阅读说明：本技术 土遗址微收缩裂隙注浆材料及其制备方法和应用 (Earthen site micro-shrinkage crack grouting material and preparation method and application thereof ) 是由 韩可竹 刘建 赵刘会 崔梦磊 侯龙君 白延 庞磊 于 2020-11-25 设计创作，主要内容包括：本发明属于遗址保护技术领域,公开了一种土遗址微收缩裂隙注浆材料及其制备方法和应用,该材料是将遗址原生土、偏高岭土、氢氧化钙、木质素磺酸盐和三氧化二铝经过筛、混匀即得。本发明的土遗址微收缩裂隙注浆材料具有微收缩、力学性能与兼容性好、耐候性强和施用后美观等特点；本发明的制备方法简单易操作；本发明的土遗址微收缩裂隙注浆材料适用于土遗址保护。(The invention belongs to the technical field of site protection, and discloses an earthen site micro-shrinkage crack grouting material, and a preparation method and application thereof. The earthen archaeological site micro-shrinkage crack grouting material has the characteristics of micro shrinkage, good mechanical property and compatibility, strong weather resistance, attractive appearance after application and the like; the preparation method is simple and easy to operate; the earthen site micro-shrinkage crack grouting material is suitable for earthen site protection.)

1. The earthen site micro-shrinkage crack grouting material is characterized in that the effective components of the earthen site micro-shrinkage crack grouting material are prepared from the following raw materials in parts by weight: 50-60 parts of original soil of the site, 8-13.5 parts of metakaolin, 9-12 parts of calcium hydroxide, 0.21-0.48 part of lignosulfonate, 0.3-0.7 part of aluminum oxide and 30-35 parts of water.

2. The earthen site micro-shrinkage crack grouting material as claimed in claim 1, wherein the earthen site original soil is prepared by sieving and drying.

3. The earthen site micro-shrinkage fracture grouting material as claimed in claim 2, wherein the mesh size of the sieved mesh is 35-45 meshes.

4. The earthen site micro-shrinkage crack grouting material as claimed in claim 2 or 3, wherein the drying temperature is 105-.

5. A preparation method of the earthen archaeological site micro-shrinkage crack grouting material as claimed in any one of claims 1 to 4, characterized in that the earthen archaeological site micro-shrinkage crack grouting material is obtained by uniformly mixing all raw materials.

6. The method for preparing the earthen site micro-shrinkage crack grouting material as claimed in claim 5, wherein the uniform mixing is performed at a rotation speed of 90-120r/min for 10-20 min.

7. The use of the earthen site micro-shrinkage fracture grouting material as claimed in any one of claims 1 to 4, wherein the earthen site micro-shrinkage fracture grouting material is used for filling the earthen site fracture, repairing and protecting the earthen site by grouting.

Technical Field

The invention belongs to the technical field of site protection, and relates to a site crack grouting material, a preparation method and application thereof, in particular to an earthen site micro-shrinkage crack grouting material, and a preparation method and application thereof.

Background

The earthen site is the intelligent crystal of ancient workers in the historical river, is a very important historical site, has great historical, scientific, artistic and social values, and is the historical responsibility of each individual to take on the shoulder. As the earthen site is exposed in the field for a long time and is influenced by natural environment, historical events and artificial activities, a plurality of earthen sites in China have serious cracks and generally face the threat of collapse and disappearance. Especially, if the continuous development of the cracks is not timely treated, secondary disasters such as collapse, collapse and the like are easily caused. Therefore, research on fracture reinforcement is urgently carried out.

At present, fracture grouting and anchoring are mostly adopted for reinforcing the cracks of the earthen site, and widely used earthen site grouting materials comprise potassium silicate (namely PS) and modified polyvinyl alcohol (namely SH), so that although the strength and the wind erosion resistance of the earthen site are improved after the soil site is reinforced by the PS grouting, the strong contractibility of the PS material easily causes the reinforced earthen site to fall off together with the earthen site body, so that the grouting reinforcement effect is influenced; SH reagent belongs to organic materials, is not high in compatibility with the site body, and is poor in weather resistance of modified polyvinyl alcohol, so that the long-term preservation effect of the soil site after grouting is poor. The fracture anchoring technology of the earthen site has high requirements on the condition of the site body, and the site body is abrupt and unattractive after being reinforced, thereby obstructing the appearance.

