Soil stabilizer for road engineering and preparation method thereof

Abstract

The invention relates to the technical field of soil stabilizers, and discloses a soil stabilizer for road engineering, which comprises the following components: 15-25% of hydroxypropyl acrylate; 20%-30% of acrylic acid; 10%-20% of styrene; 0.5%-2% of (NH4) 2S2O8; 0.5%-2% of Na2SO4; 3%-8% of an emulsifier Span80 and OP-10; 30%-50% of water; the percentage content is the mass fraction and is adjusted according to actual application requirements to form the soil stabilizer with the total mass fraction of 100%. According to the soil stabilizer for road engineering and the preparation method of the soil stabilizer, hydroxypropyl acrylate, acrylic acid and styrene serve as main raw materials, Span80 and OP-10 serve as compound emulsifiers, the soil stabilizer is prepared through an emulsion polymerization method, the soil stabilizer and cement are mixed and doped into loess, and the loess improved through the stabilizer has the advantages that the anti-scouring performance of a sample is very high, and the anti-scouring performance is good. And water flow scouring can be resisted for a long time without erosion.

Description

Technical Field

[0001] The present invention relates to the technical field of soil solidifying machines, and particularly relates to a soil solidifying agent for road engineering and a preparation method thereof. Background Art

[0002] The problem of shortage of good subgrade fillers is becoming increasingly prominent. Lime and cement-improved loess are still one of the main choices for subgrade fillers, but the production of cement and lime is the main source of carbon emissions in the industrial production process. If high-quality soil solidifying agents are used to improve loess, not only can its physical and mechanical properties be improved, but also local materials can be used, the project cost can be greatly reduced, and the usage of traditional cementing materials such as lime and cement can be reduced, which is of great significance for further carbon reduction.

[0003] The applications of cement and lime-improved loess are very extensive, but there are relatively few engineering examples of using solidifying agents to improve loess. Research shows that solidified soil with solidifying agents can greatly improve the road performance of soil such as mechanical properties, crack resistance, and water stability. However, due to the complex and changeable nature of soil in nature, the soil particle composition and mineral composition often vary due to different soil-forming conditions, resulting in great differences in the stabilizing performance of soil solidifying agents.

[0004] Although solidifying agents, as a new type of solidifying material, have been widely used in highway engineering in China and achieved good economic benefits, there are still some problems, which are manifested in the following aspects:

[0005] (1) The research on the applicability of special soil solidifying agents mainly focuses on saline soil, red sandstone, soft clay, etc. At present, there is no special soil solidifying agent for loess.

[0006] (2) At present, the research on soil solidifying agents mostly focuses on strength, and there is less research on long-term durability performance such as frost resistance, water damage resistance, and dry-wet cycle resistance at different ages, especially the research on weather resistance for the climatic characteristics of the loess area is still blank. Summary of the Invention

[0007] The present invention provides a soil solidifying agent for road engineering and a preparation method thereof. Using hydroxypropyl acrylate, acrylic acid, and styrene as the main raw materials, and Span80 and OP-10 as the composite emulsifier, the soil solidifying agent is prepared by emulsion polymerization and mixed with cement and incorporated into loess. After being improved by the solidifying agent, the anti-scouring performance of the loess sample is very strong and can resist water flow scouring for a long time without erosion.

[0008] The present invention provides a soil solidifying agent for road engineering, which comprises the following components:

[0009]

[0010] The above percentage contents are mass fractions and are adjusted according to actual application requirements to form a soil stabilizer with a total mass fraction of 100%.

[0011] Further, after emulsifier Span80 and emulsifier OP-10 are mixed at a volume ratio of 1:1, their total amount accounts for 3% - 8% of the total mass fraction.

[0012] The present invention also provides a preparation method of a soil stabilizer for road engineering. Based on the soil stabilizer for road engineering as described above, the method specifically includes:

[0013] S1. Accurately weigh a set amount of water, hydroxypropyl acrylate, acrylic acid, and styrene into a glass container, and fully mix and dissolve each monomer under stirring.

[0014] S2. Continuously add a set amount of composite emulsifier to the above mixture, and emulsify it to form a pre-emulsion under the action of a homogenizing disperser for standby.

