A brick powder sticking construction process for repairing red brick weathering damage

Abstract

The application discloses a brick powder sticking construction process for repairing red brick weathering damage, and relates to the technical field of building repair in building engineering. The specific steps of the process are as follows: first, soft light rubbing of the weathering layer is carried out by using 5% environment-friendly weak acid solution, and then high-pressure water washing and air drying are carried out; then, mixed slurry is brushed and coated for penetration and reinforcement; after surface drying, a transition layer is formed by coating a biological base adaptive liquid; after complete surface drying, a composite sticking slurry is proportionally mixed and scraped to be compacted; finally, a thin hydrophobic sealing protective layer is scraped, maintenance is carried out for 72 hours after construction, and protection is well done, so that the red brick is gradually repaired and protected. The application constructs a layered progressive red brick shallow weathering repair system, a foundation is cleared in a mild way to guarantee the completeness of the foundation, the structure is reinforced by penetration and reinforcement, the biological base layer improves the adhesion and is environment-friendly; the compatibility is ensured by using the same material brick powder for slurry mixing, each layer is scientifically matched, the functions are complementary, the damage is effectively repaired, the brick body is given long-term protection, and the structural stability and service life are improved.

Description

Technical Field

[0001] This invention relates to the field of building repair technology in construction engineering, specifically a brick powder bonding construction process for repairing weathered damage to red bricks. Background Technology

[0002] Red bricks, as a traditional building material, are widely used in various civil buildings, industrial buildings, traditional residences, and historical district buildings due to their convenient sourcing, simple construction, and good structural stability. However, many red brick buildings have suffered from shallow weathering damage over a long period due to natural environmental erosion, temperature and humidity changes, rainwater erosion, atmospheric corrosion, and other factors. If this shallow damage is not repaired in a timely and effective manner, it will gradually extend into the brick body, not only damaging the integrity of the building's appearance but also continuously reducing the structural strength of the bricks, ultimately affecting the overall safety and durability of the building. With the increasing demand for the protection of ancient buildings and the renovation of old buildings, the repair of shallow weathering damage on red brick walls has become an important research direction in the field of building restoration. The industry has an increasingly urgent need for restoration techniques that are suitable for the material characteristics of red bricks and balance the restoration effect with the preservation of the original appearance. The concept of green, environmentally friendly, and long-lasting protection in restoration has also become a development trend in this field.

[0003] Traditional methods for repairing shallow weathering damage to red bricks have many technical shortcomings and are difficult to meet actual repair needs. Some repair processes simply apply ordinary cement mortar directly to the damaged area. Cement mortar has poor compatibility with red bricks, resulting in insufficient adhesion between the two. This leads to problems such as cracking and detachment after repair, failing to form a stable repair structure and failing to fundamentally solve the weathering damage problem. Other processes do not specifically treat the loose weathered layer on the brick surface and directly repair the surface, resulting in a weak bond between the repair layer and the base. Problems such as shallow powdering and sanding will continue to develop, and the repair effect is only a temporary solution. At the same time, most traditional repair processes lack a layered protection design concept, without dedicated interface connection and internal reinforcement. The overall protective performance after repair is weak, and some repair materials do not have water-repellent properties, failing to effectively block external moisture and corrosive media erosion. The bricks are still prone to re-weathering. Some repair materials also have insufficient environmental protection, making them unsuitable for the repair of old and historical buildings. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a brick powder bonding and repair process for weathered red bricks. This process is specifically designed to repair surface damage such as powdering, sanding, and minor peeling of red bricks. It employs a layered construction approach, involving five main steps: weak erosion cleaning, bottom layer penetration reinforcement, bio-based interface coating, middle layer brick powder composite bonding, and surface water-repellent sealing and curing. The process uses brick powder of the same material as the original brick to prepare the bonding slurry, combined with modified emulsions, bio-based materials, and other environmentally friendly raw materials. Through the seamless connection of each layer, it achieves both internal reinforcement and surface damage repair of the brick, while also forming a long-lasting water-repellent protective layer. This process balances repair effectiveness with the preservation of the original appearance of the red brick building. Each step is carried out according to standardized procedures, resulting in strong adhesion and delaying further weathering. It is suitable for shallow weathering repair of various types of red brick buildings and has significant practical application and promotional value.