At present, the soil sites in multiple regions are cracked again after the protection project is implemented, and the like, so that the crack grouting material which has the advantages of micro shrinkage, good compatibility and strong weather resistance and is beneficial to long-term preservation, observation and research of the soil sites is urgently needed to be developed.

Disclosure of Invention

In order to solve the defects in the prior art, the invention aims to provide an earthen site micro-shrinkage crack grouting material so as to obtain the earthen site micro-shrinkage crack grouting material which has micro-shrinkage, good mechanical property and compatibility and strong weather resistance and is beneficial to long-term preservation, observation and research of the earthen site;

the invention also aims to provide a preparation method of the earthen site micro-shrinkage crack grouting material;

the invention also aims to provide an application of the earthen site micro-shrinkage crack grouting material.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the earthen site micro-shrinkage crack grouting material is prepared from the following raw materials of effective components in parts by weight: 50-60 parts of original soil of the site, 8-13.5 parts of metakaolin, 9-12 parts of calcium hydroxide, 0.21-0.48 part of lignosulfonate, 0.3-0.7 part of aluminum oxide and 30-35 parts of water.

As the limitation of the invention, the original site soil is prepared by sieving and drying.

As a further limitation of the invention, the screened mesh size is 35-45 mesh.

Impurities in original soil are removed in the sieving process, external impurity interference is eliminated, and the grouting effect is enhanced.

As a further limitation of the present invention, the temperature of the drying is 105-110 ℃ and the time is 11-13 h.

Organic matters in the original soil are removed to the maximum extent in the drying process, and the expansion and hardening effects of the grouting material are prevented from being interfered by the organic matters.

The composition and the dosage of the raw materials are determined by a large number of repeated screening tests according to the characteristics of the raw materials, and the expected application effect cannot be achieved by randomly changing the composition and the dosage of the raw materials.

The invention also provides a preparation method of the earthen site micro-shrinkage crack grouting material, which is to uniformly mix all the raw materials to obtain the earthen site micro-shrinkage crack grouting material.

As the limitation of the invention, the blending is to utilize a stirrer to stir for 10-20min at the rotating speed of 90-120 r/min.

The invention also provides an application of the earthen site micro-shrinkage crack grouting material, and the earthen site micro-shrinkage crack grouting material is used for filling the earthen site cracks in a grouting mode, repairing and protecting the earthen site.

Due to the adoption of the technical scheme, compared with the prior art, the invention has the following beneficial effects:

(1) the earthen site micro-shrinkage crack grouting material belongs to an inorganic reinforcing material, has good compatibility with native soil of a site, and can counteract volume shrinkage caused by water evaporation in the solidification process of the grouting material by using aluminum oxide as an expanding agent so as to prevent the grouting material from being separated from the native soil of the site;

(2) according to the soil ruins micro-shrinkage crack grouting material, lignosulfonate is added to serve as a water reducing agent, so that the grouting material has good fluidity, the interior of cracks can be fully filled when tiny cracks are reinforced, and the mechanical property of a soil body is enhanced; in the stirring process, the molecules of soil body particles have the attraction effect, so that water is wrapped among the soil particles and cannot participate in free flow and lubrication, thereby influencing the fluidity of the mixture; after the lignosulfonate is added, lignosulfonate molecules are directionally adsorbed on the surfaces of soil particles, so that the surfaces of the particles are charged with the same kind of charges, an electrostatic repulsion effect is formed, the particles are mutually dispersed, and the coated water is released to participate in flowing, so that the fluidity of the mixture is effectively increased; meanwhile, the polarity of hydrophilic groups in the lignosulfonate is very strong, so that the lignosulfonate on the surface of soil particles and water molecules form a stable solvated water film, the water film has a good lubricating effect, and the sliding resistance among soil particles can be effectively reduced, so that the fluidity is improved;