[0015] S3. Pour one-half volume of the prepared pre-emulsion into a three-necked flask, turn on the water bath heating device to raise the temperature to 60°C, then add a set amount of initiator (NH4)2S2O8, continue to raise the reaction temperature to 80°C, and react for a period of time until blue fluorescence appears.

[0016] S4. Continuously add the remaining pre-emulsion to the reaction system, raise the reaction temperature to 90°C, stop the reaction after 2 hours, and cool to room temperature to obtain a soil stabilizer for road engineering.

[0017] S5. Respectively mix the soil stabilizer with mass fractions of 0.015%, 0.02%, and 0.025% with 4%, 6%, and 8% of cement into loess to obtain nine different improved loesses, and conduct engineering property tests on the improved loesses.

[0018] Further, in step S1, the stirring speed during stirring in the glass container is 800 r / min, and the stirring time is 20 minutes.

[0019] Further, in step S2, the composite emulsifier is: Span80:OP-10 mixed at a volume ratio of 1:1.

[0020] Add the composite emulsifier to the mixture slowly in 3 times at intervals of 5 minutes. During the addition process, the homogenizing disperser continuously stirs at a speed of 15000 r / min. Meanwhile, when emulsifying under the action of the homogenizing disperser, control the temperature at 45°C.

[0021] Further, in step S3, the initiator (NH4)2S2O8 is prepared into an aqueous solution with a mass fraction of 5%, and is slowly added dropwise to the three-necked flask at a rate of 0.5 mL / min.

[0022] Further, in step S3, a fluorometer is used to monitor the fluorescence intensity in real time. When the fluorescence intensity reaches 1000 a.u., it is considered that the reaction reaches the expected stage.

[0023] Further, in step S4, when the reaction temperature is increased from 80 °C to 90 °C, the heating rate is controlled at 1.5 °C / min;

[0024] After cooling to room temperature, the obtained soil solidifying agent is filtered using a 0.45 μm microporous filter membrane to remove possible unreacted impurities or condensates; at the same time, the soil solidifying agent is subjected to vacuum degassing treatment, with the vacuum degree controlled at -0.09 MPa and the degassing time being 30 minutes.

[0025] Further, in step S4, after the reaction is completed and before cooling, the defoaming agent is slowly added dropwise to the reaction system, and at the same time, the stirring device is turned on, with the stirring speed controlled at 300 - 500 r / min and the stirring time being 10 - 15 minutes to make the defoaming agent evenly dispersed in the system.

[0026] Further, in step S5, engineering property tests are carried out on the improved loess, including:

[0027] Compaction tests, unconfined compressive strength tests, freeze-thaw cycle tests, and water stability tests are carried out on nine different improved loesses to adjust and optimize the process of the soil solidifying agent according to the test results.

[0028] The beneficial effects of the present invention are as follows:

[0029] The present invention uses hydroxypropyl acrylate, acrylic acid, and styrene as the main raw materials, Span80 and OP-10 with a volume ratio of 1:1 as the composite emulsifier, and (NH4)2S2O8 as the initiator, and prepares the soil solidifying agent by emulsion polymerization, which can effectively improve the mechanical properties, water stability, and anti-salt erosion properties of the target clay; the soil solidifying agent is mixed with cement and incorporated into the loess to form improved loess. After adding the solidifying agent and cement, the pores of the improved loess are significantly reduced, and the cementation characteristics of the soil particles are enhanced. The reaction products of the solidifying agent and cement well fill the pores between the soil particles and wrap the soil particles, making them agglomerate into larger particles and arrange more closely. The pores of the soil before and after reinforcement are mainly small pores and micro-pores, and there are fewer large pores and medium pores. Description of the Drawings

[0030] Figure 1Schematic flow chart of the preparation method of the soil stabilizer of the present invention.

[0031] Figure 2 Schematic diagram of the results obtained from the compaction test in the present invention.

[0032] Figure 3 Schematic diagram of the water content - dry density curve of loess under different curing agent dosages in the present invention.

[0033] Figure 4 Schematic diagram of the unconfined compressive strength under different curing agent dosages in the present invention.

[0034] Figure 5 Schematic diagram of the first part of the change trend of the unconfined compressive strength of loess improved by cement - based soil stabilizer with the curing agent dosage in the present invention.

[0035] Figure 6 Schematic diagram of the second part of the change trend of the unconfined compressive strength of loess improved by cement - based soil stabilizer with the curing agent dosage in the present invention.

