CN111233397B - Concrete tunnel lining material and preparation method thereof - Google Patents

Abstract

The invention discloses a concrete tunnel lining material, which is composed of cement, fly ash, polyethylene chopped fiber, polypropylene special-shaped fiber, fiber dispersion and bonding assistant, hydration regulator and polycarboxylate water reducer. It is prepared from , water and sand without reinforcement and can be constructed with the help of 3D printing equipment. The invention also discloses a preparation method of the above material. The material can quickly complete the initial lining construction after tunnel excavation with the help of 3D printing equipment. The lining concrete has the characteristics of no reinforcement, ultra-thin, toughness and crack resistance, high degree of construction automation, small material variability, and smooth inner contour surface. It is in close contact with the original excavation surface of the tunnel and has no voids. The surrounding rock above grade II (inclusive) can be directly used as a permanent lining, and the surrounding rock below grade II can form a composite lining with the waterproof interlayer and secondary lining, so as to form a composite lining for the tunnel. Long-term safety and comfort of the operating space is guaranteed.

Description

A kind of concrete tunnel lining material and preparation method thereof

technical field

The invention relates to the field of tunnel lining structures and materials, in particular to a concrete tunnel lining material and a preparation method thereof.

Background technique

With the development of railways and highways, the number and length of tunnels are increasing rapidly. At the same time, due to the objective reality of the increasingly high technical requirements of railway and highway tunnels and the gradual extension of tunnel construction to the complex geological environment in the west, the challenges faced by the modern tunnel operation environment are also increasing. Therefore, as a permanent structure to support and maintain the long-term stability of the tunnel after excavation, the quality requirements of the tunnel lining are also constantly increasing. However, due to the complexity and uncertainty of the geological environment, the different quality of tunnel construction personnel, the uneven construction technology level of tunnel lining, and the large difference in construction equipment, it is difficult to maintain a high level of construction quality of tunnel lining. This will affect the later operation safety and maintenance cycle, and even shorten the service life of the tunnel.

At present, the commonly used tunnel lining materials at home and abroad are: concrete and reinforced concrete, rubble concrete, stone or concrete prefabricated blocks, and shotcrete. The above-mentioned various lining materials have obvious advantages and disadvantages. For example, concrete and reinforced concrete linings have high strength and strong integrity, but need to erect formwork in advance, so there is the disadvantage of untimely support, and can not be quickly stopped after tunnel excavation. The development of rock deformation. In addition, although the tunnel lining built with rubble concrete, aggregated stone or concrete prefabricated blocks is less technically difficult, and does not require high technical level of construction personnel and construction equipment, there may be many gaps between the lining and the excavation surface, which is a The further loosening and deformation of the surrounding rock provides space, which is prone to stress concentration, which in turn causes problems such as cracking and water seepage. Shotcrete lining can effectively improve the problem of untimely support, but the outline of the outer surface of the lining cannot be controlled during lining construction. At the same time, limited by the level of materials and equipment, the thickness of the current shotcrete layer is very limited, and the controllability of the shotcrete quality is poor.

SUMMARY OF THE INVENTION

Aiming at the drawbacks of the current conventional tunnel lining materials, the technical problem to be solved by the present invention is to provide an unreinforced concrete tunnel lining material with toughness and crack resistance and high consistency of construction quality.

For solving the above-mentioned technical problems, the technical scheme designed by the present invention is:

A concrete tunnel lining material, the concrete tunnel lining material is composed of cement, fly ash, polyethylene chopped fiber, polypropylene special-shaped fiber, fiber dispersion and bonding assistant, hydration regulator, polycarboxylate water reducer, water The mixed sand is prepared in the following proportions: 21.8-30.9 parts by weight of cement, 10.5-19.2 parts by weight of fly ash, 0.03-0.05 parts by weight of polyethylene chopped fibers, 0.02-0.04 parts by weight of polypropylene special-shaped fibers, and fibers dispersed and bonded 0.5-1.1 parts by weight of auxiliary, 0.22-0.41 parts by weight of hydration regulator, 0.1-0.3 parts by weight of polycarboxylate water reducing agent, 10.3-18.5 parts by weight of water, 40.2-65.9 parts by weight of sand, and the sum of each component is 100 parts by weight; the concrete tunnel lining material has no reinforcement and can be constructed by means of 3D printing equipment.

The cement is ordinary 52.5 Portland cement with a strength grade of 52.5 MPa, and the fly ash is first-grade fly ash.

