Rubber concrete with high splitting tensile strength and preparation method and application thereof
By optimizing the coarse aggregate composition of rubber concrete and replacing natural crushed stone with rubber particles of specific size and content, the problem of low splitting tensile strength of rubber concrete was solved, and rubber concrete with high splitting tensile strength was prepared, thus enhancing its application potential in load-bearing structures.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DONGGUAN UNIV OF TECH
- Filing Date
- 2026-01-08
- Publication Date
- 2026-05-01
AI Technical Summary
The splitting tensile strength of existing rubber concrete is lower than that of ordinary concrete, and it decreases with the increase of rubber particle replacement rate, which limits its application in load-bearing structures.
By optimizing the composition of coarse aggregate, introducing rubber particles of specific size and content to replace natural crushed stone, and using an equal volume replacement method, rubber concrete is prepared to enhance its tensile strength.
It significantly improves the splitting tensile strength of rubber concrete, giving it greater durability in load-bearing structures.
Smart Images
Figure CN121948899A_ABST
Abstract
Description
A rubber concrete with high splitting tensile strength, its preparation method and application Technical Field
[0001] This invention relates to the field of building materials technology, and in particular to a rubber concrete with high splitting tensile strength, its preparation method, and its application. Background Technology
[0002] Rubber concrete has attracted widespread attention due to its excellent toughness and energy dissipation capacity. However, its low elastic modulus and hydrophobic surface tend to lead to an increase in internal porosity and the number of interfacial transition zones. Therefore, the mechanical properties of rubber concrete prepared in existing studies are significantly lower than those of ordinary concrete.
[0003] Although existing research has taken many measures to optimize the mechanical properties of rubber concrete, such as using surface pretreatment technology to improve the hydrophobicity of rubber particles, improving the substitution method of rubber particles for natural aggregates, and optimizing the internal packing of particles to propose rubber concrete mix proportions with high packing density, these methods can only reduce the loss rate of static mechanical strength and have not produced rubber concrete mix proportions with higher mechanical properties than ordinary concrete. Especially regarding splitting tensile strength, due to the high brittleness of concrete, its tensile strength is often lower and its toughness is poor. Due to the inherent characteristics of rubber particles, the elastic modulus of existing rubber concrete is only one-tenth that of natural aggregates. The hydrophobic surface easily increases the interfacial transition zone between mortar and rubber particles, resulting in a lower splitting tensile strength than ordinary concrete. The strength (including splitting tensile strength) of fine rubber aggregate concrete prepared by partially replacing natural river sand with fine-particle rubber aggregate is significantly lower than that of ordinary concrete. Rubber concrete has not yet been applied to major load-bearing structures. Furthermore, with the increase of the rubber particle substitution rate, the strength will show a further downward trend.
[0004] Therefore, improving the splitting tensile strength of concrete is of great significance for improving the durability of concrete structures. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a rubber concrete with high splitting tensile strength, its preparation method and application.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: Firstly, the present invention provides a rubber concrete with high splitting tensile strength, comprising cementitious materials, fine aggregate, coarse aggregate, water, and a water-reducing agent; the coarse aggregate is composed of rubber particles and natural crushed stone; the particle size range of the coarse aggregate is 4.75-19 mm; the volume ratio of coarse aggregate with a particle size range of 4.75-9.6 mm to coarse aggregate with a particle size range of 9.6-19 mm (assuming consistent density, equal volume replacement is used during replacement to maintain a consistent volume ratio before and after replacement) is 37:63; the rubber particles have a particle size range of 4.75-9.6 mm and / or 9.6-19 mm, with the volume content of rubber particles with a particle size range of 4.75-9.6 mm being 0-2.5% of the total volume of the coarse aggregate, and the volume content of rubber particles with a particle size range of 9.6-19 mm being 2.5%-5% of the total volume of the coarse aggregate.
