High-density polyethylene fiber concrete for municipal water supply and drainage pipelines and preparation method of high-density polyethylene fiber concrete

Abstract

The invention discloses high-density polyethylene fiber concrete for municipal water supply and drainage pipelines and a preparation method of the high-density polyethylene fiber concrete. The high-density polyethylene fiber concrete is prepared from the following components in percentage by mass: 366.07 kg / m < 3 > of cement, 1047.65 kg / m < 3 > of coarse aggregate, 648.03-650.63 kg / m < 3 > of dry sand, 197.65 kg / m < 3 > of water and 0-2.60 kg / m < 3 > of high-density polyethylene fiber. The method comprises the following steps: S1, fully mixing and stirring coarse aggregate, dry sand and cement for 4 minutes to obtain a dry concrete material; s2, pouring water into the concrete dry material prepared in the S1, and fully stirring for 4 minutes to prepare concrete paste; and S3, adding high-density polyethylene fibers into the concrete paste prepared in S2, and fully stirring for 4 minutes to obtain the high-density polyethylene fiber concrete. According to the high-density polyethylene fiber concrete, the influence on the environment due to the fact that daily consumed plastic waste cannot be explained can be relieved, the high tensile property and corrosion resistance of the high-density polyethylene fiber material can be exerted to the maximum extent, the mechanical property of the high-density polyethylene fiber concrete can be improved, and the service life of municipal water supply and drainage pipelines can be prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of municipal water supply and drainage pipeline building materials, in particular to a high-density polyethylene fiber concrete used for municipal water supply and drainage pipelines and a preparation method thereof. Background Art

[0002] With the rapid growth of global plastic production, many plastics are incorporated into the environment during their life cycle. Among them, high-density polyethylene has become one of the most widely used plastics in the market due to its good mechanical properties, easy processing and low cost. It is often used to make milk bottles, detergent bottles, cosmetic bottles, etc. High-density polyethylene is a thermoplastic semi-crystalline polymer, belonging to polyolefins, which is polymerized by ethylene under the action of a catalyst. Due to the lack of functional groups for microbial degradation, it remains in the environment for a long time, resulting in a large amount of polluted waste after product consumption, which is not easy to recycle and seriously pollutes the environment. On the other hand, municipal water supply and drainage concrete pipes are often mixed with steel fibers. In the sewage service environment, the steel fibers rust, causing the water supply and drainage concrete pipes to expand and rupture, resulting in the technical bottleneck problem of insufficient crack resistance and durability of municipal water supply and drainage concrete pipes. Therefore, the efficient recycling of high-density polyethylene fibers, replacing steel fibers, and using them in the research and development of municipal water supply and drainage pipeline concrete are of great scientific significance to improve the economic feasibility and environmental sustainability of plastic residue treatment, improve resource conservation, and enhance the crack resistance and durability of pipelines.

[0003] At present, there are few studies on high-density polyethylene fiber concrete. The synergistic working mechanism between high-density polyethylene fiber and various components of concrete has not been explored. There is little research data and theoretical basis, especially the influence of high-density polyethylene fiber substitution rate on the mechanical properties of concrete. This has greatly restricted the promotion and application of high-density polyethylene fiber in municipal water supply and drainage pipelines. How to efficiently recycle high-density polyethylene fibers and develop a high-density polyethylene fiber concrete with strength that meets the design requirements of municipal water supply and drainage pipelines has become the key to this technology. Summary of the invention

[0004] The purpose of the present invention is to solve the problem of insufficient research on the influence of high-density polyethylene fiber replacement rate on the mechanical properties of municipal water supply and drainage concrete pipes in the above-mentioned prior art, to provide a preparation method of high-density polyethylene fiber concrete for municipal water supply and drainage pipes, to optimize the mix ratio of high-density polyethylene fiber concrete, to maximize the corrosion resistance of high-density polyethylene fiber materials and to enhance the mechanical properties of high-density polyethylene fiber concrete, to promote the green and environmentally friendly development of my country's building materials, and to promote the application of high-density polyethylene fiber concrete in municipal water supply and drainage pipes.

[0005] The present invention is achieved through the following technical solutions:

[0006] A high-density polyethylene fiber concrete for municipal water supply and drainage pipes, the high-density polyethylene fiber concrete is composed of the following components by mass ratio: cement: 366.07kg / m 3 , coarse aggregate: 1047.65kg / m 3 , Dry sand: 648.03~650.63kg / m 3 , Water: 197.65kg / m 3 , High-density polyethylene fiber: 0-2.60kg / m 3 .