(3) metakaolin is added into the grouting material for the micro-shrinkage cracks of the earthen site, so that hydrated aluminum silicate serving as an active ingredient in the metakaolin reacts with calcium hydroxide to generate hydrated calcium-aluminum yellow feldspar and secondary C-S-H gel with gel properties, the hydration products enhance the mechanical properties of the grouting material, such as compression resistance, bending resistance, splitting tensile strength, toughness and the like, the later strength of the product generated by the hydration of the metakaolin is continuously increased, and the grouting material is favorable for repairing and protecting the earthen site for a long time;

(4) the raw material selection and the using amount of the earthen site micro-shrinkage crack grouting material are determined by a plurality of tests, the obtained grouting material has good air permeability, the compatibility between the added earthen site original soil and the earthen site body is good, and no anchoring mechanical component influences the appearance;

(5) the earthen archaeological site micro-shrinkage crack grouting material is simple in preparation method, low in cost, low in energy consumption, non-toxic, ageing-resistant and suitable for industrial production, and raw materials are selected from original earthen sites;

in conclusion, the earthen site micro-shrinkage crack grouting material disclosed by the invention is reasonable in components, not only solves the problems of over-strong shrinkage, poor compatibility and weather resistance and the like of the crack grouting material in the prior art, but also is easy to obtain raw materials, safe and environment-friendly; the preparation method is easy to control and suitable for industrial production; the preparation method is suitable for preparing the earthen site micro-shrinkage crack grouting material, and the prepared earthen site micro-shrinkage crack grouting material is suitable for earthen site protection.

Drawings

The invention will be described in further detail with reference to the accompanying drawings and specific embodiments;

FIG. 1 is a schematic representation of the preparation of a slurry-soil simulation sample according to example 16 of the present invention;

FIG. 2 is a drawing showing a slurry-soil phantom sample after being prepared in example 16 of the present invention;

FIG. 3 is a shear stress-shear displacement curve of a grouting material prepared in example 1, according to the present invention, as a result of a shear force test in example 16;

FIG. 4 is a shear stress-shear displacement curve of original soil of an earthen archaeological site, which is the result of the shear force test in example 16 of the present invention;

FIG. 5 shows the results of shrinkage tests on the grouting materials ZJ-1, ZJ-6 and ZJ-11 prepared in examples 1, 6 and 11 according to example 16 of the present invention;

FIG. 6 shows the results of color difference measurements of grouting materials ZJ-1, ZJ-6 and ZJ-11 prepared in examples 1, 6 and 11 according to example 16 of the present invention;

FIG. 7 shows the results of measurement of gas permeability of grouting materials ZJ-1, ZJ-6 and ZJ-11 prepared in example 16 of the present invention from example 1, example 6 and example 11.

Detailed Description

The present invention is further illustrated by the following specific examples, which are to be construed as merely illustrative, and not limitative of the remainder of the disclosure.

Example 1 preparation method of earthen site micro-shrinkage crack grouting material

The earthen site micro-shrinkage crack grouting material is prepared by the embodiment, wherein part of raw materials and sources are as follows:

the original site soil is taken from original soil of the original site of the elm forest region;

metakaolin was purchased from chemical reagents ltd of the national drug group;

calcium hydroxide was purchased from chemical reagents of national drug group, ltd;

lignosulfonate was purchased from chemical reagents ltd of the national drug group;

alumina was purchased from the national pharmaceutical group chemical agents limited.

The preparation method is implemented according to the following steps:

sieving original soil of the site by a 40-mesh screen, removing large particles and impurities, drying the sieved original soil and metakaolin at 105 ℃ for 12 hours, weighing 52.5kg of the dried original soil of the site and 13.2kg of metakaolin, weighing 9.8kg of calcium hydroxide, 0.35kg of lignosulfonate, 0.3kg of aluminum oxide and 34.5kg of water, adding all the raw materials into a stirrer at the rotating speed of 100r/min, and stirring for 10min to prepare a soil site micro-shrinkage crack grouting material which is marked as ZJ-1;

the obtained earthen site micro-shrinkage crack grouting material fills the earthen site cracks in a grouting mode and is used for reinforcing and protecting the earthen site.