[0007] This invention provides a rubber concrete with high splitting tensile strength. By optimizing the particle packing inside the concrete, coarse rubber aggregate is introduced to act as a "fiber," thereby enhancing the tensile strength of the concrete. Natural crushed stone is replaced with rubber particles in an equal particle size and volume replacement manner. For example, 4.75-9.6mm rubber particles are used to replace the 4.75-9.6mm portion of granite crushed stone by volume. This replacement method minimizes the impact of the rubber particles on the porosity of the concrete, maintains a high packing density, and also helps to utilize the load-bearing capacity of the coarse rubber particles.
[0008] This invention has found that by replacing natural crushed stone with rubber particles of a specific size at a specific volume ratio (i.e., a specific replacement rate), rubber concrete with higher splitting tensile strength can be obtained. Specifically, by replacing natural crushed stone with rubber particles of a size range of 4.75-9.6 mm and / or 9.6-19 mm, the volume replacement rate for the 4.75-9.6 mm particles is 2.5%, and for the 9.6-19 mm particles, it is 2.5%; or the volume replacement rate for the 9.6-19 mm particles is 5%, the prepared rubber concrete exhibits higher splitting tensile strength.
[0009] In a preferred embodiment of the rubber concrete of the present invention, the rubber particles are prepared from waste tires after cutting and screening.
[0010] The waste tires used to prepare the rubber granules in this invention are mainly truck tires and van tires, with an apparent density of 1.1 g / cm³. 3The method for preparing the rubber granules is as follows: remove the reinforcing steel bars inside the waste tires, then cut the waste tires to obtain waste tire blocks, and continue to cut them into granules, sieve, wash, dry, and sieve out the regular-shaped particles to obtain rubber granules with particle sizes of 4.75-9.6 mm or 9.6-19 mm respectively.
[0011] Both the cutting and granulation processes need to ensure sufficient randomness to avoid producing rubber granules with regular shapes. They should be kept angular and avoid forming typical granules such as circles and squares. After drying, regular-shaped granules, such as spheres, cuboids, and cubes, are manually sieved out.
[0012] In a preferred embodiment of the rubber concrete of the present invention, the rubber particles in the coarse aggregate have a particle size range of 4.75-9.6 mm and 9.6-19 mm. The volume content of rubber particles with a particle size range of 4.75-9.6 mm is 2.5% of the total volume of the coarse aggregate, and the volume content of rubber particles with a particle size range of 9.6-19 mm is 2.5% of the total volume of the coarse aggregate. The concrete corresponding to this specific particle size and specific content of coarse aggregate has a higher splitting tensile strength.
[0013] In a preferred embodiment of the rubber concrete of the present invention, the rubber particles in the coarse aggregate have a particle size range of 9.6-19 mm; the volume content of rubber particles with a particle size range of 9.6-19 mm is 5% of the total volume of the coarse aggregate. The concrete corresponding to this specific particle size and specific content of coarse aggregate has the highest splitting tensile strength.
[0014] In a preferred embodiment of the rubber concrete of the present invention, the rubber concrete comprises the following components in parts by weight: 529.46 parts of cementitious material, 651.24 parts of fine aggregate, 1053.64~1063.54 parts of coarse aggregate, 158.84 parts of water, and 3.18 parts of water-reducing agent. The rubber concrete prepared by the mix proportion proposed in this invention exhibits a significantly higher splitting tensile strength than ordinary concrete.
[0015] As a preferred embodiment of the rubber concrete of the present invention, the rubber concrete comprises the following components in parts by weight: 529.46 parts of cementitious material, 651.24 parts of fine aggregate, 1063.54 parts of coarse aggregate, 158.84 parts of water and 3.18 parts of water-reducing agent.
[0016] As a preferred embodiment of the rubber concrete of the present invention, the rubber concrete comprises the following components in parts by weight: 529.46 parts of cementitious material, 651.24 parts of fine aggregate, 0-11.22 parts of rubber particles with a particle size range of 4.74-9.6 mm, 11.22-22.44 parts of rubber particles with a particle size range of 9.6 mm-19 mm, 385.4-412.5 parts of natural crushed stone with a particle size range of 4.74-9.6 mm, 628.6-645.8 parts of natural crushed stone with a particle size range of 9.6 mm-19 mm, 158.84 parts of water, and 3.18 parts of water-reducing agent.
