CN111778034A

CN111778034A - Soil curing agent and soil curing method

Info

Publication number: CN111778034A
Application number: CN202010487879.2A
Authority: CN
Inventors: 樊亮; 李永振; 侯佳林; 周圣杰; 赵宁; 毕飞; 马士杰; 张岩; 魏慧�; 梁皓; 林江涛; 姜峰; 王林
Original assignee: Shandong Transportation Institute
Current assignee: Shandong Transportation Institute
Priority date: 2020-06-02
Filing date: 2020-06-02
Publication date: 2020-10-16

Abstract

The invention discloses a soil curing agent and a soil curing method, and belongs to the field of road engineering. The soil curing agent is prepared by mixing foamed asphalt and cement in a specific ratio. Compared with the prior art, the soil stabilizer has the advantages of high construction speed, less construction equipment, simple construction process, high strength improvement, high curing strength, good water stability and good popularization and application value.

Description

Soil curing agent and soil curing method

Technical Field

The invention relates to the field of road engineering, and particularly provides a soil curing agent and a soil curing method.

Background

In the existing engineering application, materials such as cement, lime, fly ash and the like are mostly adopted to solidify soil, so that the strength, the cohesive force and the stability of the soil are increased, and the engineering requirements are met. However, as road construction continues to progress, the consumption of construction materials and construction costs are increasing. In addition, the national requirements on environmental protection are stricter and stricter, and the exploitation of stone materials is more and more limited. How to solidify local soil to make the soil become an engineering material with high strength and good stability becomes a feasible research direction.

The applicant disclosed in patent document No. CN107285694A a method for solidifying silty soil by compounding emulsified asphalt. The method takes the emulsified asphalt, the cement and the silty soil as raw materials, can realize an available pavement material, but needs a plurality of devices such as an emulsified asphalt spraying vehicle, a rotary cultivator and the like during large-area construction, and has the defects of complex processing technology, high production cost, complex construction technology, high requirement on construction equipment and the like.

Disclosure of Invention

The invention aims at the defects of the prior art and provides the soil stabilizer which can greatly reduce the construction time, quickly improve the soil curing strength and has good water stability.

The technical scheme adopted by the invention for solving the technical problems is as follows: a soil stabilizer is prepared from the following raw materials in parts by weight:

5-20 parts of foamed asphalt;

2-20 parts of cement.

The preferable weight ratio of the raw materials is as follows:

10-16 parts of foamed asphalt;

8-16 parts of cement.

The foamed asphalt can be prepared by adopting a preparation method of foamed asphalt in the prior art, and consists of asphalt and water, wherein the content of the asphalt is preferably 95-99%, and the best content is 95-97%. The asphalt is preferably SBS modified asphalt, No. 70 asphalt and No. 90 asphalt.

The cement is portland cement, such as ordinary portland cement, portland slag cement, portland pozzolan cement or portland fly ash cement. The cement strength is preferably 32.5 or 42.5.

A further technical task of the present invention is to provide a method for solidifying soil.

When the curing agent is used for curing the silt, the curing agent is uniformly mixed with the silt. The weight ratio of the foamed asphalt, the cement and the soil is (5-20): 2-20): 85-95, and the preferable weight ratio is (10-16): 8-16): 90.

Preferably, a proper amount of additional water can be added in the process of mixing the foamed asphalt, the cement and the soil.

The dosage of the external water is calculated by subtracting the water content of the foamed asphalt and the water content of the soil from the optimal water content, and the optimal water content is obtained by a compaction test of the soil.

The soil is preferably sand-containing low liquid limit silt, low liquid limit clay andor fine-grained soil sand. In actual engineering, if the soil humidity is too high, soil curing treatment is carried out after soil turning and airing. When the indoor experiment is carried out, the dried silt is preferably adopted, and the drying procedure is not required to be added in the actual construction process.

Compared with the prior art, the soil stabilizer has the following outstanding beneficial effects:

by adopting the invention, the construction equipment can be simplified, the mixing of the curing agent and the soil can be completed by adopting a road mixer, the distribution of the asphalt in the soil after the mixing is more uniform, and the mixing effect is better than that of the traditional rotary cultivator;

by adopting the invention, the road mixer can replace an emulsified asphalt spraying vehicle and a rotary cultivator, the construction process is simple, the transportation time of the emulsified asphalt can be saved, the construction speed is high, and the transportation cost is saved;

and thirdly, the soil solidified by the invention has more uniform distribution of asphalt in the soil, so that the asphalt in the soil after compaction is easier to be connected into a net shape, the strength is increased quickly and highly, the water stability is better, the low-temperature crack resistance is better, and the freezing resistance is better.

