CN118219387A - Archaized urban wall brick and preparation method thereof - Google Patents

Abstract

The invention discloses an archaized urban wall brick and a preparation method thereof, wherein the preparation method comprises the following steps: air-drying the soil sample; crushing and sieving: the aperture diameter of the sieve holes is not more than 2mm; humidifying a soil sample: controlling the moisture content of the humidified soil sample to be 25% -35%; sealing and curing for pugging for one week; and (3) forming a green brick: putting the cured soil sample into a mould, trampling the soil sample back and forth by feet, discharging bubbles in the soil sample, and fully filling the mould with the soil sample; demolding the green bricks, stripping redundant clay on the upper surfaces of the green bricks, and trowelling the upper surfaces; dispersing water in the vertical blank: pulling the lower bottom surface of the die to stand up and dry the green bricks, inverting the green bricks after two days, scraping the surface in the inversion process to level the surfaces of the green bricks, and repeating the steps for a circle; and (5) air drying and firing. The invention also provides the size standard, the appearance quality standard, the strength standard, the lime bursting standard and the weather resistance standard of the archaizing urban wall brick, and can effectively solve the problem that the urban wall brick frequently has large-area spalling caused by the problems of machine urban brick wind, breakage, fracture, incomplete and the like.

Description

Archaized urban wall brick and preparation method thereof

Technical Field

The invention belongs to the technical field of cultural heritage protection and geotechnical engineering, and particularly relates to an archaized urban wall brick and a preparation method thereof.

Background

The urban wall in Nanjing has been subjected to over 600 years, and due to reasons such as wind and rain erosion, natural aging, biological breaking, artificial blank damage and the like, the urban bricks at the positions such as the facade and the top surface of the urban wall are subjected to weathering, breakage, fracture, incomplete and the like, and particularly the peel and fracture of the urban bricks at the facade and the broken urban bricks at the top surface are most obvious, so that the compressive strength, the frost resistance, the durability and the like of the urban bricks are greatly reduced, and the phenomenon of large-area peeling of the facade of the urban wall is frequently caused. The investigation finds that the modern urban bricks used for repairing the urban wall have diseases such as surface warping, cracking, flaking and the like, and especially the problem of the modern urban bricks positioned on the top surface of the urban wall is most serious.

The ancient brick making process is as follows:

The manufacturing process needs more than ten strict procedures, such as soil taking, mud stepping, slurry clarifying, deposition, blank making, blank airing, kiln loading, kiln burning, water drying, kiln discharging, packaging and the like. The clarifying slurry is an important link in the brick making process, firstly, selected soil is conveyed into a flat concave ground, impurities are removed, then the soil is soaked in water, and the cattle are driven to step on the soil until all mud blocks are stepped on. Then the mud which is stamped is conveyed into a large bricked pool, the mud is stirred into slurry, then a mud hole on the pool wall is opened, the slurry is saturated and flows into a parking pool below through the thick bamboo and the thin bamboo, the slurry is filtered by the two bamboo grates, and the slurry is very tired, so that the 'Chengkui' common in the brick is the procedure. The term "clarified slurry mud" means extremely greasy mud from which impurities have been removed after filtration, particularly mud for producing fine ceramics and the like. The quality of the "clarified slurry fine mud" for making bricks is similar to that of the fine ceramic mud, and the quality requirement on urban bricks is high at the moment. After the mud is deposited in the parking pool for several months, the mud is gradually coagulated into soft solid, at the moment, the plasticity of the mud is required to be mastered, when the softness and hardness of the mud are moderate, the middle most fine part is taken out and sealed, the mud to be used is at least stopped and sealed for more than four months, the mud with complete curing property can be used for blank making after the mud is completely cured, the mud with complete curing property is removed from the blank by using a brick die, and the removed mud blank still needs a dehydration and drying period of several months. The traditional method is that the solar energy is placed in a room which can be sealed and ventilated and has the adjusting function, not only is sun-proof, but also is antifreezing, and the humidity and the temperature in the room are continuously adjusted during the dehydration and drying period, so that the mud blank is prevented from freezing or cracking. Meanwhile, the mud blank is turned over frequently, so that deformation caused by uneven dry and wet conditions is avoided.

