CN110723938B - Fluidized solidified soil and preparation method thereof - Google Patents

Abstract

The application provides fluid solidified soil and a preparation method thereof, and the fluid solidified soil comprises the following formula components in parts by mass: 15-20 parts of residue soil, 5-7 parts of ceramic sand, 6-7 parts of water, 1.5-2.5 parts of cement, 0.3-0.5 part of fly ash and 0.005-0.01 part of early strength agent. The preparation method provided by the application comprises the following steps: crushing the muck, removing foreign matters and polluted and deteriorated parts in the muck, respectively weighing each component according to the formula of the fluid solidified soil, and mixing and stirring the weighed components until the texture is uniform to obtain a finished product. The fluid-state solidified soil prepared by the ceramic sand in the formula can play a grading role, so that the volume stability and the bearing capacity of the prepared fluid-state solidified soil are increased, the in-situ resource utilization of the residue soil is realized, the purchase cost of external backfill materials is reduced, and meanwhile, the utilization approaches of novel regeneration building materials such as river sediment resource ceramic sand and fly ash are increased.

Description

Fluidized solidified soil and preparation method thereof

Technical Field

The application relates to the field of civil engineering, in particular to fluidized solidified soil and a preparation method thereof.

Background

The urban construction in China is in a high-speed development stage, wherein road backfilling is a problem which is often faced, such as backfilling after pipeline burying is carried out on urban road subgrade grooving, backfilling around inspection wells, digging and backfilling, and the like.

According to the traditional road backfilling mode, excavated dregs are treated as construction wastes, and are backfilled by using a large amount of stone slag powder, fine silt and other external backfilling materials, so that the environment is polluted by a large amount of construction wastes, the pressure of traffic transportation is increased, the construction efficiency is influenced, and meanwhile, a large amount of backfilling materials are required to be purchased, and higher economic cost is caused.

Disclosure of Invention

Compared with the traditional road backfilling mode, the method takes the residue soil dug out in construction as a main backfilling material, thereby reducing the generation of construction waste and the purchase of the backfilling material, and improving the construction efficiency and the economic benefit.

The application provides fluid solidified soil which comprises the following formula components in parts by mass: 15-20 parts of residue soil, 5-7 parts of ceramic sand, 6-7 parts of water, 1.5-2.5 parts of cement, 0.3-0.5 part of fly ash and 0.005-0.01 part of early strength agent.

The grain size of the slag soil is less than or equal to 40mm, the content of grains with the grain size less than 2mm is not more than 55 wt%, and the content of grains with the grain size of 5-20mm is not more than 30 wt%.

The content of organic matters in the residue soil is not more than 5 wt%.

The muck is at least one of non-saline soil, weak saline soil or medium saline soil.

The particle size of the pottery sand is less than or equal to 20 mm.

The content of non-metal elements and heavy metal elements in the ceramic sand is less than 0.11 wt%;

the non-metallic elements include: arsenic;

the heavy metal elements include: copper, zinc and lead.

The cement is at least one of Portland cement, ordinary portland cement, slag portland cement, pozzolanic portland cement, fly ash portland cement or composite portland cement.

The fly ash adopts second-grade fly ash.

The early strength agent is at least one of a chloride early strength agent, a sulfate early strength agent, a nitrate early strength agent, an organic early strength agent or a composite early strength agent.

The preparation method of the fluid solidified soil comprises the following steps of:

s1: removing foreign matters and polluted and deteriorated parts in the residue soil;

s2: weighing the components according to the formulation of the fluid solidified soil of any one of claims 1 to 9;

s3: mixing the weighed components, stirring until the texture is uniform to obtain the finished product

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in:

as can be seen from the above, according to the fluid solidified soil and the preparation method thereof provided by the application, the dregs are used as a main component, and proper ceramic sand, water, cement, fly ash, an early strength agent and the like are added for stirring, the pottery sand is used in the formula to prepare the fluid solidified soil, so that the grading effect can be achieved, the volume stability and the bearing capacity of the prepared fluid solidified soil are increased, the in-situ resource utilization of the dregs is realized, the engineering problems of outward transportation, accumulation and treatment of the dregs are solved, the purchase cost of external backfill materials is reduced, and meanwhile, the utilization way of novel renewable building materials such as river sediment resource ceramic sand and fly ash is increased, so that the technical scheme reduces the environmental pollution and the economic cost caused in the engineering construction process.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Example one

The embodiment of the invention provides fluid solidified soil which comprises the following formula components in parts by weight:

the muck in the first embodiment may be from foundation trench excavation in building construction.