Example 2-15 preparation method of earthen site micro-shrinkage crack grouting material

Examples 2 to 15 are methods for preparing an earthen site micro-shrinkage crack grouting material, and the steps are substantially the same as those in example 1, except for differences in raw material usage and process parameters, which are specifically detailed in table 1:

table 1 example 2-8 preparation of grouting material for soil ruins micro-shrinkage cracks

Table 2 example 9-15 preparation of grouting material for soil ruins micro-shrinkage cracks

The contents of other portions of examples 2 to 15 are the same as those of example 1.

Example 16 Performance testing of earthen site micro-shrinkage crack grouting Material

The test instrument: an electronic balance (model HX1001TX of Tiandong weighing apparatus factory, Cixi city), an electronic temperature-adjusting electric heating jacket (Beijing ke Wei Yongxing apparatus Co., Ltd., model MH-2000), a freeze-thaw cycle testing machine (PT-2033C Bao Dai apparatus Co., Ltd., Dongguan city), a color difference meter (Alice color science Co., Ltd.), an universal material testing machine (Gaotai detection apparatus Co., Ltd., Dongguan), a non-metal ultrasonic instrument (Hippocampus HT-225A), a damping drill-resistant (Italy SINT Technology Co., Ltd.), and a direct shear instrument (Hebei boat letters apparatus Co., Ltd.);

I. mechanical property test

Ia. compression resistance test

Test materials:

grouting materials ZJ-1, ZJ-6 and ZJ-11 prepared in example 1, example 6 and example 11; original soil of an earthen site in an elm forest region is used as a blank sample;

processing test materials:

subjecting the test material to freeze thawing cyclic aging treatment, wherein the aging period is 7 days;

③ the test method:

according to the standard of the engineering rock mass test method (GB/T50266-2013), a uniaxial compressive strength test is carried out to carry out compressive strength tests on grouting materials ZJ-1, ZJ-6, ZJ-11 and blank samples, and the formula is as follows:

p＝P/A

note: a is the area of the section, and the square centimeter is taken as the unit; p is compressive strength, measured in kilopascals; p is pressure in kilograms;

fourthly, test results:

the uniaxial compressive strength values of the grouting material and the blank sample before and after aging treatment are respectively detected, and the test results are shown in tables 3-4:

TABLE 3 uniaxial compressive strength values of the samples

TABLE 4 uniaxial compressive strength values of the aged samples

As can be seen from the data in the table, the compressive strength of the grouting materials with the three proportions is higher than that of the reference material, and is improved by 29-48%; the compressive strength is reduced by 4.45-6.44% after 4 cycles of freeze thawing and aging, and the strength is reduced to 10.33-11.45% after 8 cycles of aging, because the freeze thawing cycle destroys the internal structure of the test material, thereby reducing the integrity of the test material, leading to the reduction of the strength of the sample during the uniaxial compressive test, but the compressive strength values of the aged ZJ-1, ZJ-6 and ZJ-11 grouting materials can still keep good values, which shows that the product prepared by the invention is beneficial to repairing and reinforcing the cracks of the earthen site.

Ib. shear force test

Test materials:

the grouting material ZJ-1 prepared in example 1 was used as a slurry;

obtaining a native soil body from an earthen site of an elm forest region to be used as an undisturbed soil body;

processing test materials:

subjecting the test material to freeze thawing cyclic aging treatment, wherein the aging period is 7 days;

preparing an undisturbed soil sample shown in figure 1: pouring a native soil body obtained from an earthen site of an elm forest area into a cutting ring die to obtain an original soil body;

a slurry-soil simulation sample as shown in fig. 1 was prepared: placing a cutting ring mould on the native soil body, and directly performing reverse mould on the grouting material ZJ-1 on the native soil body to form a slurry-body interface sample;