[0005] To solve the above-mentioned technical problems, this invention provides the following technical solution: a brick powder bonding construction process for repairing weathering damage of red bricks. This process is suitable for repairing shallow weathering damage on the surface of red bricks, including powdering, sanding, slight peeling, and no penetrating cracks or large pores. The construction process includes the following steps: S1, Weak Erosion Cleaning: Use a 5% (w / w) environmentally friendly weak acid solution to gently and evenly wipe the weathered and loose layer of the red brick wall with a soft tool, covering all powdery and sandy areas; then rinse the wall surface with high-pressure mist water from all directions to remove residue; after rinsing, place the wall surface in a ventilated place without direct sunlight to air dry naturally for 24 hours until the brick surface is dry, clean, and free of loose impurities. S2, Bottom-layer penetration reinforcement: On the air-dried red brick wall, brush on a mixed slurry made of silane coupling modified acrylic emulsion and nano silica dispersion, so that the slurry penetrates evenly into the brick body to a depth of 3-5mm, and let it stand after application. S3, Bio-based interface adapter layer coating: After the bottom penetrating reinforcement slurry is dry to the touch and no longer sticky, a bio-based interface adapter liquid composed of modified lignin sulfonate and nanocellulose whiskers is coated to form a continuous and uniform transition interface layer with a thickness of 0.1-0.2mm, covering the bottom penetrating reinforcement layer. S4, intermediate layer brick powder composite bonding: After the bio-based interface adapter layer is completely dry, mix the composite bonding slurry according to the mass ratio of red brick powder: hydrophobic inorganic mineral powder: silane coupling modified acrylic emulsion = 7:2:1, and evenly apply it to the surface of the bio-based interface adapter layer with a thickness of 1-2mm. Then compact it and remove air bubbles. S5, Surface water-repellent sealing and curing: After the intermediate brick powder composite adhesive layer is compacted and shaped, a thin layer of water-repellent brick powder sealing layer with a thickness of 0.3mm is applied and evenly covers the intermediate adhesive layer; curing is carried out for 72 hours after construction, and protective measures are taken during the curing period.

[0006] Furthermore, in S1, the weak corrosion cleaning process, the ambient temperature is 15-30℃, the relative humidity is 40%-60%, and the soft tool is a soft nylon brush or a scratch-free sponge; the high-pressure mist water rinsing pressure is 0.2-0.4MPa, and the rinsing is orderly without dead corners.

[0007] Furthermore, in S2, the mixing mass ratio of silane-coupled modified acrylic emulsion to nano-silica dispersion is 10:1. During preparation, the emulsion is added first, followed by the nano-silica dispersion, while stirring for at least 5 minutes. The nano-silica dispersion contains nano-silica particles with a diameter of 10-20 nm, which are uniformly dispersed and show no visible agglomeration after preparation.

[0008] Furthermore, in S2, during the bottom layer penetration reinforcement, the mixed slurry is applied with a wool brush or a fine-bristled roller in an alternating longitudinal and transverse manner, first in the longitudinal direction once, and then in the transverse direction after it is surface dry, with a 30-minute interval between the two applications.

[0009] Furthermore, in the S3 bio-based interface adapter coating, the mass ratio of modified lignin sulfonate to nanocellulose whiskers is 95:5. When compounding, the modified lignin sulfonate is first dissolved in deionized water and stirred until completely dissolved, and then nanocellulose whiskers are added and stirred continuously for 30 minutes; the nanocellulose whiskers have a particle size of 50-100 nm.

[0010] Furthermore, in step S3, during the coating of the bio-based interface adapter layer, the coating amount of the bio-based interface adapter liquid is 0.08-0.12 kg / m2, and the coating tool is a fine-bristled roller; the thickness of the transition interface layer is 0.1-0.2 mm, and the surface is smooth and free of bubbles; after the bottom penetrating reinforcing slurry is dry to the touch without stickiness or flow, the interface adapter liquid is then coated.

