Organic matrix effectiveness prediction method suitable for biomimetic mineralized cementing agent and application

Abstract

The invention discloses an organic matrix effectiveness prediction method suitable for a biomimetic mineralized cementing agent and application, and the prediction method comprises the following steps: respectively preparing an organic additive solution, a calcium salt solution and a carbonate solution, mixing, carrying out a reaction to obtain a precipitate, respectively carrying out XRD and thermogravimetric testing on the precipitate, and calculating the effectiveness of the biomimetic mineralized cementing agent. The proportion of the calcite crystal form in the precipitate is obtained from an XRD test, and the content of the organic matter-mineral compound in calcium carbonate is calculated from a thermogravimetric test result; soaking the precipitate and then carrying out XRD test on the precipitate again to obtain the proportion of the soaked calcite crystal form in the precipitate; and when the increment of the proportion of the calcite crystal form in the precipitate after soaking relative to the proportion of the calcite crystal form before soaking is less than or equal to a, the proportion of the calcite crystal form after soaking is less than or equal to b, and the content of the organic matter-mineral compound in calcium carbonate is more than or equal to c, the organic additive is effective. And blind selection of organic additives is avoided.

Description

Technical Field

[0001] The present invention belongs to the field of biomimetic mineralization cementation, and more specifically, relates to a method for predicting the effectiveness of an organic matrix applicable to a biomimetic mineralization cementing agent and an application thereof. Background Art

[0002] The problems of high energy consumption and high carbon emissions caused by the large-scale production of cementitious materials in China have brought a huge burden to the environment. As early as in the Northern Song Dynasty, the "oyster planting method for foundation strengthening" was adopted in the construction of the Luoyang Bridge (Wan'an Bridge), that is, artificially cultivating oysters to reinforce the bridge foundation. Tiano extracted organic matrix macromolecules from shells in the literature "Stone reinforcement by calcite crystal precipitation induced by organic matrix macromolecules" and biomimetically synthesized calcium carbonate for stone reinforcement. The biomimetic mineralization method combines the advantages of the microbial mineralization method (a method of preparing calcium carbonate by microbial deposition), which has excellent mechanical properties of the product, and the chemical mineralization reaction, which has a fast reaction rate and a complete reaction. The bio-based green building materials are a new idea for the integration of nature and engineering and can be used in fields such as sandy soil foundation and slope reinforcement, concrete crack and cultural relic restoration.

[0003] Research shows that a small amount of organic matrix and ordered microstructures are the keys to the excellent mechanical properties of natural biomineralization products (such as shells, bones, teeth, pathological stones, eggshells). The biomimetic mineralization cementing agent precisely utilizes the principle of organic matrix-inorganic mineral composite. Compared with traditional silicate cementitious materials, it has many advantages such as low cost, fast reaction rate, stable and controllable performance, low environmental dependence (not relying on microbial activity), simple operation, degradability, low environmental load, high designability, and easy combination with other technologies; compared with chemical cementing agents or grouting materials such as epoxy resins and polyurethanes, it has the advantages of being non-toxic to the environment and can be used in large-scale civil engineering. However, the mechanical properties of the biomimetic mineralization cementing agent formed by this principle largely depend on whether the exogenous organic components can be effectively doped and adapted to the composite material structure. There are significant differences in the effects of different organic additives on biomimetic mineralization cementation, and not all organic materials can effectively promote biomimetic mineralization and be used as cementing agents.