③ the test method:

performing a shear test on a slurry-soil simulation sample and an undisturbed soil body sample under the conditions of vertical loads of 50kPa, 100kPa, 200kPa, 300kPa and 400kPa respectively by using a direct shear apparatus (a six-link shear apparatus) according to geotechnical test method standard (GB/T50123-1999), detecting the slurry-soil interface performance, and calculating and drawing a shear stress-shear displacement curve (see fig. 3-4);

fourthly, test results:

ascending section: in a shear displacement-shear stress curve, a straight line segment of the shear displacement-shear stress curve reflects the strength of a structural surface on one hand and reflects the slippage condition of the shear surface under a certain load on the other hand, and the larger the slope of the straight line is, the smaller the displacement of the straight line under the certain load is; in the figures 3 and 4, the peak intensity appears at the position of 5-7mm of displacement, but the peak intensity of the undisturbed soil sample appears at the position of 5-6mm, and under the action of a certain vertical load, the slope of a straight line segment of a slurry-soil interface is smaller than that of the undisturbed soil sample, which shows that the bonding strength of the slurry-undisturbed soil interface is slightly smaller than that of the undisturbed soil.

Peak intensity: as can be seen from fig. 3 and 4, under certain conditions, the peak strength of each sample is positively correlated with the vertical load; under the action of the same vertical load, the peak strength of the two samples is close, which shows that the shear strength of the grouting material ZJ-1 and the interface of the undisturbed soil body can meet the crack reinforcement requirement.

Ic. wave velocity test

Test materials:

grouting materials: grouting materials ZJ-1, ZJ-2, ZJ-6, ZJ-7, ZJ-11 and ZJ-12 prepared in examples 1, 2, 6, 7, 11 and 12;

raw soil sample: raw soil obtained from an earthen site in an elm forest region;

processing test materials:

subjecting the test material to freeze thawing cyclic aging treatment, wherein the aging period is 7 days;

③ the test method:

according to the engineering rock mass test method standard (GB/T50266-2013), performing rock mass acoustic velocity test, and detecting the wave velocity of the test material before aging, and in 4 periods and 8 periods of aging;

fourthly, test results:

the sound wave speed depends on the compactness, water content and other conditions inside the earthen site, and is in positive correlation with the mechanical strength of the compactness of the cultural relics in the earthen site, the mechanical property strength directly reflects the current weathering degree of the earthen site, and the ultrasonic wave speed is faster when the material is more compact;

the specific wave velocity detection results are as follows:

TABLE 5 wave velocity of test materials

TABLE 6 wave velocity of test materials after aging

As can be seen from tables 5-6, the wave velocity of the grouting material is higher than that of the original soil sample, and after aging for 4 periods, the wave velocity reduction rate of the grouting material is about 3%, while the wave velocity reduction rate of the original soil sample is 8.1%; after aging for 8 periods, the wave velocity reduction rate of the grouting material is about 2.5 percent, and the wave velocity reduction rate of the original soil sample is 12.2 percent; namely, the wave velocity of the grouting material is reduced after freezing and thawing aging, and the weathering resistance effect is better.

In conclusion, the earthen site crack grouting material has the characteristic of good mechanical property.

Physical Properties

IIa, disintegration resistance test

Test materials:

grouting materials ZJ-1 and ZJ-6 prepared in examples 1 and 6;

acquiring original soil-1 and original soil-2 of the ancient ruined site from different regions of the ancient ruined site in the elm forest region;

processing test materials:

③ the test method:

performing a collapse resistance test according to the standard of an engineering rock mass test method (GB/T50266-2013), detecting the collapse resistance of a test material, and recording the phenomenon and the result;

fourthly, test results:

specific phenomena and results are shown in table 7:

TABLE 7 disintegration test results

The result shows that compared with the original soil-1 and original soil-2 of the site, the micro-shrinkage crack grouting material ZJ-1 and ZJ-6 of the site has the advantages of later slag dropping time, longer time consumption for completing disintegration and better collapse resistance.