Optionally, the muck is mainly composed of cohesive soil and sandy soil with fine particle size, when cement and water are added and stirred, various components in the cement and water in the muck generate strong hydrolysis reaction and hydration reaction, and calcium hydroxide and other hydrates are formed from the solution to harden the hydrates of the cement.

Optionally, the grain size of the residue soil is less than or equal to 40mm, the content of grains with the grain size of less than 2mm is not more than 55 wt%, and the content of grains with the grain size of 5-20mm is not more than 30 wt%.

It should be noted that, when the content of particles with a particle size of less than 2mm in the residue soil exceeds 55 wt%, the prepared fluid solidified soil has poor effect and is not economical; when the content of particles with the particle size of 5-20mm in the muck exceeds 30 wt%, the prepared fluid solidified soil has uneven properties, the quality is not easy to control, and a serious bleeding phenomenon can occur. Further, when the content of particles with the particle size of more than 40mm in the residue soil exceeds 15 wt%, the residue soil is separated out to ensure the fluidity and the strength of the fluid solidified soil.

Optionally, the content of organic matters in the residue soil is not more than 5 wt%. It should be noted that, when the content of organic matters in the residue soil is higher, the influence on the soil quality is larger, and when the content of the organic matters exceeds a certain degree, the organic matters are digested to form holes, so that the soil body is not compact, the bearing capacity and stability of the soil body are deteriorated, and different influences on the doping of different engineering materials are caused. Specifically, organic matters in a small amount of residue soil are removed, and the residue soil can be stir-fried by a pan with soil; removing organic matters in the residue soil, turning over with hoe, spreading rice straw or wheat straw, and burning with strong fire.

Optionally, the muck is at least one of non-saline soil, weak saline soil or medium saline soil. Optionally, after the strongly saline soil is treated, 4.6 strong saline soil meeting the earthwork and blasting engineering construction and acceptance criteria (GB50201-2012) can also be used. Specifically, the content of sulfate in the slag soil is not more than 2 wt%, and the content of soluble carbonate is not more than 0.5 wt%.

The salinized soil is soil which contains soluble salts such as gypsum, mirabilite and rock salt (sulfate or chloride) in the soil layer, has the content of more than 0.5 wt%, has the characteristics of solubility, expansibility and corrosivity, has large change of bearing capacity of a region backfilled by the salinized soil, changes along with the change of seasons and climates, has a crystalline state of salt during drying, has higher bearing capacity of a foundation, and reduces the bearing capacity and increases the compressibility after crystals are dissolved into liquid once soaked in water; the sulfur sulfate-containing crystals in the residual soil expand in volume, the volume is reduced after dissolution, the structure of a backfill area is easy to damage, the strength is reduced, and loose saline soil is formed; because the salt is dissolved when meeting water, the backfill area is easy to generate corrosion phenomenon, and the stability is reduced.

Optionally, the particle size of the pottery sand is less than or equal to 20 mm. Specifically, the ceramsite can be at least one of bauxite ceramsite sand, fly ash ceramsite sand, clay ceramsite sand, shale ceramsite sand, garbage ceramsite sand, coal gangue ceramsite sand and biological sludge ceramsite sand. Further, the ceramic sand can be formed by drying, raw material ball preparation, drying, presintering, roasting and cooling treatment of the river sediment. Further, the fly ash ceramsite sand is prepared by taking solid waste as a main raw material, adding a certain amount of cementing material and water, processing into balls, sintering, expanding or naturally curing.

It should be noted that in the urban water environment comprehensive treatment project, a great amount of bottom mud or sludge is generated by dredging the river channel, and the conventional treatment method is to prepare the bottom mud or sludge into ceramic sand, ceramic bricks, garden soil and the like. This application utilizes the pottery sand to replace conventional backfill material river sand, quartz sand etc. and the pottery sand granule degree of consistency is better, intensity is higher, and the flow state solidified soil mechanical properties of preparation is more stable, and the cementation action that ordinary cement produced is similar conventional concrete, can not fill up the hole between the mixture granule, and at this moment, the pottery sand can play the effect of grading, makes the flow state solidified soil volume stability of preparation increase, bearing capacity increase. Meanwhile, the slag soil and the ceramic sand are prepared into the fluid-state solidified soil, so that backfill materials required after the existing pipe network foundation trench is excavated can be replaced in a large range, and the novel regenerated building materials are effectively utilized for the ceramic sand made of the slag soil and the river channel bottom mud.