[0004] There are many difficult problems that need to be overcome in the field of biomimetic mineralization cementation technology: (1) The internal mechanism of the different effects of biomimetic cemented sand caused by different organic additives has not been fully elucidated so far. The selection of organic additives is still largely random or depends on sand fixation experiments, lacking a scientific theoretical basis. (2) Although some high-end research equipment at the molecular scale or nano-composite structure is expected to be put into use in the future, such as cryogenic transmission electron microscopy (Cryo-TEM), high-resolution focused ion beam scanning electron microscopy (FIB-SEM), and sub-molecular resolution atomic force microscopy (AFM), they are not easily accessible and the output results are not easy to analyze. (3) The types of natural and artificial organic matters are countless, and it is impossible to conduct sand fixation tests one by one. The long-term lack of a selection strategy for organic matrices has greatly restricted the application of biomimetic mineralization in civil engineering and bio-inspired building materials. To cope with the complicated screening work, a simple and feasible method for predicting the effectiveness of organic matrices is urgently needed. (4) When the organic additive is a small molecule, such as using natural aspartic acid, due to the limited functional groups on the molecule, a high dosage equivalent to calcium ions and carbonate ions needs to be added, and the cost is extremely high and it cannot be used in engineering. (5) When the dosage is too large or there are too many useless parts in the molecular structure, the overall strength and hardness will be weakened, restricting the strength growth. (6) The binding effect between carbonate and many organic additives is unstable in aqueous solution and may not even occur at all. (7) There are complex mutual restraint relationships among different influencing factors in the biomimetic mineralization cementation process, restricting the application of biomimetic mineralization cementing agents.

[0005] It can be seen that the existing biomimetic mineralization cementation technology has technical problems such as poor effects of organic matrices, blindness in the selection process and inability to screen in batches, and the lack of effectiveness prediction methods and systematic evaluation methods. Summary of the Invention

[0006] In view of the above defects or improvement requirements of the existing technology, the present invention provides a method for predicting the effectiveness of organic matrices applicable to biomimetic mineralization cementing agents and its application, thereby solving the technical problems of the existing biomimetic mineralization cementation technology, such as poor effects of organic matrices, blindness in the selection process and inability to screen in batches, and the lack of effectiveness prediction methods and systematic evaluation methods.

[0007] To achieve the above object, according to one aspect of the present invention, a method for predicting the effectiveness of organic matrices applicable to biomimetic mineralization cementing agents is provided, including the following steps:

[0008] (1) Prepare an organic additive solution, a calcium salt solution, and a carbonate solution separately. After mixing, a reaction occurs to obtain a precipitate (i.e., calcium carbonate precipitate). Conduct XRD tests and thermogravimetric tests on the precipitate respectively. Obtain the proportion of calcite crystal form in the precipitate from the XRD test, and calculate the content of the organic matter-mineral complex in calcium carbonate (here calcium carbonate includes pure calcium carbonate and the complex containing calcium carbonate) from the thermogravimetric test results;

[0009] (2) Immerse the precipitate in a solution that does not affect the mineralization process, and then conduct an XRD test on the precipitate again to obtain the proportion of the calcite crystal form in the precipitate after immersion;

[0010] (3) When the growth rate of the proportion of the calcite crystal form in the precipitate after immersion relative to the proportion of the calcite crystal form in the precipitate obtained in step (1) ≤ a, the proportion of the calcite crystal form after immersion ≤ b, and at the same time, the content of the organic matter-mineral complex in calcium carbonate ≥ c, at this time, the organic additive is effective and can be used as the organic matrix in the biomimetic mineralization cementing agent; otherwise, the organic additive is ineffective and cannot be used as the organic matrix in the biomimetic mineralization cementing agent;

[0011] Among them, the value range of a is 20%-25%, the value range of b is 90%-95%, and the value range of c is 9%-12%. The solution that does not affect the mineralization process is an aqueous solution, a potassium salt solution, or a sodium salt solution.

[0012] Further, in step (1), the viscosity of the mixed solution after mixing the organic additive solution, the calcium salt solution, and the carbonate solution ≤ 10 mPa s. The organic additive contains polar functional groups, and the solubility of the organic additive in 100 g of water ≥ 0.1 g.

[0013] Further, the concentration of the calcium salt solution in the mixed solution is 0.2 mol / L - 0.5 mol / L, and the concentration of the carbonate solution in the mixed solution is 0.2 mol / L - 0.5 mol / L.

