阅读说明：本技术 一种环保胶凝材料及其制备方法与应用 (Environment-friendly cementing material and preparation method and application thereof ) 是由 吴建勋 王庶懋 黄涛 张树文 杨永浩 姬广祥 张永恒 腾俊洋 于 2020-05-09 设计创作，主要内容包括：本发明具体涉及一种环保胶凝材料及其制备方法与应用,所述环保胶凝材料包括以下重量百分比组分：凝灰岩或凝灰熔岩60～80％、生石灰5～15％、粉煤灰15～30％、氢氧化钠0～2％、脱硫石膏0～2％,所述凝灰岩或凝灰熔岩的主要成分为SiO<Sub>2</Sub>、Al<Sub>2</Sub>O<Sub>3</Sub>和CaO,其中SiO<Sub>2</Sub>和Al<Sub>2</Sub>O<Sub>3</Sub>的质量分数不低于75％,所述生石灰的主要成分为CaO,所述生石灰中CaO的质量分数不低于80％。本发明创新的选用在我国分布广泛,价格低廉的火山凝灰岩(凝灰熔岩)作为改性垃圾土的主要原材料,并形成一套集配置、改性、制件和试验为一体的完整技术体系,能够综合考虑不同工程对垃圾土强度需求的差异性、各地区垃圾土成分的差异性和天然改性材料的差异性,给出最合适的改性方案以及相应的改性后的垃圾土力学参数值。(The invention particularly relates to an environment-friendly cementing material, a preparation method and an application thereof, wherein the environment-friendly cementing material comprises the following components in percentage by weight: 60-80% of tuff or tuff lava, 5-15% of quicklime, 15-30% of fly ash, 0-2% of sodium hydroxide and 0-2% of desulfurized gypsum, wherein the main component of the tuff or tuff lava is SiO 2 、Al 2 O 3 And CaO, wherein SiO 2 And Al 2 O 3 The mass fraction of the calcium oxide is not less than 75 percent, the main component of the quicklime is CaO, and the mass fraction of the CaO in the quicklime is not less than 80 percent. The volcanic tuff (tuff lava) which is widely distributed in China and low in price is innovatively selected as the main raw material of the modified waste soil, a complete technical system integrating configuration, modification, manufacturing and test is formed, and the differences of the requirements of different projects on the strength of the waste soil and the differences of the waste soil components in different regions can be comprehensively consideredAnd the difference between the natural modified material and the modified garbage soil mechanical parameter value is provided.)

1. An environment-friendly cementing material comprises the following components in percentage by weight: 60-80% of tuff or tuff lava, 5-15% of quicklime, 15-30% of fly ash, 0-2% of sodium hydroxide and 0-2% of desulfurized gypsum, wherein the main component of the tuff or tuff lava is SiO₂、Al₂O₃And CaO, wherein SiO₂And Al₂O₃The mass fraction of the calcium oxide is not less than 75 percent, the main component of the quicklime is CaO, and the mass fraction of the CaO in the quicklime is not less than 80 percent.

2. A method for preparing the environment-friendly cementing material of claim 1, which is characterized in that: the method comprises the following steps:

(1) crushing and grinding: respectively processing tuff or tuff lava, quicklime, fly ash, sodium hydroxide and desulfurized gypsum into powder by adopting crushing and grinding processes, and sieving;

(2) and (3) component analysis: respectively analyzing SiO in tuff or tuff lava₂、Al₂O₃And the content of CaO, and the content of CaO in quicklime;

(3) preparing materials: taking 100 parts of tuff or tuff lava, A parts of quicklime, 2A parts of fly ash, 1 part of sodium hydroxide and 1 part of desulfurized gypsum; wherein the calculation formula of A is as follows:

in the formula, A is the part of the raw lime;and T_CaOSiO in tuff or tuff lava respectively₂、Al₂O₃And the mass fraction of CaO; w_CaOThe mass fraction of CaO in the quicklime.

3. The method for preparing environment-friendly cementing material according to claim 2, characterized in that: and (2) sieving the powder of each component in the step (1) by a 200-mesh sieve to ensure that the coarsest powder in each component does not exceed 200 meshes.

