CN108505409B - Solidified muddy soil and construction waste regenerated aggregate composite inorganic material and forming method thereof - Google Patents

Abstract

The invention belongs to the technical field of solid waste resource utilization, and discloses a solidified muddy soil and construction waste regenerated aggregate composite inorganic material and a forming method thereof. The volume ratio of the construction waste regenerated aggregate to the solidified muddy soil is (80-60%): (20% to 40%). The invention adopts waste resources as main raw materials, has low cost and easy production, realizes the resource recycling and conforms to the sustainable development strategy; the composite inorganic binder has the characteristics of scouring resistance, high strength, good water stability, small dry shrinkage and the like after being formed, and is suitable for projects such as roadbed, subbase layer and base layer of urban roads of various grades, mountain filling of mountain-piling and landscaping projects and the like.

Description

Solidified muddy soil and construction waste regenerated aggregate composite inorganic material and forming method thereof

Technical Field

The invention belongs to the technical field of solid waste resource utilization, and particularly relates to a solidified muddy soil and construction waste regenerated aggregate composite inorganic material for engineering and a forming method thereof, which are suitable for construction of projects such as urban road subgrade, subbase layer, base layer, mound landscaping mountain filling and the like of various grades.

Background

With the rapid development of national economy, the process of urbanization in China is accelerated, and the construction waste yield is increasingly huge. According to statistics, the construction waste generated by construction in China each year reaches more than 4000 million tons, but the comprehensive utilization rate of the construction waste is less than 10%, most of the construction waste is directly transported to suburbs or villages by construction units without any treatment, and is treated in an open-air stacking or landfill mode, so that a large amount of cultivated land is occupied, and a large amount of construction cost such as land collection, waste clearing and transportation and the like is consumed. In addition, the problems of scattering, dust and the like in the process of transporting and stacking the construction waste cause serious environmental pollution.

In the engineering, waste slurry with a water content much larger than the liquid limit of the soil body and in a flowing state, such as slurry generated in the engineering construction process of hydraulic fill engineering, underground diaphragm walls, bored piles, trenchless horizontal directional drilling, slurry balanced jacking pipes, slurry pressurized shields and the like, can be cured and utilized on site, and the implementation of policies such as land, environmental protection, ecology and the like can be promoted to the utmost extent.

Disclosure of Invention

Based on the aim of recycling construction waste and engineering waste slurry, the invention provides a solidified muddy soil and construction waste recycled aggregate composite inorganic material and a forming method thereof, which meet the requirements of engineering such as road base layers, road subbase layers, road subgrades, mound landscaping and mountain filling, and have certain strength and stability after forming.

In order to solve the technical problems, the invention is realized by the following technical scheme:

a composite inorganic material of solidified muddy soil and construction waste regenerated aggregate is used for at least one of road base course, road subbase course, road subgrade and filling of piled mountain landscaping mountain; the composite inorganic material consists of construction waste regenerated aggregates and solidified slurry soil, the construction waste regenerated aggregates after grading and mixing form a framework structure, and gaps among the construction waste regenerated aggregates are densely filled with the solidified slurry soil; the volume fraction of the construction waste regenerated aggregate is 80-60%, and the volume fraction of the solidified muddy soil is 20-40%;

the building waste regenerated aggregate is building waste which takes waste bricks and tiles, waste concrete blocks and waste stone blocks as main components, and is crushed by mechanical equipment, impurities such as metal, plastic, wood and the like are separated, and finally, the particles are generated;

the solidified muddy soil is generated by adding a high-efficiency water-reducing powder curing agent into engineering waste mud and uniformly stirring, wherein the high-efficiency water-reducing powder curing agent accounts for 5-7% of the mass of the engineering waste mud;

the engineering waste slurry is slurry generated in any one or more engineering construction processes of hydraulic filling, underground continuous walls, cast-in-situ bored piles, trenchless horizontal directional drilling, slurry balance type jacking pipes and slurry pressure type shields.

Wherein the concrete particle content of the construction waste recycled aggregate is not less than 90%, the crushing value is not more than 30%, and the needle-shaped particle content is not more than 15%.

Wherein the water content of the engineering waste slurry is 140-160%.