[0014] Further, if the organic additive is an organic small molecule, then the concentration of the organic additive in the mixed solution is 0.2 mol / L - 0.5 mol / L, and the ratio of the concentration of the organic additive in the mixed solution to the concentration of the calcium salt solution in the mixed solution ≥ 1:1.

[0015] Further, if the organic additive is an organic macromolecule, then the concentration of the organic additive in the mixed solution is 0.6 g / L - 3 g / L, and the ratio of the concentration of the organic additive in the mixed solution to the concentration of the calcium salt solution in the mixed solution ≥ 3 g / L:0.6 mol / L.

[0016] Further, step (1) further includes:

[0017] After mixing the organic additive solution, calcium salt solution and carbonate solution for 30 to 60 minutes, the precipitate is taken out, and the precipitate is dried and ground in sequence, and then XRD test and thermogravimetric test are carried out.

[0018] Further, the mixing methods of the organic additive solution, calcium salt solution and carbonate solution include: first mixing the organic additive with the calcium salt solution, and then adding the carbonate solution, or first mixing the organic additive with the carbonate solution, and then adding the calcium salt solution. A precipitation reaction occurs in an aqueous solution environment after mixing. The purpose of the XRD test in steps (1) and (2) is to identify the crystal form of the mineralized product and calculate the proportion of different crystal forms, so as to judge whether the crystal form has changed before and after soaking. The calculation method is generally the relative intensity method, and it can also be the K value method, internal standard method or other methods. The grinding method is to pound or grind at low speed (such as manual grinding) to avoid the influence of high-speed mechanical grinding on the crystal form of the sample. The soaking time is 3 - 14 days. The precipitate is dried under vacuum or by blowing air at 50 ± 5 °C.

[0019] Further, the content of the organic matter-mineral complex in calcium carbonate is calculated by the following method:

[0020] Obtain the thermogravimetric value T1 at any point within the range of 548 °C - 552 °C, the thermogravimetric value T2 at any point within the range of 745 °C - 750 °C, and the thermogravimetric value T3 at any point within the range of 915 °C - 920 °C from the thermogravimetric test results. The content OM of the organic matter-mineral complex in calcium carbonate = (T2 - T3) / (T1 - T3) × 100%.

[0021] According to another aspect of the present invention, there is provided an application of a biomimetic mineralization cementing agent, wherein the organic matrix in the biomimetic mineralization cementing agent is an organic additive predicted to be effective by a prediction method for the effectiveness of an organic matrix applicable to the biomimetic mineralization cementing agent, and the biomimetic mineralization cementing agent is applied to sand reinforcement, concrete crack repair or cultural relic repair.

[0022] Further, the specific implementation manner of the application is as follows:

[0023] Prepare solution A and solution B. Solution A is a calcium salt solution, and solution B is a carbonate solution. Mix the organic additive solution into solution A or solution B; then alternately spray or alternately grout solution A and solution B on the engineering application site, and the engineering application site is the place where sand needs to be reinforced, the concrete crack or the cultural relic to be repaired.

[0024] Further, before solution A and solution B are used for the engineering application site, the pH of solution A or solution B mixed with the organic additive solution is adjusted so that pI ≤ pH ≤ pI + 2, where pI is the isoelectric point of the organic additive.

[0025] Furthermore, the number of rounds of alternating spraying or alternating grouting is more than 20 rounds. The method for determining the time interval of the spraying process is to observe whether the solution for grouting and sand consolidation in the previous round has completely penetrated into the sandy soil, while the time interval of the grouting process is 5 - 10 min.