4. The method for preparing environment-friendly cementing material according to claim 2, characterized in that: before the step (1), tuff or tuff lava can be calcined at 800 ℃.

5. According to claim2, the preparation method of the environment-friendly cementing material is characterized by comprising the following steps: respectively carrying out XRF quantitative analysis on tuff or tuff lava and quicklime in step (2), thereby obtaining SiO in the tuff or tuff lava₂、Al₂O₃And the content of CaO, and the content of CaO in quicklime.

6. The use of the environmentally friendly cementitious material of claim 1 in modifying waste soils.

7. The application of the environment-friendly cementing material in modified waste soil according to claim 6, is characterized in that: the method comprises the following steps:

(1) drilling waste soil of a landfill, adding 50% of water according to the mass, uniformly stirring, placing in a constant temperature and humidity box, and standing for 24 hours;

(2) respectively doping 15%, 25%, 35% and 45% of environment-friendly cementing materials into the waste soil after standing, and uniformly stirring to prepare a waste soil sample;

(3) maintaining the sample in a constant temperature and humidity box for 24 hours, and then removing the mold;

(4) and (4) after the sample is demoulded, placing the sample in a constant temperature and humidity box, curing the sample to the designed age, and then performing a mechanical test.

8. The application of the environment-friendly cementing material in modified waste soil according to claim 7, is characterized in that: and (3) preparing the sample in the step (2), wherein the diameter of the three-opening die is 39.1mm, and the height of the three-opening die is 80 mm.

9. The application of the environment-friendly cementing material in modified waste soil according to claim 7, is characterized in that: the temperature of the constant temperature and humidity box in the steps (1) and (4) is 20 ℃, and the humidity is 85%.

10. The application of the environment-friendly cementing material in modified waste soil according to claim 7, is characterized in that: and (4) obtaining the cohesive force and the internal friction angle of the modified garbage soil or the unconfined compressive strength of the modified garbage soil through a mechanical test in the step (4).

Technical Field

The invention belongs to the technical field of environmental protection, and particularly relates to an environmental-friendly cementing material, and a preparation method and application thereof.

Background

Along with the rapid development of modern city construction, the discharge amount of urban domestic garbage is increased, and the accumulation amount of garbage soil generated by the discharge amount is increased. On one hand, the projects of changing and expanding the landfill plants are increased, and on the other hand, along with the continuous expansion of the urban scale, buildings and roads need to be built on the original landfill plants. In order to meet the requirements of the engineering, the engineering properties of the waste soil are known through indoor tests, and the waste soil is modified to a certain extent if necessary, so that the waste soil is further developed and utilized.

The method has the following defects that ① continuously rises along with the vigorous development of national infrastructure, the cement price is continuously increased, the modification cost can be only slightly reduced even if the cement consumption is reduced by the aid of the fly ash, the preparation process of ② cement is complex, a calcination link exists, the method is not beneficial to energy conservation and environmental protection, ③ generally provides a fixed cement mixing amount by virtue of experience, and scientific and reasonable optimal mixing basis is lacked.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide an environment-friendly cementing material and a preparation method and application thereof.

To achieve the above objectThe technical scheme adopted by the invention is as follows: an environment-friendly cementing material comprises the following components in percentage by weight: 60-80% of tuff or tuff lava, 5-15% of quicklime, 15-30% of fly ash, 0-2% of sodium hydroxide and 0-2% of desulfurized gypsum, wherein the main component of the tuff or tuff lava is SiO₂、Al₂O₃And CaO, wherein SiO₂And Al₂O₃The mass fraction of the calcium oxide is not less than 75 percent, the main component of the quicklime is CaO, and the mass fraction of the CaO in the quicklime is not less than 80 percent.

Tuff or tuff is volcanic tuff or volcanic tuff, is a kind of well-crystallized rock gradually formed in the long-term natural transportation process after temperature and pressure of volcanic rock slurry are suddenly changed in the spraying and scattering process, and is generally formed by cementing volcanic ash with the granularity smaller than 2 mm.