Optionally, the content of non-metal elements and heavy metal elements in the ceramic sand is less than 0.11 wt%; the non-metallic elements include: arsenic; the heavy metal elements include: copper, zinc and lead. Specifically, the contents of inorganic pollutants such as lead, chromium, cadmium, mercury, arsenic, zinc, copper, nickel, fluorine and other heavy metals and non-metallic elements in the residue soil meet the national standard of soil environmental quality (GB15618-1995), and the residue soil cannot cause damage to the environment.

Optionally, the cement is at least one of portland cement, ordinary portland cement, portland slag cement, pozzolanic portland cement, portland fly ash cement, or composite portland cement. The concrete choice of which cement to prepare the fluid solidified soil can be selected according to the characteristics of the cement and the actual conditions of a construction site, such as the pozzolanic portland cement, has low early strength, faster later strength increase, lower hydration heat, poorer heat resistance, better resistance to sulfate corrosion and water resistance, and can be used for large-volume concrete engineering, civil building engineering and the like; for example, the composite Portland cement has high early strength and quick setting and hardening, and can be used for roads, underwater engineering and the like.

Optionally, the fly ash is second-grade fly ash. It should be noted that, China produces a large amount of fly ash every year, most of the fly ash is buried, land resources are occupied, and the surrounding environment is polluted.

Optionally, the early strength agent is at least one of a chloride early strength agent, a sulfate early strength agent, a nitrate early strength agent, an organic early strength agent or a composite early strength agent. The early strength agent has the main functions of accelerating the hydration speed of the cement and promoting the development of the early strength of the concrete; not only has the early strength function, but also has certain water reducing and enhancing functions.

According to the scheme, in the first embodiment of the application, the muck is used as a main backfill material, and meanwhile, regenerated building materials such as ceramic sand and fly ash are properly matched, so that the environment can be protected, the effective utilization of building garbage can be realized, the economic cost can be reduced, and the resources can be saved.

Example two

Corresponding to the fluid solidified soil of the first embodiment, a preparation method of the fluid solidified soil provided by the second embodiment of the application is provided. For convenience of explanation, only the portions related to the present embodiment are shown below.

The raw material of the fluid solidified soil is prepared by the following steps:

s1: crushing the residue soil and removing foreign matters and polluted and deteriorated parts in the residue soil;

s2: weighing the components according to the formulation of the fluid solidified soil of any one of claims 1 to 9;

s3: mixing and stirring the weighed components until the texture is uniform, thus obtaining the finished product.

For the fluid solidified soil, please refer to the description in the first embodiment, and the description thereof is omitted here.

Specifically, S1 includes: the method comprises the following steps of crushing the residue soil to a certain extent, reducing sticky blocks of the residue soil to improve the utilization rate of the residue soil, and simultaneously removing broken stones, wood chips, iron sheets, polluted and smelly river sediment and other foreign matters in the residue soil.

Specifically, S2 includes: the components are weighed according to the formula of the fluid solidified soil.

Specifically, S3 includes: mixing and stirring the weighed components until the texture is uniform, thus obtaining the finished product. Furthermore, the stirring can adopt double-shaft stirring, the mixed material is quickly stirred into a uniform flowing state by utilizing the quick stirring and scattering action of the blades, and the stirring time can be determined according to the requirements of a construction site and the attributes of backfill soil. Specifically, the stirring time may be 5 to 10 minutes.

After the preparation is completed according to the preparation method, the flow value and unconfined compressive strength of the prepared finished product need to be tested, and the method specifically comprises the following steps:

1) flow value test

The flow value testing device consists of a plexiglas flat plate and a plexiglas cylindrical barrel (only the cylindrical side part) with the height of 80mm and the diameter of 80 mm. During the test, firstly, wiping off the dust on the inner wall of the organic glass cylinder and the surface of the organic glass flat plate by using a cleaning cloth, coating a layer of vaseline on the inner wall of the organic glass, placing the organic glass cylinder on the horizontal organic glass flat plate, and wetting the surface of the organic glass flat plate; then, filling the sludge or the newly stirred and solidified sludge into an organic glass cylinder, continuously vibrating in the sample filling process to ensure that the sample is tightly filled, scraping the surface by using a scraper after the sample is filled, and wiping off the sludge scattered on the wall of the outer cylinder and the plate surface by using a rag; after the sample loading is finished, the organic glass cylinder is lifted up slightly vertically, after 30s, the maximum diameter and the minimum diameter of the spread mixture are measured by a steel ruler, and the average value of the maximum diameter and the minimum diameter is taken as a flow value. In order to ensure the reliability of the test, each group of samples needs to be subjected to 2-3 parallel tests, and the average value is taken as a final flow value;