[0026] Generally speaking, compared with the prior art, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0027] (1) Prepare organic additives, calcium salts, and carbonate solutions separately. After mixing, a reaction occurs to obtain a precipitate. The present invention uses a simple biomimetic chemical deposition test for prediction, which is highly operable. The present invention uses XRD and thermogravimetric analysis to analyze the organic matrix-inorganic mineral composite material, does not rely on high-end testing instruments, has low costs, and high accuracy. XRD can be used to determine whether a significant phase change has occurred in the precipitate. If the change is small, it indicates that the calcite crystal form is stable, that is, the binding force between the organic matter and calcium carbonate is sufficient, indicating that the organic additive is effective. Thermogravimetry is used for auxiliary judgment. If the organic-inorganic combination is tight (i.e., there is a significant heat-resistant composite), it is considered that the binding force is sufficient and the organic additive is effective. The growth rate of the proportion of calcite crystal form in the precipitate after soaking relative to that before soaking ≤ 20% - 25%, indicating that the growth rate of the proportion of calcite crystal form after soaking relative to that before soaking is not large, and the proportion of calcite crystal form after soaking ≤ 90% - 95%, that is, there is obvious vaterite attracted and stabilized by the organic matter and thus does not spontaneously transform into calcite, indicating that there is a sufficient amount of organic matrix-inorganic mineral composite in the precipitate; the content of the organic matter-mineral composite in calcium carbonate ≥ 9% - 12%, proving the large presence and good thermal stability of the composite in the precipitate. The organic additive predicted to be effective by the present invention, when applied to biomimetic mineralization cementation, makes the cementing agent have high cementing force. The present invention evaluates the molecular-scale force through the crystallography and chemical characteristics of crystalline minerals, realizes the systematic determination and prediction of the effectiveness of the organic matrix in the engineering application of the biomimetic mineralization cementing agent, avoids the blindness in selecting organic additives, and points the way for rationally designing better matrices in the future. The method for predicting the effectiveness of the organic additive proposed by the present invention combines theory and practice, and skillfully utilizes the principle that the stability of the crystal form and thermodynamic stability of the organic matrix-inorganic mineral composite are enhanced due to the internal chelation effect, providing a scientific theoretical basis for the selection of the organic matrix and helping to screen out organic matrices with better performance.

[0028] (2) Before prediction, the present invention limits the viscosity of the mixture after mixing the organic additive solution, calcium salt solution and carbonate solution, the functional groups of the organic additive, and the solubility. Using materials that are easily soluble, have low viscosity and contain polar functional groups for testing is to narrow the screening range, improve the screening efficiency, and quickly and efficiently screen out effective organic additives. Small molecules have too few polar groups that can bind to calcium carbonate, so a large amount of organic matter is required. The polar groups of macromolecules are very dense, so the dosage is very small. Designing the concentration of organic additives according to organic macromolecules and organic small molecules respectively further narrows the screening range, improves the screening efficiency, and ensures the rapid and efficient screening of effective organic additives.

[0029] (3) The present invention controls the reaction time to be relatively short, within 30 - 60 minutes, thereby ensuring that the vaterite in the crystal form does not change due to too long reaction time and ensuring the accuracy of the prediction result. The decomposition temperature range of calcium carbonate is 550 - 750 °C. Based on this, T1 is the thermogravimetric value at the starting decomposition temperature of calcium carbonate, T2 is the thermogravimetric value at the temperature where calcium carbonate is completely decomposed, and T3 is the thermogravimetric value at the end temperature of the decomposition of the composite. The index calculated therefrom can accurately verify whether the composite exists in large quantities and the quality of its thermal stability.

[0030] (4) Using the predicted effective organic additives for biomimetic mineralization cementation in the present invention can ensure the effects of sand reinforcement, concrete crack repair or cultural relic repair. The prior art discloses a method for biomimetic mineralization cementation of loose sand grains, which uses aspartic acid to pre - bind with calcium ions and then undergoes a precipitation reaction with carbonate ions to verify the potential of biomimetic mineralization cementation. This method has a certain cementing ability for sand, but one - sidedly believes that calcium carbonate is difficult to form under acidic conditions and an alkaline environment is beneficial to the stability of calcium carbonate. However, adjusting too high pH will promote the ionization of acidic groups, thus greatly reducing the availability of carboxylic acid groups and weakening the ability of organic matter to bind calcium carbonate. The present invention adjusts the pH of solution A or solution B containing organic matter additives so that pI ≤ pH ≤ pI + 2 to maintain the negative charge of the organic matter. When the solution pH is lower than pI, the amino acid is positively charged; when it is higher than pI, it is negatively charged. The pH adjustment method of the present invention can avoid or reduce the ionization of carboxylic acid groups and improve the ability of organic matter to bind calcium carbonate. Description of the Drawings

