Novel CNTs-rubber concrete bridge deck pavement material and preparation method thereof

Abstract

The invention relates to a novel CNTs-rubber concrete bridge deck pavement material and a preparation method thereof, and belongs to the technical field of building materials, the novel CNTs-rubber concrete bridge deck pavement material comprises the following raw materials by weight: 450-550 parts of cement, 800-900 parts of fine aggregate, 800-900 parts of coarse aggregate, 22.5-55 parts of rubber particles, 0-10 parts of silica fume, 0.45-2.75 parts of CNTs, 120-160 parts of water, and 4-6 parts of a water reducer. According to the prepared novel CNTs-rubber concrete bridge deck pavement material, the mechanical property of large-dosage rubber concrete can be improved, reasonable recycling of waste rubber is achieved, and meanwhile the requirements for high strength and high durability of the bridge deck pavement material can be met.

Description

Technical Field

[0001] The invention relates to the technical field of building materials, and in particular to a novel CNTs-rubber concrete bridge deck paving material and a preparation method thereof. Background Art

[0002] The bridge deck pavement is a protective layer built on the bridge deck to prevent wheels from directly wearing the bridge deck, spread the wheel load, and provide a smooth and non-slip driving surface for vehicles. Therefore, the material used for the bridge deck pavement needs to have good compressive strength, durability and overall performance.

[0003] With the rapid development of social economy and the number of vehicles, waste tire processing and bridge construction are facing two major challenges: on the one hand, waste tire processing pressure, waste tire accumulation not only occupies land, but also may cause environmental pollution and safety hazards; on the other hand, bridge construction costs are high, post-maintenance is difficult, and has a great impact on traffic. As a protective layer of the bridge, the bridge deck pavement must have a certain compressive strength, durability and crack resistance to extend the service life of the bridge and ensure the safety of the bridge structure.

[0004] Currently, extensive research has been conducted on the reuse of waste rubber in cement concrete for bridge deck pavement. Although rubber particles can improve the toughness, impact resistance and durability of concrete, they will reduce its compressive and flexural strength. Since compressive and flexural strength are the two main design criteria for concrete structures, the reduced strength of rubber concrete limits its application.

[0005] In view of the above-mentioned phenomenon, how to ensure the strength of bridge deck paving concrete while improving its toughness, impact resistance and durability, and realize the rational recycling of waste rubber to reduce the cost of bridge construction and maintenance has become a technical problem that needs to be solved urgently. Summary of the invention

[0006] The purpose of the present invention is to provide a new type of CNTs-rubber concrete bridge deck paving material and a preparation method thereof. In view of the burden on the environment caused by the treatment of waste tires and the problem that the strength of rubber concrete prepared from waste rubber is reduced and limits its application, a concrete bridge deck paving material and a preparation method thereof are proposed to achieve the reasonable recycling of waste rubber and at the same time meet the requirements of high strength and high durability of bridge deck paving materials.

[0007] The present invention provides a novel CNTs-rubber concrete bridge deck paving material, which adopts the following technical solution: A novel CNTs-rubber concrete bridge deck paving material comprises the following raw materials in parts by weight: 450-550 parts of cement, 800-900 parts of fine aggregate, 800-900 parts of coarse aggregate, 22.5-55 parts of rubber particles, 0-10 parts of silica fume, 0.45-2.75 parts of CNTs, 120-160 parts of water, and 4-6 parts of a water reducing agent.

[0008] Preferably, the CNTs are multi-walled carbon nanotubes; The diameter of the CNTs is 30-80 mm.

[0009] Preferably, the fine aggregate is medium sand; The fineness modulus of the fine aggregate is 2.5-3.0.

[0010] Preferably, the coarse aggregate is one or more of crushed stone and river pebbles; The particle size of the coarse aggregate is 5-30 mm.

[0011] Preferably, the rubber particles are obtained by granulating waste rubber tires; The rubber particles have a particle size of 1-5 mm.

[0012] Preferably, the particle size of the silica fume is 0.1-0.3 μm.

[0013] Preferably, the water reducer is a polycarboxylic acid water reducer.