[0017] As a preferred embodiment of the rubber concrete of the present invention, the rubber concrete comprises the following components in parts by weight: 529.46 parts of cementitious material, 651.24 parts of fine aggregate, 11.22 parts of rubber particles with a particle size range of 4.74-9.6 mm, 11.22 parts of rubber particles with a particle size range of 9.6 mm-19 mm, 385.4 parts of natural crushed stone with a particle size range of 4.74-9.6 mm, 645.8 parts of natural crushed stone with a particle size range of 9.6 mm-19 mm, 158.84 parts of water, and 3.18 parts of water-reducing agent.
[0018] As a preferred embodiment of the rubber concrete of the present invention, the rubber concrete comprises the following components in parts by weight: 529.46 parts of cementitious material, 651.24 parts of fine aggregate, 22.44 parts of rubber particles with a particle size range of 9.6mm-19mm, 412.5 parts of natural crushed stone with a particle size range of 4.74-9.6mm, 628.6 parts of natural crushed stone with a particle size range of 9.6mm-19mm, 158.84 parts of water, and 3.18 parts of water-reducing agent.
[0019] In a preferred embodiment of the rubber concrete of the present invention, the cementitious material is PO 42.5 grade ordinary Portland cement; the fine aggregate is natural river sand; and the water-reducing agent is polycarboxylate water-reducing agent.
[0020] In a preferred embodiment of the rubber concrete of the present invention, the particle size range of the natural river sand is 0~4.75mm; the water-reducing agent is a polycarboxylate high-efficiency water-reducing agent.
[0021] Secondly, the present invention provides a method for preparing the above-mentioned rubber concrete, comprising the following steps: S1, thoroughly mixing fine aggregate, coarse aggregate and half of the water to ensure uniform mixing between each particle, so that each aggregate surface is coated with a water film to obtain an aggregate mixture; S2, mixing the aggregate mixture obtained in step S1 with the cementitious material, and then adding the other half of the water and water-reducing agent while stirring, and mixing thoroughly to obtain suitable rheological properties of the concrete to obtain rubber concrete.
[0022] Thirdly, the present invention provides the application of the above-mentioned rubber concrete as a building material.
[0023] Compared with existing technologies, the beneficial effects of this invention are as follows: The rubber concrete of this invention does not undergo complex modification treatments; it achieves high splitting tensile strength simply by optimizing the particle size range of rubber particles in the coarse aggregate. This solves the problem that existing concrete with added rubber particles has significantly lower splitting tensile strength than ordinary concrete, resulting in poor durability of the concrete structure under long-term loads, thus providing a new option for high-strength rubber concrete. Attached Figure Description
[0024] Figure 1 is a cross-sectional view of the rubber concrete of Example 1 after hardening according to the present invention, after the splitting tensile strength test, wherein the black particles are rubber particles; Figure 2 is a cross-sectional view of the rubber concrete of Example 2 after hardening according to the present invention, after the splitting tensile strength test, wherein the black particles are rubber particles; Figure 3 is a cross-sectional view of the rubber concrete of Comparative Example 1 after hardening according to the present invention, after the splitting tensile strength test, wherein the black particles are rubber particles; Figure 4 is a cross-sectional view of the rubber concrete of Comparative Example 11 after hardening according to the present invention, after the splitting tensile strength test. Detailed Implementation
[0025] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.
[0026] Unless otherwise specified, all other materials and reagents used in the examples are commercially available.