[0007] As a further improvement of the technical solution of the invention, the high-density polyethylene fibers are derived from discarded milk bottles, detergent bottles, cosmetic bottles or barrels; after the obtained high-density polyethylene fiber waste products are washed, the top and bottom of the bottle / barrel are excluded, and only the middle part of the bottle / barrel is taken and cut to obtain uniform high-density polyethylene fibers.

[0008] As a further improvement of the technical solution of the invention, the high-density polyethylene fiber has a thickness of 0.05 mm, a cutting length of 10 mm or 30 mm, and a width of 3 to 4 mm.

[0009] As a further improvement of the technical solution of the invention, the basic physical properties of the high-density polyethylene fiber are: water absorption: 0.255%, density: 0.955g / cm 3 ; Tensile strength: 15.05MPa, elastic modulus: 463MPa.

[0010] As a further improvement of the technical solution of the invention, the particle size of the coarse aggregate is 5 mm to 19 mm; the particle size of the dry sand is less than 4.75 mm; and the cement is 42.5R Portland cement.

[0011] As a further improvement of the technical solution of the invention, a method for preparing high-density polyethylene fiber concrete for municipal water supply and drainage pipes, wherein the components in the high-density polyethylene fiber concrete are specifically as follows according to the mass fraction: 366.07 parts of cement, 1047.65 parts of coarse aggregate, 648.03-650.63 parts of dry sand, 197.65 parts of water, and 0-2.60 parts of high-density polyethylene fiber material; specifically comprising the following steps:

[0012] Step S1. The coarse aggregate, dry sand and cement are fully mixed and stirred for 4 minutes to obtain dry concrete;

[0013] Step S2. Pour water into the dry concrete material obtained in step S1 and stir thoroughly for 4 minutes to obtain a concrete paste;

[0014] Step S3. Add high-density polyethylene fiber to the concrete paste obtained in step S2, and stir thoroughly for 4 minutes to obtain high-density polyethylene fiber concrete.

[0015] In summary, the present invention has the following beneficial effects:

[0016] The present invention provides a high-density polyethylene fiber concrete for municipal water supply and drainage pipelines, which can not only alleviate the impact of daily consumer plastic waste on the environment, but also maximize the high tensile strength and corrosion resistance of high-density polyethylene fiber materials, and improve the mechanical properties of high-density polyethylene fiber concrete, thereby extending the service life of municipal water supply and drainage pipelines. The present invention overcomes the technical bottleneck problems of insufficient crack resistance and short service life of water supply and drainage pipelines. Its research and development process is simple and easy to operate, has good application prospects, and can be applied to the production of municipal water supply and drainage pipelines. DETAILED DESCRIPTION

[0017] In order to make the purpose, features, and advantages of this application more obvious and easy to understand, the technical solutions in the embodiments of this application are clearly and completely described. Obviously, the embodiments described below are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0018] A high-density polyethylene fiber concrete for municipal water supply and drainage pipes, the high-density polyethylene fiber concrete is composed of the following components by mass ratio: cement: 366.07kg / m 3 , coarse aggregate: 1047.65kg / m 3 , Dry sand: 648.03~650.63kg / m 3 , Water: 197.65kg / m 3 , High-density polyethylene fiber: 0-2.60kg / m 3 .

[0019] Specifically, in this embodiment, the high-density polyethylene fibers are derived from discarded milk bottles, detergent bottles, cosmetic bottles or barrels; after the obtained high-density polyethylene fiber waste products are washed, the top and bottom of the bottle / barrel are excluded, and only the middle part of the bottle / barrel is taken and cut to obtain uniform high-density polyethylene fibers.

[0020] Specifically, in this embodiment, the high-density polyethylene fiber has a thickness of 0.05 mm, a cutting length of 10 mm or 30 mm, and a width of 3 to 4 mm.

[0021] Specifically, in this embodiment, the basic physical properties of the high-density polyethylene fiber are: water absorption rate: 0.255%, density: 0.955g / cm 3 ; Tensile strength: 15.05MPa, elastic modulus: 463MPa.

[0022] Specifically, in this embodiment, the particle size of the coarse aggregate is 5 mm to 19 mm; the particle size of the dry sand is less than 4.75 mm; and the cement is 42.5R Portland cement.