The polyethylene chopped fibers have a length of 1.5-2.5 cm, a diameter of 25-35 μm, a tensile strength of 2800-3000 MPa, and a density of 0.98 g/cm ³ . The polypropylene special-shaped fibers have a length of 4-6 cm, a diameter of 0.8-1.2 mm, a tensile strength of 550-650 MPa, and a density of 0.90 g/cm ³ .

The fiber dispersion and bonding assistant is prepared from polyvinylpyrrolidone and ultrafine zeolite powder in a weight ratio of 1:10. Wherein, the solid content of the polyvinylpyrrolidone powder particles is greater than 96%, and the fineness of the ultrafine zeolite powder is 200-400 meshes.

The hydration regulator is prepared by mixing triethanolamine and tartaric acid in a weight ratio of 1:(2.1-3.7).

The triethanolamine, tartaric acid and polycarboxylate water reducer are all commercial additives.

The present invention also provides a method for preparing the above-mentioned concrete tunnel lining material, which comprises the following steps:

1) Calculate and weigh cement, fly ash, polyethylene chopped fibers, polypropylene special-shaped fibers, fiber dispersing and bonding aids, hydration regulators, polycarboxylate water reducers, water and sand according to the material composition ratio. ;

2) Take 15% to 25% of water and add fiber dispersing and bonding aid into it, place it in an ice-water bath and use ultrasonic treatment for 30 to 60 minutes to obtain fiber dispersion and bonding aid suspension; then add polyethylene chopped fibers And continue to use ultrasonic treatment for 10-30min to obtain stable polyethylene chopped fiber dispersion A, ready for use;

3) evenly mixing the weighed cement, fly ash and sand to obtain mixture B;

4) After adding polypropylene special-shaped fiber, hydration regulator and polycarboxylate water reducing agent to the remaining water and stirring evenly, add it to mixture B together with A, stir at a slow speed for 10-30s, then quickly stir for 1-5min, and finally Stir at slow speed for 30 to 60 s.

The invention controls the setting time of concrete and improves its fluidity by adding a relatively large proportion of fly ash and using hydration regulator, so that the construction of the primary lining can be quickly completed with the help of 3D printing equipment after tunnel excavation, so as to ensure that the primary lining and the The excavation surface is in close contact and has no voids; moreover, the inner contour surface of the 3D printed concrete lining is flat and smooth, which can be directly used as a permanent lining in the surrounding rock above Grade II (inclusive), or with the subsequent waterproof interlayer (isolation layer) and secondary The lining together forms a permanent lining in the surrounding rock below Grade II, thereby providing a guarantee basis for the long-term safety and comfort of the tunnel operating space.

In particular, it should be noted that the combined use of hydration regulator and fiber dispersion and bonding agent can make the concrete mixed with the two fibers have good fluidity and extrudability, and ensure that the concrete material can pass through 3D homogeneously quickly and homogeneously. The printing construction equipment is used for printing construction, and the thick and thin fibers are not agglomerated or delaminated during the printing construction process. On the other hand, after the printing construction is completed, the concrete quickly solidifies and hardens, which is conducive to the overlapping between the thick and thin fibers and the close bonding with the concrete, forming a stable spatial network structure, which effectively replaces the steel bars in the ordinary lining concrete and makes the tunnel lining concrete. It has the characteristics of no reinforcement, ultra-thinning and toughness and crack resistance.

In addition, the polyethylene chopped fiber is used in combination with the thickness, length and tensile strength of the polypropylene special-shaped fiber, which can ensure that the lining concrete still has sufficient strength without using steel bars and reducing the thickness of the lining, and at the same time It also has excellent toughness, which guarantees its tough deformation ability and crack resistance, so that the lining concrete can allow and control its deformation when the surrounding rock is loose and deformed.

Detailed ways

In order to better illustrate the present invention, the content of the present invention is further described below in conjunction with specific embodiments, but the present invention is not limited to the following embodiments.

Comparative example A ₀ :

Cement: fly ash: polycarboxylate water reducing agent: water: sand = 25 parts: 10 parts: 0.25 parts: 12.5 parts: 52.25 parts.

First, weigh cement, fly ash, polycarboxylate water-reducing agent, water and sand according to the proportion of ingredients, and set aside. Then, use a mixer to stir the cement, fly ash and sand evenly to obtain mixture A; at the same time, add the weighed polycarboxylate water reducing agent into water and stir to obtain solution B; then, add B into mixture A, Stir at slow speed for 30 s, then quickly stir for 3 min, and finally stir at slow speed for 60 s.