[0031] Figure 1 is the flow chart of the prediction method provided by the embodiment of the present invention;

[0032] Figure 2 is the thermogravimetric curve provided by Embodiment 1 of the present invention;

[0033] Figure 3 is the XRD pattern before sample immersion provided by Embodiment 1 of the present invention;

[0034] Figure 4 It is the XRD pattern of the sample after soaking provided in Embodiment 1 of the present invention;

[0035] Figure 5 It is the calcite crystal form ratio diagram of the sample before and after soaking provided in Embodiment 1 of the present invention;

[0036] Figure 6 It is the stress-strain curve diagram of the sand column grouted and reinforced with the biomimetic mineralization cementing agent provided in Embodiment 2 of the present invention. Detailed implementation manners

[0037] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0038] In view of the fact that organic matter usually has two aspects of functions. On the one hand, the polar functional groups contained therein can enrich calcium ions in the local microenvironment of the solution and promote nucleation, and the locally excessive saturation will promote the formation of vaterite crystal form calcium carbonate. On the other hand, organic matter also has the function of promoting the formation of organic matrix-inorganic mineral composites to stabilize the vaterite crystal form. The present invention evaluates the molecular-scale interaction forces through the crystallography and chemical characteristics of crystalline minerals, realizes the systematic determination and prediction of the effectiveness of the organic matrix in the engineering application of the biomimetic mineralization cementing agent, points out the direction for rationally designing better matrices in the future, and at the same time solves the problem that the application conditions of this technology are unclear, such as how to regulate the pH of the reaction system is unclear.

[0039] Embodiment 1

[0040] The present invention provides a method for predicting the effectiveness of an organic matrix applicable to a biomimetic mineralization cementing agent, including:

[0041] Step S1: Initially judge whether the organic matrix has the property of chelating with inorganic minerals through the dissolution characteristics, viscosity and infrared spectrogram of the organic matter. The specific steps are as follows:

[0042] Seven kinds of organic matters, aspartic acid, lysine, polyglutamic acid, polyacrylic acid, polyacrylamide, carboxylated chitosan, and sodium alginate, are selected. It is initially judged that they all have good solubility, show low viscosity (<10 mPa·s) at the concentration prepared in the next step S2, and have polar (negatively charged) functional groups such as carboxyl, amino or hydroxyl groups. The functional groups can be judged through the infrared spectrogram.

[0043] Step S2: Prepare an organic additive solution, a calcium salt solution, and a carbonate solution, and mix them to carry out a precipitation reaction in an aqueous solution environment. The specific steps are as follows:

[0044] Prepare 250 ml of 0.6 mol / L calcium chloride solution and an equal volume and concentration of sodium carbonate solution respectively. Add the organic matter selected in S1 to the calcium chloride solution so that the organic matter concentration therein meets the following requirements: for small molecules (aspartic acid, lysine), it is 0.6 mol / L, and for large molecules (polyglutamic acid, polyacrylic acid, polyacrylamide, carboxylated chitosan, sodium alginate), it is 3.6 g / L. First, mix the organic matter solution with the calcium chloride solution and stir for 30 minutes, and then add the sodium carbonate solution. At this time, the concentrations of all solutes in the reaction system are approximately halved.

[0045] Step S3: Immediately take out the precipitate after 60 minutes, dry the precipitate in a blast dryer at 50 °C, and then conduct XRD testing and thermogravimetric testing on the precipitate. Calculate the content index of the organic matter-mineral complex in the total calcium carbonate, that is, define OM = (TG 745℃ -TG 915℃ ) / (TG 550℃ -TG 915℃ )×100%, where TG 550℃ , TG 745℃ , TG 915℃ represent the thermogravimetric values at 550 °C (the starting decomposition temperature of calcium carbonate), 745 °C, and 915 °C respectively. The thermogravimetric curve is as shown in Attachment Figure 2 . The calculation results of OM are shown in Table 1.

