阅读说明：本技术 一种透水性土基固化液及其在透水性土基制备中的应用 (Water-permeable soil-based curing liquid and application thereof in preparation of water-permeable soil-based ) 是由 李辉 杨炳 李昊臻 谢宁 张恒基 于 2019-10-24 设计创作，主要内容包括：本发明涉及一种透水性土基固化液,所述的透水性土基固化液由脲酶溶液和粘结液配制而成,其中脲酶溶液和粘结液的体积比为1:1～3:2。与现有技术相比,采用本发明中透水性土基固化液处理后的土基具有优良的强度,能够满足路基的承载力要求,并且具有较高的透水系数,即使在强降雨天气下,也能够满足雨水的入渗要求；本发明中透水性土基固化液处理方法兼顾土基力学性能和水文性能,能够进一步拓展透水路面的潜在应用范围；直接采用人工合成的生物酶,与采用细菌等微生物相比,具体实施时的操作条件易于控制,无需考虑微生物的失活问题,稳定性高。(The invention relates to a water-permeable soil-based curing liquid which is prepared from a urease solution and a binding liquid, wherein the volume ratio of the urease solution to the binding liquid is 1: 1-3: 2. Compared with the prior art, the soil base treated by the water-permeable soil base curing liquid has excellent strength, can meet the bearing capacity requirement of a roadbed, has higher water permeability coefficient, and can meet the infiltration requirement of rainwater even in heavy rainfall weather; the treatment method of the water-permeable soil-based curing liquid has the advantages that the mechanical property and the hydrological property of the soil-based curing liquid are taken into consideration, and the potential application range of the water-permeable pavement can be further expanded; compared with the method using bacteria and other microorganisms, the method directly uses artificially synthesized biological enzyme, has easy control of operation conditions during specific implementation, does not need to consider the problem of inactivation of the microorganisms, and has high stability.)

1. The water-permeable soil-based curing liquid is characterized by being prepared from a urease solution and a binding liquid, wherein the volume ratio of the urease solution to the binding liquid is 1: 1-3: 2.

2. The water-permeable soil-based solidification solution according to claim 1, wherein the urease solution is an aqueous urease solution.

3. The water-permeable soil-based solidification solution according to claim 2, wherein the urease solution decomposes urea at a rate of 3.11 to 8.55 mmol/min.

4. The water-permeable soil-based solidification solution according to claim 1, wherein the binder solution is a mixed aqueous solution of urea and chloride.

5. The water-permeable soil-based curing liquid according to claim 4, wherein the concentration of urea in the binding liquid is 15-90 g/L.

6. The water-permeable soil-based solidification solution according to claim 5, wherein the chloride is calcium chloride, and a molar ratio of urea to calcium ions is 1: 1.

7. The use of the soil-based solidifying liquid of claim 1 in the preparation of a water-permeable soil-based on a fully water-permeable pavement, which comprises the following steps:

s1: mixing the air-dried soil with a urease solution, uniformly stirring, adding a binding solution, and uniformly stirring to obtain a soil precursor;

s2: covering a plastic film on the soil precursor obtained in the step S1, standing for 5-10 days, removing the plastic film, and airing for 18-36 hours under natural conditions to obtain a primary soil finished product;

s3: and (3) rolling the primary soil finished product to ensure that the compaction degree is 90% -93%, and obtaining a finished product of the permeable soil base of the full permeable pavement.

8. The application of the soil-based curing liquid in the preparation of the permeable soil-base of the full permeable pavement according to claim 7, wherein the sum of the volumes of the urease solution and the binding liquid in S1 is 0.5-1 time of the pore volume of the air-dried soil.

9. The application of the soil-based curing liquid in the preparation of the permeable soil-based product of the full permeable pavement according to claim 7, wherein the permeability coefficient of the finished product of the permeable soil-based product of the full permeable pavement in S3 is not less than 5 x 10^-5cm/s。

Technical Field

The invention relates to the field of highway construction engineering, in particular to a water-permeable soil matrix curing liquid and application thereof in preparation of a water-permeable soil matrix.

Background

The full-permeable water surface allows rainwater to enter the road surface and even a roadbed, the whole structure body is softened by the infiltration and scouring of the moisture on the structure layer materials, and the part which is most affected by the moisture is the soil foundation. Under the combined action of water and load, the soil foundation easily loses the integral strength and stability, thereby causing the destabilization damage of the whole pavement structure. Therefore, it is necessary to search for a method for reinforcing a permeable pavement soil base material that can satisfy both the bearing capacity and the permeability. Common soil foundation improvement technologies comprise technologies of adding natural or synthetic materials, chemical grouting, reinforcing by adopting sand piles or gravel piles and the like, at present, chemical improvement methods are mostly adopted, wherein cement soil formed after cement is added for reinforcement is widely applied due to the characteristics of high strength, low compressibility, low permeability and the like, but the permeability obviously cannot meet the functional requirement of water drainage of a permeable pavement through a roadbed. The application of the microorganism-induced carbonate deposition technology in concrete, mortar and other materials shows excellent effects, but the research and application of the technology in low-compactness and high-water-content roadbed soil are less due to the complex process and other reasons, and a simpler method for improving soil by microorganisms and further research on a water-permeable soil foundation need to be found.