The preparation method of the environment-friendly cementing material comprises the following steps:

(1) crushing and grinding: respectively processing tuff or tuff lava, quicklime, fly ash, sodium hydroxide and desulfurized gypsum into powder by adopting crushing and grinding processes, and sieving;

(2) and (3) component analysis: respectively analyzing SiO in tuff or tuff lava₂、Al₂O₃And the content of CaO, and the content of CaO in quicklime;

(3) preparing materials: taking 100 parts of tuff or tuff lava, A parts of quicklime, 2A parts of fly ash, 1 part of sodium hydroxide and 1 part of desulfurized gypsum; wherein the calculation formula of A is as follows:

in the formula, A is the part of the raw lime;and T_CaOSiO in tuff or tuff lava respectively₂、Al₂O₃And the mass fraction of CaO; w_CaOThe mass fraction of CaO in the quicklime.

Preferably, the powders of each component in step (1) are sieved through a 200 mesh sieve, so that the coarsest powder in each component does not exceed 200 mesh.

Preferably, the tuff or tuff lava in the step (1) is generally used directly, or the tuff or tuff lava is calcined at 800 ℃ before crushing and grinding, wherein it needs to be noted that the performance of the cementing material can be obviously improved after calcination, but the energy-saving and environment-friendly characteristics of the whole cementing material are influenced to a certain extent correspondingly.

Preferably, XRF quantitative analysis is respectively carried out on tuff or tuff lava and quicklime in the step (2), so that SiO in the tuff or tuff lava is obtained₂、Al₂O₃And the content of CaO, and the content of CaO in quicklime.

The application of the environment-friendly cementing material in modified waste soil comprises the following steps:

(1) drilling waste soil of a landfill, adding 50% of water according to the mass, uniformly stirring, placing in a constant temperature and humidity box, and standing for 24 hours;

(2) respectively doping 15%, 25%, 35% and 45% of environment-friendly cementing materials into the waste soil after standing, and uniformly stirring to prepare a waste soil sample;

(3) maintaining the sample in a constant temperature and humidity box for 24 hours, and then removing the mold;

(4) and (4) after the sample is demoulded, placing the sample in a constant temperature and humidity box, curing the sample to the designed age, and then performing a mechanical test.

Preferably, the diameter of the three-opening die used for preparing the sample in the step (2) is 39.1mm, and the height is 80 mm.

Preferably, the temperature of the constant temperature and humidity chamber in the steps (1) and (4) is 20 ℃ and the humidity is 85%.

Preferably, the mechanical test in the step (4) adopts a triaxial compression test method of section 19 in the standard of soil engineering test methods (GB/T50123-2019) to obtain the cohesive force and the internal friction angle of the modified waste soil; or the unconfined compressive strength of the modified waste soil is obtained by adopting the unconfined compressive strength test method in the section 20.

Preferably, the design age in step (4) is 3 days, 7 days, 17 days, 28 days.

The invention innovatively selects the volcanic tuff or the volcanic tuff lava which is widely distributed in China and has low price as the main raw material of the modified garbage soil, and is supplemented with a small amount of quicklime, fly ash, sodium hydroxide and desulfurized gypsum to form the environment-friendly cementing material through reasonable proportioning; mixing the mixing amount of the environment-friendly cementing material with different proportions with the waste soil to prepare a modified waste soil test piece, carrying out strength test to obtain the corresponding relation between the mixing amount and the strength parameter, and giving the optimal mixing amount of the cementing material under the optimal proportioning condition and the corresponding modified waste soil strength parameter.

The invention forms a complete technical system integrating configuration, modification, manufacturing and test, can comprehensively consider the differences of different projects on the strength requirements of the waste soil, the differences of the waste soil components in various regions and the differences of natural modified materials, and provides the most appropriate modification scheme and the corresponding modified mechanical parameter values of the waste soil.

By adopting the scheme, the invention has the following advantages:

(1) in the invention, tuff (tuff lava) is selected as a main modification material for modifying the waste soil, and is widely distributed in China and can be taken nearby around the engineering; tuff (tuff lava) is low in price, and the price of stone powder after mechanical activation is about 1/6 of cement; therefore, the invention can obviously reduce the modification cost.