[0011] Furthermore, in S4, the intermediate layer brick powder composite adhesive, the original red brick powder is made by grinding red bricks of the same material and firing process as the wall to be repaired, and then screening it through a 400-mesh standard sieve; the hydrophobic inorganic mineral powder is talc powder with a particle size of 200 mesh and a purity of ≥99%.

[0012] Furthermore, in S4, the composite bonding process of the intermediate brick powder is as follows: First, dry mix the original red brick powder with the hydrophobic inorganic mineral powder for 3 minutes at a speed of 300 r / min; then slowly add the silane coupling modified acrylic emulsion and wet mix for 5-8 minutes at a speed of 500 r / min until a paste-like slurry is formed; when the thickness is 2 mm, apply it in two coats, the first coat is 1 mm thick, and the second coat is applied after 1 hour of surface drying, with a total thickness of 1-2 mm.

[0013] Furthermore, in S4, during the intermediate layer brick powder composite bonding process, a stainless steel trowel is used for troweling with a blade angle of 30-45°, and the trowel is advanced at a uniform speed; a rubber roller is used for compaction, rolling and compacting at a uniform speed twice to remove air bubbles.

[0014] Furthermore, in S5, during the surface hydrophobic sealing and curing process, the hydrophobic brick powder sealing layer is composed of red brick powder and hydrophobic inorganic mineral powder in a mass ratio of 8:2, and then 5% of silane coupling modified acrylic emulsion and an appropriate amount of deionized water are added and stirred into a paste. The paste is then thinly scraped with a stainless steel thin knife at an angle of 15-20°, resulting in a sealing layer thickness of 0.3±0.05mm. The curing environment temperature is 15-30℃, and the relative humidity is 40%-60%. During the curing period, direct sunlight, rain splashes, and external contact should be avoided.

[0015] Compared with existing technologies, this brick powder bonding construction process for repairing weathered red bricks has the following advantages: I. This invention constructs a layered, progressive shallow weathering repair system for red bricks, specifically addressing shallow damage such as pulverization and sandblasting. The gentle erosion and cleaning method acts mildly on the weathered layer of the brick, thoroughly removing loose impurities while avoiding secondary damage to intact bricks, thus ensuring the integrity of the brick base. The bottom-layer penetrating reinforcing grout effectively penetrates into the brick's interior, filling tiny pores and fundamentally strengthening the brick's structural strength, solving the core problem of surface looseness. The bio-based interface adaptation layer achieves seamless connection between the bottom reinforcing layer and the middle adhesive layer, enhancing the adhesion between layers and creating an organic whole in the repair structure. Furthermore, the selection of bio-based materials aligns with the concept of green repair, meeting the environmental requirements of old building repair and providing a solid foundation for subsequent adhesive bonding work.

[0016] II. This invention uses brick powder of the same material as the original brick to formulate the adhesive mortar, ensuring compatibility between the repaired area and the original red brick at the material level. This maintains a uniform appearance and texture of the repaired wall, avoiding problems such as color difference and texture variation, and preserving the original appearance of the red brick building to the greatest extent. The scientific formulation of the intermediate composite adhesive mortar enables precise filling of surface damage to the brick. The compaction treatment further enhances the density of the adhesive layer, eliminates internal air bubbles, and strengthens the adhesive effect. The surface water-repellent sealing layer forms a dense protective barrier on the brick surface, effectively blocking the contact between moisture and external corrosive media and the brick, fundamentally slowing down the rate of red brick re-weathering. The functions of each repair stage are complementary and well-connected, achieving effective repair of shallow weathering damage and giving the brick long-term protective performance, significantly improving the structural stability and service life of the repaired brick.

[0017] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0019] Figure 1 Flowchart of layered construction process for shallow weathering repair of red bricks; Figure 2 Diagram showing the compatibility and preparation process of mortar for each layer of red brick repair; Figure 3 This is a comparison image showing the effects of repairing weathered red bricks before and after the damage. Detailed Implementation

[0020] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below. Example

[0021] Shallow weathering repair of the exterior walls of a residential red brick house.

