High-freezing-resistance super-hydrophobic rubber concrete and preparation method thereof

Abstract

The invention discloses high-freezing-resistance super-hydrophobic rubber concrete and a preparation method thereof, and belongs to the technical field of building materials, and the high-freezing-resistance super-hydrophobic rubber concrete is prepared from the following raw material components in parts by weight: 190-210 parts of water, 380-420 parts of cement, 1050-1150 parts of stone, 650-695 parts of sand, 28-32 parts of rubber particles, 19-21 parts of nano silicon dioxide and 65-70 parts of polydimethylsiloxane. The high-freezing-resistance super-hydrophobic rubber concrete provided by the invention has excellent freezing resistance and durability, and the healthy service life of a concrete structure building in a cold region can be remarkably prolonged.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and particularly relates to a highly frost-resistant super-hydrophobic rubber concrete and a preparation method thereof. Background Art

[0002] Because the concrete surface is porous and hydrophilic, water and salt easily penetrate the interior of the concrete. This, in cold climates, can easily lead to freeze-thaw damage. According to the hydrostatic and osmotic pressure theories of freeze-thaw degradation, during the freezing process, water in the large pores of concrete transforms into ice and expands in volume. This forces unfrozen water to migrate to smaller pores, generating hydrostatic pressure and causing the development of primary cracks in the concrete. Furthermore, this increases the concentration of the solution within the pores, creating a concentration difference between large and small pores. This causes water to migrate from small to large pores, generating osmotic pressure and causing cracks and damage in the concrete. Therefore, improving the anti-seepage properties of concrete can improve its frost resistance.

[0003] At present, the anti-seepage measures for concrete include: adding dense fillers, traditional sealing coatings, and super-hydrophobic coatings. By adding dense fillers, the density of concrete can be increased, the porosity can be reduced, and the concrete has high impermeability, but the workability is poor and it is not easy to construct. Traditional sealing coatings form a dense protective film on the surface of concrete by brushing or spraying, isolating the concrete from external moisture. This method has a significant waterproof effect, but the bonding interface between the coating material and the concrete does not have the ability to resist freezing, and a "double skin" is easily formed after freezing and thawing. The super-hydrophobic coating method uses silanes and siloxanes with low surface energy as the main materials, and forms a highly hydrophobic concrete surface layer through surface coating or internal mixing, which can effectively improve the frost resistance and impermeability of concrete. Among them, the bonding performance of the hydrophobic coating of the coating method with concrete is poor (same as traditional sealing coatings), while the bonding strength of the internal mixing method (cement-based super-hydrophobic coating) is higher, becoming a research hotspot at home and abroad in recent years.

[0004] Preventing external water from seeping into concrete to improve its frost resistance is only a temporary solution. Existing moisture within concrete can still cause freeze-thaw damage in cold climates. Therefore, improving concrete's inherent frost resistance is the fundamental solution. Studies have shown that incorporating rubber particles into ordinary concrete (i.e., rubberized concrete) can effectively improve its frost resistance and enhance its workability. Freeze-thaw tests conducted according to the "Testing Procedures for Hydraulic Concrete" at equivalent compressive strength show that rubberized concrete can withstand two to three times as many freeze-thaw cycles as ordinary concrete, and maintains its integrity when the freeze-thaw cycle test is stopped (while ordinary concrete tends to break down). This is primarily due to the rubber particles acting as "elastic centers," effectively alleviating stress concentration within the concrete and providing deformation space for the volume expansion caused by frozen water. This significantly reduces the occurrence and development of cracks, thereby minimizing frost heave damage in concrete. Summary of the Invention

[0005] The present invention provides a highly frost-resistant super-hydrophobic rubber concrete and a preparation method thereof. The coating has the characteristics of super-hydrophobicity, high impermeability, high frost resistance, and being green and environmentally friendly. It can effectively protect concrete, greatly reduce freeze-thaw damage, and significantly extend the healthy service life of concrete structure buildings in cold regions.

[0006] Based on the above purpose, the technical solution adopted by the present invention is as follows: A highly frost-resistant super-hydrophobic rubber concrete is prepared from the following raw material components in parts by weight: 190-210 parts of water, 380-420 parts of cement, 1050-1150 parts of gravel, 650-695 parts of sand, 28-32 parts of rubber particles, 19-21 parts of nano-silicon dioxide, and 65-70 parts of polydimethylsiloxane.