(2) The environment-friendly cementing material is formed by taking tuff (tuff lava) as a main modified material and adding a small amount of quick lime, fly ash, sodium hydroxide and desulfurized gypsum through reasonable proportioning, and then is mixed with garbage soil, wherein the fly ash and the desulfurized gypsum are byproducts of industrial production and are selected as raw materials of the technology, so that the environment-friendly cementing material has the significance of waste utilization, the tuff (tuff lava) and the quicklime are ground to 200 meshes and can be used for preparation, and the grinding operation of the two raw materials is simple and the energy consumption is low; therefore, the whole modification process has the characteristics of simple operation, low equipment requirement, energy conservation and environmental protection.

(3) The method comprises the steps of firstly detecting raw materials, configuring an optimal environment-friendly cementing material according to a detection result, and finally performing a strength test on the modified waste soil by taking the doping amount of the cementing material as a design variable to obtain a corresponding relation between the doping amount and the strength parameter of the modified waste soil; therefore, the invention can comprehensively consider the differences of raw materials, the waste soil and engineering requirements, and give the optimal doping amount of the cementing material under the optimal proportioning condition and the corresponding strength parameters of the modified waste soil.

Detailed Description

The invention will be better understood from the following examples. However, those skilled in the art will readily appreciate that the specific material ratios, process conditions and results thereof described in the examples are illustrative only and should not be taken as limiting the invention as detailed in the claims.

The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental reagents and materials involved are conventional biochemical reagents and materials unless otherwise specified.

The invention relates to an environment-friendly cementing material which comprises the following components in percentage by weight: 60-80% of tuff or tuff lava, 5-15% of quicklime, 15-30% of fly ash, 0-2% of sodium hydroxide and 0-2% of desulfurized gypsum, wherein the main component of the tuff or tuff lava is SiO₂、Al₂O₃And CaO, wherein SiO₂And Al₂O₃The mass fraction of the calcium oxide is not less than 75 percent, the main component of the quicklime is CaO, and the mass fraction of the CaO in the quicklime is not less than 80 percent.

The invention relates to a preparation method of an environment-friendly cementing material, which comprises the following steps:

(1) crushing and grinding: respectively processing tuff or tuff lava, quicklime, fly ash, sodium hydroxide and desulfurized gypsum into powder by adopting crushing and grinding processes, and sieving the powder by a 200-mesh sieve;

(2) and (3) component analysis: respectively carrying out XRF (X-ray fluorescence spectroscopy) quantitative analysis on tuff or tuff lava and quicklime so as to obtain SiO in tuff or tuff lava₂、Al₂O₃And CaO content, and green stoneThe content of CaO in the ash;

(3) preparing materials: taking 100 parts of tuff or tuff lava, A parts of quicklime, 2A parts of fly ash, 1 part of sodium hydroxide and 1 part of desulfurized gypsum; wherein the calculation formula of A is as follows:

in the formula, A is the part of the raw lime;and T_CaOSiO in tuff or tuff lava respectively₂、Al₂O₃And the mass fraction of CaO; w_CaOThe mass fraction of CaO in the quicklime.

The invention relates to an application of an environment-friendly cementing material in modified garbage soil, which comprises the following steps:

(1) drilling waste soil of a landfill, adding 50% of water according to the mass, uniformly stirring, placing in a constant temperature and humidity box with the temperature of 20 ℃ and the humidity of 85%, and standing for 24 hours;

(2) respectively doping 15%, 25%, 35% and 45% of environment-friendly cementing materials into the settled waste soil, uniformly stirring, and preparing a waste soil sample by adopting a three-die opening die (the diameter is 39.1mm, and the height is 80 mm);

(3) maintaining the sample in a constant temperature and humidity box for 24 hours, and then removing the mold;

(4) after the sample is demoulded, the sample is placed in a constant temperature and humidity box with the temperature of 20 ℃ and the humidity of 85 percent, and is maintained to the designed age (3, 7, 17 and 28 days), and then a mechanical test is carried out.

The mechanical test adopts a triaxial compression test method in section 19 of geotechnical test method standard (GB/T50123-2019) to obtain cohesive force and an internal friction angle of the modified waste soil; or the unconfined compressive strength of the modified waste soil is obtained by adopting the unconfined compressive strength test method in the section 20.