[0022] This embodiment addresses the repair of shallow weathering damage on the south-facing exterior wall of an old urban red-brick residential building. The wall surface exhibits extensive powdering and localized sandblasting, but no penetrating cracks or large holes. The construction environment is a normal temperature environment in spring, and the construction area is approximately 20 square meters. 2 The work was carried out strictly following the brick powder bonding construction process for repairing weathered red bricks, with each step performed as follows: Figure 1 As shown: S1, Weak Erosion Removal: Before construction, confirm that the ambient temperature is 22℃ and the relative humidity is 50%, meeting the construction requirements. Use a 5% citric acid solution and a soft nylon brush to evenly and lightly scrub the weathered and loose layer of the red brick wall, ensuring that the brushing area covers all powdery and sandy areas without any omissions. After scrubbing, use a high-pressure mist of water at 0.3MPa to thoroughly and systematically rinse the wall surface, ensuring no dead corners are reached and completely removing any weak acid solution residue and loose impurities. After rinsing, place the wall surface in a well-ventilated environment without direct sunlight to air dry naturally for 24 hours, until the brick surface is dry and clean, and no loose impurities fall off when touched.

[0023] S2, Bottom Layer Penetration Reinforcement: First, prepare a mixed slurry by mixing silane-coupled modified acrylic emulsion and nano-silica dispersion at a mass ratio of 10:1. The nano-silica dispersion contains 15nm nano-silica particles that are uniformly dispersed without visible agglomeration. During preparation, first add the silane-coupled modified acrylic emulsion, then slowly add the nano-silica dispersion while continuously stirring for 6 minutes. Use a wool brush to apply the mixed slurry to the dried red brick wall surface in an alternating vertical and horizontal pattern. Apply one vertical coat first, and after the slurry is surface dry, apply a second horizontal coat after a 30-minute interval to ensure uniform penetration into the brick body to a depth of 4mm. After application, allow the slurry to fully penetrate. The silane coupling modification is achieved by modifying the acrylic emulsion with KH-570.

[0024] S3, Bio-based Interface Adaptor Layer Coating: After the bottom penetrating reinforcement slurry has dried to a non-sticky and non-flowing state, begin preparing the bio-based interface adaptor solution. The solution is prepared by mixing modified lignin sulfonate and nanocellulose whiskers at a mass ratio of 95:5, where the nanocellulose whiskers have a particle size of 80nm. During preparation, first dissolve the modified lignin sulfonate in deionized water and stir until completely dissolved. Then add the nanocellulose whiskers and continue stirring for 30 minutes. Use a fine-bristled roller to coat the adaptor solution onto the surface of the bottom penetrating reinforcement layer, controlling the coating amount to 0.10 kg / m². 2 This ensures the formation of a continuous, uniform, smooth, and bubble-free transition interface layer with a thickness of 0.15mm, completely covering the underlying penetration reinforcement layer.

[0025] S4, Mid-layer Brick Powder Composite Adhesive: After the bio-based interface adaptation layer is completely dry, the composite adhesive slurry is prepared and applied. The original red brick powder is made from red bricks of the same material and firing process as the exterior walls of this residence, ground and screened through a 400-mesh standard sieve. The hydrophobic inorganic mineral powder is talc powder, prepared at a mass ratio of original red brick powder: talc powder: silane coupling modified acrylic emulsion = 7:2:1. During preparation, the original red brick powder and talc powder are first dry-mixed for 3 minutes at a stirring speed of 300 rpm. After uniform dry mixing, the silane coupling modified acrylic emulsion is slowly added, and wet-mixed for 7 minutes at a stirring speed of 500 rpm until a uniform paste-like slurry is formed. The thickness of this application is set at 2mm, and it is applied in two passes. A stainless steel trowel with a 40° angle is used to apply the trowel at a uniform speed. The first pass is 1mm thick, and after it is 1 hour dry, the second pass is 1mm thick. After the first pass is completed, a rubber roller is used to roll and compact the adhesive layer at a uniform speed. This process is repeated twice to completely remove air bubbles from the slurry.