A forming method of the solidified muddy soil and construction waste regenerated aggregate composite inorganic material comprises the following steps:

(1) preparing construction waste recycled aggregate:

carrying out secondary crushing, impurity sorting, screening and mud removal on a construction waste raw material which is taken from a construction waste disposal plant and subjected to primary crushing and sorting to prepare a construction waste regenerated aggregate with concrete particle content not less than 90%, crushing value not more than 30% and needle-shaped particle content not more than 15%;

(2) preparing construction waste regeneration graded aggregate:

grading the construction waste recycled aggregate obtained in the step (1) according to the porosity of 20-40%, wherein the particle composition range of the recycled graded aggregate is shown in Table 1; blending after grading to uniformly mix particles with various sizes;

TABLE 1 particle composition ranges for reclaimed grade aggregates

Mesh size (mm)	Percent by mass (%)
		37.5	100
31.5	90～95
		19.0	60～79
9.5	35～58
		4.75	22～40
2.36	14～28
		0.6	5～13
0.075	0～3

(3) Preparing solidified slurry soil:

transporting the collected engineering waste slurry to a slurry pool, and controlling the water content of the engineering waste slurry to be 140-160%; adding a high-efficiency water-reducing powder curing agent accounting for 5-7% of the mass of the engineering waste slurry and uniformly stirring;

(4) paving, pouring, molding and maintaining:

paving the construction waste regeneration graded aggregate obtained in the step (2), wherein the loose paving coefficient is 1.25-1.40; leveling and shaping are carried out after paving, and rolling is carried out until the compactness required by design is achieved, so as to form a structural layer; pumping the solidified slurry soil obtained in the step (3) into a structural layer by using a slurry pump, stopping pumping when the solidified slurry soil overflows from the surface of the structural layer after a gap in the structural layer is completely filled with the solidified slurry soil, and continuously stirring the solidified slurry soil to prevent delamination in the construction process; the maintenance adopts the covering of the permeable geotextile for watering and maintenance.

Wherein, the mixing in the step (2) adopts a centralized plant mixing method or a road mixing method.

Wherein, the paving in the step (4) adopts mechanical paving.

The invention has the beneficial effects that:

(1) the solidified muddy soil and construction waste regenerated aggregate composite inorganic material and the forming method thereof adopt the construction waste regenerated aggregate and the engineering waste mud as raw materials, and are doped with the high-efficiency water-reducing powder curing agent for preparation, thereby realizing the regeneration and utilization of waste resources, further saving the construction materials, reducing the construction cost, being beneficial to absorbing and treating the construction waste, reducing the environmental and social economic costs caused by the treatment of the construction waste, promoting the urbanization process, realizing the green, environment-friendly and sustainable development of the construction industry, and meeting the national sustainable development strategic requirements of resource conservation, construction greenization and development ecology.

(2) The solidified muddy soil and construction waste regenerated aggregate composite inorganic material has the characteristics of scouring resistance, high strength, good water stability, small dry shrinkage and the like after being molded, and is suitable for the construction of projects such as urban road subgrade, subbase layer, base layer, hilltop landscaping mountain filling and the like of various grades.

Drawings

FIG. 1 is a schematic view of a forming structure of a solidified muddy soil and construction waste regenerated aggregate composite inorganic material provided by the present invention; in the figure: 1: building waste regeneration aggregate; 2: and solidifying the muddy soil.

Detailed Description

The invention is described in further detail below by means of specific examples:

the following examples are presented to enable those skilled in the art to more fully understand the present invention and are not intended to limit the invention in any way.

The raw materials used in the examples of the present invention are illustrated below:

building waste regeneration collecting: the building garbage is prepared by taking a building garbage raw material which is obtained from a building garbage disposal plant and subjected to primary crushing and sorting through the processes of secondary crushing, screening and the like in a laboratory; meets the requirements of the industry standard DB13(J) T155.

Engineering waste slurry: taking slurry generated from a cast-in-situ bored pile construction site; the slurry can represent slurry generated in engineering construction processes of hydraulic filling, underground continuous walls, cast-in-place bored piles, trenchless horizontal directional drilling, slurry balance type jacking pipes, slurry pressurizing type shields and the like, the water content of the slurry needs to be 140% -160%, and measures such as airing, clay adding, water adding and the like are adopted when the water content of the slurry is not met.

High-efficiency water-reducing powder curing agent: a powder curing agent, model GURS-501, was supplied by International Union, Inc. (Taiwan).

The solidified muddy soil and construction waste regeneration aggregate composite inorganic material is used as a road base layer, a road subbase layer and a road subgrade, and the concrete construction steps are as follows:

examples 1, 2 and 3 in tables 2 to 6 represent the preparation of composite inorganic materials for use as a road base layer, a road subbase layer and a road roadbed, respectively.

