue: 5.4 kg / m³ 3 The modified bamboo residue dosage is 0.6% of the total concrete volume.

[0137] The method for preparing bamboo chips and bamboo residue is the same as in Example 19.

[0138] The method for preparing recycled concrete is the same as in Example 3.

[0139] Example 22 High-performance modified bamboo residue-rubber-recycled concrete (BRC5-0.8)

[0140] A high-performance modified bamboo residue-rubber-recycled concrete (BRC5-0.8) is prepared from the following raw materials: cement 360kg / m³. 3 Fine aggregate 812.25 kg / m³ 3 776 kg / m³ of crushed stone 3 203.767 kg / m³ of recycled aggregate 3 Water 108.88 kg / m 3 Water-reducing agent 4.14 kg / m 3 Rubber granules 19.36 kg / m 3 7.2 kg / m³ of bamboo chips and bamboo residue 3 The modified bamboo residue dosage is 0.8% of the total concrete volume.

[0141] The method for preparing bamboo chips and bamboo residue is the same as in Example 19.

[0142] The method for preparing recycled concrete is the same as in Example 3.

[0143] Performance testing

[0144] The concrete specimens prepared in Examples 1-22 above were subjected to mechanical property tests, including cubic compressive strength, axial compressive strength, splitting tensile strength and flexural strength tests. The test results are shown in Table 1.

[0145] Table 1. Test results of concrete mechanical properties in each embodiment

[0146]

[0147] As shown in Table 1, compared with ordinary concrete (Example 1), the mechanical properties of rubber recycled concrete (Example 2) incorporating recycled aggregate and rubber particles decreased. This was mainly due to the lower strength of the recycled aggregate and the poor adhesion between the rubber particles and the cement matrix. However, the mechanical properties of the concrete were significantly improved after incorporating modified bamboo residue (Examples 3-22). In particular, when the modified bamboo residue content was 0.6% (Examples 5, 9, 13, 17, 21), the strength indicators were optimized, and some even exceeded those of ordinary concrete. This indicates that within the dosage range of 0.2-0.8%, modified bamboo residue plays a good reinforcing role in concrete, effectively compensating for the strength loss caused by the incorporation of recycled aggregate and rubber particles, with 0.6% being the optimal dosage.

[0148] Figure 2 and Figure 3 The crack development of Example 2 (rubber recycled concrete) under axial compressive load is shown. The initial failure morphology reveals that cracks first appear at the interface between the recycled aggregate and the cement paste, then rapidly propagate and penetrate, forming obvious macroscopic cracks, ultimately leading to specimen failure. This indicates that the interface between the recycled aggregate and the cement paste is the weakest point in concrete.

[0149] Figure 4-8 The images show the final crack development morphology of concrete under axial compressive load after incorporating different forms of modified bamboo residue. It can be seen that within the dosage range of 0.2-0.8%, the failure mode of the concrete changed significantly after incorporating modified bamboo residue. Crack development became more dispersed, with a large number of microcracks appearing instead of just a few macrocracks. This is especially true at a dosage of 0.6% (…). Figure 4-8 Figure (c) shows the most uniform crack distribution, and the specimen maintained good integrity even upon failure. This indicates that within this dosage range, modified bamboo slag plays a good bridging and crack-preventing role in concrete, effectively preventing crack propagation and improving the toughness and crack resistance of concrete.

[0150] The effects of different forms of modified bamboo residue on concrete performance also vary. Fine-stemmed bamboo residue (Examples 3-6) and medium-stemmed bamboo residue (Examples 7-10) show better reinforcing effects, especially when the admixture dosage is 0.6%, resulting in optimal mechanical properties of the concrete. Coarse-stemmed bamboo residue (Examples 11-14) shows slightly weaker reinforcing effects, possibly due to the relatively smaller bonding area between coarse-stemmed bamboo residue and the cement matrix. Bamboo powder residue (Examples 15-18) and bamboo chips residue (Examples 19-22) show relatively weaker reinforcing effects, but still significantly improve the mechanical properties of recycled rubber concrete.

[0151] This invention utilizes three solid wastes—recycled aggregate, rubber granules, and modified bamboo residue—into concrete, achieving not only resource utilization of waste and reducing environmental pollution, but also producing environmentally friendly concrete with high mechanical properties. The modified bamboo residue, added at a volume ratio of 0.2-0.8%, effectively solves the problem of reduced concrete strength caused by the incorporation of recycled aggregate and rubber granules, while simultaneously improving the concrete's crack resistance and toughness. The preparation method provided by this invention is simple, easy to operate, and readily applicable to industrial production, showing promising prospects for widespread application.