[0014] The present invention also provides a method for preparing a novel CNTs-rubber concrete bridge deck paving material, using the novel CNTs-rubber concrete bridge deck paving material described above, comprising the following preparation steps: S1. Evenly mix the water reducer with 4 / 5 of the total amount of water, then slowly add CNTs with stirring, and use ultrasonic dispersion for 20-30 minutes to obtain a CNTs suspension; S2. Add cement, fine aggregate, coarse aggregate, rubber particles and silica fume into a concrete mixer and stir for 30-50 seconds to obtain a base material; S3, adding the CNTs suspension prepared in step S1 to the base material prepared in step S2, stirring continuously for 30-50 seconds, and then adding the remaining water accounting for 1 / 5 of the total amount, stirring continuously for 60-90 seconds to obtain a slurry; S4, paving the slurry prepared in step S3 on the bridge deck, compacting and curing to form a concrete bridge deck paving material.

[0015] Preferably, the apparent density of the concrete bridge deck paving material in step S4 is 2300-2400 kg / m 3 .

[0016] In summary, the present invention includes the following beneficial technical effects: The present invention combines the multi-phase and multi-layer structural characteristics of concrete and uses nano-enhancement means to produce a CNTs-rubber concrete for bridge deck pavement to achieve high performance of bridge deck pavement concrete. CNTs-rubber concrete can improve the toughness, impact resistance and durability of bridge deck pavement concrete while ensuring strength, and also achieves reasonable recycling of waste rubber. The bridge deck pavement material of the present invention can greatly improve the crack resistance and impact toughness of the bridge deck pavement layer, thereby extending the service life of the surface layer and ensuring the performance of the main structure of the bridge. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a graph showing the compressive strength changes of CNTs-rubber concrete, traditional bridge deck paving concrete and ordinary rubber concrete at different curing ages in the present invention.

[0018] Figure 2 It is a graph showing the change in flexural strength of CNTs-rubber concrete, traditional bridge deck paving concrete and ordinary rubber concrete at different curing ages in the present invention. DETAILED DESCRIPTION

[0019] The following is combined with the embodiments and the attached Figure 1-2 The present invention is described in further detail.

[0020] Example 1 A method for preparing a novel CNTs-rubber concrete bridge deck paving material comprises the following steps: S1. Take 6 kg of water reducer and mix it evenly in 96 kg of water, then slowly add 0.45 kg of CNTs while stirring, and use ultrasonic dispersion for 20-30 minutes to obtain a CNTs suspension; S2, add 450kg cement, 900kg fine aggregate, 800kg coarse aggregate and 22.5kg rubber particles into a concrete mixer, stir for 30-50s to obtain a base material; S3, adding the CNTs suspension prepared in step S1 to the base material prepared in step S2, stirring continuously for 30-50 seconds, and then adding the remaining 24 kg of water, stirring continuously for 60-90 seconds to obtain a slurry; S4, paving the slurry prepared in step S3 on the bridge deck, compacting and curing to form a concrete bridge deck paving material, the apparent density of the concrete bridge deck paving material is 2300kg / m 3 .

[0021] Among them, CNTs are multi-walled carbon nanotubes with a purity greater than 98%, and the diameter of CNTs is 30-80mm; the water reducer is a polycarboxylic acid water reducer; the fine aggregate in this embodiment is Class II fine aggregate, the fine aggregate is medium sand, and the fineness modulus of the fine aggregate is 2.5-3.0; the fine aggregate in this embodiment is Class II coarse aggregate, the coarse aggregate is one or more of crushed stone and river pebbles, and the particle size of the coarse aggregate is 5-30mm; the rubber particles are obtained by granulating waste rubber tires, and the particle size of the rubber particles is 1-5mm; the particle size of silica fume is 0.1-0.3μm.

[0022] Example 2 A method for preparing a novel CNTs-rubber concrete bridge deck paving material comprises the following steps: S1. Take 6 kg of water reducer and mix it evenly in 96 kg of water, then slowly add 1.35 kg of CNTs while stirring, and use ultrasonic dispersion for 20-30 minutes to obtain a CNTs suspension; S2, add 450kg cement, 850kg fine aggregate, 850kg coarse aggregate, 22.5kg rubber particles and 3kg silica fume into a concrete mixer, stir for 30-50s to obtain a base material; S3, adding the CNTs suspension prepared in step S1 to the base material prepared in step S2, stirring continuously for 30-50 seconds, and then adding the remaining 24 kg of water, stirring continuously for 60-90 seconds to obtain a slurry; S4, paving the slurry prepared in step S3 on the bridge deck, compacting and curing to form a concrete bridge deck paving material, the apparent density of the concrete bridge deck paving material is 2300kg / m 3 .