2) unconfined compressive strength test

Unconfined compressive strength testing was performed according to geotechnical test method Standard (GB/T50123-1999). The instrument used in the test is a YYYW-2 strain control type unconfined pressure instrument produced by Nanjing soil instrument factory, and the compression rate is 1.18 mm/min. In order to ensure the reliability of the test, each group of samples needs to be subjected to 2-3 parallel tests, and the average value is taken as the final unconfined compressive strength;

3) california Bearing Ratio (CBR)

And pouring the mixed fluidized soil into a CBR steel cylinder, curing, and performing a penetration experiment after the curing age is reached. Firstly, a test piece is placed on a lifting table of a pavement material strength tester, an eccentric seat is adjusted, the test piece is aligned and leveled, a penetration rod is enabled to be in full contact with the top surface of the test piece, and 4 load bearing plates are placed around the penetration rod. Secondly, a 45N load is applied to the penetration rod, then pointers of dial indicators for measuring force and deformation are adjusted to be integral numbers, and initial reading is recorded. Thirdly, loading to press the penetration rod into the test piece at a speed of 1-1.25mm/min, and simultaneously measuring and recording the readings of the three dial indicators. The penetration was recorded for some whole reading (e.g. 20, 40, 60) of the dial gauge in the dynamometer and care was taken that more than 5 readings were possible for a penetration of 250 x 10-2 mm. The first reading in the dynamometer should therefore be taken at a penetration of around 30 x 10-2mm and after completion of the reading, the ratio of the specific pressure at a penetration of 2.5mm to the standard pressure is generally used as the load ratio of the material (CBR value). If the bearing ratio when the penetration amount is 5mm is larger than that when the penetration amount is 2.5mm, the test should be redone. If the results are still the same, the load ratio at 5mm is adopted as the load ratio of the material (CBR value).

In the embodiment of the application, the test qualification standard is defined as:

1) the flow value is 180-250mm, and can be modified according to the requirements of a backfill area under the condition of special requirements;

2) the unconfined compressive strength is more than 50-100kPa for 1 day, the unconfined compressive strength is about 300-400kPa for 7 days, and the unconfined compressive strength is less than or equal to 500-900kPa for 28 days;

3) the CBR test was carried out by taking samples on site, and when the value of the pressure gauge reached 780kPa at a penetration of 2.5mm, the corresponding CBR value was about 11%.

The CBR value of the fluid solidified soil satisfies the quality standards of the "road bed design rule" (JTG D30-2015) in our country, and the flow value and the unconfined compressive strength load satisfy the methods of the JHS a313-1992 specifications エアモルタル and the crotch エアミルク test in japan construction province.

According to the scheme, in the second embodiment of the application, the muck is crushed, and according to the actual situation of a construction site, proper ceramic sand, water, cement, fly ash and an early strength agent are mixed, uniformly stirred and poured into a backfill area, so that the treatment work of construction waste can be reduced, and the cost for purchasing backfill materials can be saved.

EXAMPLE III

Selecting the following components in parts by mass:

wherein, the content of the particles with the particle diameter less than 2mm in the weak saline soil is 50 wt%, and the content of the particles with the particle diameter of 5-20mm is 25 wt%; the content of organic matters in the weak saline soil is 2 wt%.

The preparation process comprises the following steps:

s1: the weak saline soil is crushed to a certain degree, and then the crushed stones, wood chips, iron sheets, polluted and smelly river sediment and other foreign matters in the soil are removed.

S2: the components are weighed according to the formula of the fluid solidified soil.

S3: and (3) mixing and stirring the weighed components for 5 minutes by adopting double-shaft stirring until the texture is uniform, thus obtaining the finished product.

Example results of the three-fluid solidified soil relevant performance test:

water-solid ratio: 0.275

Fluidity: 185mm

Unconfined compressive strength: 65kPa for 1 day, 310kPa for 7 days, and 500kPa for 28 days

CBR value: 10 percent.

According to the scheme, when the backfill construction of the abutment backs of the bridges and culverts of the expressway is faced, the early strength is required to be high, the setting and hardening are fast, in the third embodiment of the application, materials such as composite portland cement, fly ash pottery sand and the like are selected to be mixed with muck, and tests show that the CBR value of the fluidized solidified soil meets the quality standard of the design specification of highway subgrade (JTG D30-2015) in China, and the flow value and the unconfined compressive strength meet the methods of test of JHS A313-1992 specifications エアモルタル and difined エアミルク in Japan construction province.

Example four

Selecting the following components in parts by mass:

wherein, the content of the particles with the particle diameter less than 2mm in the weak saline soil is 55wt percent, and the content of the particles with the particle diameter of 5-20mm is 25wt percent; the content of organic matters in the weak saline soil is 3 wt%.

