CN116622317A - Adhesive material for protecting sandstone stone cultural relics and protection method - Google Patents

Abstract

The application discloses a bonding material and a protection method for protecting a sandstone stone cultural relic body, which relate to the technical field of sandstone cultural relic protection and are technically characterized in that: the grouting material comprises bonding materials and grouting materials, wherein the bonding materials consist of the following components in percentage by mass: 12-18% of superfine silicate cement, 0.5-1% of water glass, 8-12% of water and 70-76% of hydraulic lime; the grouting material consists of the following components: 97-98% of epoxy resin and 2-3% of metakaolin. According to the application, the bonding material is adopted to repair the cultural relics, so that the compressive strength, the tensile strength and the shear strength of the sandstone cultural relics are obviously improved, the weathering resistance and the corrosion resistance of the sandstone cultural relics are further improved, and the method has important significance for protecting the cultural relics and improving the safety performance of the cultural relics.

Description

Adhesive material for protecting sandstone stone cultural relics and protection method

Technical Field

The application relates to the technical field of sandstone cultural relics, in particular to an adhesive material for protecting a sandstone cultural relic body and a protection method.

Background

In recent thousands of years, the body of sandstone stone cultural relics generates a certain degree of hollows, flaking, cracks and other diseases under the influence of long-term natural stress. The structural surfaces for controlling the stability of the rock mass have a certain degree of expansion, the sandstone rock mass is poor in weather resistance, particularly the weather resistance of the expandable laminated fracture surfaces is weaker, and the tensile strength of the laminated surfaces of the weathered rock mass is easy to reach a limit state along with the influence of the gradual increase of the weather damage. The anti-static falling blocks can be generated under the working conditions of heavy rain, earthquake and the like, and the safety of cultural relics and visitors is greatly threatened. Therefore, the control treatment needs to be performed by taking necessary measures, and the following application study is performed. After the protective measures are planned to be implemented by adopting the bonding material, the problems of weathering, cracking and the like of the sandstone stone cultural relics are effectively solved.

In view of this, the present patent is filed.

Disclosure of Invention

The application aims to solve the problems, and provides the bonding material for protecting the bodies of sandstone-type cultural relics, which is respectively suitable for rock blocks with different thickness and crack sizes.

In order to achieve the above object, the technical scheme of the present application is as follows:

the bonding material for protecting the body of the sandstone stone cultural relics comprises bonding materials and grouting materials, wherein the bonding materials consist of the following components in percentage by mass: 12-18% of superfine silicate cement, 0.5-1% of water glass, 8-12% of water and 70-76% of hydraulic lime.

The principle of the application is as follows: in the binder, the main component is hydraulic lime, the hardening of the hydraulic lime is divided into two stages, the first stage is a hydraulic stage, the hydraulic lime is mixed with water to perform preliminary hardening, and then the hydraulic lime is subjected to a pneumatic hardening process which is gradually completed after the hydraulic hardening is completed, and the process is maintained for a period of several months, so that the hardness of the binder provided by the application is gradually improved in the process of repairing cultural relics, that is, the weather resistance of the cultural relics is also gradually improved. The hardening of superfine silicate cement includes four stages, including initial reaction stage, induction stage, setting stage and hardening stage, and during the hardening stage, crystal and gel form netted structure gradually becoming compact and capillary pores between the grains gradually becoming smaller to develop slurry strength continuously. When the hydraulic lime and the superfine silicate cement are mixed for use, the hydraulic lime and the superfine silicate cement harden under the condition of uniform mixing, so that the adhesive force is enhanced, and the adhesive can bond sandstone stone relics together. The adhesive material fully permeates and solidifies on the surface of stone relics, and the optimum material is prepared by combining laboratory tests according to the rock size and different disease types through fine adjustment of the proportion of each component in terms of shearing resistance, compressive resistance and tensile resistance so as to achieve the best adhesive effect.