By examining the modern city brick production process, the modern archaized city wall brick production process is found to have the following problems:

1. The manufacturing process of the archaized urban wall bricks cannot be complicated like ancient times, and most of the prior art is to replace manual bricks with machine bricks.

2. The clay is not stepped on mud, clarified slurry, deposited, etc. to make blank directly, there are large granular hard cores inside the blank, and after brick is formed, a great amount of unburnt grains can be seen on its section, and the subsequent lime burst test proves that these grains are easy to expand when meeting water, so-called lime burst, thus causing cracks on the surface of brick body.

3. The existing green brick making machine forms green bricks by the principle of spiral pushing and forward extrusion, so that the cross section of the produced city bricks is in a spiral structure, the longitudinal section is in a segment structure, a large number of continuous gaps (shown in figure 1) are densely distributed, and the city bricks are not as dense as the ancient city bricks in the section.

Disclosure of Invention

The technical problems to be solved are as follows: aiming at the technical problems, the invention provides an archaized urban wall brick and a preparation method thereof, wherein the earth materials obtained by brick making are crushed and sieved to control the fineness of the earth materials, and a manual brick making process is used for replacing a machine brick making process, so that the problems of lime bursting and dense continuous gaps of brick bodies caused by the machine brick making can be effectively solved.

The technical scheme is as follows: a preparation method of an archaizing city wall brick comprises the following steps:

Step one, air-drying a soil sample;

Step two, crushing and sieving: the aperture diameter of the sieve holes is not more than 2mm;

step three, humidifying the soil sample: controlling the moisture content of the humidified soil sample to be 25% -35%;

sealing and maintaining for pugging for one week;

step five, green brick molding: putting the cured soil sample into a prepared detachable urban wall brick mold, trampling the mold back and forth by feet, discharging bubbles in the soil sample, and fully filling the mold with the soil sample;

Step six, demolding the green bricks, stripping redundant clay on the upper surfaces of the green bricks, and trowelling the upper surfaces;

Step seven, dispersing water from the vertical blank: pulling the lower bottom surface of the die to stand up and dry the green bricks, inverting the die after two days to ensure that the moisture of the green bricks is dispersed uniformly, scraping the surface in the inversion process to ensure that the surfaces of the green bricks are smooth, and repeating the process for a circle to form the green bricks;

Step eight, air-drying and firing: and (5) after air-drying for one month, firing the green bricks to obtain the archaized urban wall bricks.

Preferably, in the first step, the soil sample is clay with a plasticity index of more than 10.

Preferably, in the third step, the water content is controlled to be 25% -30% when the plasticity index of the soil sample is (10, 15), and the water content is controlled to be 30% -35% when the plasticity index of the soil sample is (15, 17).

Preferably, the time of humidification in step three is 1h.

Preferably, in the fifth step, straw ash is attached to the inner surface of the mold before the soil sample is put into the mold so as to facilitate demolding.

Preferably, in the seventh step, water is sprayed on the surface of the green brick in the drying process to prevent the surface of the green brick from cracking.

The archaized urban wall brick prepared by the method.

Preferably, the size standard of the archaized urban wall tile is as follows: the allowable deviation of the dimension of 400mm is +/-6, the allowable deviation of the dimension of 200mm is +/-5, and the allowable deviation of the dimension of 100mm is +/-4;

the appearance quality standard is as follows: the opposite height difference is less than or equal to 5mm, the bending is less than or equal to 5mm, the protruding height of impurities is less than or equal to 5mm, the continuous length of an internal gap is less than or equal to 50mm, the width of the internal gap is less than or equal to 3mm, and the length of an external gap is less than or equal to 100mm;

the intensity criteria are as follows: compressive strength is more than or equal to 10.0MPa, and flexural strength is more than or equal to 4.0MPa;

the lime burst criteria are as follows: burst areas with maximum burst sizes greater than 2mm and less than 15mm, no more than 15 tiles per group, no more than 7 tiles greater than 10mm, no burst areas with maximum burst sizes greater than 15mm are allowed;