[0007] Specifically, it is made from the following raw material components in parts by weight: 200 parts of water, 400 parts of cement, 1100 parts of gravel, 665 parts of sand, 30 parts of rubber particles, 20 parts of nano-silicon dioxide, and 67 parts of polydimethylsiloxane.

[0008] Wherein, the sand is river sand with a fineness modulus of 3.0~3.2.

[0009] Among them, the rubber particles are made by crushing the outer rubber of waste automobile tires, and the particle size is 60 mesh to 80 mesh.

[0010] Among them, nano-silica is hydrophilic, spherical particles with a diameter of 17~40nm.

[0011] The preparation method of the above-mentioned highly frost-resistant super-hydrophobic rubber concrete is as follows: first, gravel, sand, rubber particles, cement, and nano-silica are taken in proportion and added to a mixing container and stirred evenly; then, water is added while stirring and the stirring is continued; finally, polydimethylsiloxane is added and stirred evenly.

[0012] The present invention provides a novel super-hydrophobic rubber concrete, wherein: (1) rubber particles provide deformation space for volume expansion caused by water freezing, effectively alleviating stress concentration within the concrete, significantly reducing the occurrence and development of cracks, and thus reducing frost heave damage to the concrete; (2) nano-silica can fill micropores in the concrete, improve the pore structure, and enhance the concrete's impermeability; and (3) polydimethylsiloxane can enhance the hydrophobicity of the concrete surface and internal pore walls, thereby reducing capillary water absorption by the concrete and improving the rubber concrete's impermeability. The present invention can effectively protect concrete and significantly reduce freeze-thaw damage, thereby significantly extending the healthy service life of concrete structures in cold regions.

[0013] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention provides a highly frost-resistant superhydrophobic rubber concrete having the characteristics of high impermeability and high frost resistance.

[0014] (2) The present invention provides a highly frost-resistant super-hydrophobic rubber concrete having the characteristic of super-hydrophobicity.

[0015] (3) The present invention provides a highly frost-resistant super-hydrophobic rubber concrete that is green and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The water absorption rate comparison results of the embodiment and the comparative example are shown in FIG. DETAILED DESCRIPTION

[0017] The present invention is further described below by way of examples.

[0018] Example 1: This embodiment provides a highly frost-resistant super-hydrophobic rubber concrete, which is made of the following raw material components in parts by weight: 200 parts of water, 400 parts of cement, 1100 parts of gravel, 665 parts of sand, 30 parts of rubber particles, 20 parts of nano-silicon dioxide, and 67 parts of polydimethylsiloxane.

[0019] The highly frost-resistant, super-hydrophobic rubber concrete described in this example was prepared by first adding 1100 parts gravel, 665 parts sand, 30 parts rubber particles, 400 parts cement, and 20 parts nano-silica to a mixing vessel and stirring evenly. Then, 200 parts water was added while stirring and continued to stir evenly. Finally, 67 parts polydimethylsiloxane was added and stirred evenly. The mixture was poured into a 150 mm x 150 mm x 150 mm test mold. After one day, the mold was removed to produce a cubic mortar specimen, which was then cured under standard conditions (temperature 20 ± 3°C, humidity > 99%) for 28 days.

[0020] Comparative Example 1: This comparative example provides an ordinary cement concrete, which is made from the following raw material components in parts by weight: 200 parts of water, 400 parts of cement, 1100 parts of gravel, and 700 parts of sand.

[0021] The ordinary cement concrete described in this comparative example was prepared by first adding 1100 parts gravel, 700 parts sand, and 400 parts cement to a mixing vessel and mixing them uniformly. Then, 200 parts water was added while stirring and continued to mix uniformly. The mixture was poured into a 150 mm x 150 mm x 150 mm test mold. After one day, the mold was removed to produce a cubic mortar specimen, which was then cured under standard conditions (temperature 20 ± 3°C, humidity > 99%) for 28 days.

[0022] Comparative Example 2: This comparative example provides a rubber concrete, which is made from the following raw material components in parts by weight: 200 parts of water, 400 parts of cement, 1100 parts of gravel, 665 parts of sand, and 30 parts of rubber particles.

[0023] The rubberized concrete described in this comparative example was prepared by first adding 1100 parts gravel, 665 parts sand, 30 parts rubber granules, and 400 parts cement to a mixing vessel and mixing them uniformly. Then, 200 parts water was added while stirring, and mixing continued. The mixture was poured into a 150 mm x 150 mm x 150 mm test mold. After one day, the mold was removed to produce a cubic mortar specimen, which was then cured under standard conditions (temperature 20 ± 3°C, humidity > 99%) for 28 days.