[0152] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A high-performance modified bamboo residue-rubber-recycled concrete, characterized in that, The following raw materials are included in the preparation: cement 350-380 kg / m³ 3 Coarse aggregate 700-1100 kg / m³ 3 Fine aggregate 800-860kg / m³ 3 200-210 kg / m³ of recycled aggregate 3 Rubber granules 15-20 kg / m 3 Water 100-110kg / m 3 Water-reducing agent 4-6 kg / m³ 3 And modified bamboo residue; the modified bamboo residue is added at a rate of 0.2-0.8% of the total volume of concrete; the modified bamboo residue includes: fine bamboo residue with a diameter of 0.6-1.18 mm and a length of 20-40 mm; medium bamboo residue with a diameter of 1.18-2.36 mm and a length of 20-40 mm; coarse bamboo residue with a diameter of 2.36-4 mm and a length of 20-40 mm; bamboo powder and bamboo residue; bamboo chips and bamboo residue; The method for preparing the improved bamboo residue includes the following steps: (1) Place the raw material bamboo residue in a vibrator to remove the surface soil and some stains to obtain C1; (2) Place C1 in a drying oven and bake for 3 hours. The baking is divided into three steps: the first step is preheating, and the temperature is set at 85±2℃ for one hour; the second step is accelerated drying, and the temperature is set at 100±5℃ for one hour; the third step is adaptation treatment, and the temperature is set at 90±5℃ for one hour; to obtain C2. (3) The dried C2 is placed in the improvement solution for soaking treatment to obtain C3. The improvement solution is obtained by mixing 40-45% water-soluble phenolic resin and 50-55% melamine-urea-phenolic resin at a mass ratio of 1:

1. (4) Place C3 in a drying oven and dry it for 2 hours at a drying temperature of 70±5℃ to obtain C4; (5) Place C4 in a dry and ventilated indoor area to allow it to naturally return to room temperature to obtain C5; (6) C5 is then screened by a sieve or crushed by a shredder to obtain improved bamboo residue in different forms.

2. The high-performance modified bamboo residue-rubber-recycled concrete according to claim 1, characterized in that, The fine aggregate is river sand; the coarse aggregate is crushed stone; the volume ratio of the fine aggregate to rubber particles is 19:5, and the volume ratio of the coarse aggregate to recycled aggregate is 3:

1.

3. The high-performance modified bamboo residue-rubber-recycled concrete according to claim 2, characterized in that, The fineness modulus of the river sand is 2.8, and the fine aggregate is in a dry state.

4. The high-performance modified bamboo residue-rubber-recycled concrete according to claim 3, characterized in that, The rubber particles have a particle size of less than 1 mm. After being washed with a 1-3% NaOH solution, the rubber particles are rinsed with water and then air-dried.

5. The high-performance modified bamboo residue-rubber-recycled concrete according to claim 4, characterized in that, The coarse aggregate is continuously graded crushed stone with a particle size of 5-30mm, and the coarse aggregate is in a dry state after being washed with water and naturally air-dried.

6. The high-performance modified bamboo residue-rubber-recycled concrete according to claim 5, characterized in that, The water-reducing agent is a polycarboxylate high-efficiency water-reducing agent with a water reduction rate of 23-25%.

7. The high-performance modified bamboo residue-rubber-recycled concrete according to claim 6, characterized in that, The recycled aggregate has a particle size of 5-30mm and is waste concrete with an original strength of C30.

8. The high-performance modified bamboo residue-rubber-recycled concrete according to claim 1, characterized in that, The cement is P·O42.5 silicate cement.

9. The method for preparing high-performance modified bamboo residue-rubber-recycled concrete according to any one of claims 1-8, characterized in that, Includes the following steps: (1) Pour the coarse aggregate, fine aggregate, and recycled aggregate into a forced mixer and mix them; (2) Pour in cement, rubber granules and modified bamboo residue and mix; (3) Pour in some water and stir; (4) Pour the remaining water and water-reducing agent into the mixture and stir. After stirring, pour the mixture into a mold and vibrate it to obtain high mechanical properties bamboo residue-rubber-recycled concrete.

10. The preparation method according to claim 9, characterized in that, The independent stirring and mixing time in steps (1), (2), (3), and (4) is 1-2 minutes.

11. The preparation method according to claim 9, characterized in that, The vibration is performed in two stages. The mixture is filled halfway into the mold for the first vibration, and then the second vibration is performed. The vibration time for each stage does not exceed 60 seconds.

12. The preparation method according to claim 10, characterized in that, The standard curing temperature for the concrete is 20±2℃, the curing humidity is >95%, and the curing time is 28-32 days.

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