The weathering criteria are as follows: the average value of natural water absorption is less than or equal to 15 percent, and the maximum value of a single block is less than or equal to 18 percent; the average value of boiling water absorption is less than or equal to 18 percent, and the maximum value of a single block is less than or equal to 20 percent; the average value of saturation coefficients is less than or equal to 0.88 percent, and the maximum value of a single block is less than or equal to 0.90 percent.

Preferably, the size standard of the archaized urban wall tile is as follows: the allowable deviation of the dimension of 400mm is +/-5, the allowable deviation of the dimension of 200mm is +/-4, and the allowable deviation of the dimension of 100mm is +/-4;

The appearance quality standard is as follows: the opposite height difference is less than or equal to 4mm, the bending is less than or equal to 3mm, the impurity protruding height is less than or equal to 3mm, the continuous length of an internal gap is less than or equal to 40mm, the width of the internal gap is less than or equal to 2mm, and the length of an external gap is less than or equal to 80mm;

the intensity criteria are as follows: compressive strength is more than or equal to 10.0MPa, and flexural strength is more than or equal to 4.0MPa;

The lime burst criteria are as follows: burst areas with maximum burst sizes greater than 2mm and less than 10mm, where each set of bricks is not more than 15, do not allow burst areas with maximum burst sizes greater than 10mm to occur;

The weathering criteria are as follows: the average value of natural water absorption is less than or equal to 15 percent, and the maximum value of a single block is less than or equal to 18 percent; the average value of boiling water absorption is less than or equal to 18 percent, and the maximum value of a single block is less than or equal to 20 percent; the average value of saturation coefficients is less than or equal to 0.88 percent, and the maximum value of a single block is less than or equal to 0.90 percent.

Preferably, the size standard of the archaized urban wall tile is as follows: the allowable deviation of the dimension of 400mm is +/-4, the allowable deviation of the dimension of 200mm is +/-3, and the allowable deviation of the dimension of 100mm is +/-3;

the appearance quality standard is as follows: the opposite height difference is less than or equal to 3mm, the bending is less than or equal to 2mm, the impurity protruding height is less than or equal to 2mm, the continuous length of an internal gap is less than or equal to 30mm, the width of the internal gap is less than or equal to 1mm, and the length of an external gap is less than or equal to 50mm;

the intensity criteria are as follows: compressive strength is more than or equal to 10.0MPa, and flexural strength is more than or equal to 4.0MPa;

the lime burst criteria are as follows: burst areas with maximum burst sizes greater than 2mm are not allowed to occur;

The weathering criteria are as follows: the average value of natural water absorption is less than or equal to 15 percent, and the maximum value of a single block is less than or equal to 18 percent; the average value of boiling water absorption is less than or equal to 18 percent, and the maximum value of a single block is less than or equal to 20 percent; the average value of saturation coefficients is less than or equal to 0.88 percent, and the maximum value of a single block is less than or equal to 0.90 percent.

The beneficial effects are that: according to the soil sample for preparing the manual brick, the grain size of soil particles is controlled below 2mm, and the improvement mechanism comprises the following aspects: large-particle quicklime particles exist in the brick body, and the expansion amount generated by hydration is large, so that large stress is generated in the brick body, and when the internal stress exceeds the elastic deformation range of the brick body, the brick body is swelled. The larger the limestone particle size, the greater the concentrated stress created by hydration of the slaked lime within the finished brick. When the limestone particles are smaller than 2mm, the hazard degree of lime bursting is reduced by more than 80%. Moreover, by adopting a fully stirring mode, the limestone fine particles in the raw materials are in a high dispersion state, so that the calcium carbide particles in the finished brick are prevented from gathering, the concentrated stress generated by hydration is prevented, and the harm caused by 'lime burst' is greatly reduced. The manual brick making process can fully stir the soil materials, the soil particles in the manufactured green bricks are uniformly distributed, and the phenomenon that the existing green brick making machine forms green bricks based on the principle of spiral pushing and forward extrusion, so that the produced urban bricks have spiral cross sections and section-shaped longitudinal sections and are densely provided with a large number of continuous gaps is effectively reduced.