[0026] S5, Surface Water-Repellent Sealing and Curing: After the intermediate brick powder composite adhesive layer has been compacted and shaped, prepare the water-repellent brick powder sealing slurry. Mix the powder according to a mass ratio of red brick powder to talc powder of 8:2, then add 5% of the total powder mass of silane-coupled modified acrylic emulsion and an appropriate amount of deionized water, stirring thoroughly to form a paste. Use a stainless steel thin knife with an 18° angle to thinly apply the sealing slurry to the surface of the intermediate adhesive layer, controlling the sealing layer thickness to 0.3mm to ensure even coverage. After construction, proceed to the curing stage. Maintain the curing environment at a temperature of 22℃ and a relative humidity of 50% for 72 hours. During curing, take measures to provide shade and protection from rain, avoiding direct sunlight and rain splashes. Also, set up protective barriers to prevent external forces from touching the repaired wall surface.

[0027] In summary, this embodiment addresses the shallow weathering problem of south-facing exterior walls in residential red brick houses. It strictly adheres to the brick powder bonding and repair process, rigorously controlling temperature, humidity, mixing ratios, and operational standards at each step. A clean base layer is created through gentle wiping with a weak acid and high-pressure washing; a penetrating reinforcing mortar fills the micropores of the brick to strengthen its structure; a bio-based adhesive connects each layer to improve adhesion; a composite bonding layer precisely fills defects and restores the smoothness of the brick surface; and a water-repellent sealing layer forms a dense protective layer. The entire process is characterized by standardized parameters, meticulous operation, and synergistic effects of each layer, effectively solving the problem of exterior wall powdering and sandblasting, improving the brick's weathering resistance, ensuring a tight bond between the repair layer and the original brick, and maintaining a well-formed finish, thus meeting the long-term service needs of residential exterior walls. Example

[0028] Shallow weathering repair of red brick antique-style wall.

[0029] This embodiment addresses the repair of shallow weathering damage to a red brick antique-style wall within a scenic area. Due to outdoor environmental factors, the wall exhibits localized powdering, slight peeling, and sand-like phenomena on the brick surface, but no through cracks or large holes. The construction environment is a normal temperature environment in autumn, and the construction area is approximately 10 square meters. 2 The repair is carried out in a refined manner according to the construction process of this invention, and the operation of each step is as follows: Figure 2 As shown: S1, Weak Erosion Removal: Before construction, the ambient temperature was tested at 18℃ and the relative humidity at 45%, meeting the construction environment requirements. A 5% (w / w) environmentally friendly weak acid solution was used, and a scratch-free sponge was used to evenly and lightly wipe the weathered and loose layer of the wall, completely covering areas of powdering, sanding, and slight peeling. Subsequently, a high-pressure mist of water at 0.25 MPa was used to thoroughly and systematically rinse the wall surface, removing weak acid residue and loose impurities. After rinsing, the wall surface was placed in a well-ventilated area without direct sunlight to air dry naturally for 24 hours, until the brick surface was dry and clean, with no loose impurities adhering to it.

[0030] S2, Underlying Penetration Reinforcement: Prepare the underlying penetration reinforcement slurry by mixing silane-coupled modified acrylic emulsion and nano-silica dispersion at a mass ratio of 10:1. The nano-silica dispersion has a particle size of 12nm, is uniformly dispersed without visible agglomerations. When preparing, add the emulsion first, then the dispersion, stirring continuously for 5 minutes. Use a fine-bristled roller to apply the slurry in an alternating longitudinal and transverse pattern. Apply one longitudinal coat, and after it is surface dry, apply a second transverse coat after a 30-minute interval to ensure that the slurry penetrates evenly into the brick body to a depth of 3mm. After application, allow the slurry to stand and fully penetrate and cure.

[0031] S3, Bio-based Interface Adaptor Layer Coating: After the underlying penetration and reinforcing slurry has dried to a non-sticky and non-flowing state, prepare the bio-based interface adaptor solution. Modified lignin sulfonate and nanocellulose whiskers are mixed at a mass ratio of 95:5. The nanocellulose whiskers have a particle size of 60nm. First, dissolve the modified lignin sulfonate in deionized water until completely dissolved, then add the nanocellulose whiskers and stir continuously for 30 minutes. Use a fine-bristled roller to coat the adaptor solution, controlling the coating amount to 0.09kg / m². 2 A transition interface layer with a thickness of 0.12mm, continuous and uniform, with a smooth surface and no bubbles, is formed on the surface of the bottom penetration reinforcement layer to ensure complete coverage of the bottom area.