[0024] Comparative Example 3: This comparative example provides a super-hydrophobic rubber concrete, which is made from the following raw material components in parts by weight: 200 parts of water, 400 parts of cement, 1100 parts of gravel, 665 parts of sand, 30 parts of rubber particles, and 67 parts of polydimethylsiloxane.

[0025] The superhydrophobic rubber concrete described in this comparative example was prepared by first adding 1100 parts gravel, 665 parts sand, 30 parts rubber particles, and 400 parts cement to a mixing vessel and stirring thoroughly. Then, 200 parts water was added while stirring and continued to stir thoroughly. Finally, 67 parts polydimethylsiloxane was added and stirred thoroughly. The mixture was poured into a 150 mm x 150 mm x 150 mm test mold. After one day, the mold was removed to produce a cubic mortar specimen, which was then cured under standard conditions (temperature 20 ± 3°C, humidity > 99%) for 28 days.

[0026] Performance testing: The concrete prepared in Examples 1, 2, 3 and Comparative Example 1 were subjected to the following performance tests, including: (1) Contact angle test: The contact angle of the coating is tested using a contact angle meter of model KRUSS DSA100. The larger the contact angle, the stronger the hydrophobicity and the better the anti-seepage ability.

[0027] The contact angle results are shown in Table 1 below: Table 1 Contact angle comparison As can be seen from Table 1, the contact angle of the highly frost-resistant super-hydrophobic rubber concrete of the present invention is increased by 172.9% compared with ordinary cement concrete and rubber concrete.

[0028] (2) Water absorption rate: The test is carried out in accordance with the test method of "Standard for Test Methods of Basic Properties of Building Mortar" (JGJ / T70-2009). The lower the water absorption rate, the better the anti-seepage ability.

[0029] The water absorption test results are as follows: Figure 1 As shown, from Figure 1 It can be seen that the high frost resistance super-hydrophobic rubber concrete of the present invention absorbs the least water, which is close to that of super-hydrophobic rubber concrete and much less than that of ordinary cement concrete and rubber concrete.

[0030] (2) Compressive strength after 100 freeze-thaw cycles: The test was carried out in accordance with the test method of "Test Procedure for Hydraulic Concrete" (SL / T352-2020).

[0031] The test results of the compressive strength loss rate after freeze-thaw are shown in Table 2 below: Table 2 Comparison of compressive strength loss rate after 100 freeze-thaw cycles As can be seen from Table 2, the high frost resistance and super-hydrophobic rubber concrete modified by the present invention has the smallest compressive strength loss after 100 freeze-thaw cycles, while the ordinary cement concrete has the largest compressive strength loss after 100 freeze-thaw cycles, followed by rubber concrete and super-hydrophobic rubber concrete. This shows that the high frost resistance and super-hydrophobic rubber concrete has the best frost resistance performance, which is much greater than that of ordinary cement concrete.

Claims

1. A highly frost-resistant super-hydrophobic rubber concrete, characterized by: The invention is prepared from the following raw material components in parts by weight: 190-210 parts of water, 380-420 parts of cement, 1050-1150 parts of gravel, 650-695 parts of sand, 28-32 parts of rubber particles, 19-21 parts of nano silicon dioxide and 65-70 parts of polydimethylsiloxane.

2. The highly frost-resistant super-hydrophobic rubber concrete according to claim 1, wherein: 200 parts of water, 400 parts of cement, 1100 parts of gravel, 665 parts of sand, 30 parts of rubber particles, 20 parts of nano-silicon dioxide, and 67 parts of polydimethylsiloxane.

3. The highly frost-resistant super-hydrophobic rubber concrete according to claim 1, wherein: The sand is river sand with a fineness modulus of 3.0~3.

2.

4. The highly frost-resistant super-hydrophobic rubber concrete according to claim 1, wherein: The rubber particles are made by crushing the rubber of waste automobile tires, with a particle size of 60-80 mesh.

5. The highly frost-resistant super-hydrophobic rubber concrete according to claim 1, wherein: Nano-silica is hydrophilic, spherical particles with a diameter of 17~40nm.

6. The method for preparing the highly frost-resistant super-hydrophobic rubber concrete according to any one of claims 1 to 5, wherein: The process is as follows: first, add gravel, sand, rubber particles, cement, and nano-silica into a mixing container in proportion and mix evenly; then, add water while stirring and continue to stir evenly; finally, add polydimethylsiloxane and stir evenly.

Images