Therefore, the invention has the following beneficial effects: first, the improved handmade tile has fewer internal voids and fewer surface cracks than modern machine tiles. Secondly, the manual brick making process can fully stir the soil materials, thereby reducing the boiling water absorption rate of the finished product. Third, the improved manual brick has significantly increased flexural strength relative to the machine brick. Fourth, the lime bursting phenomenon of the manual improved brick is obviously reduced.

Drawings

FIG. 1 is a cross section (left view) and a vertical section (right view) of a modern machine city wall brick;

FIG. 2 is a longitudinal section view of an archaized urban wall tile (hand tile) made in accordance with the present invention;

FIG. 3 is a graph of freeze-thaw damage to a modern machine city wall brick (left graph) and a graph of freeze-thaw damage to an archaized city wall brick (hand brick) made in accordance with the present invention (right graph).

Detailed Description

The invention is further described below with reference to the drawings and specific embodiments.

Example 1

An archaizing urban wall brick comprises the following specific preparation steps:

The first step: and (5) air-drying the soil sample. And (3) taking powdery clay with the plasticity index of 10-15, flattening the powdery clay by 8-10 cm, and air-drying.

And a second step of: and (5) crushing the soil sample. Taking 5000kg of dry soil sample, and crushing and sieving by a crusher, wherein the aperture is not more than 1mm.

And a third step of: and wetting the soil sample. Taking a sieved soil sample, flattening, controlling the thickness to be 8cm, spraying and humidifying, and controlling the water content to be 25% -30% according to the soil sample condition, namely taking 1250 kg-1500 kg of water. The humidification time was controlled at 1 hour.

Fourth step: and (5) sealing and curing the soil sample for pugging. The soil samples are piled up, and the surface is wrapped and maintained for one week by a plastic film.

Fifth step: and (5) forming green bricks. And (3) putting the cured clay into a prepared detachable urban wall brick mold, trampling the mold back and forth by feet, discharging bubbles in the clay, and fully filling the mold with the clay. Straw ash is attached to the inner surface of the mould before the soil sample is put into the mould, so that the green brick is easy to demould.

Sixth step: and stripping the green bricks from the mould. After this process is completed, the excess clay on the upper surface is stripped off with hard iron wires. And finally, trowelling the upper surface by using a scraper to demould.

Seventh step: and (5) dispersing water in the vertical blank. Pulling the lower bottom surface of the mould to stand up the urban wall green bricks for air drying, beating two ends when standing up the green bricks, ensuring the consistency of the two ends, inverting after two days to ensure that the urban wall green bricks are uniformly dispersed, scraping the surface with a scraper in the inversion process to smooth the surface of the urban wall green bricks, and repeating the steps for one week to form the urban wall green bricks. Because urban wall adobe is great, moisture migration inhomogeneous when standing the adobe and airing leads to the adobe to warp easily, and surface spraying water scattering purpose prevents surface cracking, prevents insolatedly in the setting process, should place in the canopy that ventilates better.

Eighth step: firing. After air-drying for one month, the green bricks are put into a kiln for firing.

Example 2

An archaizing urban wall brick comprises the following specific preparation steps:

the first step: and (5) air-drying the soil sample. Taking clay with a plasticity index of 15-17, flattening the clay by 8-10 cm, and air-drying.

And a second step of: and (5) crushing the soil sample. Taking 5000kg of dry soil sample, and crushing and sieving by a crusher, wherein the aperture is not more than 2mm.

And a third step of: and wetting the soil sample. Taking a sieved soil sample, flattening, controlling the thickness to be 8cm, spraying and humidifying, and controlling the water content to be 30% -35% according to the soil sample condition, namely taking 1500 kg-1750 kg of water. The humidification time was controlled at 1 hour.