Preferably, the grouting material comprises the following components in percentage by mass: 97-98% of epoxy resin and 2-3% of metakaolin. The grouting adhesive mainly comprises epoxy resin, and utilizes the characteristics of convenient curing, strong adhesive force, low contractility and the like of the epoxy resin, and then assists a small amount of water glass components to moderately enhance the tensile strength of the grouting adhesive, so that the large rock mass can be bonded with high strength. In practical application, the adhesion of the large rock mass should be realized so that the surface is cleaned up, dust and impurities are not contained, the smearing is even, the repeated adhesion is firm, the large rock mass needs to be smeared for many times, the adhesion is convenient and firm, the small rock mass needs to be smeared for many times, and the body is not damaged by smearing.

More preferably, the epoxy resin has an epoxy value of 0.25 to 0.45. The larger the epoxy value is, the lower the viscosity is, the better the fluidity is, and the epoxy value is selected to be 0.25-0.45, so that the viscosity can be ensured, the bonding requirement of larger rock blocks is met, and the tensile strength of the bonded rock blocks is close to that of the original rock.

The application also relates to a construction process of the bonding material for protecting the body of the sandstone stone cultural relics, which comprises the following steps:

s1, removing sand dust in cracks;

preferably, sand dust in the cracks is treated by adopting an air compressor to supply air under the pressure of 0.2-0.5 MPa. If the pressure is too large, cracks and blocks can be damaged, the cultural relic body is damaged, and the ash removal effect cannot be achieved if the pressure is too small. After air supply, the air supply is carried out until no redundant impurities and dust weathered products exist in the cracks. Thus, the bonding material is convenient to better contact and bond with the rock mass, and the reinforcement effect is fully achieved.

S2, embedding a grouting pipe in the crack;

preferably, the spacing between grouting pipes is 0.5-1m, the pipe diameter of the grouting pipes is matched with the crack opening gap, and the embedding depth is 0.2-0.4m. The method is characterized in that the method is designed according to the minimum intervention principle in the cultural relics, and the method is improved on the basis of a full test. Otherwise, damage can be caused to the surface layer and the interior of the cultural relics, if the internal compressive stress is too large, brittle failure and tensioning cracks can be caused, so that the spacing is not suitable to be too dense, and the depth is not suitable to be too deep.

S3, sealing the joint, namely sealing the joint by using cement, wherein the cement can be river mud on site, and sealing the joint from bottom to top to enable the sealing cement to be tightly adhered with the rock mass;

s4, gas detection, namely introducing gas into the grouting pipe, detecting the sealing effect of the crack, and performing repair sealing treatment on the gas leakage part;

preferably, the pressure of the gas introduced into the grouting pipe is 0.15-0.2MPa. The excessive air pressure can cause pipe blockage and accelerated condensation.

S5, preparing slurry, namely preparing grouting materials and bonding materials corresponding to the corresponding bonding materials according to the sizes of the cracks and the thicknesses of the rock masses;

s6, grouting, namely grouting the grouting material prepared in the S5 from bottom to top according to a pre-buried grouting pipe; the small cracks at the deepest part of the cracks, which are not paved by the grouting pipe, are filled in through a syringe or a drilling small hole;

preferably, the slurry is poured at a pressure of 0.15-0.2MPa. The body is damaged due to the overlarge pressure, and the bonding effect is obviously reduced due to the overlarge pressure.

And S7, sealing, namely sealing the surface cracks and the grouting pipe by using the sealing material prepared in the step S5, and performing distressing treatment on the surface by using rock powder, mineral pigment and repair mortar.

Compared with the prior art, the beneficial effect of this scheme:

1. the adhesive material provided by the application comprises grouting material and adhesive material, wherein the grouting material is suitable for repairing rock mass with cracks larger than 5mm, the internal friction angle of sandstone repaired by the grouting material can be restored to 98.79% of the internal friction angle of original rock, and the cohesive force can be restored to 98.01% of the cohesive force of the original rock; the adhesive is suitable for repairing rock mass with crack smaller than 5mm, because the epoxy resin has high adhesive strength, but the defect of high expansibility is not suitable for repairing fragile small rock mass, and the rock mass with small crack and thin thickness cannot bear the stress caused by expansion of the epoxy resin to the rock mass, so that the rock mass is possibly damaged.