Comparative Example A ₁ :

Cement: Fly Ash: Polyethylene Chopped Fiber: Fiber Dispersion Bonding Auxiliary: Hydration Regulator: Polycarboxylate 0.1 servings: 10.8 servings: 53.24 servings. The fiber dispersing and bonding aid is prepared by mixing polyvinylpyrrolidone and ultrafine zeolite powder in a weight ratio of 1:10. The hydration regulator is prepared by mixing triethanolamine and tartaric acid in a weight ratio of 1:3.

Take 20% of water (i.e. 10.8*20%=2.16 parts) and add the fiber dispersion bonding aid to it, place it in an ice-water bath and use ultrasonic treatment for 45min to obtain the fiber dispersion bonding aid suspension; then add polyethylene The chopped fibers are continuously treated with ultrasonic waves for 20 min to obtain a stable polyethylene chopped fiber dispersion C, which is ready for use; the weighed cement, fly ash and sand are mixed uniformly to obtain a mixture D; triethanolamine, tartaric acid and polyethylene are mixed. Carboxylic acid water reducing agent is added to the remaining water (ie 10.8*80%=8.64 parts) and stirred evenly, then added to mixture D together with C, stirred at a slow speed for 10s, then quickly stirred for 3 minutes, and finally stirred at a slow speed for 30s. .

Comparative Example A ₂ :

Cement: Fly Ash: Polypropylene Shaped Fiber: Fiber Dispersion Bonding Auxiliary: Hydration Regulator: Polycarboxylate Servings: 10.8 Servings: 53.25 Servings. The fiber dispersing and bonding aid is prepared by mixing polyvinylpyrrolidone and ultrafine zeolite powder in a weight ratio of 1:10. The hydration regulator is prepared by mixing triethanolamine and tartaric acid in a weight ratio of 1:3.

Take 20% water (i.e. 10.8*20%=2.16 parts) and add the fiber dispersion and bonding aid to it, place it in an ice-water bath and use ultrasonic treatment for 45min to obtain the fiber dispersion bonding aid suspension; Mix the cement, fly ash and sand evenly to obtain mixture E; add polypropylene special-shaped fiber, triethanolamine, tartaric acid and polycarboxylate water reducer to the remaining water (ie 10.8*80%=8.64 parts) and stir evenly , together with the fiber dispersion and bonding aid suspension, add it to the mixture E, stir at a slow speed for 10 s, then quickly stir for 3 min, and finally stir at a slow speed for 30 s.

Comparative Example _A3 :

Cement: Fly Ash: Polyethylene Chopped Fiber: Polypropylene Shaped Fiber: Hydration Regulator: Polycarboxylate : 10.8 servings: 53.21 servings. The hydration regulator is prepared by mixing triethanolamine and tartaric acid in a weight ratio of 1:3.

Mix the weighed cement, fly ash and sand evenly to obtain mixture F; add polyethylene chopped fibers, polypropylene special-shaped fibers, triethanolamine, tartaric acid and polycarboxylate water reducer into water and stir evenly and then add to the mixture. In mixture F, stir at slow speed for 10 s, then quickly stir for 3 min, and finally stir at slow speed for 30 s.

Comparative Example _A4 :

Cement: Fly Ash: Polyethylene Chopped Fiber: Polypropylene Shaped Fiber: Fiber Dispersion Bonding Aid: Sodium Carbonate: Polycarboxylate Water Reducer: Water: Sand=22.5 parts: 12.6 parts: 0.04 parts: 0.03 parts: 0.5 servings: 0.22 servings: 0.1 servings: 10.8 servings: 53.21 servings. The fiber dispersing and bonding aid is prepared by mixing polyvinylpyrrolidone and ultrafine zeolite powder in a weight ratio of 1:10.

Take 20% of water (i.e. 10.8*20%=2.16 parts) and add the fiber dispersion bonding aid to it, place it in an ice-water bath and use ultrasonic treatment for 45min to obtain the fiber dispersion bonding aid suspension; then add polyethylene chopped fibers and continue to use ultrasonic treatment for 20min to obtain stable polyethylene chopped fiber dispersion G, which is ready for use; mix the weighed cement, fly ash and sand evenly to obtain mixture H; mix polypropylene special-shaped fibers, sulfuric acid Sodium and polycarboxylate superplasticizer were added to the remaining water (ie 10.8*80%=8.64 parts) and stirred evenly, then added to the mixture H together with G, stirred at a slow speed for 10s, then quickly stirred for 3 minutes, and finally stirred at a slow speed 30s is enough.