Fourth step: and (5) sealing and curing the soil sample for pugging. The soil samples are piled up, and the surface is wrapped and maintained for one week by a plastic film.

Fifth step: and (5) forming green bricks. And (3) putting the cured clay into a prepared detachable urban wall brick mold, trampling the mold back and forth by feet, discharging bubbles in the clay, and fully filling the mold with the clay. Straw ash is attached to the inner surface of the mould before the soil sample is put into the mould, so that the green brick is easy to demould.

Sixth step: and stripping the green bricks from the mould. After this process is completed, the excess clay on the upper surface is stripped off with hard iron wires. And finally, trowelling the upper surface by using a scraper to demould.

Seventh step: and (5) dispersing water in the vertical blank. Pulling the lower bottom surface of the mould to stand up the urban wall green bricks for air drying, beating two ends when standing up the green bricks, ensuring the consistency of the two ends, inverting after two days to ensure that the urban wall green bricks are uniformly dispersed, scraping the surface with a scraper in the inversion process to smooth the surface of the urban wall green bricks, and repeating the steps for one week to form the urban wall green bricks. Because urban wall adobe is great, moisture migration inhomogeneous when standing the adobe and airing leads to the adobe to warp easily, and surface spraying water scattering purpose prevents surface cracking, prevents insolatedly in the setting process, should place in the canopy that ventilates better.

Eighth step: firing. After air-drying for one month, the green bricks are put into a kiln for firing.

Example 3 detection criteria for archaized wall tiles

The archaized urban wall bricks (modified handmade bricks) and the modern machine urban bricks prepared in example 1 were subjected to surface quality, water absorption, flexural compressive strength, lime burst test, freeze thawing test and frosting test.

The comparison results are shown in Table 1:

table 1 machine tile and hand tile test data comparison table

As can be seen from the table, compared with the modern machine city brick, the manual improvement of the brick is greatly improved in the aspects of internal structural condition, water absorption, flexural strength, lime burst, freeze thawing, frosting and the like. The concrete improvement effect is as follows: first, the problem of segment-like bonding is opposed to the large number of continuous voids densely packed in machine tiles, with fewer voids and fewer surface cracks in the hand-modified tile, as shown in FIG. 2. Secondly, the average boiling water absorption of modern machine city bricks is 18.28%; the average value of the water absorption rate of the manual improved brick boiling is 13.72 percent. The boiling water absorption of the manual improved brick is obviously reduced compared with that of the machine city brick, and the manual improved brick has lower void fraction. Thirdly, the average flexural strength of the improved manual brick is 4.07Mpa which is larger than the flexural strength of the machine brick by 1.52Mpa, and the size of the gap is proved to seriously influence the flexural strength of the urban wall brick. Fourth, the machine city bricks were tested for lime burst, with a large number of burst areas, and the maximum broken size was greater than 15mm, while the manual modified bricks were tested for lime burst, with only a small number of burst areas less than 2 mm. Fourth, through the freeze-thaw test, the crack of the machine tile fracture began to propagate and the crack widened, while the manual tile cross section was essentially unchanged, as shown in fig. 3.

The reason for obtaining the above improvement effect is as follows: when the modern machine city brick is prepared, the earth material is directly manufactured into a blank without being crushed, larger granular hard cores exist in the brick blank, and the grains are easy to expand when meeting water, namely lime burst occurs, so that the surface of the brick body is cracked; secondly, the section of the green brick formed by the existing green brick making machine is in a spiral structure, the vertical section is in a segment structure, a large number of continuous gaps are densely distributed, the bonding is poor, the bonding part begins to shrink in the firing process, the spiral gaps are finally formed, frost heaving is extremely easy to cause in winter in rainy and snowy days, and the urban wall brick layer is cracked. The manual improvement of the brick can effectively reduce the phenomena of lime bursting and continuous void densely distributed in the urban brick by controlling the fineness of the particles of the soil material and adopting a manual process, thereby improving the internal structure quality of the urban brick, reducing the water absorption rate of the urban brick and improving the mechanical strength of the urban brick.

