A coral sand reinforcing material, a preparation method and application thereof
The polyurethane polymer chains formed by the reaction of polyols and isocyanates reinforce coral sand, solving the problem of coral sand's fragility, improving its seismic resistance and engineering stability, and enabling rapid maintenance and environmentally friendly construction.
Patent Information
- Application Number
- CN202510067077.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-16
- Publication Date
- 2025-11-25
- Estimated Expiration
- 2045-01-16
AI Technical Summary
When coral sand is used as an infrastructure material, it is easily broken and highly compressible, resulting in low foundation bearing capacity and high looseness, which poses safety hazards. Furthermore, existing reinforcement methods suffer from environmental sensitivity, technical complexity, or long maintenance time.
Using polyols and isocyanates as raw materials, a three-dimensional network structure of coral sand reinforcement material is formed through polyurethane reaction, which improves the internal structure and particle contact mode of coral sand, thereby enhancing its integrity and vibration resistance.
It significantly improves the dynamic shear modulus of coral sand with low polymer incorporation, shortens curing time, enhances seismic resistance, ensures the stability and service life of engineering facilities, and is also environmentally friendly and easy to construct.
Smart Images
Figure CN120004544B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of calcareous sand materials technology, specifically to a coral sand reinforcement material, its preparation method, and its application. Background Technology
[0002] Coral sand typically contains over 90% calcium, making it prone to breakage, with irregular particle shapes, high specific gravity, and numerous pores. This results in high compressibility and fragility in its engineering properties. When used as an infrastructure building material, coral sand is easily eroded by rainwater and waves, leading to low foundation bearing capacity, high looseness, and uneven foundation settlement, among other safety hazards that severely impact the usability of the infrastructure.
[0003] Currently, there are no unified standards for the treatment of coral sand foundations, and scholars both domestically and internationally have explored various reinforcement methods. Adhesive materials based on polymer compounds are increasingly widely used in various fields of modern industry, and in recent years have been widely used in the construction of water conservancy projects, bridges and tunnels, and rock support. Research on the mechanical properties of polymer-reinforced sand materials has also been carried out. Other studies have used microbial reinforcement, utilizing microorganisms to induce calcium carbonate precipitation to improve the mechanical properties of coral sand foundations; however, this method is environmentally sensitive and technically complex, making it difficult to promote widespread application. Other studies have used cement reinforcement, which can significantly improve the strength of the consolidated soil. However, cement-solidified sand requires a long curing time, and while increasing strength, it also increases the soil's stiffness and brittleness, making it prone to cracking under seismic loads. Therefore, how to use polymer compounds to reinforce coral sand to produce high-strength building materials is a problem that needs to be solved. Summary of the Invention
[0004] To overcome the problems existing in the prior art, one objective of this invention is to provide a coral sand reinforcement material. A second objective is to provide a method for preparing the aforementioned coral sand reinforcement material. A third objective is to provide applications of the aforementioned coral sand reinforcement material.
[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0006] The first aspect of the present invention provides a coral sand reinforcement material, comprising the following raw materials: 7-30 parts of polyol, 7-30 parts of isocyanate, and 1000 parts of coral sand.
[0007] The coral sand reinforcement material of the present invention uses polyol as white component and isocyanate as black component. The polyol contains multiple hydroxyl (-OH) functional groups. After the black and white components are mixed, polyurethane polymer chains are formed through the reaction between isocyanate groups and hydroxyl groups (called polyurethane reaction). These polymer chains intertwine to form a three-dimensional network structure, thereby obtaining the coral sand reinforcement material.
[0008] Preferably, it is prepared from the following raw materials: 20-30 parts of polyol, 20-30 parts of isocyanate alcohol, and 1000 parts of coral sand.
[0009] Preferably, the polyol is selected from at least one of ethylene glycol, glycerol, 1,4-butanediol, and pentaerythritol.