[0027] Examples 1-2 and Comparative Examples 1-11 describe a rubber concrete with high splitting tensile strength, comprising cementitious materials, fine aggregate, coarse aggregate, water, and a water-reducing agent; the coarse aggregate is composed of rubber particles and natural crushed stone, and the particle size range of the coarse aggregate is 4.75~19mm; the volume ratio of coarse aggregate with a particle size range of 4.75-9.6mm to coarse aggregate with a particle size range of 9.6-19mm is 37:63; the rubber particles have a particle size range of 4.75-9.6mm and / or 9.6-19mm, with the volume content of rubber particles with a particle size range of 4.75-9.6mm being 0~2.5% of the total volume of the coarse aggregate, and the volume content of rubber particles with a particle size range of 9.6-19mm being 2.5%~5% of the total volume of the coarse aggregate.
[0028] The cementitious material is PO 42.5 grade ordinary Portland cement; the fine aggregate is natural river sand with a particle size range of 0~4.75mm; and the water-reducing agent is polycarboxylate water-reducing agent.
[0029] The rubber granules are prepared from waste tires through cutting and sieving, with a particle size range of 4.75~19mm. The waste tires used to prepare the rubber granules are mainly truck tires and van tires, with an apparent density of 1.06. The preparation method of the rubber granules is as follows: the reinforcing steel bars inside the waste tires are removed, and then the waste tires are cut to obtain waste tire blocks, which are further cut into granules, sieved, washed, dried, and regular-shaped particles are removed, resulting in rubber granules with a particle size range of 4.75-9.6mm or 9.6mm-19mm.
[0030] Both the cutting and granulation processes need to ensure sufficient randomness to avoid producing rubber granules with regular shapes. They should be kept angular and avoid forming typical granules such as circles and squares. After drying, regular-shaped granules, such as spheres, cuboids, and cubes, are manually sieved out.
[0031] The amount of rubber granules added is converted into a replacement rate. The replacement rate is calculated based on the volume of the rubber granules, which is the percentage of the volume of the rubber granules to the total volume of the coarse aggregate.
[0032] The method for preparing rubber concrete includes the following steps: S1, fine aggregate (natural river sand), coarse aggregate (granite crushed stone, rubber granules) and half of the water are put into a forced mixer and thoroughly mixed to ensure that the particles are evenly mixed and that each aggregate is coated with a water film to obtain an aggregate mixture; S2, the aggregate mixture obtained in step S1 is mixed with cementitious material (ordinary Portland cement), and then the other half of the water and water-reducing agent are added while stirring, and thoroughly mixed to give the concrete suitable rheological properties, thus obtaining rubber concrete.
[0033] The composition and content of the rubber concrete in the examples and comparative examples are shown in Table 1. The total volume of coarse aggregate in the examples and comparative examples is the same. Table 1 The test examples tested the splitting tensile strength of the hardened rubber concrete in the embodiment and the comparative example.
[0034] The well-mixed rubber concrete was poured into a plastic mold and vibrated to ensure it filled the mold completely. After the concrete hardened for one day, it was demolded and placed in a curing room for further curing. After 28 days of curing, the splitting tensile strength of different types of rubber concrete was tested according to the test method for splitting tensile strength in the "GBT 50081-2019 Standard for Test Methods of Physical and Mechanical Properties of Concrete".
[0035] The splitting tensile strength of the rubber concrete in Examples 1-4 was 6.19-6.38 MPa, which was significantly higher than that of the ordinary concrete and rubber concrete in the comparative examples. Figure 1 shows the cross-sectional view of the hardened rubber concrete of Example 1 after the splitting tensile strength test, where the black particles are rubber particles; Figure 2 shows the cross-sectional view of the hardened rubber concrete of Example 2 after the splitting tensile strength test, where the black particles are rubber particles; Figure 3 shows the cross-sectional view of the hardened rubber concrete of Comparative Example 1 after the splitting tensile strength test, where the black particles are rubber particles; and Figure 4 shows the cross-sectional view of the hardened ordinary concrete of Comparative Example 11 after the splitting tensile strength test.