Comparative Example _A5 :

Cement: Fly Ash: Polyethylene Chopped Fiber: Polypropylene Shaped Fiber: Fiber Dispersion Bonding Auxiliary: Triethanolamine: Polycarboxylate Superplasticizer: Water: Sand=22.5 parts: 12.6 parts: 0.04 parts: 0.03 parts 0.5 part: 0.075 part: 0.1 part: 10.8 part: 53.355 part. The fiber dispersing and bonding aid is prepared by mixing polyvinylpyrrolidone and ultrafine zeolite powder in a weight ratio of 1:10.

Take 20% of water (i.e. 10.8*20%=2.16 parts) and add the fiber dispersion bonding aid to it, place it in an ice-water bath and use ultrasonic treatment for 45min to obtain the fiber dispersion bonding aid suspension; then add polyethylene Chopped fibers and continue to use ultrasonic treatment for 20min to obtain stable polyethylene chopped fiber dispersion I, set aside; the weighed cement, fly ash and sand are evenly mixed to obtain mixture J; polypropylene special-shaped fibers, three Ethanolamine and polycarboxylate water reducer are added to the remaining water (i.e. 10.8*80%=8.64 parts) and stirred evenly, then added to mixture J together with I, stirred at a slow speed for 10s, then quickly stirred for 3min, and finally stirred at a slow speed 30s is enough.

Comparative Example _A6 :

Cement: Fly Ash: Polyethylene Chopped Fiber: Polypropylene Shaped Fiber: Fiber Dispersion Bonding Auxiliary: Tartaric Acid: Polycarboxylate Servings: 0.225 Servings: 0.1 Servings: 10.8 Servings: 53.205 Servings. The fiber dispersing and bonding aid is prepared by mixing polyvinylpyrrolidone and ultrafine zeolite powder in a weight ratio of 1:10.

Take 20% of water (i.e. 10.8*20%=2.16 parts) and add the fiber dispersion bonding aid to it, place it in an ice-water bath and use ultrasonic treatment for 45min to obtain the fiber dispersion bonding aid suspension; then add polyethylene chopped fibers and continue to use ultrasonic treatment for 20min to obtain a stable polyethylene chopped fiber dispersion K, which is ready for use; mix the weighed cement, fly ash and sand evenly to obtain a mixture L; mix polypropylene special-shaped fibers, tartaric acid Add polycarboxylate water reducing agent and polycarboxylate to the remaining water (ie 10.8*80%=8.64 parts) and stir evenly, add to mixture L together with K, stir at slow speed for 10s, then quickly stir for 3min, and finally stir at slow speed for 30s That's it.

Comparative Example _A7 :

Cement: Fly Ash: Polyethylene Chopped Fiber: Polypropylene Shaped Fiber: Fiber Dispersion Bonding Auxiliary: Hydration Regulator: Polycarboxylate Water Reducer: Water: Sand = 22.5 parts: 12.6 parts: 0.04 parts: 0.03 Servings: 0.5 Servings: 0.3 Servings: 0.1 Servings: 10.8 Servings: 53.13 Servings. The fiber dispersing and bonding aid is prepared by mixing polyvinylpyrrolidone and ultrafine zeolite powder in a weight ratio of 1:10. The hydration regulator is prepared by mixing triethanolamine and tartaric acid in a weight ratio of 2:1.

Take 20% of water (i.e. 10.8*20%=2.16 parts) and add the fiber dispersion bonding aid to it, place it in an ice-water bath and use ultrasonic treatment for 45min to obtain the fiber dispersion bonding aid suspension; then add polyethylene The chopped fibers are continuously treated with ultrasonic waves for 20 minutes to obtain a stable polyethylene chopped fiber dispersion M, which is ready for use; the weighed cement, fly ash and sand are mixed uniformly to obtain a mixture N; polypropylene special-shaped fibers, three Ethanolamine, tartaric acid and polycarboxylate water reducer were added to the remaining water (ie 10.8*80%=8.64 parts) and stirred evenly, then added to the mixture N together with N, stirred at a slow speed for 10s, then quickly stirred for 3 minutes, and finally slowly Stir at high speed for 30s.