A. Preparing construction waste recycled aggregate:

preparing building garbage recycled aggregate from building garbage disposal plants by primary crushing and sorting according to the following steps: (1) crushing the raw material to a particle size of below 40mm by using a jaw crusher in a laboratory; (2) manually sorting and removing impurities such as glass, plastics and the like; (3) placing the crushed construction waste subjected to impurity sorting into a sieving machine in batches for sieving, and stacking the sieved aggregates according to the particle size; (4) and putting the aggregate into a washing pool, washing with water to remove mud, and then sending into an electrothermal blowing drying oven for drying.

The content of concrete particles in the prepared construction waste recycled aggregate is not less than 90%, the crushing value is not more than 30%, and the content of needle-shaped particles is not more than 15%.

B. Preparing construction waste regeneration graded aggregate:

the prepared construction waste recycled aggregate is subjected to mix proportion design, and the porosity of the construction waste recycled graded aggregate is ensured to be 20% -40%, as shown in Table 2.

The aggregate quantity required by each grain diameter is calculated according to the table 2, the aggregate is poured into a stirrer to be stirred for not less than 2 minutes, and when the aggregate is used in actual engineering, a centralized plant mixing method or a road mixing method can be adopted to ensure that the mixture is uniform.

TABLE 2 construction waste regeneration grading aggregate particle composition

C. Preparing solidified slurry soil:

and (3) pouring the collected slurry generated in the construction process of the cast-in-situ bored pile into three slurry barrels (marked as 1#, 2#, and 3# barrels), sampling and measuring the water content to ensure that the water content of the slurry is 140% -160%, and taking measures such as airing, clay adding, water adding and the like when the water content of the slurry is not satisfied.

After the amount of the GURS-501 curing agent required to be added is calculated according to the mass fractions of 5%, 6% and 7%, the corresponding GURS-501 curing agent is sequentially added into No. 1, No. 2 and No. 3 mud buckets and is uniformly stirred. The mud buckets 1#, 2#, and 3# correspond to example 1, example 2, and example 3, respectively. The evenly stirred solidified muddy soil is poured within 30 minutes.

D. Compacting, pouring and forming:

selecting inorganic binder stable material compaction test method C according to JTG E51, adopting heavy type II standard compaction method, preparing the prepared construction waste regeneration graded aggregate according to 3 layers compaction method, wherein each layer of the compaction method has 98 times of hammering times, and the average unit compaction work is 2677kJ/cm³The volume of the test tube is 2177cm³。

A group of test pieces are respectively selected from three examples to measure the bulk density and porosity of the construction waste regeneration graded aggregate.

And (3) conveying the prepared solidified slurry soil to a test cylinder by using a grouting pipe, and stopping grouting after the gap of the building waste regenerated aggregate is completely filled by the solidified slurry soil and the solidified slurry soil overflows along the surface of the test piece. In the grouting process, the muddy soil should be continuously stirred and solidified to prevent delamination.

E. Health preserving: and (3) watering and maintaining by covering the permeable geotextile, keeping the surface of the structural layer moist, keeping the maintenance for at least 7 days, and forbidding motor vehicles to pass during the maintenance.

And (4) measuring the relevant road performance index of the test piece after the test piece is cultured.

The test results of the above examples are as follows:

performance test of construction waste regenerated aggregate

The performance test of the construction waste recycled aggregate prepared in the step A in the examples 1-3 is carried out, and the test results are shown in Table 3. Wherein the content of concrete particles in the reclaimed aggregate is performed with reference to DB13 (J)/T155; the crushing value is carried out according to the T0316-; the content of the needle-shaped particles is carried out according to the test method of T0312-; the apparent density was determined by reference to the T0304-2005 test method in JTG E42.

TABLE 3 Performance test results of construction waste recycled aggregates

(II) Performance test of construction waste recycled graded aggregate

The test results of the bulk density and the porosity of the construction waste recycling graded aggregate prepared in the examples 1-3 by referring to the test method of T0309-2005 in JTG E42 are shown in Table 4. As can be seen from Table 4, the porosity of the construction waste recycled graded aggregate is 20-40%, i.e. the volume fraction of the construction waste recycled aggregate is 80-60%, and the volume fraction of the solidified muddy soil is 20-40%.

TABLE 4 Performance test results of construction waste recycled graded aggregate

(III) testing of the Properties of the slurries

The water content of the slurries used in examples 1 to 3 was measured by referring to test method T0103-1993 in JTG E40, and the results are shown in Table 5. As is clear from Table 5, the water content of the treated waste slurry was 140% to 160%.