2. The construction process of the bonding material provided by the application is convenient to operate, is generally suitable for repairing sandstone cultural relics, and can flexibly select different construction methods according to different crack widths and rock mass layering thicknesses.

3. The adhesive material provided by the application can be used for adjusting the fluidity according to the proportion, so that the adhesive speed of sandstone rock mass can be increased, the adhesive material is convenient to solidify, has strong adhesive force, low contractibility and the like, and the tensile property and ageing resistance of the adhesive material can be moderately enhanced.

Drawings

FIG. 1 is a schematic illustration of a sample preparation process in an experiment of the present application;

FIG. 2 is a schematic illustration of a direct shear test specimen after repair of different bonding materials in the test of the present application;

FIG. 3 is a schematic view of a split sample after repair of different bonding materials in the test of the present application;

FIG. 4 shows the shear failure modes of the direct shear test specimens after the repair of different bonding materials in the test of the present application under different normal stresses

FIG. 5 is a shear failure mode of a direct shear test specimen under different normal stresses in an experiment of the present application;

FIG. 6 is a graph showing shear failure of epoxy bonded direct shear specimens under different normal stresses in the test of the present application;

FIG. 7 is a graph showing the shear strength envelope of a direct shear test specimen after repair of different bonding materials in the test of the present application;

FIG. 8 is a tensile failure mode of a split sample after repair of a different bonding material in an experiment of the present application;

FIG. 9 is a graph of vertical pressure versus time for a split sample during a tensile test in accordance with the present application.

Detailed Description

In order that those skilled in the art will better understand the present application, a more particular description of the application will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings, wherein it is to be understood that the illustrated embodiments are merely exemplary of some, but not all, of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, shall fall within the scope of the present application.

It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other. The present application will be described in detail with reference to examples.

Example 1

An adhesive material for protecting the bodies of sandstone stone cultural relics is prepared by the following method: mixing 17% of superfine cement, 1% of water glass, 70% of hydraulic lime and 12% of water to obtain an off-white liquid bonding material.

The bonding material prepared in the embodiment is suitable for repairing flaky rock blocks with the thickness of 1-5 mm, and the rock blocks are injected by using pinholes.

Example 2

The bonding material for protecting the body of the sandstone stone cultural relics comprises slurry for grouting and plugging material, and is prepared by the following method:

preparing grouting material: mixing 97% epoxy resin and 3% metakaolin uniformly to obtain slurry.

Preparing a bonding material: uniformly mixing 15% of superfine cement, 1% of water glass, 10% of water and 74% of hydraulic lime to obtain the adhesive.

The adhesive material prepared in this example is suitable for use with a thickness of 5mm or more and an area of 0.5m ² The above rock mass repair.

Example 3

An adhesive material for protecting the bodies of sandstone stone cultural relics is prepared by the following method: and uniformly mixing 76% of hydraulic lime, 12% of superfine cement, 1% of water glass and 11% of water to obtain the bonding material.

The bonding material prepared in the embodiment is suitable for rock blocks with the thickness of less than 1mm, and the rock blocks are injected in a mode of drilling small holes.

Example 4

A construction process of an adhesive material for protecting a sandstone stone cultural relic body comprises the following steps:

s1, removing sand dust in cracks; and (3) air is supplied to the sand dust in the cracks by adopting an air compressor at the pressure of 0.5MPa for treatment.

S2, embedding a grouting pipe in the crack; the spacing between the grouting pipes is 0.7m, the pipe diameters of the grouting pipes are matched with the crack opening gap, and the embedding depth is 0.3m.

S3, sealing the joint, and sealing the joint by using cement, wherein the cement is obtained by adding hydraulic lime into viscous soil, and the joint is sealed from bottom to top, so that the sealing cement is tightly adhered with the rock mass.

S4, gas detection, namely introducing gas into the grouting pipe, detecting the sealing effect of the crack, and performing repair sealing treatment on the gas leakage part; the pressure of the gas introduced into the grouting pipe is 0.2MPa. The excessive air pressure can cause pipe blockage and accelerated condensation.