[0010] This invention utilizes structurally regular polyols to synthesize polyurethane adhesives, resulting in adhesives with strong crystallinity and high adhesive strength. Glycerol is further used as a raw material. The role of glycerol in the synthesis of polyurethane adhesives is as follows: 1. Polyol component: As a polyol component, glycerol can undergo condensation reactions with other reactants to generate polymer chains, thus forming the basic framework of the polyurethane adhesive; 2. Improved flexibility: The introduction of glycerol increases the flexibility of the polyurethane molecular chains, thereby improving the elasticity and tensile properties of the polyurethane adhesive; 3. Improved water solubility: As a hydrophilic group, glycerol increases the water solubility of the polyurethane adhesive, making it easier to disperse in water and improving its applicability in certain applications.
[0011] Preferably, the mass ratio of the polyol to the isocyanate is 1:(0.8-1.2).
[0012] Preferably, the coral sand has a particle size of less than 2 mm; and / or, the coral sand has a porosity of 0.655 to 1.554.
[0013] Preferably, the coral sand originates from the South China Sea.
[0014] The second aspect of the present invention provides a method for preparing the coral sand reinforcement material described in the first aspect, comprising the following steps: mixing polyol, isocyanate and coral sand to obtain a mixture, pouring it into a mold, and curing it to obtain the coral sand reinforcement material.
[0015] Preferably, the coral sand is washed and dried before mixing.
[0016] Preferably, the mixing step includes: first mixing isocyanate with coral sand, and then adding polyol to mix and obtain a mixture.
[0017] More preferably, the mixing time of the isocyanate and coral sand is 40 to 120 seconds.
[0018] More preferably, a polyol is added and mixed for 20–40 seconds.
[0019] Preferably, the specific process of pouring the mixture into the mold includes: filling the mold with the mixture using a layered compaction method.
[0020] Preferably, the curing time is 20 to 100 hours.
[0021] The third aspect of this invention provides the application of the coral sand reinforcement material described in the first aspect in the preparation of coral sand foundations.
[0022] Preferably, the coral sand reinforcement material is used in the preparation of coral sand-based artificial islands and reefs.
[0023] The beneficial effects of this invention are:
[0024] This invention provides a coral sand reinforcement material. The material uses polyol as the white component and isocyanate as the black component. The polyol contains multiple hydroxyl (-OH) functional groups. After mixing, the isocyanate groups react with the hydroxyl groups to form polyurethane polymer chains. These polymer chains intertwine to form a three-dimensional network structure, altering the internal structure and interparticle contact of the coral sand sample. This effectively improves the integrity of the coral sand sample and its ability to dissipate vibrational energy. With low polymer content, compared to coral sand reinforced without polymers, its dynamic shear modulus can reach 240 MPa, solving the problem of coral sand's fragility and ensuring the normal use and maintenance of island and reef engineering facilities under seismic loads. The polymer in the reinforced coral sand of this invention reacts faster than polymers containing combined polyethers and isocyanates. The coral sand sample reaches 90% strength after 24 hours of curing, and reaches its optimal state after 3 days of curing, which helps to shorten the curing time. Furthermore, the cohesion of the coral sand reinforcement material shows a good linear relationship with the curing time. Attached Figure Description
[0025] Figure 1 The preparation process of coral sand reinforcement materials;
[0026] Figure 2 A diagram of the mixer used in the preparation process;
[0027] Among them, 1 is the control console for setting the mixing program; 2 is the mixing chamber; 3 is the white material nozzle; 4 is the black material nozzle; and 5 is the mounting frame.
[0028] Figure 3 Results of strengthening the dynamic shear modulus of coral sand with different polymer incorporation amounts;
[0029] Figure 4 The results of reinforcing the damping ratio of coral sand with different polymer incorporation amounts. Detailed Implementation
[0030] The present invention will be further described in detail below through specific embodiments. Unless otherwise specified, the raw materials used in the following embodiments can be obtained from conventional commercial channels or prepared and isolated through simple synthesis; unless otherwise specified, the processes employed are conventional processes in the art.
[0031] The raw materials used in the following examples and comparative examples are as follows: Isocyanate was purchased from Shanghai Guangsheng Building Materials Co., Ltd., and is polymeric MD; Glycerin was purchased from the National Pharmaceutical Reagent Network, and the brand is Hushi.