Detailed Description

The present invention is further illustrated by the following examples, which are not to be construed as limiting the invention.

Unless otherwise specified, the contents of the respective components used below are weight percent contents.

The first embodiment is as follows:

the curing agent of the invention is used for curing the silt with sand and low liquid limit. The material proportion of the curing agent and the curing soil is as follows:

the curing method comprises the following steps:

s1, weighing the dried sand-containing low liquid limit silt and the dried cement according to the weight ratio, placing the mixture in a mixing pot, and fully mixing the mixture by using a stirrer;

s2, weighing water according to the weight ratio, adding the water into the sufficiently mixed silt mixture, and sufficiently mixing the mixture by using a stirrer;

s3, introducing the matrix asphalt, water and air into a foaming mixer to obtain foamed asphalt with the asphalt mass percentage content of 95%, weighing the foamed asphalt according to the weight ratio, adding the weighed foamed asphalt into the mixture, and fully mixing by using a stirrer;

s4, placing the mixed mixture into a mold, forming a test piece according to 95% compactness, and bagging and curing for 3 days, 5 days and 7 days at room temperature.

Comparative example curing method:

s2, preparing an emulsifier aqueous solution according to a mass ratio, then passing the matrix asphalt and the emulsifier aqueous solution through a colloid mill to obtain emulsified asphalt with the asphalt mass percentage content of 53%, then weighing the emulsified asphalt according to the weight ratio, adding the weighed emulsified asphalt into a mixing pot, and fully mixing the weighed emulsified asphalt with a stirrer;

s3, placing the mixed mixture into a mold, forming a test piece according to 95% compactness, and bagging and curing for 3 days, 5 days and 7 days at room temperature.

The test pieces obtained after curing are subjected to unconfined compressive strength tests of different curing dates according to the test regulations of inorganic binder stabilizing materials for highway engineering (JTG E51-2009), the test results are shown in the following table,

example two:

the curing method is the same as in example one, except that: the mass percentage of the asphalt in the foamed asphalt is 97%.

Carrying out unconfined compressive strength tests on test pieces obtained after curing according to highway engineering inorganic binder stable material test regulation (JTG E51-2009) on different curing dates, wherein the test results are shown in the following table:

the tests of the first and second examples show that when the curing agent is used for curing soil, the strength of the soil cured by foamed asphalt is increased faster than that of the soil cured by emulsified asphalt, and meanwhile, the strength after 7 days is higher than that of the soil cured by emulsified asphalt, and the water stability coefficient is higher than that of the soil cured by emulsified asphalt.

The above-described embodiments are merely preferred embodiments of the present invention, and general changes and substitutions by those skilled in the art within the technical scope of the present invention are included in the protection scope of the present invention.

Claims

1. The soil curing agent is characterized by being prepared from the following raw materials in parts by weight:

5-20 parts of foamed asphalt;

2-20 parts of cement.

2. The soil stabilizer according to claim 1, wherein the weight ratio of the raw materials is as follows:

10-16 parts of foamed asphalt;

8-16 parts of cement.

3. The soil solidifying agent according to claim 1 or 2, wherein: the foamed asphalt consists of asphalt and water, and the content of the asphalt is 95-99%.

4. The soil stabilizer according to claim 3, wherein: the cement is portland cement.

5. The soil stabilizer according to claim 4, wherein: the cement strength was 32.5 or 42.5.

6. The soil solidification method is characterized by comprising the following steps: the soil is solidified by the solidifying agent of claim 1, the weight ratio of the foamed asphalt, the cement and the soil is (5-20): 2-20): 85-95.

7. The soil curing method of claim 6, wherein: proper amount of water is added during the mixing process of the foamed asphalt, the cement and the soil.

8. The soil curing method of claim 8, wherein: the dosage of the external water is calculated by subtracting the water content of the foamed asphalt and the water content of the soil from the optimal water content, and the optimal water content is obtained by a compaction test of the soil.