[0046] Step S4: Mash the precipitate in a mortar and soak it in clean water for 7 days, and then conduct XRD testing again. By comparing the crystal form transformation before and after soaking, the effectiveness of the organic additive can be determined. The XRD testing of the sample before soaking is shown in Attachment Figure 3 , and the XRD testing of the sample after soaking is shown in Attachment Figure 4 . Since the product is mainly calcium carbonate and there are only two crystal forms, calcite and vaterite, the change in the proportion of the calcite crystal form can be conveniently calculated by the relative intensity method from Attachment Figure 3 and Attachment Figure 4 , as shown in Attachment Figure 5 .

[0047] Table 1 Thermogravimetric test results of Example 1

[0048]

[0049] Step S5: Judge the effectiveness of the organic additive by integrating the XRD and thermogravimetric results. ① If the growth rate of the proportion of calcite crystal form after soaking is not large (≤25%) compared with that before soaking and the proportion of calcite crystal form after soaking ≤ 95%, that is, there is obvious vaterite (≥5%) that has not spontaneously transformed into calcite, indicating the existence of a sufficient amount of organic matrix-inorganic mineral complex; ② If OM ≥ 10%, further verify the existence and thermal stability of the complex. Considering comprehensive criteria ① and ②, it is found that aspartic acid, polyacrylic acid, carboxylated chitosan, and sodium alginate simultaneously meet these two conditions, the crystal form is not prone to the phase change accompanied by aging, and there are more organic matrix-inorganic mineral complexes, that is, it is predicted that they have outstanding cementing effectiveness; on the contrary, lysine, polyglutamic acid, and polyacrylamide do not meet the conditions, that is, it is predicted that they do not have outstanding cementing effectiveness.

[0050] In Example 1, the value of a is 25%, the value of b is 95%, and the value range of c is 10%. In fact, any value of a within 20%-25%, any value of b within 90%-95%, and any value of c within 9%-12% can ensure the accuracy of the effectiveness prediction result.

[0051] In Example 1, the thermogravimetric value TG at 550 °C is obtained from the thermogravimetric test result s50℃ , the thermogravimetric value TG at 745 °C 745℃ and the thermogravimetric value TG at 915 °C 915℃ are used to calculate the OM value. In fact, the thermogravimetric value T1 at any point within the range of 548 °C - 552 °C, the thermogravimetric value T2 at any point within the range of 740 °C - 750 °C, and the thermogravimetric value T3 at any point within the range of 910 °C - 920 °C are obtained from the thermogravimetric test result to calculate the content OM of the organic matter-mineral complex in calcium carbonate, and the purpose of accurate prediction can be achieved.

[0052] In Example 1, the concentration values of the calcium salt, carbonate, and organic additive are specifically given. In fact, the concentration of the calcium salt solution in the mixed solution is 0.2 mol / L - 0.5 mol / L, and the concentration of the carbonate solution in the mixed solution is 0.2 mol / L - 0.5 mol / L. If the organic additive is an organic small molecule, the concentration of the organic additive in the mixed solution is 0.2 mol / L - 0.5 mol / L, and the ratio of the concentration of the organic additive in the mixed solution to the concentration of the calcium salt solution in the mixed solution ≥ 1:1. If the organic additive is an organic macromolecule, the concentration of the organic additive in the mixed solution is 0.6 g / L - 3 g / L, and the ratio of the concentration of the organic additive in the mixed solution to the concentration of the calcium salt solution in the mixed solution ≥ 3 g / L:0.6 mol / L. Such a concentration range can achieve the purpose of reducing the screening range, improving the screening efficiency, and quickly and efficiently screening out effective organic additives.