Patent No. 201810024719.7 discloses a method for solidifying red mud road-based microorganisms by Bayer process and an application method thereof, which comprises the steps of fully mixing a microorganism liquid containing Paenibacillus pasteurianus with a road bed, filling a nutrient solution and a cementing solution, and utilizing the Paenibacillus pasteurianus to generate calcium carbonate crystals in red mud pores to solidify the red mud. However, the activity and the number of the pasteurella as a microbial bacterium are influenced by many factors, and the pasteurella is often sharply reduced and killed in the process of culturing, so that the curing effect is far lower than the expected standard. Furthermore, the patent does not consider the effect of the curing method on the water permeability of the soil base.

Patent No. 201810658578.4 discloses a "road subgrade compaction method based on biological cementation", which also adopts the method of bacillus pasteurianus and the method of mixing urea and calcium chloride, but the process is more complicated and is not easy to control.

Patent No. 201710977377.1 discloses "a method for preparing a biological soil stabilizer" by culturing bacillus pasteurii and bacillus subtilis to obtain an enzyme catalyzing the decomposition of urea, thereby preparing a biological stabilizer. The preparation process of the curing agent is complex and difficult to control, and is not suitable for large-scale engineering application.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide the water-permeable soil-based curing liquid suitable for the fully permeable pavement, and the soil base treated by the water-permeable soil-based curing liquid has enough water permeability coefficient, can meet the water permeability function of the fully permeable pavement, has higher strength and meets the requirement of roadbed bearing capacity.

The purpose of the invention can be realized by the following technical scheme:

the water-permeable soil-based curing liquid is prepared from a urease solution and a binding liquid, wherein the volume ratio of the urease solution to the binding liquid is 1: 1-3: 2.

Further, the urease solution is a urease aqueous solution.

The concentration of the urease is not fixed, the concentration of the urease needs to be determined according to the rate of decomposing urea by the urease, the activity of the urease from different urease sources is different, the concentration of the urease can be relatively reduced when the activity of the urease is high, and the concentration of the urease needs to be increased when the activity of the urease is low.

Further, the urea decomposition speed of the urease solution is 3.11-8.55 mmol/min. Obtained by decomposing urea in this range

The target amount of calcium carbonate can be generated in the soil, within the range, the increase of the urease dosage can improve the unconfined compressive strength and the modulus of resilience, the water permeability coefficient can be reduced, but the design standard of soil-based solidification is completely met.

Further, the binding liquid is a mixed aqueous solution of urea and chloride.

Furthermore, the concentration of urea in the binding liquid is 15-90 g/L.

Further, the chloride is calcium chloride, wherein the molar ratio of urea to calcium ions is 1: 1.

Furthermore, the urease is obtained by artificial synthesis, so that industrial mass production can be realized, and the implementation is easy.

The application of the soil-based solidifying liquid in the preparation of the water-permeable soil base of the full water-permeable road surface comprises the following steps:

s1: mixing the air-dried soil with a urease solution, uniformly stirring, adding a binding solution, and uniformly stirring to obtain a soil precursor;

s2: covering a plastic film on the soil precursor obtained in the step S1, standing for 5-10 days, removing the plastic film, and airing for 18-36 hours under natural conditions to obtain a primary soil finished product;

s3: and (3) rolling the primary soil finished product to ensure that the compaction degree is 90% -93%, and obtaining a finished product of the permeable soil base of the full permeable pavement.

Furthermore, the sum of the volumes of the urease solution and the binding liquid in the S1 is 0.5-1 time of the pore volume of the air-dried soil.

Further, the water permeability coefficient of the finished product of the water permeable soil base of the full permeable pavement in S3 is more than or equal to 5 multiplied by 10^-5cm/s。

Compared with the prior art, the invention has the following advantages:

1) the soil foundation treated by the water-permeable soil foundation curing liquid has excellent strength, can meet the bearing capacity requirement of a roadbed, has higher water permeability coefficient, and can meet the infiltration requirement of rainwater even in heavy rainfall weather.

2) Compared with the conventional biological reinforcement method, the treatment method of the water-permeable soil-based curing liquid has the mechanical property and the hydrological property of the soil-based, and can further expand the potential application range of the permeable pavement.

3) The method directly adopts artificially synthesized biological enzyme, and compared with microorganism such as bacteria, the method has the advantages of easily controlled operation conditions, no consideration of microorganism inactivation, and high stability.

4) The method adopts a field mixing mode in the concrete application process of the water-permeable soil-based curing liquid, can be carried out under conventional conditions, is simple and easy to implement in the treatment and maintenance methods, and is suitable for large-scale engineering application.

Detailed Description

The present invention is described in detail below with reference to specific examples, but the present invention is not limited thereto in any way.