[0036] Figure 7 Schematic diagram of the first part of the change trend of the unconfined compressive strength of loess improved by cement - based soil stabilizer with the compaction degree in the present invention.

[0037] Figure 8 Schematic diagram of the second part of the change trend of the unconfined compressive strength of loess improved by cement - based soil stabilizer with the compaction degree in the present invention.

[0038] Figure 9 Schematic diagram of the first part of the change trend of the unconfined compressive strength of loess improved by cement - based soil stabilizer with the curing age in the present invention.

[0039] Figure 10 Schematic diagram of the second part of the change trend of the unconfined compressive strength of loess improved by cement - based soil stabilizer with the curing age in the present invention.

[0040] Figure 11 Schematic diagram of the unconfined compressive strength after freeze - thaw cycles with different curing agent dosages in the present invention.

[0041] Figure 12 Schematic diagram of the first part of the curve of the freeze - thaw cycle strength with different curing agent dosages varying with the cement dosage in the present invention.

[0042] Figure 13 Schematic diagram of the second part of the curve of the freeze - thaw cycle strength with different curing agent dosages varying with the cement dosage in the present invention.

[0043] Figure 14 Schematic diagram of the unconfined compressive strength of specimens with different numbers of wet - dry cycles in the present invention.

[0044] Figure 15This is a schematic diagram of the SEM image (1000×) of the improved loess microstructure in the present invention.

[0045] The realization of the object, functional features and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0046] 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.

[0047] Soil stabilizer is one of the most common geotechnical solidifying agents. Incorporating soil stabilizer into geotechnical materials can produce physical and chemical reactions with soil particles, thereby improving the quality of geotechnical materials and enhancing the bonding strength of solidified soil, enabling the solidified geotechnical materials to meet the requirements of highway construction.

[0048] The present invention provides a soil stabilizer for road engineering, comprising the following components:

[0049]

[0050] The above percentage contents are mass fractions, which are adjusted according to actual application requirements to form a soil stabilizer with a total mass fraction of 100%. Among them, after emulsifier Span80 and emulsifier OP-10 are mixed in a volume ratio of 1:1, their total amount accounts for 3% - 8% of the total mass fraction.

[0051] As Figure 1 shown, the present invention also provides a preparation method of a soil stabilizer for road engineering. Based on the soil stabilizer for road engineering as described above, the method specifically includes:

[0052] S1. Accurately weigh a set amount of water, hydroxypropyl acrylate, acrylic acid and styrene into a glass container, and fully mix and dissolve each monomer under stirring.

[0053] Before weighing the raw materials, use a high-performance liquid chromatograph to detect the purity of hydroxypropyl acrylate, acrylic acid and styrene, and require that the purity reaches more than 99%; for water, use a conductivity meter to detect to ensure that the conductivity is less than 5 μS / cm, so as to ensure the stable quality of the raw materials and avoid affecting the reaction effect and the performance of the stabilizer due to raw material impurities.

[0054] The stirring speed during stirring in the glass container is 800 r / min, and the stirring time is 20 minutes. Under this stirring condition, each monomer can be fully mixed and dissolved, and the solution is uniform and transparent, without obvious particles or stratification.

[0055] S2. Continuously add a set amount of composite emulsifier (Span80:OP-10 mixed by volume ratio of 1:1) to the above-mentioned mixed solution, and emulsify it to form a pre-emulsion under the action of a homogenizing disperser (HR-25D type laboratory homogenizing disperser) for standby.

[0056] Add the composite emulsifier to the mixed solution slowly in 3 times, with an interval of 5 minutes each time. During the addition process, the homogenizing disperser continuously stirs at a speed of 15000 r / min. In this way, the emulsifier can be more evenly dispersed in the mixed solution, and the stability of the formed pre-emulsion is significantly improved. There is no obvious stratification phenomenon after standing at room temperature for 24 hours.

[0057] Meanwhile, when emulsifying under the action of the homogenizing disperser, control the temperature at 45 °C. At this temperature, the viscosity of the mixed solution is moderate, the emulsifier can play a better role, the emulsification efficiency is increased by about 20%, and the stability of the pre-emulsion is the best.

