Basement milling pin type steel fiber wear-resistant floor and construction method thereof

Abstract

This invention discloses a milled-fiber reinforced concrete (MLC) floor for basements and its construction method. The MLC floor comprises, from top to bottom, a dense wear-resistant surface layer, a main steel fiber reinforced concrete layer, an interface transition bonding layer, and a base layer. The main steel fiber reinforced concrete layer consists of an upper high-dosage zone and a lower medium-dosage zone. The milled-fiber reinforced concrete (MLC) content in the upper high-dosage zone is 30–40 kg / m². 3 This invention establishes an upper high-dosage zone and a lower medium-dosage zone within the main steel fiber reinforced concrete layer. The amount of milled steel fiber in the upper high-dosage zone is controlled at 30–40 kg / m³. 3 The lower intermediate blending zone should be controlled at 18-25 kg / m³. 3 This allows the wear resistance and impact resistance requirements to be concentrated in the surface area, while the main area maintains an economically reasonable crack resistance. The steel fibers are evenly dispersed in the concrete and have clear functional zones, which significantly improves the overall strength, wear resistance and crack resistance of the ground, while reducing material costs.

Description

Technical Field

[0001] This invention relates to a milled steel fiber wear-resistant floor for basements and its construction method, belonging to the field of building construction technology. Background Technology

[0002] With the continuous development and utilization of urban underground space, basements, as an important component of residential, commercial, and public buildings, have their floor construction quality directly affecting the building's functionality and durability. Milled steel fiber reinforced plastic (CFRP) wear-resistant flooring, due to its high strength, good wear resistance, excellent crack resistance, and strong integrity, is widely used in heavy-duty and high-frequency areas such as underground garages, equipment rooms, and civil defense projects.

[0003] Existing steel fiber reinforced concrete wear-resistant floors in basements generally adopt a monolithic cast structure with a single, uniform dosage of steel fiber reinforced concrete. This structure has obvious shortcomings: on the one hand, the steel fiber uses the same dosage throughout the entire thickness range. If the dosage is too low, the surface wear resistance and impact resistance will be insufficient, and it will easily lead to sanding, exposed fibers, and premature wear. Excessive fiber content significantly increases material costs and leads to low steel fiber utilization in the lower areas, resulting in unnecessary waste. Furthermore, the lack of a dedicated interface transition layer between the surface layer and the base layer, relying solely on direct pouring after simple cleaning, results in insufficient interfacial bond strength. Under the damp environment of a basement and repeated dynamic loads from vehicles, interfacial stress concentrates, gradually causing delamination. Once delamination forms, local stiffness decreases, and cracks extend from the edges of the delamination outwards, further reducing the overall integrity and service life of the floor. The aforementioned unreasonable functional zoning of steel fibers and weak interfacial bonding interact, ultimately leading to poor floor durability, high maintenance costs, and a low first-pass yield, making it difficult to meet the requirements of heavy-duty and long-term basement use. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a milled steel fiber wear-resistant floor for basements and its construction method, so as to solve the problems in the existing technology.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: A milled-fiber reinforced concrete (MRP) wear-resistant flooring for basements comprises, from top to bottom, a dense wear-resistant surface layer, a main steel fiber reinforced concrete layer, an interface transition bonding layer, and a base layer. The main steel fiber reinforced concrete layer consists of an upper high-dosage zone and a lower medium-dosage zone. The milled-fiber reinforced concrete (MRP) content in the upper high-dosage zone is 30–40 kg / m². 3 The fiber content of the milled steel profile in the lower intermediate mixing zone is 18-25 kg / m. 3 The interface transition bonding layer is a polymer-modified cement mortar layer with a thickness of 4-8 mm, containing short-cut fibers; the base surface has uniform, rough, shallow keyways after treatment.

[0006] As a further improvement, the surface dense wear-resistant layer has a thickness of 3-8 mm and is formed by high-doping zone on the upper part of the main steel fiber concrete layer through slurry raising and calendering. The surface is rich in milled steel fibers and fine slurry.

[0007] As a further improvement, the upper high-doping zone has a thickness of 40-60 mm, and the lower medium-doping zone has a thickness equal to the remaining main body layer thickness; the fiber doping content at the junction of the upper high-doping zone and the lower medium-doping zone exhibits a transitional distribution.

[0008] As a further improvement, the short-cut fibers incorporated into the interface transition bonding layer have a length of 6-12 mm and a volume content of 0.5-1.5%; the polymer-modified cement mortar has low shrinkage characteristics.

[0009] As a further improvement, the surface roughness Ra of the base layer is 1.5 to 3.0 mm; or the depth of the regular shallow keyways is 2 to 4 mm and the spacing is 80 to 150 mm.