[0032] S4, Middle Layer Brick Powder Composite Adhesive: After the bio-based interface adapter layer is completely surface dry, the composite adhesive slurry is prepared. The original red brick powder is made from red bricks of the same material and firing process as the antique wall, ground and screened through a 400-mesh standard sieve. The hydrophobic inorganic mineral powder is talc powder, mixed in a mass ratio of 7:2:1. First, the original red brick powder and talc powder are dry-mixed at 300 r / min for 3 minutes, then silane coupling modified acrylic emulsion is slowly added, and wet-mixed at 500 r / min for 6 minutes to form a uniform paste slurry. The thickness of this application is determined to be 1.5 mm. A stainless steel trowel with a 35° angle is used to apply the slurry evenly to the surface of the interface adapter layer. After application, a rubber roller is immediately used to roll and compact the slurry twice at a uniform speed to remove air bubbles and ensure a tight bond between the adhesive layer and the base layer.

[0033] S5, Surface Water-Repellent Sealing and Curing: After the intermediate brick powder composite adhesive layer is compacted and shaped, prepare the water-repellent brick powder sealing slurry. Mix the original red brick powder and talc powder at a mass ratio of 8:2, add 5% of the total powder mass of silane-coupled modified acrylic emulsion and an appropriate amount of deionized water, and stir until a paste is formed. Use a 16° stainless steel thin blade to thinly apply the sealing slurry, controlling the sealing layer thickness to 0.3mm, evenly covering the intermediate adhesive layer. During the curing stage, maintain an ambient temperature of 18℃ and a relative humidity of 45%, with a curing time of 72 hours. During the curing period, take protective measures for the wall to avoid direct sunlight and rain splashes, and prohibit tourists from touching the repaired areas to ensure the stable curing of the repair layer.

[0034] In summary, this embodiment addresses the shallow weathering damage of a red brick antique-style wall in a scenic area through meticulous repair. The entire process adheres to strict technical requirements, controlling each step of the operation. A gentle cleaning process removes loose layers while protecting the original brick structure. A penetrating reinforcement layer enhances the brick's density. A bio-based adhesive eliminates interlayer gaps. A composite bonding layer uses brick powder of the same material to restore the antique appearance and fill defects. A water-repellent sealing layer blocks external erosion and slows weathering. The construction balances repair effectiveness with the preservation of the antique appearance. Each step is performed according to standardized procedures and precise parameters. The repair layer structure is stable and compatible with the original brick structure, effectively solving the problem of wall powdering and peeling, extending its service life, and meeting the usage and appearance requirements of antique-style facilities in scenic areas. Figure 3 As shown. Example

[0035] Optimization and verification of weak corrosion cleaning process parameters.

[0036] This embodiment focuses on optimizing and verifying the process parameters for the weak erosion removal process in the repair of weathered red bricks. It explores the effects of different construction environment temperatures, relative humidity, and high-pressure mist water flushing pressure on the removal effect. The remaining construction materials and subsequent process parameters are consistent with those in Embodiment 1.

[0037] Verification of different construction environment temperatures: Three test groups were set up. The relative humidity of the construction environment was 50% and the pressure of the high-pressure mist water washing was 0.3MPa. Only the ambient temperature was adjusted to 15℃, 22℃ and 30℃ respectively. The red brick wall surface with the same degree of weathering was subjected to weak erosion cleaning operation. After completion, it was naturally air-dried for 24 hours, and the cleanliness of the brick surface and the removal rate of loose impurities were tested.

[0038] The results showed that after drying, the wall surface in the 15℃ group still had slight weak acid residue in some areas, with a loose impurity removal rate of 92%; the wall surface in the 22℃ group was clean and residue-free after drying, with a loose impurity removal rate of 98%; and the wall surface in the 30℃ group was residue-free after drying, with a loose impurity removal rate of 97%. This indicates that the optimal cleaning effect is achieved at an ambient temperature range of 15-30℃, with 20-25℃ being the best. Temperatures that are too low will cause the weak acid solution to evaporate slowly, resulting in residue, while temperatures that are too high will cause the weak acid solution to dry quickly, reducing the effectiveness of light wiping.