[0058] S3. Pour one-half volume of the above-prepared pre-emulsion into a three-necked flask, turn on the water bath heating device (SHJ type constant temperature water bath) to raise the temperature to 60 °C, then add a set amount of initiator (NH4)2S2O8, and continue to raise the reaction temperature to 80 °C. After reacting for a period of time until blue fluorescence appears.

[0059] Prepare an aqueous solution of the initiator (NH4)2S2O8 with a mass fraction of 5% and slowly drip it into the three-necked flask at a speed of 0.5 mL / min. It can more accurately control the addition amount of the initiator and the reaction rate, the reaction process is more stable, avoiding problems such as local overheating or violent polymerization caused by too violent reaction, and the product performance is more stable.

[0060] Generally, blue fluorescence will appear after reacting for 45 minutes. The fluorescence intensity can also be monitored in real time by a fluorometer. When the fluorescence intensity reaches 1000 a.u., it is considered that the reaction reaches the expected stage and the next step can be carried out to ensure the accuracy of the reaction process.

[0061] S4. Continuously add the remaining pre-emulsion to the reaction system, raise the reaction temperature to 90 °C, stop the reaction after 2 h, and cool it to room temperature to obtain a soil solidifying agent for road engineering.

[0062] When raising the reaction temperature from 80 °C to 90 °C, control the heating rate at 1.5 °C / min; this heating rate can make the reaction system reach the target temperature more smoothly, reduce the influence of temperature fluctuation on the reaction, and the performance stability of the product is increased by about 15%.

[0063] After cooling to room temperature, the obtained soil stabilizer was filtered using a 0.45 μm microporous filter membrane to remove any possible unreacted impurities or aggregates. At the same time, the soil stabilizer was subjected to vacuum degassing treatment with a vacuum degree controlled at -0.09 MPa and a degassing time of 30 minutes to effectively remove any dissolved gases therein and avoid problems such as air bubbles during use.

[0064] If there were still air bubbles, after the reaction ended and before cooling, the defoamer was slowly added dropwise to the reaction system while starting the stirring device with a stirring speed controlled at 300 - 500 r / min and a stirring time of 10 - 15 minutes to evenly disperse the defoamer in the system.

[0065] S5. The soil stabilizers with mass fractions of 0.015%, 0.02%, and 0.025% were respectively mixed with 4%, 6%, and 8% cement into loess to obtain nine different improved loesses, and engineering property tests were carried out on the improved loesses.

[0066] The engineering property tests on the improved loesses included compaction tests, unconfined compressive strength tests, freeze-thaw cycle tests, and water stability tests to adjust and optimize the process of the soil stabilizer based on the test results.

[0067] (1) Compaction test

[0068] For each cement content and stabilizer content, the results of the compaction tests on the improved loesses are as Figure 2 shown, and the compaction curves are as Figure 3 shown.

[0069] It can be seen from Figure 3 that the compaction curves of the loess improved with cement and soil stabilizer still show a trend of increasing first and then decreasing. At a stabilizer content of 0.015%, the optimum moisture contents for cement contents of 4%, 6%, and 8% are 12.25%, 12.55%, and 12.80% respectively, and the corresponding maximum dry densities are 1.92 g / cm 3 ³, 1.91 g / cm 3 ³, 1.90 g / cm 3 ³. As the cement content increases, the optimum moisture content shows a gradually increasing trend, and the maximum dry density shows a gradually decreasing trend. At a stabilizer content of 0.02%, the optimum moisture contents for cement contents of 4%, 6%, and 8% are 12.80%, 13.00%, and 12.45% respectively, and the corresponding maximum dry densities are 1.90 g / cm 3 ³, 1.93 g / cm 3 ³, 1.88 g / cm 3, as the cement content increases, the optimum moisture content and the maximum dry density first increase and then decrease; at a curing agent content of 0.025%, the optimum moisture contents for cement contents of 4%, 6%, and 8% are 12.35%, 12.55%, and 12.40% respectively, and the corresponding maximum dry densities are 1.90 g / cm 3 , 1.91 g / cm 3 , 1.86 g / cm 3 , as the cement content increases, the optimum moisture content and the maximum dry density first increase and then decrease. Under the three cement contents, the dry density of the cement-improved loess increases rapidly before reaching the maximum dry density and decreases rapidly after reaching the maximum dry density.