S5, preparing slurry corresponding to the corresponding bonding materials according to the size of the cracks and the thickness of the rock mass, and respectively adopting bonding materials with different formulas for wide and narrow cracks, wherein the bonding materials are shown in the embodiments 1-3;

s6, grouting, namely grouting the slurry prepared in the step S5 from bottom to top according to a pre-buried grouting pipe; the small cracks at the deepest part of the cracks, which are not paved by the grouting pipe, are filled in through a syringe or a drilling small hole; the slurry infusion pressure was 0.2MPa.

S7, sealing, namely sealing the surface cracks and the grouting pipe by using adhesive, and performing distressing treatment on the surface by using rock powder, mineral pigment and repair mortar.

Comparative example 1

An adhesive material for protecting the bodies of sandstone stone cultural relics is prepared by the following method: mixing 10% of superfine cement, 1% of water glass, 78% of hydraulic lime and 12% of water to obtain an off-white liquid bonding material.

Comparative example 2

An adhesive material for protecting the bodies of sandstone stone cultural relics is prepared by the following method: mixing 20% of superfine cement, 0.5% of water glass, 69.5% of hydraulic lime and 10% of water to obtain an off-white liquid bonding material.

Comparative example 3

Comparative example 3 differs from example 2 in that the prepared grouting material is different from, specifically: mixing 90% of epoxy resin and 10% of metakaolin uniformly to obtain slurry.

Comparative example 4

Comparative example 4 differs from comparative example 3 in that the grouting material used pure epoxy resin, and no metakaolin was added.

Test

1. Sample preparation: the method comprises the steps of taking complete sandstone adopted in the test from rock under a cliff of a cliff modeling site to cut, preparing a cylindrical sample with the diameter of 5cm and the height of 5cm, preparing the sample in the actual preparation process shown in the figure 1, preparing a direct shear sample and a split sample from the cylindrical sample, and preparing the direct shear sample by the following steps: the sandstone cylinder samples were cut along the middle cross section, and bonded with bonding materials (grouting materials in example 1 and example 2, example 3, comparative example 1, comparative example 2, comparative example 3 and comparative example 4) respectively; the preparation method of the cleavage sample comprises the following steps: the sandstone cylinder samples were cut radially and bonded with bonding materials (grouting materials in example 1, example 2, example 3, comparative example 1, comparative example 2, comparative example 3, comparative example 4), the direct shear samples were used for shear strength test, the split samples were used for tensile strength test, the direct shear samples after repair of the different bonding materials were shown in fig. 2, and the split samples after repair of the different bonding materials were shown in fig. 3.

2. The basic physical properties of the sample sandstone are shown in Table 1.

TABLE 1 basic physical Properties of sandstone

As can be seen from Table 1, the indexes of the unrepaired sandstone-like cultural relics are as described above, wherein the cohesive force is 1.51MPa, the internal friction force is 41.23 DEG, the average compressive strength is 20.58MPa, and the average tensile strength is 1.87MPa.

3. The diameter and height of the test specimen were measured using a vernier caliper, and the mass thereof was measured using an electronic balance, and the measurement results of the diameter and height of the repaired test specimen are shown in table 2.

TABLE 2 sample size and mass after repair

As is clear from Table 2, the samples used for the test were classified into direct shear samples and cleavage samples, and the samples after the repair were repaired using the binders of examples 1 to 3 and comparative examples 1 to 4, respectively, and the quality, height and diameter of the repaired samples are shown in the above tables.

4. Shear Strength test

With reference to the national standard "cement mortar strength test method" (GB/T17671-1999), a 1036PC type universal material tester is used for testing the mechanical properties of the samples.

1. The test failure mode is shown in FIG. 4.

As can be seen from fig. 4, the cultural relic sandstone direct shear test sample after being repaired by different bonding materials is broken under different normal stresses, and the test sample is basically broken along the contact surface of the bonding materials and sandstone, so that the section is relatively flat. All the samples are brittle failure, and the sandstone is seriously weathered, so that the strength of the samples is lower, and longitudinal cracks appear in different degrees after the samples are broken.

