阅读说明：本技术 弃土再生回填材料及其制备方法 (Spoil regeneration backfill material and preparation method thereof ) 是由 徐浩 薛信恺 蒋自胜 侯志强 苏良缘 商放泽 李金波 于 2019-09-24 设计创作，主要内容包括：本申请提供了一种弃土再生回填材料及其制备方法,该配方将弃土作为主要成分,掺入适量的水泥、水、早强剂,混合搅拌制备成弃土再生回填材料；该制备方法包括以下步骤：除去异物、污染变质部分,按照配方分别称取各组分,将称取好的各组分进行混合搅拌至质地均匀,即得成品。上述弃土再生回填材料及其制备方法实现了对弃土的再利用,减小了管道开挖作业对环境的污染,降低了回填作业的工程造价,增强了回填材料的流动性。(The application provides a spoil regeneration backfill material and a preparation method thereof, the formula takes spoil as a main component, and proper amount of cement, water and early strength agent are added, mixed and stirred to prepare the spoil regeneration backfill material; the preparation method comprises the following steps: removing foreign matters and polluting deteriorated parts, respectively weighing the components according to the formula, and mixing and stirring the weighed components until the texture is uniform to obtain the finished product. The spoil regeneration backfill material and the preparation method thereof realize the reutilization of spoil, reduce the pollution of pipeline excavation operation to the environment, reduce the engineering cost of backfill operation and enhance the fluidity of the backfill material.)

1. The waste soil regeneration backfill material is characterized by comprising the following formula components in parts by mass:

2. the spoil reclamation backfill material according to claim 1 wherein the organic matter content of the spoil does not exceed 5 wt%.

3. The improved spoil regenerative backfill of claim 1, wherein:

the particle size of the waste soil particles is not more than 40mm, the content of particles with the particle size of less than 2mm is not more than 60 wt%, and the content of particles with the particle size of 5-20mm is not more than 30 wt%.

4. The spoil reclamation backfill material of claim 1 wherein the cement is at least one of a general purpose cement, a special purpose cement, or a specialty cement.

5. The spoil reclamation backfill material according to claim 4, wherein the universal cement is at least one of portland cement, portland cement, portland slag cement, pozzolanic portland cement, fly ash portland cement, or composite portland cement.

6. The spoil reclamation backfill material 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.

7. The preparation method of the waste soil regeneration backfill material is characterized by comprising the following steps:

s1, pretreatment: pretreating the waste soil to remove foreign matters and pollute a deteriorated part;

s2, proportioning design: weighing the components according to the formula of the spoil regeneration backfill material according to any one of the claims 1-6;

s3, sludge removal treatment: mixing and stirring the waste soil treated by the S1 and water to obtain a mixture;

s4, mixing operation: and mixing and stirring the mixture, the cement and the early strength agent to obtain a finished product.

Technical Field

The application relates to the field of civil engineering materials, in particular to a spoil regeneration backfill material and a preparation method thereof.

Background

At present, China is in a high-speed construction and development period, and urban pipe network construction generates a large number of foundation trenches or pipe ditches to be filled and repaired, so that foundation trench backfilling and pipe ditch backfilling are problems which are frequently faced in the field.

Disclosure of Invention

The application provides a spoil regeneration backfill material and a preparation method thereof, which take spoil as a main material, greatly reduces the preparation cost of the backfill material, and the spoil regeneration backfill material has good fluidity.

In order to achieve the technical effect, the application provides, in a first aspect, an abandoned soil regeneration backfill material, which comprises the following formula components in parts by mass:

in a first possible implementation form, based on the first aspect of the application, the organic matter content of the spoil is not more than 5 wt%.

In a second possible implementation form, based on the first aspect of the present application, the above-mentioned spoil particles have a particle size of not more than 40mm, and the content of particles having a particle size of less than 2mm is not more than 60 wt%, and the content of particles having a particle size of 5 to 20mm is not more than 30 wt%.

In a third possible implementation manner based on the first aspect of the present application, the cement is at least one of general purpose cement, special purpose cement, or special purpose cement.

In a fourth possible implementation manner according to the third possible implementation manner of the first aspect of the present application, the general-purpose cement is at least one of portland cement, ordinary portland cement, portland slag cement, portland pozzolanic cement, portland fly ash cement, or composite portland cement.

In a fifth possible implementation manner according to the first aspect of the present application, 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 application in a second aspect provides a preparation method of the spoil regeneration backfill material, which comprises the following steps:

s1, pretreatment: pretreating the waste soil to remove foreign matters and pollute a deteriorated part;

s2, proportioning design: weighing each component according to the formula of the spoil regeneration backfill material according to the first aspect of the application and any one of the five possible implementation modes based on the first aspect of the application;

s3, sludge removal treatment: mixing and stirring the waste soil treated by the S1 and water to obtain a mixture;

s4, mixing operation: and mixing and stirring the mixture, the cement and the early strength agent to obtain a finished product.