[0039] Verification at different relative humidity levels: Three test groups were set up. The ambient temperature was 25℃ and the pressure of high-pressure mist water washing was 0.3MPa. Only the relative humidity was adjusted to 40%, 55% and 60% respectively. The red brick walls with the same degree of weathering were subjected to weak erosion cleaning operation. After completion, they were naturally air-dried for 24 hours. The drying speed of the brick surface and the effect of loose layer peeling were tested.

[0040] The results showed that in 40% of the groups, the wall surface dried for 20 hours, with the loose layer completely peeled off and no residue remaining; in 55% of the groups, the wall surface dried for 24 hours, with the loose layer completely peeled off and the brick surface smooth; and in 60% of the groups, the wall surface dried for 28 hours, with some areas of the loose layer not completely peeled off due to high humidity, requiring a second light wiping. This indicates that the optimal relative humidity for the construction environment is between 40% and 60%, with 45% to 55% yielding the best cleaning results. Too low humidity will cause the wall surface to dry too quickly, while too high humidity will prolong the drying time and affect subsequent processes.

[0041] Verification under different flushing pressures: Three test groups were set up, with an ambient temperature of 25℃ and a relative humidity of 50% for all groups. The pressure of the high-pressure mist water washing was adjusted to 0.2MPa, 0.35MPa and 0.4MPa respectively. The red brick walls with the same degree of weathering were subjected to weak erosion cleaning operation. After completion, the walls were naturally air-dried for 24 hours, and the integrity of the brick surface and the effect of residue removal were tested.

[0042] The results showed that in the 0.2 MPa group, local weak acid residues on the wall surface were not completely removed, the loose impurity removal rate was 90%, and the brick surface was undamaged; in the 0.35 MPa group, the wall residues were completely removed, the loose impurity removal rate was 99%, and the brick surface was undamaged; in the 0.4 MPa group, the wall residues were completely removed, but slight erosion marks appeared on the surface of some red bricks, affecting the integrity of the bricks. This indicates that a high-pressure mist water rinsing pressure within the range of 0.2-0.4 MPa, and specifically 0.3-0.35 MPa, can thoroughly remove residues while ensuring the integrity of the red brick wall surface.

[0043] Based on the above verification results, the optimal process parameters for the weak corrosion cleaning process are: ambient temperature of 20-25℃, relative humidity of 45%-55%, and high-pressure mist water flushing pressure of 0.3-0.35MPa. Under these parameters, the brick surface after cleaning can meet the process requirements for subsequent bottom layer penetration reinforcement.

[0044] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A brick powder bonding construction process for repairing weathered damage of red bricks, characterized in that, This technique is suitable for repairing shallow weathering damage on red brick surfaces, such as powdering, sanding, and slight peeling, without penetrating cracks or large pores. The construction process includes the following steps: S1, Weak Erosion Cleaning: Use a 5% (w / w) environmentally friendly weak acid solution to gently and evenly wipe the weathered and loose layer of the red brick wall with a soft tool, covering all powdery and sandy areas; then rinse the wall surface with high-pressure mist water from all directions to remove residue; after rinsing, place the wall surface in a ventilated place without direct sunlight to air dry naturally for 24 hours until the brick surface is dry, clean, and free of loose impurities. S2, Bottom-layer penetration reinforcement: On the air-dried red brick wall, brush on a mixed slurry made of silane coupling modified acrylic emulsion and nano silica dispersion, so that the slurry penetrates evenly into the brick body to a depth of 3-5mm, and let it stand after application. S3, Bio-based interface adapter layer coating: After the bottom penetrating reinforcement slurry is dry to the touch and no longer sticky, a bio-based interface adapter liquid composed of modified lignin sulfonate and nanocellulose whiskers is coated to form a continuous and uniform transition interface layer with a thickness of 0.1-0.2mm, covering the bottom penetrating reinforcement layer. S4, intermediate layer brick powder composite bonding: After the bio-based interface adapter layer is completely dry, mix the composite bonding slurry according to the mass ratio of red brick powder: hydrophobic inorganic mineral powder: silane coupling modified acrylic emulsion = 7:2:1, and evenly apply it to the surface of the bio-based interface adapter layer with a thickness of 1-2mm. Then compact it and remove air bubbles. S5, Surface water-repellent sealing and curing: After the intermediate brick powder composite adhesive layer is compacted and shaped, a thin layer of water-repellent brick powder sealing layer with a thickness of 0.3mm is applied and evenly covers the intermediate adhesive layer; curing is carried out for 72 hours after construction, and protective measures are taken during the curing period.