[0023] Specifically, in this embodiment, a method for preparing high-density polyethylene fiber concrete for municipal water supply and drainage pipes comprises the following steps:

[0024] Step S1. The coarse aggregate, dry sand and cement are fully mixed and stirred for 4 minutes to obtain dry concrete;

[0025] Step S2. Pour water into the dry concrete material obtained in step S1 and stir thoroughly for 4 minutes to obtain a concrete paste;

[0026] Step S3. Add high-density polyethylene fiber to the concrete paste obtained in step S2, and stir thoroughly for 4 minutes to obtain high-density polyethylene fiber concrete.

[0027] Example 1

[0028] The formula (weight parts) of the high-density polyethylene fiber concrete with a high-density polyethylene fiber replacement rate of 0% in the embodiment of the present application is as follows:

[0029] 366.07 parts of cement, 1047.65 parts of coarse aggregate, 650.63 parts of dry sand, 197.65 parts of water, and 0 parts of high-density polyethylene fiber material. Among them, the cement is 42.5R Portland cement, the particle size of the coarse aggregate is 5mm to 19mm or less, and the dry sand is river sand with a particle size of 4.75mm or less.

[0030] The preparation method of high-density polyethylene fiber concrete is as follows:

[0031] The coarse aggregate, dry sand and cement are fully stirred for 4 minutes to obtain the concrete dry material, and then tap water is added to the dry material and stirred for 4 minutes to obtain the concrete paste. Finally, high-density polyethylene fibers of different sizes are randomly added to the concrete paste, and the mixture is stirred evenly for 4 minutes to obtain high-density polyethylene fiber concrete. Finally, the mixture is vibrated into the mold. Among them, half of the mold is filled and vibrated for 25 seconds, and then the mold is filled and vibrated for 25 seconds. After curing and curing at room temperature, high-density polyethylene fiber concrete is obtained.

[0032] Comparative Example 1

[0033] According to the preparation method of Example 1 and the following formula (parts by weight), a high-density polyethylene fiber concrete with a high-density polyethylene fiber replacement rate of 0.2% was prepared:

[0034] 366.07 parts of cement, 1047.65 parts of coarse aggregate, 649.33 parts of dry sand, 197.65 parts of water, and 1.30 parts of high-density polyethylene fibers, wherein the length of the high-density polyethylene fibers is 30 mm.

[0035] Comparative Example 2

[0036] According to the preparation method of Example 1 and the following formula (parts by weight), a high-density polyethylene fiber concrete with a high-density polyethylene fiber replacement rate of 0.2% was prepared:

[0037] 366.07 parts of cement, 1047.65 parts of coarse aggregate, 649.33 parts of dry sand, 197.65 parts of water, and 1.30 parts of high-density polyethylene fiber material, wherein the length of the high-density polyethylene fiber is 10 mm.

[0038] Comparative Example 3

[0039] According to the preparation method of Example 1 and the following formula (parts by weight), a high-density polyethylene fiber concrete with a high-density polyethylene fiber replacement rate of 0.4% was prepared:

[0040] 366.07 parts of cement, 1047.65 parts of coarse aggregate, 648.03 parts of dry sand, 197.65 parts of water, and 2.60 parts of high-density polyethylene fiber material, wherein the length of the high-density polyethylene fiber is 30 mm.

[0041] Comparative Example 4

[0042] According to the preparation method of Example 1 and the following formula (parts by weight), a high-density polyethylene fiber concrete with a high-density polyethylene fiber replacement rate of 0.4% was prepared:

[0043] 366.07 parts of cement, 1047.65 parts of coarse aggregate, 648.03 parts of dry sand, 197.65 parts of water, and 2.60 parts of high-density polyethylene fiber material, wherein the length of the high-density polyethylene fiber is 10 mm.

[0044] Test Case

[0045] According to the American ASTM C 143 standard practice for preparation and curing of field concrete specimens and the ASTM C231 standard test method for air content of fresh concrete by pressure method, the products prepared in Example 1 and Comparative Examples 1 to 4 were tested for slump and air content working performance, and the test results are shown in Table 1 below.

[0046] According to the American standard ATMC 39 standard standard test method for compressive strength of cylindrical concrete specimens and the American standard ASTM C78 standard standard test method for flexural strength of concrete, the products prepared in Example 1 and Comparative Examples 1 to 4 were tested for compressive performance and flexural performance at 0.35 MPa / s and 1.21 MPa / min, respectively. The test results are shown in Table 1 below.

[0047] The results of Example 1 and Comparative Examples 1 to 4 show that the slump of high-density polyethylene fiber concrete decreases with the increase of high-density polyethylene fiber material. Compared with Example 1, the slump of Comparative Examples 1 to 4 decreases by 21.43%, 35.71%, 21.43% and 28.57%, respectively, indicating that the high-density polyethylene fiber material has a greater influence on the slump.