[0010] As a further improvement, a layer of galvanized steel wire mesh or synthetic fiber mesh is provided in the lower part of the intermediate mixing zone of the main steel fiber concrete layer.

[0011] As a further improvement, the ground is provided with a cut, the depth of which is not less than 1 / 3 of the ground thickness, and the cut is aligned with the structural columns and walls; the lower part of the cut is filled with foam rods, and the upper part is filled with elastic sealant.

[0012] A construction method for milled steel fiber wear-resistant flooring in basements includes the following steps: S1. Base treatment: The basement floor base is washed with a high-pressure water gun, loose parts are removed and fine grinding is performed to form a uniform, rough, shallow keyway. After cleaning, it is kept dry and clean, and a three-level acceptance is carried out. S2. Construction of the interface transition bonding layer: After the base layer passes the acceptance inspection, apply the interface agent, and then spread the polymer modified cement mortar transition layer with a thickness of 4-8mm. Short chopped fibers are added to the layer, and the layer is compacted and smoothed. S3. Preparation and Gradient Pouring of Steel Fiber Reinforced Concrete: The lower layer of medium-strength steel fiber reinforced concrete and the upper layer of high-strength steel fiber reinforced concrete are prepared separately. The steel fibers are precisely measured using a dedicated electronic metering device. A dry-mixing followed by a wet-mixing process is adopted. The lower layer of medium-strength concrete is poured first and vibrated to compact it. Then, the upper layer of high-strength concrete is poured continuously to form the gradient main layer. The slump is strictly controlled during transportation and pouring. Unqualified concrete is removed from the site, and the addition of water is strictly prohibited. S4. Surface preparation and polishing: The timing of polishing is determined by a penetration tester. The disc preparation and blade polishing are carried out in stages to form a dense and wear-resistant layer on the surface of the upper high-mixed area. The corners are polished manually. S5. Cutting and Filling Joints: Cut joints promptly after the concrete strength reaches the specified range. The depth of the cut joints shall not be less than 1 / 3 of the ground thickness. After cleaning, fill the joints with sealant according to structural requirements. S6. Curing and Finished Product Protection: After the polishing is completed, wet curing shall begin within the specified time. After the curing is completed, finished product protection measures shall be taken.

[0013] As a further improvement, in step S1, the chiseling depth is not less than 5 mm; the shallow keyway formed by grinding or light milling has a depth of 2-4 mm and a spacing of 80-150 mm; and the roughness Ra is controlled at 1.5-3.0 mm.

[0014] As a further improvement, in step S3, the sand and gravel aggregate is first dry-mixed with steel fibers for no less than 30 seconds, and then wet-mixed with cementitious materials for no less than 90 seconds; the steel fiber content in the lower intermediate concrete is 18-25 kg / m³. 3 The upper high-strength concrete has a steel fiber content of 30-40 kg / m³. 3 The thickness of the upper high-mixture zone should be controlled at 40-60mm during pouring.

[0015] As a further improvement, in step S4, when the concrete penetration reaches 3.0 to 3.5 MPa, the first round of disc grouting is performed, with the walking route being crisscrossed; subsequently, when the penetration further increases, the second round of blade finishing is performed, with the blade-type grouting machine rotating at a higher speed than the first round.

[0016] As a further improvement, in step S2, the interface transition bonding layer is laid out within the open time and connected with the subsequent concrete pouring to ensure wet bonding; the chopped fiber length is 6-12mm and the volume content is 0.5-1.5%.

[0017] Beneficial effects 1. This invention establishes an upper high-dosage zone and a lower medium-dosage zone within the main steel fiber reinforced concrete layer. The amount of milled steel fiber in the upper high-dosage zone is controlled at 30–40 kg / m². 3 The lower intermediate blending zone should be controlled at 18-25 kg / m³. 3 This allows the wear resistance and impact resistance requirements to be concentrated in the surface area, while the main area maintains an economically reasonable crack resistance. The steel fibers are evenly dispersed in the concrete and have clear functional zones, which significantly improves the overall strength, wear resistance and crack resistance of the ground, while reducing material costs.

[0018] 2. A polymer-modified cement mortar interface transition bonding layer with a thickness of 4-8mm is set and short-cut fibers are added to it. This makes the transition layer flexible and has high bonding strength, which can adapt to changes in basement humidity and micro-movements of the base layer. This effectively improves the bonding performance between the surface layer and the base layer, and reduces the occurrence of hollowing and cracking from the root.