[0070] (2) Unconfined compressive strength test

[0071] Set the cement admixture ratios to 4%, 6%, and 8%, and add water. The conclusions are as follows: at a curing agent content of 0.015%, the optimum moisture contents are 12.25%, 12.55%, and 12.80% respectively, and the maximum dry densities are 1.92 g / cm 3 , 1.91 g / cm 3 , 1.90 g / cm 3 ; at a curing agent content of 0.02%, the optimum moisture contents are 12.80%, 13.00%, and 12.45% respectively, and the maximum dry densities are 1.90 g / cm 3 , 1.93 g / cm 3 , 1.88 g / cm 3 ; at a curing agent content of 0.025%, the optimum moisture contents are 12.35%, 12.55%, and 12.40% respectively, and the maximum dry densities are 1.90 g / cm 3 , 1.91 g / cm 3 , 1.86 g / cm 3 .

[0072] In the test, the curing time was designed as 7 d, 14 d, and 28 d, and the compaction degree was still designed as 92%, 94%, and 96%.

[0073] 1> Analysis of the influence of curing agent content on unconfined compressive strength

[0074] The unconfined compressive strengths under different curing agent contents are as Figure 4 shown, and their variation curves are as Figure 5 , Figure 6 shown.

[0075] From Figure 5 , Figure 6It can be seen that under different curing ages and compaction standards, as the dosage of the curing agent increases, the unconfined compressive strength curve shows a gradually increasing trend. When other conditions remain unchanged, when 0.015% of the curing agent is incorporated, the strength change is unstable, increasing and decreasing at times. However, when 0.02% and 0.025% of the curing agent are incorporated, the strength change of the improved loess is significant. Taking the cement-improved loess as an example, with a cement content of 6%, a compaction degree of 92%, and a curing period of 7 days, when 0.015% of the curing agent is incorporated, the strength is increased by 13.3% compared with the cement-improved loess; when 0.02% of the curing agent is incorporated, the strength is increased by 20% compared with the cement-improved loess; when 0.025% of the curing agent is incorporated, the strength is increased by 53.3% compared with the cement-improved loess. Thus, it can be seen that as the dosage of the curing agent increases, the unconfined compressive strength of the improved loess gradually increases, and more curing agent reacts with the hydration products of cement itself to form new minerals, and the resulting cementation strength gradually increases.

[0076] 2>Analysis of the influence of compaction degree on unconfined compressive strength

[0077] It can be seen from Figure 7 and Figure 8 that: Similar to the cement-improved loess, as the compaction degree of the loess improved with cement and curing agent increases, the increase in the unconfined compressive strength also increases. Taking the cement-improved loess as an example, with a cement content of 6%, a curing agent content of 0.02%, and a curing period of 7 days, when the compaction degree is 92%, the strength is increased by 20% compared with the cement-improved loess; when the compaction degree is 94%, the strength is increased by 10% compared with the cement-improved loess; when the compaction degree is 96%, the strength is increased by 10% compared with the cement-improved loess. This shows that the compaction degree has a significant influence on the unconfined compressive strength of the improved loess, and the unconfined compressive strength of the loess improved with cement and curing agent can be significantly increased by increasing the compaction degree.

[0078] 3>Analysis of the influence of curing age on unconfined compressive strength

[0079] It can be seen from Figure 9 and Figure 10 that: As the curing age increases, the strength of the loess improved with cement and curing agent increases significantly, and with the increase in the cement content, the strength increase of the sample with 0.025% curing agent content changes most significantly with the curing age. Taking the cement-improved loess as an example, with a cement content of 6%, a curing agent content of 0.02%, and a compaction degree of 92%, when the curing period is 7 days, the strength is increased by 20% compared with the cement-improved loess; when the curing period is 14 days, the strength is increased by 21.1% compared with the cement-improved loess; when the curing period is 28 days, the strength is increased by 19% compared with the cement-improved loess.