[0032] Raw material processing: Coral sand from the South China Sea is washed and dried. The coral sand is then cooled to room temperature and placed in a vibrating screen to remove coral sand particles larger than 2 mm. The porosity of the coral sand varies from 0.655 to 1.554, and the specific gravity (Gs) of the coral sand is 2.81 tons / cubic meter.
[0033] Example 1
[0034] This embodiment provides a coral sand reinforcement material. The raw materials used, by weight, are: 7.5 parts white material, 7.5 parts black material, and 985 parts coral sand; wherein the black material is isocyanate, the white material is glycerol, and G... c The content is 1.5%; the preparation method and process of coral sand reinforcement material are as follows: Figure 1 The details are as follows:
[0035] S1. Add 985 parts of coral sand to the mixture as follows: Figure 2 In the mixer shown, first set the mixing time to 5 minutes to evenly distribute the coral sand of different particle sizes. Then, add 7.5 parts of white material through the side white material nozzle 3, and start the switch to make it fully mixed. The mixing time is 60 seconds to prepare a mixture of coral sand and white material. Then, add 7.5 parts of black material through the black material nozzle 4 and mix it fully to prepare a mixture. The mixing time is 30 seconds.
[0036] S2. The mixture is compacted in layers. The sample is divided into four layers, compacted and roughened, and then placed into a mold. The sample in the mold is cured for 3 days to obtain the coral sand reinforcement material.
[0037] Example 2
[0038] This embodiment provides a coral sand reinforcement material, the raw materials used being: 15 parts white material, 15 parts black material, and 970 parts coral sand by weight; wherein the black material is isocyanate, the white material is glycerol, and G... c The content is 3%; the preparation method and process of coral sand reinforcement material are as follows: Figure 1 The details are as follows:
[0039] S1. Add 970 parts of coral sand to the mixture as follows: Figure 2 In the mixer shown, first set the mixing time to 5 minutes to evenly distribute the coral sand of different particle sizes. Then add 15 parts of white material through the side white material nozzle 3, start the switch to make it fully mixed, and the mixing time is 60 seconds to prepare a mixture of coral sand and white material. Then add 15 parts of black material through the black material nozzle 4, and mix it fully to prepare a mixture, and the mixing time is 30 seconds.
[0040] S2. The mixture is compacted in layers. The sample is divided into four layers, compacted and roughened, and then placed into a mold. The sample in the mold is cured for 3 days to obtain the coral sand reinforcement material.
[0041] Example 3
[0042] This embodiment provides a coral sand reinforcement material. The raw materials used, by weight, are: 22.5 parts white material, 22.5 parts black material, and 955 parts coral sand; wherein the black material is isocyanate, the white material is glycerol, and G... c The content is 4.5%; the preparation method and process of coral sand reinforcement material are as follows: Figure 1 The details are as follows:
[0043] S1. Add 955 parts of coral sand to the mixture as follows: Figure 2 In the mixer shown, first set the mixing time to 5 minutes to evenly distribute the coral sand of various particle sizes. Then, add 22.5 parts of white material through the side white material nozzle 3, and start the switch to make it fully mixed. The mixing time is 60 seconds to prepare a mixture of coral sand and white material. Then, add 22.5 parts of black material through the black material nozzle 4 and mix it fully to prepare a mixture. The mixing time is 30 seconds.
[0044] S2. The mixture is compacted in layers. The sample is divided into four layers, compacted and roughened, and then placed into a mold. The sample in the mold is cured for 3 days to obtain the coral sand reinforcement material.
[0045] Comparative Example 1
[0046] Comparative Example 1 provides an unreinforced coral sand, the raw materials used being: 1000 parts coral sand, G c The content is 0%; the preparation method is as follows:
[0047] Coral sand is prepared by layered compaction. The sample is divided into four layers, each layer is compacted and roughened, and then placed into a mold. The sample in the mold is cured for 3 days to obtain the coral sand material.
[0048] Experimental Analysis
[0049] Test specimens were prepared using the coral sand reinforcement materials from Examples 1-3 and the material from Comparative Example 1. The dry density of the specimens was 1.5 g / cm³. 3The specimen was a cylinder with a diameter of 50 mm and a height of 100 mm, and a resonant column test was conducted under a consolidation pressure of 200 kPa.