[0019] 3. The base surface is treated to form uniform, rough, shallow keyways, which provide mechanical interlocking. Combined with the chemical bonding of the interface transition adhesive layer, a double interface reinforcement is formed, which further improves the interlayer shear and peel resistance and avoids bonding failure under dynamic loads and humid environments.

[0020] 4. The dense wear-resistant surface layer is formed by slurry pressing and calendering from the upper high-mix zone, with a thickness controlled between 3 and 8 mm. This allows the milled steel fibers and fine slurry to accumulate on the surface, improving surface density and wear resistance, reducing sanding and fiber exposure, and extending the service life of the floor.

[0021] 5. During construction, the amount of steel fiber is precisely controlled by using specialized electronic metering equipment, and a mixing method of dry mixing followed by wet mixing is adopted to effectively solve the problems of steel fiber clumping and inaccurate dosage, ensuring that the steel fiber is evenly dispersed in the concrete and guaranteeing the performance of the gradient structure from the source of materials. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the cross-sectional structure of a milled steel fiber wear-resistant floor for basements according to the present invention.

[0024] Figure 2 This is a step diagram illustrating the construction method of milled steel fiber wear-resistant flooring for basements according to the present invention.

[0025] 1. Dense wear-resistant surface layer; 2. Main steel fiber reinforced concrete layer; 21. Upper high-dosage zone; 22. Lower medium-dosage zone; 3. Interface transition bonding layer; 4. Base layer; 5. Cut joint; 51. Foam rod; 52. Polyurethane sealant. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] In the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] Example 1 Reference Figure 1-2 As shown, a milled-fiber reinforced concrete (MRP) wear-resistant floor for basements comprises, from top to bottom, a dense wear-resistant surface layer 1, a main steel fiber reinforced concrete layer 2, an interface transition bonding layer 3, and a base layer 4. The main steel fiber reinforced concrete layer 2 consists of an upper high-dosage zone 21 and a lower medium-dosage zone 22. The milled-fiber reinforced concrete (MRP) content in the upper high-dosage zone 21 is 30–40 kg / m². 3 The fiber content of the milled steel profile in the lower intermediate mixing zone 22 is 18-25 kg / m. 3 The interface transition bonding layer 3 is a polymer-modified cement mortar layer with a thickness of 4-8 mm, containing short-cut fibers. The surface of the base layer 4 is treated to have uniform, rough, shallow keyways.

[0029] The thickness of the upper high-doping zone 21 is 40-60 mm.

[0030] The thickness of the lower intermediate mixed zone 22 is the remaining thickness of the main steel fiber reinforced concrete layer 2.

[0031] The total thickness of the main layer of steel fiber reinforced plastic (SFL) wear-resistant flooring in basements is typically 120–180 mm. Therefore: When the total thickness of the main layer is 150mm and the upper high-doping zone 21 is 50mm, the thickness of the lower medium-doping zone 22 is 100mm. When the total thickness of the main layer is 120mm and the upper high-doping zone 21 is 40mm, the thickness of the lower medium-doping zone 22 is 80mm.

[0032] This ratio allows high-content steel fibers to be concentrated in the surface layer, which is subjected to wear and impact, while a medium content is used in the lower part to meet the requirements for crack resistance and load-bearing capacity, thus balancing performance and economy.

[0033] The above-mentioned ground structure addresses the problems of unreasonable functional zoning of steel fibers and weak interfacial bonding in existing single uniform steel fiber reinforced concrete floors.

[0034] The upper high-doping zone 21 concentrates the milled steel fibers with a higher dosage in the area close to the surface, directly bearing the effects of vehicle crushing, equipment impact and surface wear. The lower medium-doping zone 22 adopts a moderate dosage to ensure the overall crack resistance and load-bearing capacity, while avoiding excessive consumption of steel fibers in the lower area.

[0035] The interface transition bonding layer 3 is placed between the main steel fiber reinforced concrete layer 2 and the base layer 4. Through polymer modification and short-cut fiber reinforcement, it forms a transition interface with flexibility and high bonding strength, which can adapt to the damp environment of the basement and the micro-deformation of the base layer. The uniform rough shallow keyways on the surface of the base layer 4 provide mechanical interlocking, which, together with the chemical bonding of the interface transition bonding layer 3, significantly improves the interlayer shear and peel resistance.

[0036] In use, the ground surface bears the dynamic load of vehicles and the static load of equipment. The upper high-dosage zone 21 and the dense wear-resistant surface layer 1 work together to resist wear and impact. The lower medium-dosage zone 22 and the interface transition bonding layer 3 jointly constrain shrinkage stress and transfer the load to the base layer 4, forming a composite stress system with clear functional zoning and reliable interfaces. Compared with the existing single uniform dosing structure, this ground surface reduces the total amount of steel fiber while ensuring surface wear resistance and impact resistance. Interface voids and irregular cracks are significantly reduced, and long-term durability is improved.