The epoxy bonded sandstone samples were accompanied by a pronounced sound of rock fracture upon failure, and a layer of sandstone was adhered to the failure face adhesive, indicating a stronger adhesion using epoxy, as shown in fig. 6. The other samples are subjected to larger horizontal stress and normal stress during the breaking, the cracking is serious, obvious friction scratches can be seen on the shearing surface of part of the samples, the section sandstone is already powder, and the phenomenon of viscose fracture can be seen, as shown in fig. 5.

2. Respectively calculating peak normal stress and peak tangential stress according to the peak normal force and peak tangential force obtained by the test, as shown in table 3; the shear strength failure envelope is plotted as shown in fig. 7. The least square method is used for carrying out linear fitting on the data, and the internal friction angle of the sample is obtained according to the molar-coulomb intensity criterionAnd cohesion c, the results are shown in Table 4.

Table 3 shear strength test results of cultural relic sandstone samples after repair with different bonding materials

Table 4 shear strength index of cultural relic sandstone samples after repair with different bonding materials

As can be seen from tables 3 and 4: (1) The internal friction angle of the sandstone after the bonding and repairing of the epoxy resin can be restored to 98.79 percent of the internal friction angle of the original rock, the cohesive force can be restored to 98.01 percent of the cohesive force of the original rock, and the bonding property of the bonding material is required to be higher as the thickness of the rock mass is larger in combination with the construction process, so that the bonding material consisting of 97 percent of epoxy resin and 3 percent of metakaolin is suitable for repairing the rock mass with the thickness of more than 5 mm; (2) For two bonding materials, namely hydraulic lime+5% ultrafine cement and hydraulic lime+12% ultrafine cement, the two indexes of internal friction angle and cohesion are respectively recovered to 60.08%, 36.42%, 65.78% and 36.42%, and meanwhile, the economic applicability of the formula is considered, so that the adhesive of the formula is suitable for repairing rock blocks with the thickness of less than 5 mm; (3) From the shear strength recovery degree, the repairing effect of the bonding material is as follows from good to poor in sequence: from examples 2, 1, 3, 4, and 2, it can be demonstrated that the adhesive materials provided in this embodiment have better recovery effects on shear strength, and have remarkable differences and unexpected technical effects.

5. Tensile Strength test

With reference to the national standard "cement mortar strength test method" (GB/T17671-1999), a 1036PC type universal material tester is used for testing the mechanical properties of the samples.

1. The test failure mode is shown in FIG. 8. At the end of the test, the test results were valid, with the samples of each group being basically broken along the loading diameter direction (adhesion crack).

The epoxy bonded sandstone sample is brittle, and is accompanied by obvious fracture sound during fracture. In addition, a layer of sandstone is adhered to the adhesive on the inner breaking surface of the sample, which is probably caused by the fact that the weathering of the sandstone of the sample is low in tensile capacity, and the adhesive permeates into the sandstone pores in the bonding process to enhance the tensile capacity of the sandstone and the sandstone. The cleavage surface inside the sample has concave or convex parts, which is probably caused by uneven stress in the loading process due to poor anisotropy of the adhesive filling over sandstone. The sandstone samples bonded by the hydraulic lime (+ 5% of superfine cement and 0.5% of water glass) and the hydraulic lime (+ 12% of superfine cement and 1% of water glass) are broken along the bonding surface, and weak fracture sound, brittle fracture and substantial unbroken rock are caused during the breaking.

2. In the process of the split sample test, the vertical pressure and time of the sample are changed as shown in fig. 9, and it can be seen from the graph that all the sandstone samples repaired by the three bonding materials are brittle failure.

3. The peak pressure of the sample was determined from the failure curve and then substituted into the tensile strength calculation formula to obtain the tensile strength of the sample, and the calculation results are shown in table 5.