[0053] In Example 1, the precipitate was taken out immediately after 60 minutes. In fact, taking out the precipitate immediately after 30 - 60 minutes can ensure that the vaterite in the crystal form does not change due to too long reaction time, thus ensuring the accuracy of the prediction result.

[0054] Example 2

[0055] The application of a biomimetic mineralization cementing agent includes:

[0056] Step R1: In the application of sand grouting reinforcement, first prepare a biomimetic mineralization cementing agent containing at least two components, that is, prepare a calcium salt solution (Solution A) and a carbonate solution (Solution B). The specific steps are as follows:

[0057] Prepare 250 ml of 0.5 mol / L calcium chloride solution (Solution A) and an equal volume and concentration of sodium carbonate solution (Solution B).

[0058] Step R2: Mix the organic additive solution into at least one of Solution A or Solution B. The specific steps are as follows:

[0059] Add the organic matter selected in Example 1 to Solution A so that the organic matter concentration therein meets: for small molecules (aspartic acid, lysine) it is 0.5 mol / L, and for large molecules (polyglutamic acid, polyacrylic acid, polyacrylamide, carboxylated chitosan, sodium alginate) it is 3 g / L. First mix the organic matter solution with Solution A and stir for 30 min. First mix the organic matter solution with the calcium chloride solution and stir for 30 min.

[0060] Step R3: Adjust the pH of the biomimetic mineralization cementing agent. The specific steps are as follows. Since aspartic acid shows strong acidity, adjust the pH of Solution A containing aspartic acid above its isoelectric point. Here, it is adjusted to pH = 4.8, and the other additives already meet the pH range and do not need to be adjusted.

[0061] Step R4: Apply Solution A and Solution B to the engineering application site. In Example 2, a sand column with a diameter of 39.1 mm and a height of 80 mm made of Xiamen medium sand was used, and it was grouted alternately and at intervals for 25 rounds. Before each round of grouting, observe whether the solution poured in the previous round has completely penetrated into the sand. After the grouting is completed, the sample is dried and then subjected to an unconfined compressive strength test. The test results are shown in the appendix Figure 6 .

[0062] From the compressive strength of the biomimetic cemented sand column obtained in Example 2 (appendix Figure 6 ), it can be seen that in Example 1, aspartic acid, polyacrylic acid, carboxylated chitosan, and sodium alginate, which were predicted to be highly effective, are consistent with the compressive strength test verification in Example 2, indicating that such organic additives have application prospects as biomimetic mineralization cementing agents.

[0063] Example 2 gives a specific example of the application of the present invention to sand reinforcement. In fact, the present invention can also be used for concrete crack repair and cultural relic repair. The present invention can predict the engineering application effect of the biomimetic mineralization cementing agent in advance through rapid and simple deposition tests and conventional material analysis means, avoiding the blindness of selecting organic additives, facilitating the selection or design of cheap and easily available organic additives. In addition, a method for adjusting the application environment of the biomimetic mineralization cementing agent is given, greatly promoting the practical application of the biomimetic mineralization technology in bioconstruction and providing a key technical path for the research and development of future biomimetic construction materials.

[0064] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for predicting the effectiveness of an organic matrix suitable for a biomimetic mineralization binder, characterized in that: The steps include: (1) preparing an organic additive solution, a calcium salt solution and a carbonate solution respectively, mixing them to react and obtaining a precipitate, performing an XRD test and a thermogravimetric test on the precipitate respectively, obtaining the proportion of the calcite crystal form in the precipitate from the XRD test, and calculating the content of the organic matter-mineral complex in the calcium carbonate from the thermogravimetric test result; (2) After the precipitate is immersed in a solution that does not affect the mineralization process, the precipitate is again subjected to an XRD test to obtain the proportion of the calcite crystal form in the precipitate after immersion; (3) When the increase in the proportion of the calcite crystal form in the precipitate after immersion relative to the proportion of the calcite crystal form in the precipitate obtained in step (1) is ≤ a, the proportion of the calcite crystal form after immersion is ≤ b, and the content of the organic matter-mineral complex in the calcium carbonate is ≥ c, then the organic additive is effective and can be used as an organic matrix in the biomimetic mineralization binder; otherwise, the organic additive is invalid and cannot be used as an organic matrix in the biomimetic mineralization binder; Among them, the value range of a is 20%-25%, the value range of b is 90%-95%, and the value range of c is 9%-12%.