Example B ₁ :

Cement: Fly Ash: Polyethylene Chopped Fiber: Polypropylene Shaped Fiber: Fiber Dispersion Bonding Auxiliary: Hydration Regulator: Polycarboxylate Water Reducer: Water: Sand = 22.5 parts: 12.6 parts: 0.04 parts: 0.03 Servings: 0.5 Servings: 0.22 Servings: 0.1 Servings: 10.8 Servings: 53.21 Servings.

Example B2 _:

Cement: Fly Ash: Polyethylene Chopped Fiber: Polypropylene Shaped Fiber: Fiber Dispersion Bonding Auxiliary: Hydration Regulator: Polycarboxylate Water Reducer: Water: Sand=30.5 parts: 11 parts: 0.04 parts: 0.03 Servings: 0.5 Servings: 0.4 Servings: 0.2 Servings: 15.25 Servings: 42.08 Servings.

Example _B3 :

Cement: Fly Ash: Polyethylene Chopped Fiber: Polypropylene Shaped Fiber: Fiber Dispersion Bonding Auxiliary: Hydration Regulator: Polycarboxylate Water Reducer: Water: Sand = 26.3 parts: 15.8 parts: 0.05 parts: 0.02 Servings: 0.8 Servings: 0.31 Servings: 0.2 Servings: 11.5 Servings: 45.02 Servings.

Example _B4 :

Cement: Fly Ash: Polyethylene Chopped Fiber: Polypropylene Shaped Fiber: Fiber Dispersion Bonding Auxiliary: Hydration Regulator: Polycarboxylate Water Reducer: Water: Sand=30.3 parts: 15.53 parts: 0.03 parts: 0.04 Servings: 1 Serving: 0.4 Servings: 0.28 Servings: 12.2 Servings: 40.22 Servings.

In the preparation method of concrete tunnel lining material of embodiment B1～B4:

First, calculate and weigh cement, fly ash, polyethylene chopped fibers, polypropylene special-shaped fibers, fiber dispersing and bonding aids, hydration regulators, polycarboxylate water reducers, water and sand according to the material composition ratio. .

in:

The cement is ordinary 52.5 Portland cement with a strength grade of 52.5 MPa, and the fly ash is first-grade fly ash.

The polyethylene chopped fibers have a length of 1.5-2.5 cm, a diameter of 25-35 μm, a tensile strength of 2800-3000 MPa, and a density of 0.98 g/cm ³ . The polypropylene special-shaped fibers have a length of 4-6 cm, a diameter of 0.8-1.2 mm, a tensile strength of 550-650 MPa, and a density of 0.90 g/cm ³ .

The fiber dispersion and bonding assistant is prepared by mixing polyvinylpyrrolidone and ultrafine zeolite powder in a weight ratio of 1:10. Wherein, the solid content of the polyvinylpyrrolidone powder particles is greater than 96%, and the fineness of the ultrafine zeolite powder is 200-400 meshes.

The hydration regulator is prepared by mixing triethanolamine and tartaric acid in a weight ratio of 1:3.

The triethanolamine, tartaric acid and polycarboxylate water reducer are all commercial additives.

Next, take 20% of water and add polyvinylpyrrolidone and ultrafine zeolite powder into it, place it in an ice-water bath and use ultrasonic treatment for 45min to obtain a suspension of fiber dispersion and bonding aid; then add polyethylene chopped fibers and continue to use Ultrasonic treatment for 20min obtains stable polyethylene chopped fiber dispersion O, which is ready for use; the weighed cement, fly ash and sand are evenly mixed to obtain mixture P; polypropylene special-shaped fibers, triethanolamine, tartaric acid and polycarboxylate are mixed After adding the acid water reducing agent to the remaining water and stirring evenly, it is added to the mixture P together with O, stirred at a slow speed for 10 s, then quickly stirred for 3 min, and finally stirred at a slow speed for 30 s.