Table 5 tensile Strength test results of cultural relic sandstone samples after repair with different bonding materials

As can be seen from table 5: the tensile strength of the sandstone after bonding and repairing by 97% of epoxy resin and 3% of metakaolin can be recovered to 72.19% of the tensile strength of the original rock, which shows that the repairing capability of the epoxy resin and the metakaolin is stronger, the bonding effect is excellent, and the method is suitable for repairing cultural relics with large bonding quality and rock blocks; the tensile strength of the sandstone sample after the repairing of two materials of 84.5% hydraulic lime, 5% superfine cement, 0.5% water glass, 10% water and 76% hydraulic lime binder, 12% superfine cement, 1% water glass and 11% water is recovered to 637.97% and 43.32% of the original rock respectively; from the tensile strength recovery degree, the repairing effect of the bonding material is as follows from good to poor in sequence: 97% of epoxy resin, 3% of metakaolin, 76% of hydraulic lime binder, 12% of superfine cement, 1% of water glass, 11% of water, 84.5% of hydraulic lime, 5% of superfine cement, 0.5% of water glass and 10% of water, and the tensile strength recovery effect of the bonding material obtained in each comparative example is poorer.

In summary, the bonding material provided by the application comprises the bonding material and the grouting material, which are respectively suitable for repairing rock blocks with cracks of different thickness and different specifications, the fluidity of the grouting material is superior to that of the bonding material, and the grouting material is suitable for repairing larger rock blocks, mainly because the larger the rock blocks are, the larger the gravity is, the larger the risk of falling off the rock blocks is, the bonding material with stronger viscosity is suitable for repairing larger rock blocks, and the repairing of peeled relatively thinner rock blocks cannot be performed by using epoxy resin.

In addition, this patent is only applicable to the bonding of specific slice efflorescence district sandstone class stone historical relics and uses, and other types sandstone diseases can combine corresponding test data to carry out the suitability adjustment.

The above specific embodiments are provided for illustrative purposes only and are not intended to limit the application, and modifications, no inventive contribution, will be made to the embodiments by those skilled in the art after having read the present specification, as long as they are within the scope of the patent statutes.

Claims (8)

1. The bonding material for protecting the body of the sandstone stone cultural relics is characterized by comprising bonding materials and grouting materials, wherein the bonding materials consist of the following components in percentage by mass: 12-18% of superfine silicate cement, 0.5-1% of water glass, 8-12% of water and 70-76% of hydraulic lime.

2. The bonding material for protecting bodies of sandstone-type stone relics according to claim 1, wherein the grouting material comprises the following components in mass ratio: 97-98% of epoxy resin and 2-3% of metakaolin.

3. An adhesive material for the protection of bodies of sandstone-type stone relics according to claim 2, wherein the epoxy resin has an epoxy value of 0.25-0.45.

4. A method for protecting a body of a sandstone-type stone relic according to any one of claims 1 to 3, comprising the steps of:

s1, removing sand dust in cracks;

s2, embedding a grouting pipe in the crack;

s3, sealing the seam, and sealing the slit opening from bottom to top;

s4, gas detection, namely introducing gas into the grouting pipe, detecting the sealing effect of the crack, and performing repair sealing treatment on the gas leakage part;

s5, preparing slurry, namely preparing grouting materials and bonding materials corresponding to the corresponding bonding materials according to the sizes of the cracks and the thicknesses of the rock masses;

s6, grouting, namely grouting the grouting material prepared in the S5 from bottom to top according to a pre-buried grouting pipe; filling adhesive into the deepest small cracks which are not paved by the grouting pipe in the cracks through a syringe or a small drill hole;

s7, sealing, namely plugging the surface cracks and the grouting pipe by using the adhesive prepared in the S5, and performing distressing treatment on the surface by using rock powder, mineral pigment and repair mortar.

5. The method for protecting a sandstone-type stone cultural relic body according to claim 4, wherein in the step S1, sand dust in the fissure is treated by adopting an air compressor to supply air under the pressure of 0.2-0.5 MPa.

6. The method according to claim 4, wherein in the step S2, the distance between grouting pipes is 0.5-1m, the pipe diameter of the grouting pipes is matched with the crack opening gap, and the embedding depth is 0.2-0.4m.

7. The method for protecting a body of a sandstone-type stone relic according to claim 4, wherein in S4, the pressure of the gas introduced into the gas sensor is 0.15 to 0.2MPa.

8. The method according to claim 4, wherein the slurry filling pressure is 0.15-0.2MPa in S6.