The invention provides a brick standard for protecting and repairing Nanjing urban wall according to experimental results by repeatedly testing an improved manual brick and a modern machine urban brick.

The dimensional criteria are shown in table 2:

TABLE 2 dimensional tolerance (mm)

Note that: the number of samples measured was 1000 blocks in one unit.

Appearance quality criteria, as shown in table 3:

TABLE 3 deviation of appearance quality (mm)

Note that: the section should not have spiral lines, and the vertical section should not have continuous gaps or continuous spiral gaps. The number of samples measured 50 blocks is one unit.

Intensity criteria, as shown in 4:

Through the experimental study of the new ancient city bricks, the compressive strength of the city wall bricks can meet the requirements of the current clay baked bricks (the compressive strength of the city wall bricks is more than 5MPa in terms of the height of the city wall and can meet the strength requirements, the safety coefficient is considered, the standard is preferably more than 10 MPa), the detection method is to adopt a superposition compressive test, and the surface of the city wall bricks is subjected to bonding treatment.

TABLE 4 Strength Standard (MPa)

Lime bursting standard

High-grade product: burst areas with maximum burst sizes greater than 2mm are not allowed.

First grade product: a burst area with a maximum broken blank size of more than 2mm and less than or equal to 10mm, wherein each group of bricks are not more than 15; burst areas with maximum burst sizes greater than 10mm are not allowed.

Qualified products: the maximum burst size is greater than 2mm and less than 15mm burst area, with each set of tiles being less than 15. Wherein no more than 7 points greater than 10 mm; burst areas with maximum burst sizes greater than 15mm are not allowed.

Weather resistance criteria, as shown in table 5:

TABLE 5 anti-weathering criteria

Claims (10)

1. The preparation method of the archaizing city wall brick is characterized by comprising the following steps:

Step one, air-drying a soil sample;

Step two, crushing and sieving: the aperture diameter of the sieve holes is not more than 2mm;

Step three, humidifying the soil sample: controlling the moisture content of the humidified soil sample to be 25% -35%;

sealing and maintaining for pugging for one week;

step five, green brick molding: putting the cured soil sample into a prepared detachable urban wall brick mold, trampling the mold back and forth by feet, discharging bubbles in the soil sample, and fully filling the mold with the soil sample;

Step six, demolding the green bricks, stripping redundant clay on the upper surfaces of the green bricks, and trowelling the upper surfaces;

Step seven, dispersing water from the vertical blank: pulling the lower bottom surface of the die to stand up and dry the green bricks, inverting the die after two days to ensure that the moisture of the green bricks is dispersed uniformly, scraping the surface in the inversion process to ensure that the surfaces of the green bricks are smooth, and repeating the process for a circle to form the green bricks;

Step eight, air-drying and firing: and (5) after air-drying for one month, firing the green bricks to obtain the archaized urban wall bricks.

2. The method for producing an archaized urban wall tile according to claim 1, wherein the soil sample in the first step is clay with a plasticity index greater than 10.

3. The method for manufacturing an archaized urban wall tile according to claim 1, wherein in the third step, when the plasticity index of the soil sample is (10, 15), the water content is controlled to be 25% -30%, and when the plasticity index of the soil sample is (15, 17), the water content is controlled to be 30% -35%.

4. The method for producing an archaized urban wall tile according to claim 1, wherein the humidifying time in the third step is 1h.

5. The method for manufacturing an archaized urban wall tile according to claim 1, wherein in the fifth step, straw ash is attached to the inner surface of the mold before the soil sample is put into the mold so as to facilitate demolding.

6. The method for manufacturing an archaized urban wall tile according to claim 1, wherein in the seventh step, water is sprayed on the surface of the green brick in the air drying process, so as to prevent the surface of the green brick from cracking.