TABLE 5 test results of the water content of the engineering waste slurry after treatment

Examples	1	2	3
				Water content of undisturbed slurry(％)	145	145	145
Percentage of water content of slurry after treatment (%)	140	150	160

(IV) Performance test of cured muddy soil and construction waste regenerated aggregate composite inorganic material

The cured muddy soil and construction waste recycled aggregate composite inorganic material prepared in examples 1 to 3 were subjected to performance tests, and the test results are shown in table 6. Wherein the 7-day unconfined compressive strength is carried out according to the test method T0805-1994 in JTG E51; the modulus of resilience is carried out according to test method T0807-1994 in JTG E51; freezing resistance is carried out after 28 days of curing according to a T0858-2009 freezing and thawing test method in JTG E51; the drying shrinkage performance was performed according to the T0854-2009 drying shrinkage test method in JTG E51; the antiscour performance is carried out after 28 days of health maintenance according to the T0860-2009 test method in JTG E51.

TABLE 6 road-use Properties of composite inorganic Material

The results of the road performance tests in table 6 show that the solidified muddy soil prepared in examples 1 to 3 and the construction waste recycled aggregate composite inorganic material can be completely and respectively used for the roadbed, the subbase and the base course of the urban road of each grade, and the main performance indexes of the inorganic material can meet the requirements of the existing industry standard CJJ 169.

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and those skilled in the art can make various changes and modifications within the spirit and scope of the present invention without departing from the spirit and scope of the appended claims.

Claims (4)

1. A solidified muddy soil and construction waste regenerated aggregate composite inorganic material is characterized by being used for at least one of road base course, road subbase course, road subgrade and mound landscaping mountain filling; the composite inorganic material consists of construction waste regenerated aggregates and solidified slurry soil, the construction waste regenerated aggregates after grading and mixing form a framework structure, and gaps among the construction waste regenerated aggregates are densely filled with the solidified slurry soil; the volume fraction of the construction waste regenerated aggregate is 80-60%, and the volume fraction of the solidified muddy soil is 20-40%;

the building waste regenerated aggregate is building waste which takes waste bricks and tiles, waste concrete blocks and waste stone blocks as main components, and is crushed by mechanical equipment, impurities are separated out, and finally, the aggregate is generated;

the solidified muddy soil is generated by adding a high-efficiency water-reducing powder curing agent into engineering waste mud and uniformly stirring, wherein the high-efficiency water-reducing powder curing agent accounts for 5-7% of the mass of the engineering waste mud;

the engineering waste slurry is slurry generated in any one or more engineering construction processes of hydraulic filling, underground continuous walls, cast-in-situ bored piles, trenchless horizontal directional drilling, slurry balance type jacking pipes and slurry pressure type shields.

2. The inorganic material as claimed in claim 1, wherein the concrete particle content of the construction waste recycled aggregate is not less than 90%, the crushing value is not more than 30%, and the needle-shaped particle content is not more than 15%.

3. The inorganic composite material of the solidified muddy soil and construction waste regenerated aggregate according to claim 1, wherein the water content of the engineering waste mud is 140% -160%.

4. A process for forming a solidified muddy soil and construction waste regenerated aggregate composite inorganic material as claimed in any one of claims 1 to 3, characterized by comprising the steps of:

(1) preparing construction waste recycled aggregate:

carrying out secondary crushing, impurity sorting, screening and mud removal on a construction waste raw material which is taken from a construction waste disposal plant and subjected to primary crushing and sorting to prepare a construction waste regenerated aggregate with concrete particle content not less than 90%, crushing value not more than 30% and needle-shaped particle content not more than 15%;

(2) preparing construction waste regeneration graded aggregate:

grading the construction waste recycled aggregate obtained in the step (1) according to the porosity of 20-40%, and mixing after grading to uniformly mix particles of all sizes;

(3) preparing solidified slurry soil:

the collected engineering waste slurry is transported to a slurry pool, and the water content of the engineering waste slurry is controlled to be 140% -160%; adding a high-efficiency water-reducing powder curing agent accounting for 5-7% of the mass of the engineering waste slurry, and uniformly stirring;

(4) paving, pouring, molding and maintaining:

paving the construction waste regeneration graded aggregate obtained in the step (2), wherein the loose paving coefficient is 1.25-1.40; leveling and shaping are carried out after paving, and rolling is carried out until the compactness required by design is achieved, so as to form a structural layer; pumping the solidified slurry soil obtained in the step (3) into a structural layer by using a slurry pump, stopping pumping when the solidified slurry soil overflows from the surface of the structural layer after a gap in the structural layer is completely filled with the solidified slurry soil, and continuously stirring the solidified slurry soil to prevent delamination in the construction process; the maintenance adopts the covering of the permeable geotextile for watering and maintenance.

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