[0023] Among them, CNTs are multi-walled carbon nanotubes with a purity greater than 98%, and the diameter of CNTs is 30-80mm; the water reducer is a polycarboxylic acid water reducer; the fine aggregate in this embodiment is Class II fine aggregate, the fine aggregate is medium sand, and the fineness modulus of the fine aggregate is 2.5-3.0; the fine aggregate in this embodiment is Class II coarse aggregate, the coarse aggregate is one or more of crushed stone and river pebbles, and the particle size of the coarse aggregate is 5-30mm; the rubber particles are obtained by granulating waste rubber tires, and the particle size of the rubber particles is 1-5mm; the particle size of silica fume is 0.1-0.3μm.

[0024] Example 3 A method for preparing a novel CNTs-rubber concrete bridge deck paving material comprises the following steps: S1. Take 4 kg of water reducer and mix it evenly in 112 kg of water, then slowly add 2.5 kg of CNTs while stirring, and use ultrasonic dispersion for 20-30 minutes to obtain a CNTs suspension; S2, add 500kg cement, 850kg fine aggregate, 850kg coarse aggregate, 25kg rubber particles and 6kg silica fume into a concrete mixer, stir for 30-50s to obtain a base material; S3, adding the CNTs suspension prepared in step S1 to the base material prepared in step S2, stirring continuously for 30-50 seconds, then adding the remaining 28 kg of water, stirring continuously for 60-90 seconds, to obtain a slurry; S4, paving the slurry prepared in step S3 on the bridge deck, compacting and curing to form a concrete bridge deck paving material, the apparent density of the concrete bridge deck paving material is 2400kg / m 3 .

[0025] Among them, CNTs are multi-walled carbon nanotubes with a purity greater than 98%, and the diameter of CNTs is 30-80mm; the water reducer is a polycarboxylic acid water reducer; the fine aggregate in this embodiment is Class II fine aggregate, the fine aggregate is medium sand, and the fineness modulus of the fine aggregate is 2.5-3.0; the fine aggregate in this embodiment is Class II coarse aggregate, the coarse aggregate is one or more of crushed stone and river pebbles, and the particle size of the coarse aggregate is 5-30mm; the rubber particles are obtained by granulating waste rubber tires, and the particle size of the rubber particles is 1-5mm; the particle size of silica fume is 0.1-0.3μm.

[0026] Example 4 A method for preparing a novel CNTs-rubber concrete bridge deck paving material comprises the following steps: S1. Take 4 kg of water reducer and mix it evenly in 128 kg of water, then slowly stir and add 0.5 kg of CNTs, and use ultrasonic dispersion for 20-30 minutes to obtain a CNTs suspension; S2, add 500kg cement, 800kg fine aggregate, 900kg coarse aggregate, 50kg rubber particles and 8kg silica fume into a concrete mixer, stir for 30-50s to obtain a base material; S3, adding the CNTs suspension prepared in step S1 to the base material prepared in step S2, stirring continuously for 30-50 seconds, then adding the remaining 12 kg of water, stirring continuously for 60-90 seconds, to obtain a slurry; S4, paving the slurry prepared in step S3 on the bridge deck, compacting and curing to form a concrete bridge deck paving material, the apparent density of the concrete bridge deck paving material is 2400kg / m 3 .

[0027] Among them, CNTs are multi-walled carbon nanotubes with a purity greater than 98%, and the diameter of CNTs is 30-80mm; the water reducer is a polycarboxylic acid water reducer; the fine aggregate in this embodiment is Class II fine aggregate, the fine aggregate is medium sand, and the fineness modulus of the fine aggregate is 2.5-3.0; the fine aggregate in this embodiment is Class II coarse aggregate, the coarse aggregate is one or more of crushed stone and river pebbles, and the particle size of the coarse aggregate is 5-30mm; the rubber particles are obtained by granulating waste rubber tires, and the particle size of the rubber particles is 1-5mm; the particle size of silica fume is 0.1-0.3μm.

[0028] Example 5 A method for preparing a novel CNTs-rubber concrete bridge deck paving material comprises the following steps: S1. Take 4 kg of water reducer and mix it evenly in 128 kg of water, then slowly add 1.65 kg of CNTs while stirring, and use ultrasonic dispersion for 20-30 minutes to obtain a CNTs suspension; S2, add 550kg cement, 800kg fine aggregate, 800kg coarse aggregate, 55kg rubber particles and 10kg silica fume into a concrete mixer, stir for 30-50s to obtain a base material; S3, adding the CNTs suspension prepared in step S1 to the base material prepared in step S2, stirring continuously for 30-50 seconds, then adding the remaining 12 kg of water, stirring continuously for 60-90 seconds, to obtain a slurry; S4, paving the slurry prepared in step S3 on the bridge deck, compacting and curing to form a concrete bridge deck paving material, the apparent density of the concrete bridge deck paving material is 2350kg / m 3 .