According to the "Highway Engineering Cement and Cement Concrete Test Regulations JTG E30-2005", the fluidity, 6h and 28d compressive strength, flexural strength and 28d flexural limit mid-span deflection of the embodiment of the present invention and the control example were tested. The results are summarized in Table 1. It can be seen from the test results of the indicators in the table that the strength of the comparative examples A ₀ and A ₆ has not yet formed at 6h. Although the comparative examples A ₁ to A ₄ have added hydration regulators or other conventional accelerators, the present invention _The 6h and 28d compressive strengths, flexural compressive strengths and toughness (i.e. ultimate mid-span deflection) of Examples B1 to B4 are significantly greater _than those of the control example, indicating that the concrete tunnel lining materials listed in the examples of the present invention have early strength development Speed advantage. The fluidity of the embodiment of the present invention is moderate, which is beneficial to control the printing construction of the concrete tunnel lining material. Compared with the control examples A ₁ and A ₂ , the combined use of polyethylene chopped fibers and polypropylene profiled fibers is significantly better than the use of either fiber alone in terms of strength and toughness. Compared with the control example A ₃ , the fibers in the examples of the present invention have a more significant synergistic effect after using the fiber dispersion and bonding assistant, which is manifested as better strength and toughness. Compared with the control examples A ₄ , A ₅ and A ₇ , when other accelerators are used or only triethanolamine is used as the accelerator or the ratio of triethanolamine/tartaric acid is not appropriate, although the lining material also has the characteristics of fast setting and early strength, However, the strength and toughness of 28d are significantly lower than those of the examples of the present invention.

Table 1 Embodiment in the present invention and comparative example performance test result

Claims (4)

1. A concrete tunnel lining material, characterized in that: the concrete tunnel lining material is not provided with reinforcing bars, can be constructed by 3D printing equipment and is prepared from cement, fly ash, polyethylene chopped fibers, polypropylene profiled fibers, fiber dispersion bonding auxiliary agents, hydration regulator, polycarboxylic acid water reducing agent, water and sand according to the following proportion: 21.8 to 30.9 parts of cement, 10.5 to 19.2 parts of fly ash, 0.03 to 0.05 part of polyethylene chopped fiber, 0.02 to 0.04 part of polypropylene profiled fiber, 0.5 to 1.1 part of fiber dispersion bonding auxiliary agent, 0.22 to 0.41 part of hydration regulator, 0.1 to 0.3 part of polycarboxylic acid water reducing agent, 10.3 to 18.5 parts of water and 40.2 to 65.9 parts of sand, wherein the sum of the components is 100 parts by weight; the hydration regulator is prepared from triethanolamine and tartaric acid according to the weight ratio of 1: (2.1-3.7) by weight; the fiber dispersion bonding auxiliary agent is prepared from polyvinylpyrrolidone and ultrafine zeolite powder according to the weight ratio of 1: 10, the solid content of the polyvinylpyrrolidone powdery particles is more than 96 percent, and the fineness of the superfine zeolite powder is 200-400 meshes.

2. The concrete tunnel lining material according to claim 1, wherein:

the cement is common 52.5 portland cement with the strength grade of 52.5MPa, and the fly ash is first-grade fly ash.

3. The concrete tunnel lining material according to claim 1 or 2, wherein:

the polyethylene chopped fiber has the length of 1.5-2.5 cm, the diameter of 25-35 mu m, the tensile strength of 2800-3000 MPa and the density of 0.98g/cm³(ii) a The polypropylene profiled fiber has the length of 4-6 cm, the diameter of 0.8-1.2 mm, the tensile strength of 550-650 MPa and the density of 0.90g/cm³。

4. A method for preparing a concrete tunnel lining material as recited in any one of claims 1 to 3, wherein:

the method comprises the following steps:

1) weighing cement, fly ash, polyethylene chopped fiber, polypropylene profiled fiber, fiber dispersion bonding auxiliary agent, hydration regulator, polycarboxylic acid water reducer, water and sand according to the material composition proportion for later use;

2) taking water with the water content of 15-25%, adding the fiber dispersion bonding auxiliary agent into the water, and placing the mixture in an ice water bath for ultrasonic treatment for 30-60 min to obtain a fiber dispersion bonding auxiliary agent suspension; then adding polyethylene chopped fibers and continuously using ultrasonic waves for treatment for 10-30 min to obtain a stable polyethylene chopped fiber dispersion A for later use;

3) uniformly mixing the weighed cement, fly ash and sand to obtain a mixture B;

4) and adding the polypropylene profiled fiber, the hydration regulator and the polycarboxylic acid water reducing agent into the residual water, uniformly stirring, adding the mixture and the polyethylene chopped fiber dispersion A into the mixture B, slowly stirring for 10-30 s, then quickly stirring for 1-5 min, and finally slowly stirring for 30-60 s.