[0080] (3) Freeze-thaw cycle test

[0081] The unconfined compressive strength of different curing agent dosages after freeze-thaw cycles is as Figure 11 shown, and the trend chart is asFigure 12 , Figure 13 as shown in

[0082] It can be obtained from Figure 12 and Figure 13 that as the content of the curing agent and the content of cement increase, the strength decay after 10 freeze-thaw cycles becomes less and less. When the content of the curing agent is 0.015%, 0.02%, 0.025%, the content of cement is 6%, and the compaction degree is 96%, the strength after 10 freeze-thaw cycles decreases by 0.16 MPa, 0.05 MPa, and 0.05 MPa respectively compared with that after 0 freeze-thaw cycles. It can be seen that on the basis of cement-improved loess, adding a curing agent has a better anti-freezing effect and a higher strength retention rate after freeze-thaw. The deterioration effect of freeze-thaw cycles on improved loess is relatively significant. The reason is that after freeze-thaw cycles, the volume expands and contracts, the size of the pores changes, the bonding force between the hydration products generated by cement hydration and the soil particles changes, resulting in a slight displacement of the soil skeleton structure and a weakening effect of the bonding force between soil particles.

[0083] (4) Water stability test

[0084] Prepare cylindrical specimens with a diameter of Φ50 mm and a height of h50 mm, with the cement content being 4%, 6%, 8%, the curing agent content being 0.015%, 0.02%, 0.025%, and the curing age being 7 d, 14 d, 28 d.

[0085] It can be seen from Figure 14 that the unconfined compressive strength generally decreases gradually with the increase of the number of dry-wet cycles. After 5 cycles, the unconfined compressive strength generally decreases by nearly 20 - 30%, which is higher than that of cement-improved loess.

[0086] By comparing the microstructures of the soil before and after curing, the changes in the pore structure before and after the action of cement and curing agent on loess can be directly understood, and the macroscopic strength of the solidified soil can also be reflected from the microscopic perspective. As Figure 15 shown, through a GeminiSEM 500 type electron microscope, the compacted loess, the improved loess with a cement content of 6%, and the improved loess with 6% cement plus 0.02% curing agent are scanned by electron microscopy, and the electron microscopy photos of the improved loess are processed using IPP6.0 micropore analysis software, where red and gray represent pores and soil skeleton structures respectively.

[0087] It can be seen from Figure 15 (a) that in the compacted loess, small pores are developed, the fine particles are randomly arranged in a grain cluster stacking structure, and the particles are mostly squeezed and spliced in a point-plane contact form, forming a complex overhead pore structure. It can be seen from Figure 15(b), it can be seen that the minerals in the cement and the water in the loess undergo hydration and hydrolysis reactions, and the cement hydrates and other gelling substances generated change the connection mode between soil particles from the point-to-point and point-to-surface contact connections of remolded loess to a connection mode mainly based on cementation between particles. After the cement is incorporated, the pore distribution in the improved loess tends to be uniform, and the structure is denser than that of remolded loess. The reason for the decrease in pores is that on the one hand, large pores are damaged or filled with cement reaction products, and on the other hand, the main constituent substance SiO2 in the soil can react with the water in the soil to generate some silicic acid colloid particles. These fine particles are attached with Na+ and K+ on the surface, and produce adsorption exchange with a large amount of Ca2+ ionized by the cement hydration products, resulting in a reduction in the thickness of the double electric layer of soil particles and a shrinkage of the pores between soil particles. From Figure 15 (c), (d), and (e), it can be seen that after adding the curing agent, the pores of the improved loess are significantly reduced, and the cementation characteristics of soil particles are enhanced. The reaction products of the curing agent and the cement well fill the pores between soil particles and form a coating on the soil particles, making them agglomerate into larger particles and arrange more closely, indicating that the curing agent + cement improvement improves the connection mode between soil particles and enhances the connection strength between soil particles.

[0088] The present invention uses hydroxypropyl acrylate, acrylic acid, and styrene as the main raw materials, Span80 and OP-10 in a volume ratio of 1:1 as the composite emulsifier, and (NH4)2S2O8 as the initiator to prepare a soil curing agent by emulsion polymerization method, which can effectively improve the mechanical properties, water stability, and anti-salt erosion properties of the target clay; the soil curing agent is mixed with cement and incorporated into the yellow clay to form improved loess. After adding the curing agent and cement, the pores of the improved loess are significantly reduced, and the cementation characteristics of soil particles are enhanced. The reaction products of the curing agent and the cement well fill the pores between soil particles and form a coating on the soil particles, making them agglomerate into larger particles and arrange more closely. The pores of the soil before and after reinforcement are mainly small pores and micro-pores, and there are fewer large pores and medium pores.