[0029] Among them, CNTs are multi-walled carbon nanotubes with a purity greater than 98%, and the diameter of CNTs is 30-80mm; the water reducer is a polycarboxylic acid water reducer; the fine aggregate in this embodiment is Class II fine aggregate, the fine aggregate is medium sand, and the fineness modulus of the fine aggregate is 2.5-3.0; the fine aggregate in this embodiment is Class II coarse aggregate, the coarse aggregate is one or more of crushed stone and river pebbles, and the particle size of the coarse aggregate is 5-30mm; the rubber particles are obtained by granulating waste rubber tires, and the particle size of the rubber particles is 1-5mm; the particle size of silica fume is 0.1-0.3μm.

[0030] Example 6 A method for preparing a novel CNTs-rubber concrete bridge deck paving material comprises the following steps: S1. Take 4 kg of water reducer and mix it evenly in 128 kg of water, then slowly add 2.75 kg of CNTs while stirring, and use ultrasonic dispersion for 20-30 minutes to obtain a CNTs suspension; S2, add 550kg cement, 800kg fine aggregate, 800kg coarse aggregate, 55kg rubber particles and 10kg silica fume into a concrete mixer, stir for 30-50s to obtain a base material; S3, adding the CNTs suspension prepared in step S1 to the base material prepared in step S2, stirring continuously for 30-50 seconds, then adding the remaining 12 kg of water, stirring continuously for 60-90 seconds, to obtain a slurry; S4, paving the slurry prepared in step S3 on the bridge deck, compacting and curing to form a concrete bridge deck paving material, the apparent density of the concrete bridge deck paving material is 2350kg / m 3 .

[0031] Among them, CNTs are multi-walled carbon nanotubes with a purity greater than 98%, and the diameter of CNTs is 30-80mm; the water reducer is a polycarboxylic acid water reducer; the fine aggregate in this embodiment is Class II fine aggregate, the fine aggregate is medium sand, and the fineness modulus of the fine aggregate is 2.5-3.0; the fine aggregate in this embodiment is Class II coarse aggregate, the coarse aggregate is one or more of crushed stone and river pebbles, and the particle size of the coarse aggregate is 5-30mm; the rubber particles are obtained by granulating waste rubber tires, and the particle size of the rubber particles is 1-5mm; the particle size of silica fume is 0.1-0.3μm.

[0032] Comparative Example 1 A method for preparing a novel CNTs-rubber concrete bridge deck paving material comprises the following steps: S1. Take 4 kg of water reducer and mix it evenly in 128 kg of water to obtain a mixed solution; S2, add 500kg cement, 800kg fine aggregate, 900kg coarse aggregate, 25kg rubber particles and 8kg silica fume into a concrete mixer, stir for 30-50s to obtain a base material; S3, adding the mixed solution obtained in step S1 to the base material obtained in step S2, stirring for 30-50 seconds, and then adding the remaining 12 kg of water, stirring for 60-90 seconds to obtain a slurry; S4, paving the slurry prepared in step S3 on the bridge deck, compacting and curing to form a concrete bridge deck paving material.

[0033] Among them, the water reducer is a polycarboxylic acid water reducer; the fine aggregate in this embodiment is Class II fine aggregate, the fine aggregate is medium sand, and the fineness modulus of the fine aggregate is 2.5-3.0; the fine aggregate in this embodiment is Class II coarse aggregate, the coarse aggregate is one or more of crushed stone and river pebbles, and the particle size of the coarse aggregate is 5-30mm; the rubber particles are obtained by granulating waste rubber tires, and the particle size of the rubber particles is 1-5mm; the particle size of silica fume is 0.1-0.3μm.

[0034] Comparative Example 2 A method for preparing a novel CNTs-rubber concrete bridge deck paving material comprises the following steps: S1. Take 4 kg of water reducer and mix it evenly in 128 kg of water to obtain a mixed solution; S2, add 500kg cement, 800kg fine aggregate, 900kg coarse aggregate, 50kg rubber particles and 8kg silica fume into a concrete mixer, stir for 30-50s to obtain a base material; S3, adding the mixed solution obtained in step S1 to the base material obtained in step S2, stirring for 30-50 seconds, and then adding the remaining 12 kg of water, stirring for 60-90 seconds to obtain a slurry; S4, paving the slurry prepared in step S3 on the bridge deck, compacting and curing to form a concrete bridge deck paving material.