7. The archaized urban wall tile produced by the method of claim 1.

8. The archaized city wall brick of claim 7, wherein the archaized city wall brick has the following dimensional criteria: the allowable deviation of the dimension of 400mm is +/-6, the allowable deviation of the dimension of 200mm is +/-5, and the allowable deviation of the dimension of 100mm is +/-4;

the appearance quality standard is as follows: the opposite height difference is less than or equal to 5mm, the bending is less than or equal to 5mm, the protruding height of impurities is less than or equal to 5mm, the continuous length of an internal gap is less than or equal to 50mm, the width of the internal gap is less than or equal to 3mm, and the length of an external gap is less than or equal to 100mm;

The intensity criteria are as follows: the compressive strength is more than or equal to 10.0MPa, and the flexural strength is more than or equal to 4.0 MPa;

the lime burst criteria are as follows: burst areas with maximum burst sizes greater than 2mm and less than 15mm, no more than 15 tiles per group, no more than 7 tiles greater than 10mm, no burst areas with maximum burst sizes greater than 15mm are allowed;

the weathering criteria are as follows: the average value of natural water absorption is less than or equal to 15 percent, and the maximum value of a single block is less than or equal to 18 percent; the average value of boiling water absorption is less than or equal to 18 percent, and the maximum value of a single block is less than or equal to 20 percent; the average value of saturation coefficients is less than or equal to 0.88 percent, and the maximum value of a single block is less than or equal to 0.90 percent.

9. The archaized city wall brick of claim 7, wherein the archaized city wall brick has the following dimensional criteria: the allowable deviation of the dimension of 400mm is +/-5, the allowable deviation of the dimension of 200mm is +/-4, and the allowable deviation of the dimension of 100mm is +/-4;

The appearance quality standard is as follows: the opposite height difference is less than or equal to 4mm, the bending is less than or equal to 3mm, the impurity protruding height is less than or equal to 3mm, the continuous length of an internal gap is less than or equal to 40mm, the width of the internal gap is less than or equal to 2mm, and the length of an external gap is less than or equal to 80mm;

The intensity criteria are as follows: the compressive strength is more than or equal to 10.0MPa, and the flexural strength is more than or equal to 4.0 MPa;

The lime burst criteria are as follows: burst areas with maximum burst sizes greater than 2mm and less than 10mm, where each set of bricks is not more than 15, do not allow burst areas with maximum burst sizes greater than 10mm to occur;

the weathering criteria are as follows: the average value of natural water absorption is less than or equal to 15 percent, and the maximum value of a single block is less than or equal to 18 percent; the average value of boiling water absorption is less than or equal to 18 percent, and the maximum value of a single block is less than or equal to 20 percent; the average value of saturation coefficients is less than or equal to 0.88 percent, and the maximum value of a single block is less than or equal to 0.90 percent.

10. The archaized city wall brick of claim 7, wherein the archaized city wall brick has the following dimensional criteria: the allowable deviation of the dimension of 400mm is +/-4, the allowable deviation of the dimension of 200mm is +/-3, and the allowable deviation of the dimension of 100mm is +/-3;

the appearance quality standard is as follows: the opposite height difference is less than or equal to 3mm, the bending is less than or equal to 2mm, the impurity protruding height is less than or equal to 2mm, the continuous length of an internal gap is less than or equal to 30mm, the width of the internal gap is less than or equal to 1mm, and the length of an external gap is less than or equal to 50mm;

The intensity criteria are as follows: the compressive strength is more than or equal to 10.0MPa, and the flexural strength is more than or equal to 4.0 MPa;

the lime burst criteria are as follows: burst areas with maximum burst sizes greater than 2mm are not allowed to occur;

the weathering criteria are as follows: the average value of natural water absorption is less than or equal to 15 percent, and the maximum value of a single block is less than or equal to 18 percent; the average value of boiling water absorption is less than or equal to 18 percent, and the maximum value of a single block is less than or equal to 20 percent; the average value of saturation coefficients is less than or equal to 0.88 percent, and the maximum value of a single block is less than or equal to 0.90 percent.