[0089] In summary, after the soil curing agent is blended with local loess and used to replace cement-stabilized gravel for road bases, etc., the use of sand, gravel, and cement materials is reduced, which can achieve resource conservation, reduce the material extraction and transportation costs, and has a positive significance for reducing carbon emissions.

[0090] It should be noted that in this text, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, device, article or method. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, device, article or method including such element.

[0091] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A soil stabilizer for road engineering, characterized in that, It includes the following components: The above percentage contents are mass fractions and are adjusted according to actual application requirements to form a soil stabilizer with a total mass fraction of 100%.

2. The soil stabilizer for road engineering according to claim 1, characterized in that, After emulsifier Span80 and emulsifier OP-10 are mixed at a volume ratio of 1:1, their total amount accounts for 3% - 8% of the total mass fraction.

3. A preparation method of a soil stabilizer for road engineering, characterized in that, Based on the soil stabilizer for road engineering described in any one of claims 1 - 2, the method specifically includes: S1. Accurately weigh a set amount of water, hydroxypropyl acrylate, acrylic acid, and styrene into a glass container, and fully mix and dissolve each monomer under stirring; S2. Continuously add a set amount of composite emulsifier to the above mixture, and emulsify it under the action of a homogenizing disperser to form a pre-emulsion for standby; S3. Pour one-half volume of the prepared pre-emulsion into a three-necked flask, turn on the water bath heating device to raise the temperature to 60 °C, then add a set amount of initiator (NH4)2S2O8, and continue to raise the reaction temperature to 80 °C. After reacting for a period of time until blue fluorescence appears; S4. Continuously add the remaining pre-emulsion to the reaction system, raise the reaction temperature to 90 °C, stop the reaction after 2 h, and after cooling to room temperature, obtain a soil stabilizer for road engineering; S5. Respectively mix the soil stabilizer with mass fractions of 0.015%, 0.02%, and 0.025% with 4%, 6%, and 8% of cement into loess to obtain nine different improved loesses, and conduct engineering property tests on the improved loesses.

4. The preparation method of the soil stabilizer for road engineering according to claim 3, characterized in that, In step S1, the stirring speed during stirring in the glass container is 800 r / min, and the stirring time is 20 minutes.

5. The preparation method of the soil solidifying agent for road engineering according to claim 3, characterized in that, In step S2, the composite emulsifier is: Span80:OP-10 mixed at a volume ratio of 1:1; Add the composite emulsifier to the mixture slowly in 3 times at intervals of 5 minutes. During the addition process, the homogenizing disperser continuously stirs at a speed of 15000 r / min. At the same time, when emulsifying under the action of the homogenizing disperser, control the temperature at 45 °C.

6. The preparation method of the soil stabilizer for road engineering according to claim 3, characterized in that, In step S3, prepare an aqueous solution of initiator (NH4)2S2O8 with a mass fraction of 5% and slowly drip it into the three-necked flask at a speed of 0.5 mL / min.

7. The preparation method of the soil stabilizer for road engineering according to claim 3, characterized in that, In step S3, use a fluorometer to monitor the fluorescence intensity in real time. When the fluorescence intensity reaches 1000 a.u., it is considered that the reaction reaches the expected stage.

8. The preparation method of the soil stabilizer for road engineering according to claim 3, characterized in that, In step S4, when raising the reaction temperature from 80 °C to 90 °C, control the heating rate at 1.5 °C / min; After cooling to room temperature, filter the obtained soil stabilizer using a 0.45 μm microporous filter membrane to remove possible unreacted impurities or aggregates; at the same time, conduct vacuum degassing treatment on the soil stabilizer, control the vacuum degree at -0.09 MPa, and the degassing time is 30 minutes.

9. The preparation method of the soil stabilizer for road engineering according to claim 3, characterized in that, In step S4, after the reaction ends and before cooling, slowly drip the defoaming agent into the reaction system, and at the same time turn on the stirring device, control the stirring speed at 300 - 500 r / min, and the stirring time is 10 - 15 minutes to make the defoaming agent evenly disperse in the system.

10. The preparation method of the soil stabilizer for road engineering according to claim 3, characterized in that, In the step S5, engineering property tests are carried out on the improved loess, including: Carrying out compaction tests, unconfined compressive strength tests, freeze-thaw cycle tests, and water stability tests on nine different types of improved loess, so as to adjust and optimize the process of the soil stabilizer according to the test results.

Images