[0048] The results of Example 1 and Comparative Examples 1 to 4 show that the length of high-density polyethylene fibers has a great influence on the air content and porosity of concrete. Compared with Example 1, the air content and porosity of Comparative Examples 1 to 4 changed by -33.33%, -28.57%, -14.29%, +9.52% and -7.88%, -8.14%, -3.99%, +0.46%, respectively, indicating that when the high-density polyethylene fiber substitution rate is low, the short-length high-density polyethylene fibers can reduce the air content of concrete, but due to the aggregation of short fibers, the porosity of high-density polyethylene fiber concrete will increase, thereby improving the high-density polyethylene fiber substitution rate. The air content and porosity of Comparative Example 4 are higher than those of Example 1.

[0049] On the other hand, compared with Example 1, the 7d compressive strength of Comparative Examples 1 to 4 decreased by 5.66%, 19.62%, 4.15% and 4.91%, respectively, but the 28d compressive strength changed by +4.95%, -11.76%, -8.05% and -10.84%, respectively, indicating that high-density polyethylene fiber is not conducive to the early strength development of concrete, but the high-density polyethylene fiber has a small substitution rate and a longer length, which contributes to the later strength of concrete.

[0050] In addition, compared with Example 1, the 28d flexural strength of Examples 1 to 4 changed by -17.78%, -22.22%, +2.22% and -11.11%, respectively, indicating that increasing the high-density polyethylene fiber replacement rate and increasing the high-density polyethylene fiber length can help improve the flexural properties of concrete.

[0051] Based on the above properties, it is recommended that the high-density polyethylene fiber substitution rate be controlled below 0.4% and the length be 30 mm.

[0052] The above results show that the high-density polyethylene fiber concrete prepared in this application has good working performance and mechanical properties. It can efficiently recycle plastic waste, give full play to the corrosion resistance of polyethylene fiber, and improve the crack resistance of concrete and extend the service life. It is a green and excellent building material for municipal water supply and drainage pipes.

[0053] Table 1 Working performance and mechanical properties test results of Example 1 and Comparative Examples 1 to 3

[0054]

[0055] The technical solutions provided by the embodiments of the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present invention. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, according to the embodiments of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A high-density polyethylene fiber concrete for municipal water supply and drainage pipes, characterized in that: The high-density polyethylene fiber concrete is composed of the following components in terms of mass ratio: cement: 366.07 kg / m 3 , coarse aggregate: 1047.65kg / m 3 , Dry sand: 648.03~650.63kg / m 3 , Water: 197.65kg / m 3 , High-density polyethylene fiber: 0-2.60kg / m 3 .

2. The high-density polyethylene fiber concrete for municipal water supply and drainage pipes according to claim 1, characterized in that: The high-density polyethylene fibers are derived from discarded milk bottles, detergent bottles, cosmetic bottles or barrels; the obtained high-density polyethylene fiber waste products are washed, the top and bottom of the bottle / barrel are excluded, and only the middle of the bottle / barrel is taken and cut to obtain uniform high-density polyethylene fibers.

3. The high-density polyethylene fiber concrete for municipal water supply and drainage pipes according to claim 1, characterized in that: The high-density polyethylene fiber has a thickness of 0.05 mm, a cutting length of 10 mm or 30 mm, and a width of 3 to 4 mm.

4. The high-density polyethylene fiber concrete for municipal water supply and drainage pipes according to claim 2, characterized in that: The basic physical properties of the high-density polyethylene fiber are: water absorption: 0.255%, density: 0.955g / cm 3 ; Tensile strength: 15.05MPa, elastic modulus: 463MPa.

5. The high-density polyethylene fiber concrete for municipal water supply and drainage pipes according to claim 1, characterized in that: The particle size of the coarse aggregate is 5 mm to 19 mm; the particle size of the dry sand is less than 4.75 mm.

6. A method for preparing high-density polyethylene fiber concrete for municipal water supply and drainage pipes, characterized in that: The following steps are involved: Step S1. The coarse aggregate, dry sand and cement are fully mixed and stirred for 4 minutes to obtain dry concrete; Step S2. Pour water into the dry concrete material obtained in step S1 and stir thoroughly for 4 minutes to obtain a concrete paste; Step S3. Add high-density polyethylene fiber to the concrete paste obtained in step S2, and stir thoroughly for 4 minutes to obtain high-density polyethylene fiber concrete.

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