[0037] The dense, wear-resistant surface layer 1, with a thickness of 3–8 mm, is formed by slurry preparation and troweling of the high-dosage zone 21 above the main steel fiber reinforced concrete layer 2. The surface is enriched with milled steel fibers and fine cement paste. During the slurry preparation process, some steel fibers and cement paste in the upper high-dosage zone 21 float to the surface and are compacted, forming a dense area with controllable thickness on the outermost layer. This dense area allows for a tighter bond between the steel fibers and the matrix, reducing surface porosity and effectively resisting wheel friction and impacts from hard objects, minimizing sandblasting and exposed fibers. In actual use, the dense, wear-resistant surface layer 1 and the upper high-dosage zone 21 form a unified whole, constituting the main working surface of the ground, maintaining a smooth and dense state under long-term heavy loads.

[0038] The upper high-doped zone 21 has a thickness of 40–60 mm, while the lower medium-doped zone 22 has a thickness equal to the remaining main layer thickness. The fiber doping level at the boundary between the upper high-doped zone 21 and the lower medium-doped zone 22 exhibits a transitional distribution. No weak points with abrupt changes in doping levels are formed at the boundary; the steel fiber distribution changes continuously from high to low, resulting in more uniform stress transmission. This arrangement allows the high-doped steel fibers to concentrate their surface wear resistance and impact resistance, while the medium-doped steel fibers provide necessary crack-resistant constraints in the lower part. The overall performance transitions continuously, avoiding interlaminar shear failure or localized cracking caused by abrupt changes in doping levels.

[0039] The short-cut fibers incorporated into the interface transition bonding layer 3 have a length of 6–12 mm and a volumetric content of 0.5–1.5%. The polymer-modified cement mortar exhibits low shrinkage characteristics. These short-cut fibers form a three-dimensional randomly distributed network within the transition layer, limiting the propagation of microcracks. The polymer component enhances the bond strength between the mortar and the upper and lower interfaces, while the low shrinkage characteristics compensate for early concrete shrinkage, further reducing interfacial tensile stress. This transition layer maintains stable bonding even under humid environments and temperature variations, effectively preventing voids from initiating at the interface and spreading outwards.

[0040] The surface roughness Ra of the base layer 4 is 1.5–3.0 mm, or the depth of the regular shallow keyways is 2–4 mm, and the spacing is 80–150 mm. The roughness or keyways create a mechanical interlock between the base layer 4 and the interface transition bonding layer 3, increasing the contact area and shear resistance. The selection of keyway depth and spacing ensures sufficient interlocking depth while avoiding excessive damage to the base layer structure. Under actual stress, horizontal shear force is transmitted through the keyway teeth, while vertical tensile force is borne by the adhesive force of the polymer mortar; this dual action jointly inhibits interface separation.

[0041] A layer of galvanized steel wire mesh or synthetic fiber mesh is installed in the lower part of the intermediate admixture zone 22 of the main steel fiber reinforced concrete layer 2. This mesh, located in the lower middle part of the intermediate admixture zone 22, can restrain the early shrinkage deformation of the bottom concrete, disperse temperature stress and drying shrinkage stress, and further reduce the occurrence of through cracks. The mesh, together with the surrounding steel fibers, forms a composite restraint system, providing additional tensile strength when the ground is subjected to concentrated loads.

[0042] A slit 5 is provided in the ground, with a depth of not less than 1 / 3 of the ground thickness. The slit is aligned with the structural columns and walls. The lower part of the slit is filled with foam rods 51, and the upper part is filled with elastic sealant. The slit 5 divides a large area of ​​the ground into smaller sections, guiding the release of shrinkage stress at predetermined locations and preventing irregular cracks. The lower foam rods 51 provide elastic support for the sealant and reserve space for compression. After the upper elastic sealant is filled, it adheres firmly to the slit wall, which can accommodate the expansion and contraction of the sections while preventing moisture and debris from entering the slit, maintaining the integrity and functionality of the ground.

[0043] The depth of the cut 5 shall not be less than 1 / 3 of the ground thickness, where the ground thickness refers to the total thickness of the newly poured wear-resistant ground, the dense wear-resistant surface layer 1 and the main steel fiber concrete layer 2.