According to the spoil regeneration backfill material and the preparation method provided by the application, spoil is used as a main component, a proper amount of cement, water and an early strength agent are added, and the spoil regeneration backfill material is prepared by mixing and stirring. Wherein, various components in the cement in the mixture prepared according to the formula have strong hydrolysis reaction and hydration reaction with water to form calcium hydroxide and other hydrates; as the hydrate of cement needs to be hardened in an alkaline medium, the content of the particles and the clay in the waste soil is high, the particle size of the particles and the clay is small, the probability of chemical action between the surfaces of the particles is greatly increased, and calcium hydroxide will firstly react with the particles and the clay to cause that the alkaline medium cannot be smoothly formed, thereby preventing the normal hardening of the cement hydrate and leading the mixture to have good fluidity. Therefore, the technical scheme reasonably recycles the waste soil, and prepares the waste soil regeneration backfill material by matching with other materials, thereby reducing the pollution of pipeline excavation operation on the environment, reducing the engineering cost of backfill operation and enhancing the fluidity of the backfill material.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application more clearly apparent, the present application is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The weight of the related components mentioned in the description of the embodiments of the present application may not only refer to the specific content of each component, but also represent the proportional relationship of the weight among the components, and therefore, the enlargement or reduction of the proportion of the related components according to the description of the embodiments of the present application is within the scope disclosed in the description of the embodiments of the present application. Specifically, the weight described in the specification of the examples of the present application may be a mass unit known in the chemical industry field such as μ g, mg, g, kg, etc.

The embodiment of the application provides a spoil regeneration backfill material, which comprises the following formula components in parts by mass (all dry mass of the components):

optionally, the waste soil is engineering waste soil (such as waste soil dug in urban pipe network foundation trench), and the waste soil mainly comprises cohesive soil and sandy soil with fine particle size.

Optionally, the content of organic matters in the waste soil is not more than 5 wt%, the organic matters can affect the later strength of the backfill material, and if the content of the organic matters is too high, the later strength cannot meet the required quality requirement.

Optionally, if the content of the particles with the particle size of less than 2mm in the waste soil exceeds 60 wt%, the prepared waste soil regeneration backfill material has poor effect and is uneconomical; if the content of the particles with the particle size of 5-20mm exceeds 30 wt%, the produced spoil regeneration backfill material can generate serious bleeding phenomenon, the properties of the backfill material can be uneven, and the quality is not easy to control; if the particle size of the waste soil particles is larger than 40mm, the quality of the backfill material is negatively affected; in summary, the particle size of the above-mentioned spoil particles should be not more than 40mm, the content of particles having a particle size of less than 2mm should be not more than 60 wt%, and the content of particles having a particle size of 5-20mm should be not more than 30 wt%.

Optionally, the cement is at least one of general cement, special cement and special cement. Further, the general cement is at least one of portland cement, ordinary portland cement, portland slag cement, pozzolanic portland cement, fly ash portland cement or composite portland cement; the special cement is special cement, such as: grade G oil well cement, road portland cement; the characteristic cement is cement with outstanding performance, such as: rapid hardening portland cement, low-heat slag portland cement, expanded sulphoaluminate cement, phosphoaluminate cement or phosphate cement. When the waste soil regeneration backfill material is prepared, which cement needs to be used is considered according to actual conditions, and a proper cement type is selected according to the characteristics and the characteristics of the cement required by a construction site;

preferably, when the early strength type backfill material is needed, the cement can adopt sulphoaluminate cement; when the backfill material which needs to keep a longer flowing state is needed, the cement can adopt Portland cement; when the cost of backfill materials (the cost of sulphoaluminate cement is higher) and the early strength characteristic of certain backfill materials need to be considered, sulphoaluminate cement and silicate cement which are mixed according to a certain proportion can be adopted for the cement.

The concrete is cement concrete prepared by mixing cement as a cementing material, auxiliary materials and a proper amount of water.

Optionally, the water meets the regulation of JGJ63-2006 Water for concrete Standard; wherein, if the water meets the drinking water required by the current national standard GB5749-2006 sanitary Standard for Drinking Water, the water can be used as concrete water without inspection.

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.

Correspondingly, the embodiment of the application also provides a preparation method of the spoil regeneration backfill material, which comprises the following steps:

s1, pretreatment: pretreating the waste soil to remove foreign matters and pollute a deteriorated part;

s2, proportioning design: weighing the components according to the formula of the spoil regeneration backfill material;

s3, sludge removal treatment: mixing and stirring the waste soil treated by the S1 and water to obtain a mixture;

s4, mixing operation: and mixing and stirring the mixture, the cement and the early strength agent to obtain a finished product.

Specifically, the step S1 of pretreating the waste soil includes:

1) removing foreign matters such as wood chips and iron chips mixed in the waste soil;

2) when the river sediment with foul pollution is used as a raw material, the polluted and deteriorated part is removed;

specifically, in step S2, the target attribute range of the waste soil is determined according to the use purpose and the engineering requirement of the waste soil recycled material, and finally the mix proportion design of the waste soil recycled material is determined. The formula of the waste soil regeneration backfill material comprises the following components in range: 2500 portions of spoil 2800 portions, 150 portions of cement 200 portions, 800 portions of water 900 portions and 0.3 to 0.8 portion of early strength agent.