2. The brick powder bonding construction process for repairing weathered damage of red bricks according to claim 1, characterized in that, In S1, the weak corrosion cleaning process uses a soft nylon brush or a scratch-free sponge as the soft tool; the high-pressure mist water rinsing pressure is 0.2-0.4 MPa, and the rinsing is orderly and thorough.

3. The brick powder bonding construction process for repairing weathered damage of red bricks according to claim 1, characterized in that, In the S2 sub-layer penetration reinforcement, the mixing mass ratio of silane coupling modified acrylic emulsion to nano silica dispersion is 10:

1. When preparing the mixture, add the emulsion first, then add the nano silica dispersion, and stir for at least 5 minutes while adding the emulsion.

4. The brick powder bonding construction process for repairing weathered damage of red bricks according to claim 1, characterized in that, In the S2 layer penetration reinforcement process, the mixed slurry is applied with a wool brush or a fine-bristled roller in an alternating longitudinal and transverse manner. First, apply one longitudinal coat, and after it is surface dry, apply a second transverse coat, with a 30-minute interval between the two coats.

5. The brick powder bonding construction process for repairing weathered damage of red bricks according to claim 1, characterized in that, In the S3 bio-based interface adapter coating, the modified lignin sulfonate and nanocellulose whiskers are mixed in a mass ratio of 95:

5. When mixing, the modified lignin sulfonate is first dissolved in deionized water and stirred until completely dissolved. Then, nanocellulose whiskers are added and stirred continuously for 30 minutes.

6. The brick powder bonding construction process for repairing weathered damage of red bricks according to claim 1, characterized in that, In step S3, during the coating of the bio-based interface adapter layer, the coating amount of the bio-based interface adapter solution is 0.08-0.12 kg / m³. 2 The coating tool is a fine-bristled roller; the thickness of the transition interface layer is 0.1-0.2mm, and the surface is smooth and free of bubbles.

7. The brick powder bonding construction process for repairing weathered damage of red bricks according to claim 1, characterized in that, In S4, the intermediate layer brick powder composite adhesive is made by grinding red bricks of the same material and firing process as the wall to be repaired, and then screening them through a 400-mesh standard sieve.

8. The brick powder bonding construction process for repairing weathered damage of red bricks according to claim 1, characterized in that, In the S4 intermediate layer brick powder composite adhesive filling process, the composite adhesive filling slurry preparation process is as follows: First, dry mix the original red brick powder with the hydrophobic inorganic mineral powder for 3 minutes at a speed of 300 r / min; then slowly add the silane coupling modified acrylic emulsion and wet mix for 5-8 minutes at a speed of 500 r / min until a paste-like slurry is formed; when the thickness is 2 mm, apply it in two coats, the first coat is 1 mm, and the second coat is applied after 1 hour of surface drying, with a total thickness of 1-2 mm.

9. The brick powder bonding construction process for repairing weathered damage of red bricks according to claim 1, characterized in that, In S4, during the intermediate layer brick powder composite bonding process, a stainless steel trowel is used for troweling with a blade angle of 30-45° and a uniform speed for application; a rubber roller is used for compaction, rolling and compacting repeatedly at a uniform speed twice to remove air bubbles.

10. The brick powder bonding construction process for repairing weathered damage of red bricks according to claim 1, characterized in that, In the S5, the surface hydrophobic sealing and curing process, the hydrophobic brick powder sealing layer is made by compounding red brick powder and hydrophobic inorganic mineral powder in a mass ratio of 8:2, then adding 5% of the total mass of the powder, silane coupling modified acrylic emulsion and an appropriate amount of deionized water, and stirring until it becomes a paste.

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