IIb shrinkage test

Test materials:

grouting materials: grouting material ZJ-1 prepared in example 1, grouting material ZJ-6 prepared in example 6, grouting material ZJ-11 prepared in example 11;

raw soil material: original soil of an earthen site in an elm forest region;

the test method comprises the following steps:

carrying out a contractibility test by referring to 'Standard test methods for basic Performance of building mortar' (JGJ/T70-2009) to detect the contractibility of the grouting material;

③ the test result:

the soil has the property of shrinking in the airing process, and the long-term stability of the earthen site is influenced by the shrinkage degree of the grouting material when the earthen site is reinforced;

as shown in fig. 5, it can be seen that the shrinkage deformation of each material is divided into three periods as a whole: the early stage is approximately linear shrinkage, and the shrinkage of the material is fast; the middle period of transient transition gradually slows down the dehydration speed along with the reduction of the water content; after the later period is stable, the material is similar to a straight line, the shrinkage rate is basically stable, and the material does not shrink any more;

according to the change of the shrinkage rate days, the three grouting materials lose water and shrink faster than the original soil material, and the shrinkage rate is close to 1% in 30 days; the shrinkage of the original soil material is slow, and the shrinkage reaches about 0.7% in 30 days; the shrinkage rate is in a smaller variation range; therefore, the grouting material can reinforce the cracks of the earthen site and can be tightly combined with the soil body close to the cracks.

Iic color difference detection

Test materials:

grouting materials ZJ-1, ZJ-6 and ZJ-11 prepared in example 1, example 6 and example 11; the test method comprises the following steps:

measuring a color coordinate system delta E of a color space of object colors by referring to a CIE1976 color difference formula and a color appearance system CIELAB, wherein the delta E is [ (delta L) 2+ (delta a) 2+ (delta b) 2]1/2, the delta L is a brightness difference, the delta a is a red-green chroma discoloration, and the delta b is a yellow-blue chroma difference, the three numerical values are calculated together to obtain a color difference delta E, and the specific evaluation standard of the delta E is shown in Table 8; carrying out color difference detection on the color change of the sample after the water is evaporated; judging the influence of the grouting material on the site observation after use;

TABLE 8. DELTA.E evaluation criteria

Grade	Class requirement	Delta E value
			0	No color change	≤1.50
1	Very slight discoloration	1.60-3.00
			2	Slight discoloration	3.10-6.00
3	Obvious color change	6.10-9.00
			4	Greater discoloration	9.10-12.00
5	Severe discoloration	>12.00

③ the test result:

the detection result is shown in figure 6, and the color difference value of three grouting materials ZJ-1, ZJ-6 and ZJ-11 with different components is 2.7-3.3 after water is evaporated, and the grouting materials are in very slight color change and slight color change grades; the grouting materials with different proportions have small change with color after water evaporation, and are beautiful after the relics of the site are repaired by grouting, and the appearance is not influenced.

Iid gas permeability test

Test materials:

grouting materials ZJ-1, ZJ-6, ZJ-11 prepared in example 1, example 6 and example 11 and earthen site original soil in elm forest region were used as slurries respectively;

obtaining a native soil body from an earthen site of an elm forest region to be used as an undisturbed soil body;

processing test materials:

primary soil group: pouring the native soil into a cutting ring mould as a native soil group;

simulation grouting sample group: placing a cutting ring mould on the native soil body, and respectively performing reverse moulding on the grouting material on the native soil body to simulate the grouting process;

③ the test method:

the air permeability is another important performance index for inspecting the earthen site protection; if the exchange channel between the inside of the earthen site and the outside is damaged after the grouting material is treated, the air permeability is changed, and the site is subjected to protective damage, so that more serious damage is caused;

detecting the water loss quality of different slurries before and after reinforcement, wherein the delta m is the quality before water loss and the quality after water loss, the air permeability is represented by the reinforced delta m and the unreinforced delta m, the larger the water loss coefficient of the slurry is, the better the air permeability after reinforcement is, the smaller the influence on the breathing function is, and the good effect of repairing the site is achieved;

fourthly, test results:

as can be seen from FIG. 7, the grouting materials ZJ-1, ZJ-6 and ZJ-11 have different blending ratios but have small changes in air permeability compared to the original soil group, indicating that the grouting material of the present invention has good and stable air permeability.

It should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and the present invention is not limited thereto, and the present invention is described in detail with reference to the above-mentioned embodiments, and it will be apparent to those skilled in the art that modifications and equivalents of the technical features described in the above-mentioned embodiments may be made, or equivalents and partial technical features may be substituted. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.