[0036] The splitting tensile strength test results of rubber concrete in Examples 1-2 and Comparative Examples 1-11 are shown in Table 2. The results in Table 2 show that the splitting tensile strength of the rubber concrete in the example is higher than that in the comparative example, and Example 1 has a higher splitting tensile strength.
[0037] As shown in Comparative Examples 1-10, the changes in rubber particle replacement rate and particle size have a significant impact on the splitting tensile strength value.
[0038] As can be seen from Example 1 and the comparative example, replacing natural crushed stone of a corresponding particle size in coarse aggregate with modified rubber of a specific particle size at a specific substitution rate can improve the splitting tensile strength of rubber concrete.
[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.
Claims
1. A rubber concrete with high splitting tensile strength, characterized in that, The mixture includes cementitious materials, fine aggregate, coarse aggregate, water, and a water-reducing agent; the coarse aggregate is composed of rubber particles and natural crushed stone; the particle size range of the coarse aggregate is 4.75-19 mm; the volume ratio of coarse aggregate with a particle size range of 4.75-9.6 mm to coarse aggregate with a particle size range of 9.6-19 mm is 37:63; the rubber particles have a particle size range of 4.75-9.6 mm and / or 9.6-19 mm, with the volume content of rubber particles with a particle size range of 4.75-9.6 mm being 0-2.5% of the total volume of the coarse aggregate, and the volume content of rubber particles with a particle size range of 9.6-19 mm being 2.5%-5% of the total volume of the coarse aggregate.
2. The rubber concrete as described in claim 1, characterized in that, In the coarse aggregate, the rubber particles have a particle size range of 4.75-9.6 mm and 9.6-19 mm. The volume content of rubber particles with a particle size range of 4.75-9.6 mm is 2.5% of the total volume of the coarse aggregate, and the volume content of rubber particles with a particle size range of 9.6-19 mm is 2.5% of the total volume of the coarse aggregate.
3. The rubber concrete as described in claim 1, characterized in that, In the coarse aggregate, the rubber particles have a particle size range of 9.6-19 mm; the volume content of rubber particles with a particle size range of 9.6-19 mm is 5% of the total volume of the coarse aggregate.
4. The rubber concrete as described in claim 1, characterized in that, The rubber concrete comprises the following components in parts by weight: 529.46 parts of cementitious material, 651.24 parts of fine aggregate, 1053.64~1063.54 parts of coarse aggregate, 158.84 parts of water, and 3.18 parts of water-reducing agent.
5. The rubber concrete as described in claim 4, characterized in that, The rubber concrete comprises the following components in parts by weight: 529.46 parts of cementitious material, 651.24 parts of fine aggregate, 0-11.22 parts of rubber particles with a particle size range of 4.74-9.6 mm, 11.22-22.44 parts of rubber particles with a particle size range of 9.6 mm-19 mm, 385.4-412.5 parts of natural crushed stone with a particle size range of 4.74-9.6 mm, 628.6-645.8 parts of natural crushed stone with a particle size range of 9.6 mm-19 mm, 158.84 parts of water, and 3.18 parts of water-reducing agent.
6. The rubber concrete according to any one of claims 1 to 5, characterized in that, The rubber granules are prepared from waste tires after cutting and screening; and / or, the cementitious material is PO 42.5 grade ordinary silicate cement; and / or, the fine aggregate is natural river sand; and / or, the water-reducing agent is polycarboxylate water-reducing agent.
7. The rubber concrete as described in claim 6, characterized in that, The particle size range of the natural river sand is 0~4.75mm; and / or, the water-reducing agent is a polycarboxylate superplasticizer.
8. The method for preparing rubber concrete according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Thoroughly mix the fine aggregate, coarse aggregate, and half of the water to obtain an aggregate mixture; S2. Mix the aggregate mixture obtained in step S1 with the cementitious material, and then add the other half of the water and water-reducing agent while stirring, and mix thoroughly to obtain rubber concrete.
9. The use of the rubber concrete according to any one of claims 1 to 7 as a building material.