Specifically, in step S3, the soil is subjected to the soil-loosening treatment, and the soil and water subjected to step S1 are stirred. The mud-removing treatment aims at the problem that the content of particles with the particle size of less than 2mm in the waste soil is high (especially when the content of clay is high), before the final mixing and stirring, the waste soil and water are subjected to mud-removing treatment, so that the uniformity and the mixing property of the backfill material can be improved, and the quality of the backfill material is improved;

optionally, in the step S3, before the spoil subjected to the step S1 is stirred with water, the spoil subjected to the step S1 is crushed.

Specifically, in the step S4, the mixture of the waste soil and the water obtained in the step S3 is mixed with the cement and the early strength agent for final mixing and stirring, so as to obtain a finished backfill material;

optionally, the stirring may be performed by using efficient double-shaft stirring (low-speed stirring and high-speed stirring are performed simultaneously), and the cement, the early strength agent, the mixture of the waste soil and the water are stirred together to a uniform flowing state by using the rapid stirring and scattering effects of the blades, and the specific mixing and stirring time is determined by the actual soil quality and the machine stirring speed.

After the preparation is completed according to the preparation method, the finished product needs to be tested for the flow value and the unconfined compressive strength, 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) CBR test

Pouring mixed fluidized soil into a CBR steel cylinder, curing, carrying out a penetration test after the maintenance age is reached, ① putting a test piece on a lifting platform of a pavement material strength tester, adjusting an eccentric ball seat, aligning, leveling and fully contacting a penetration rod with the top surface of the test piece, placing 4 load-bearing plates around the penetration rod ② firstly applying 45N load on the penetration rod, then adjusting pointers of dial indicators for measuring force and deformation to be integral numbers, recording initial readings, ③ loading to press the penetration rod into the test piece at a speed of 1-1.25mm/min, simultaneously recording the readings of three dial indicators, recording the penetration of the dial indicators (such as 20, 40 and 60) in a dynamometer, and taking care that the penetration is 250 multiplied by 10 ^-2mm, there can be more than 5 readings. Therefore, the first reading in the dynamometer should be at a penetration of 30 × 10 ^-2About mm. After the reading is finished, the processing is carried out, and the ratio of the unit pressure at the penetration of 2.5mm to the standard pressure is generally used as the bearing ratio (CBR value) of the material. 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 160-200 mm;

2) the unconfined compressive strength of 1 day is more than 50kPa, the unconfined compressive strength of 7 days is about 200-300 kPa, and the unconfined compressive strength of 28 days is not more than 500 kPa;

3) when the penetration was 2.5mm, the value of the pressure gauge reached 700kPa, which corresponds to a CBR value of about 10%.

Optionally, when special requirements exist (for example, when the structure of a backfill region is complex), the water content in the formula can be increased, the fluidity of the waste soil regeneration backfill material is increased to adapt to the structure of the complex backfill region, and the qualified upper limit of the fluidity value is adjusted to 300mm, namely the qualified fluidity value is 160-300 mm;

the above-mentioned pass standards are within the quality requirements of the "road bed design specification" (JTG D30-2015) and the "エアモルタル and the method of the intake rib エアミルク test" (JHS a313-1992) in japan ministry of construction.

The present application will now be described in further detail with reference to a specific formulation of the spoil reclamation backfill material and its preparation. Wherein, the water-solid ratio refers to the dry mass ratio of water to solid materials (including waste soil and cement), and the lime-sand ratio refers to the dry mass ratio of cement to waste soil, so the water-solid ratio and the lime-sand ratio of the formula are in the following ranges: the water-solid ratio is 0.267-0.339, and the sand-lime ratio is 0.054-0.080.

It should be noted that the backfill material prepared according to the formula and the preparation method has certain fluidity and certain strength, and the specific influence factors are as follows:

1) fluidity: the fluidity is mainly influenced by water, the waste soil contains a large amount of powder particles and clay particles, the mineral content of the waste soil is high, hydration reaction can be generated by adding water, so that clay minerals are subjected to expansion deformation, the difference between the cementing material and the cementing material degree can cause the difference of water absorption expansion rates, the speed of the hydration reaction is influenced, the hardening of a mixture is influenced, and the mixture has certain fluidity, so that the fluidity is mainly influenced by the water-solid ratio, and the fluidity is increased along with the increase of the water-solid ratio;

2) strength: the strength is mainly influenced by the hydration of cement, so that the early strength and the later strength are mainly influenced by the sand-lime ratio, and the strength is increased along with the increase of the sand-lime ratio; in addition, the early strength can be improved by increasing the content of the early strength agent or increasing the content of sulphoaluminate cement in the cement.