[0035] Among them, the water reducer is a polycarboxylic acid water reducer; the fine aggregate in this embodiment is Class II fine aggregate, the fine aggregate is medium sand, and the fineness modulus of the fine aggregate is 2.5-3.0; the fine aggregate in this embodiment is Class II coarse aggregate, the coarse aggregate is one or more of crushed stone and river pebbles, and the particle size of the coarse aggregate is 5-30mm; the rubber particles are obtained by granulating waste rubber tires, and the particle size of the rubber particles is 1-5mm; the particle size of silica fume is 0.1-0.3μm.

[0036] Performance testing Concrete bridge deck paving materials were prepared and cured according to the methods of Examples 1-5 and Comparative Examples 1-2, respectively. According to the Standard for Test Methods for Physical and Mechanical Properties of Concrete (GB / T 50081-2019), performance tests were performed on concrete cured for 3d and 28d, respectively. The test results are shown in Table 1.

[0037]

[0038] From the test data in Table 1, it can be seen that the concrete bridge deck paving material prepared in this application after 28 days of curing has an optimal compressive strength of 56.7 MPa, an optimal flexural strength of 10.6 MPa, and a minimum resistivity of 6596.3 Ω•cm. The concrete bridge deck paving material prepared in Example 3 of this application exhibits good comprehensive performance.

[0039] Reference Figure 1 and Figure 2 It can be seen from the data of Example 3 and Comparative Examples 1-2 that since Comparative Example 1-2 does not add the CNTs in Example 3, Comparative Example 1 shows a poor result, indicating that CNTs-rubber concrete can improve the toughness, impact resistance and durability of bridge deck pavement concrete while ensuring strength, and CNTs can cooperate well with rubber concrete.

[0040] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A new type of CNTs-rubber concrete bridge deck paving material, characterized by: The raw material composition comprises the following parts by weight: 450-550 parts of cement, 800-900 parts of fine aggregate, 800-900 parts of coarse aggregate, 22.5-55 parts of rubber particles, 0-10 parts of silica fume, 0.45-2.75 parts of CNTs, 120-160 parts of water and 4-6 parts of water reducing agent.

2. A novel CNTs-rubber concrete bridge deck paving material according to claim 1, characterized in that: The CNTs are multi-walled carbon nanotubes; The diameter of the CNTs is 30-80 mm.

3. The novel CNTs-rubber concrete bridge deck paving material according to claim 1, characterized in that: The fine aggregate is medium sand; The fineness modulus of the fine aggregate is 2.5-3.

0.

4. The novel CNTs-rubber concrete bridge deck paving material according to claim 1, characterized in that: The coarse aggregate is one or more of crushed stone and river pebbles; The particle size of the coarse aggregate is 5-30 mm.

5. The novel CNTs-rubber concrete bridge deck paving material according to claim 1, characterized in that: The rubber particles are obtained by granulating waste rubber tires; The rubber particles have a particle size of 1-5 mm.

6. The novel CNTs-rubber concrete bridge deck paving material according to claim 1, characterized in that: The particle size of the silica fume is 0.1-0.3 μm.

7. The novel CNTs-rubber concrete bridge deck paving material according to claim 1, characterized in that: The water reducing agent is a polycarboxylic acid water reducing agent.

8. A method for preparing a novel CNTs-rubber concrete bridge deck paving material, characterized in that: The novel CNTs-rubber concrete bridge deck paving material as claimed in any one of claims 1 to 7 comprises the following preparation steps: S1. Evenly mix the water reducer with 4 / 5 of the total amount of water, then slowly add CNTs with stirring, and use ultrasonic dispersion for 20-30 minutes to obtain a CNTs suspension; S2. Add cement, fine aggregate, coarse aggregate, rubber particles and silica fume into a concrete mixer and stir for 30-50 seconds to obtain a base material; S3, adding the CNTs suspension prepared in step S1 to the base material prepared in step S2, stirring continuously for 30-50 seconds, and then adding the remaining water accounting for 1 / 5 of the total amount, stirring continuously for 60-90 seconds to obtain a slurry; S4, paving the slurry prepared in step S3 on the bridge deck, compacting and curing to form a concrete bridge deck paving material.

9. A method for preparing a novel CNTs-rubber concrete bridge deck paving material, characterized in that: The apparent density of the concrete bridge deck paving material in step S4 is 2300-2400 kg / m 3 .

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