The preparation process comprises the following steps:

s1: the weak saline soil is crushed to a certain degree, and then the crushed stones, wood chips, iron sheets, polluted and smelly river sediment and other foreign matters in the soil are removed.

S2: the components are weighed according to the formula of the fluid solidified soil.

S3: and mixing and stirring the weighed components for 10 minutes until the texture is uniform, thus obtaining the finished product.

Example four test results of the relevant properties of fluid-state solidified soil:

water-solid ratio: 0.233

Fluidity: 200mm

Unconfined compressive strength: 50kPa for 1 day, 310kPa for 7 days, and 525kPa for 28 days

CBR value: 11 percent.

It can be seen from the foregoing solutions that, in the face of civil construction engineering backfill construction, it is necessary that the sulfate corrosion resistance and water resistance are good, in the fourth embodiment of the present application, materials such as pozzolana portland cement and fly ash pottery sand are selected to be mixed with muck, and tests show that the CBR value of the fluid solidified soil meets the quality standard of the highway subgrade design specification (JTG D30-2015) in China, and the flow value and the unconfined compressive strength meet the methods of the JHS a313-1992 specification エアモルタル and the fell エアミルク test in japan construction province.

EXAMPLE five

Selecting the following components in parts by mass:

wherein, the content of the particles with the particle diameter less than 2mm in the weak saline soil is 50 wt%, and the content of the particles with the particle diameter of 5-20mm is 27 wt%; the content of organic matters in the weak saline soil is 3 wt%.

The preparation process comprises the following steps:

s1: the weak saline soil is crushed to a certain degree, and then the crushed stones, wood chips, iron sheets, polluted and smelly river sediment and other foreign matters in the soil are removed.

S2: the components are weighed according to the formula of the fluid solidified soil.

S3: and (3) mixing and stirring the weighed components for 8 minutes by adopting double-shaft stirring until the texture is uniform, thus obtaining the finished product.

Example five test results of the relevant properties of the fluid-state solidified soil:

water-solid ratio: 0.246

Fluidity: 185mm

Unconfined compressive strength: 80kPa for 1 day, 350kPa for 7 days, and 500kPa for 28 days

CBR value: 10 percent.

As can be seen from the foregoing, in the case of pipeline backfill construction, it is necessary to have high early strength and rapid setting and hardening, in the third embodiment of the present application, materials such as fly ash portland cement and fly ash pottery sand are selected and mixed with the muck, and tests show that the CBR value of the fluid solidified soil meets the quality standard of the "road foundation design specification" (JTG D30-2015) in our country, and the flow value and the unconfined compressive strength meet the methods of the specifications エアモルタル and 35 test "of the japan construction province JHS a313-1992 specifications of エアモルタル and outrigger エアミルク.

The above description is only an example of the present invention and should not be construed as limiting the scope of the present invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (8)

1. The fluid solidified soil is characterized by comprising the following formula components in parts by mass:

the grain size of the slag soil is less than or equal to 40mm, the content of grains with the grain size less than 2mm is not more than 55 wt%, and the content of grains with the grain size of 5-20mm is not more than 30 wt%;

the cement is at least one of Portland cement, ordinary portland cement, slag portland cement, pozzolanic portland cement, fly ash portland cement or composite portland cement.

2. The fluidized solidified soil according to claim 1, wherein the content of organic matter in the muck is not more than 5 wt%.

3. The fluidized solidified soil according to claim 1, wherein the muck is at least one of non-saline soil, weakly saline soil or moderately saline soil.

4. The fluidized solidified soil according to claim 1, wherein the grain size of the ceramic sand is less than or equal to 20 mm.

5. The fluidized solidified soil according to claim 4, wherein the content of non-metal elements and heavy metal elements in the ceramic sand is less than 0.11 wt%;

the non-metallic elements include: arsenic;

the heavy metal elements include: copper, zinc and lead.

6. The fluidized solidified soil according to claim 1, wherein the fly ash is secondary fly ash.

7. The fluidized solidified soil according to claim 1, wherein the early strength agent is at least one of a chloride early strength agent, a sulfate early strength agent, a nitrate early strength agent, an organic early strength agent or a composite early strength agent.

8. A method for preparing fluid solidified soil, which is characterized in that the raw material of the fluid solidified soil according to any one of claims 1 to 7 is prepared by the following steps:

s1: crushing the residue soil and removing foreign matters and polluted and deteriorated parts in the residue soil;

s2: weighing the components according to the formula of the fluid solidified soil according to any one of claims 1 to 7;

s3: mixing and stirring the weighed components until the texture is uniform, thus obtaining the finished product.