2. The method for predicting the effectiveness of an organic matrix suitable for a biomimetic mineralization binder according to claim 1, characterized in that: In the step (1), the viscosity of the mixed solution of the organic additive solution, the calcium salt solution and the carbonate solution is ≤10 mPa s, the organic additive contains a polar functional group, and the solubility of the organic additive in 100 g of water is ≥0.1 g.

3. The method for predicting the effectiveness of an organic matrix suitable for a biomimetic mineralization binder according to claim 2, characterized in that: The concentration of the calcium salt solution in the mixed solution is 0.2 mol / L-0.5 mol / L, and the concentration of the carbonate solution in the mixed solution is 0.2 mol / L-0.5 mol / L.

4. The method for predicting the effectiveness of an organic matrix suitable for a biomimetic mineralization binder according to claim 3, characterized in that: If the organic additive is an organic small molecule, the concentration of the organic additive in the mixed solution is 0.2 mol / L-0.5 mol / L, and the ratio of the concentration of the organic additive in the mixed solution to the concentration of the calcium salt solution in the mixed solution is ≥1:

1.

5. The method for predicting the effectiveness of an organic matrix suitable for a biomimetic mineralization binder according to claim 3, characterized in that: If the organic additive is an organic macromolecule, the concentration of the organic additive in the mixed solution is 0.6g / L-3g / L, and the ratio of the concentration of the organic additive in the mixed solution to the concentration of the calcium salt solution in the mixed solution is ≥3g / L:0.6mol / L.

6. A method for predicting the effectiveness of an organic matrix suitable for a biomimetic mineralization binder according to any one of claims 1 to 5, characterized in that: The step (1) further comprises: After the organic additive solution, the calcium salt solution and the carbonate solution are mixed for 30 to 60 minutes, the precipitate is taken out, and the precipitate is dried and ground in sequence, and then an XRD test and a thermogravimetric test are performed.

7. A method for predicting the effectiveness of an organic matrix suitable for a biomimetic mineralization binder according to any one of claims 1 to 5, characterized in that: The content of the organic matter-mineral complex in calcium carbonate is calculated as follows: From the thermogravimetric test results, obtain the thermogravimetric value T1 at any point in the range of 548°C-552°C, the thermogravimetric value T2 at any point in the range of 745°C-750°C, and the thermogravimetric value T3 at any point in the range of 915°C-920°C. The content of organic matter-mineral complex in calcium carbonate OM = (T2-T3) / (T1-T3)×100%.

8. An application of a bionic mineralized binder, characterized in that: The organic matrix in the bionic mineralized binder is an effective organic additive predicted by the method for predicting the effectiveness of an organic matrix suitable for a bionic mineralized binder as described in any one of claims 1 to 7, and the bionic mineralized binder is used for sand reinforcement, concrete crack repair or cultural relic restoration.

9. The use of a biomimetic mineralization binder as claimed in claim 8, characterized in that: The specific implementation of the application is as follows: Liquid A and liquid B are prepared, wherein liquid A is a calcium salt solution and liquid B is a carbonate solution, and an organic additive solution is mixed into liquid A or liquid B; then liquid A and liquid B are alternately sprayed or alternately grouted on the project application site, wherein the project application site is a site where sand and soil are to be reinforced, a site where concrete cracks are to be repaired, or a site where cultural relics are to be repaired.

10. The use of a biomimetic mineralization binder according to claim 9, characterized in that: Before the A solution and the B solution are used in the engineering application site, the pH of the A solution or the B solution mixed with the organic additive solution is adjusted so that pI≤pH≤pI+2, wherein pI is the isoelectric point of the organic additive.

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