[0050] Figure 3 The results of strengthening the dynamic shear modulus of coral sand with different polymer incorporation amounts were obtained by... Figure 3 It can be seen that the position of the shear modulus of different curves shifts upward with the increase of polymer content. When the polymer content increases from 0.0% to 1.5%, the increase in dynamic shear modulus is relatively small. As the content continues to increase, the growth rate of dynamic shear modulus increases significantly. The growth rate of dynamic shear modulus increases with the increase of polymer content. Under a confining pressure of 200 kPa, with the increase of polymer content (0.0%–4.5%), the dynamic shear modulus increased by 10, 40, and 80 MPa respectively compared with that of plain coral sand, thereby enhancing the ability to resist shear deformation. The stronger the ability to resist deformation under seismic action, the more stable the sample.
[0051] Figure 4 The results of strengthening the damping ratio of coral sand with different polymer incorporation amounts were obtained by... Figure 4 It can be seen that the damping ratio of solidified coral sand is higher than that of pure coral sand. In addition, the damping ratio of solidified coral sand increases with the increase of polymer content. The larger the damping ratio, the greater the maximum damping ratio in the range of 0.0% to 4.5% polymer content, the 200%, 280%, and 350% of the damping ratio of pure coral sand, respectively. Moreover, the faster the vibration decay rate of the sample, the more stable the sample.
[0052] In summary, this invention uses polyol as the white component. Polyol contains multiple hydroxyl (-OH) functional groups. After mixing the white and black components, polyurethane polymer chains are formed through the reaction between isocyanate groups and hydroxyl groups. These polymer chains intertwine to form a three-dimensional network structure, altering the internal structure and interparticle contact of the coral sand sample. This effectively improves the integrity of the coral sand sample and its ability to dissipate vibrational energy, solving the problem of coral sand's fragility and ensuring the normal use and maintenance of island and reef engineering facilities under seismic loads. Compared to polymers containing combined polyethers and isocyanates, the polymer in the reinforced coral sand of this invention reacts faster. The coral sand sample reaches 90% strength within 24 hours of curing, and reaches its optimal state after 3 days of curing, which helps to shorten the curing time. Furthermore, the cohesive force of the coral sand reinforcement material shows a good linear relationship with the curing time. In addition, the preparation method of this invention only requires sand and polymers, without the need for water mixing, making construction convenient and the reaction rate fast, meeting the efficiency and cost requirements of engineering projects. Simultaneously, the material is environmentally friendly, reducing pollution and damage to the marine ecosystem.
[0053] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.
Claims
1. A coral sand reinforcement material, characterized in that, The preparation raw materials include the following parts by weight: 7-24 parts of polyol, 7-24 parts of isocyanate, and 1000 parts of coral sand; The polyol is selected from at least one of ethylene glycol, glycerol, 1,4-butanediol, and pentaerythritol; The mass ratio of the polyol to the isocyanate is 1:(0.8-1.2).
2. The coral sand reinforcement material according to claim 1, characterized in that, The coral sand has a particle size of less than 2 mm; and / or, the coral sand has a porosity of 0.655 to 1.
554.
3. The method for preparing the coral sand reinforcement material according to any one of claims 1-2, characterized in that, The process includes the following steps: mixing polyol, isocyanate, and coral sand to obtain a mixture, pouring it into a mold, and curing it to obtain a coral sand reinforcement material.
4. The method for preparing the coral sand reinforcement material according to claim 3, characterized in that, The mixing steps include: first mixing isocyanate with coral sand, then adding polyol to mix and obtain a mixture.
5. The method for preparing the coral sand reinforcement material according to claim 4, characterized in that, The isocyanate is mixed with coral sand for 40-120 s; and / or, a polyol is added for mixing for 20-40 s.
6. The method for preparing the coral sand reinforcement material according to claim 3, characterized in that, The specific process of pouring the mixture into the mold includes: filling the mold with the mixture using a layered compaction method.
7. The method for preparing the coral sand reinforcement material according to claim 3, characterized in that, The curing time is 20~100 hours.
8. The application of the coral sand reinforcement material according to any one of claims 1-2 in the preparation of coral sand foundations.