[0044] The cut actually penetrates part of the dense wear-resistant surface layer 1, the main steel fiber reinforced concrete layer 2, the upper high-dosage zone 21, and the lower medium-dosage zone 22, but does not penetrate the interface transition bonding layer 3 and the base layer 4. Because the cut is made from top to bottom with a cutting machine after the concrete has reached a certain strength, the depth is only controlled to be more than 1 / 3 of the thickness of the newly poured layer. The purpose is to guide shrinkage cracks to appear in the predetermined position, rather than to sever the bond with the base layer.

[0045] Example 2 This embodiment is applied to the floor of an underground parking garage. The surface dense wear-resistant layer 1 has a thickness of 5mm, the upper high-fiber layer 21 has a thickness of 50mm, and the milled steel fiber content is 35kg / m². 3 The fiber content of the 22 milled steel profiles in the lower middle mixing zone is 22 kg / m. 3 The interface transition bonding layer 3 is 6mm thick, incorporating 8mm long chopped steel fibers at a volumetric content of 1.0%. The surface roughness Ra of the base layer 4 is controlled at approximately 2.0mm. The depth of the cut 5 is 1 / 3 of the ground thickness, aligned with the structural column grid. The lower part of the cut 5 is filled with foam rods 51, and the upper part is filled with polyurethane sealant 52. This combination of parameters ensures that the surface wear resistance meets the requirements of frequent vehicle traffic in the garage, the interface bonding is reliable, and hollow areas and cracks are effectively controlled during long-term use.

[0046] Cut width: 12-15mm, cut spacing: 5m, cut depth: not less than 1 / 3 of the ground thickness (if the total ground thickness is 150mm, then the depth is ≥50mm). Reducing the spacing is to more effectively release shrinkage stress in heavy-load areas and reduce the risk of cracking.

[0047] Typical filling method for foam rod 51 and sealant, taking a cut width of 15mm and a depth of 50mm as an example: The lower foam rod 51 has a diameter 1-2 mm larger than the cut width (approximately 16-18 mm), and its filling height is approximately 1 / 2 to 2 / 3 of the cut depth (i.e., 25-35 mm). The foam rod 51 serves to provide support and reserve compression space, preventing the sealant from adhering to all three sides.

[0048] The thickness of the upper polyurethane sealant 52 is generally 1 / 2 to 2 / 3 of the cut width (about 8 to 12 mm), and a 1 to 2 mm recess is reserved on the surface, that is, the sealant surface is slightly lower than the ground to avoid direct wear of the sealant when vehicles run over it.

[0049] Foam rod 51 provides elastic support at the bottom, allowing the sealant to primarily withstand tensile deformation rather than shear, thus extending its service life.

[0050] A moderate sealant thickness ensures sufficient deformation capacity and bonding strength; too thick and it's prone to cracking, too thin and the sealing effect is poor. Leaving a 1-2mm margin on the surface prevents the sealant from being rolled up or worn by wheels, and also facilitates future replacement. The overall structure forms a lower elastic support and an upper seal, which can accommodate the expansion and contraction of the slabs while preventing water and debris from entering, maintaining the integrity of the ground surface.

[0051] Example 3 This embodiment is applied to the floor of an equipment room. The equipment room has a large load, and the fiber content of the 21-section milled steel in the upper high-fiber zone is increased to 38 kg / m². 3 The thickness is maintained at 50mm, and the dosage in the lower intermediate mixing zone 22 is 20kg / m². 3 The thickness of the interface transition bonding layer 3 is adjusted to 7mm, the chopped fiber volume fraction is 1.2%, and the base layer 4 adopts regular shallow keyways with a depth of 3mm and a spacing of 100mm. The spacing of the cut seams 5 is appropriately reduced to about 5m. This arrangement enhances the surface impact resistance, adapts to the concentrated loads generated by equipment installation and operation, and at the same time enhances the interface shear resistance through a thicker transition layer and keyways.

[0052] Example 4 This embodiment is applied to the ground of a civil defense area. Civil defense areas have higher requirements for sealing and impact resistance; the upper high-fiber sizing zone uses 32 kg / m² milled steel fiber. 3 The dosage of admixture in the lower intermediate admixture zone is 23 kg / m³. 3 The interface transition bonding layer 3 uses polymer-modified mortar with better sealing performance, with a thickness of 6mm, short chopped fiber length of 10mm, and volume content of 1.0%. The cut 5 avoids the joints of the civil defense structure and is filled with civil defense-specific sealant. These parameters meet the basic requirements for crack resistance and wear resistance while taking into account the protective sealing needs of civil defense projects, ensuring that the ground can be used normally in both wartime and peacetime.

[0053] Example 5 A construction method for a milled-pin steel fiber gradient composite wear-resistant floor structure for basements includes the following steps: S1. Base treatment: The basement floor base is washed with a high-pressure water gun, loose parts are removed and fine grinding is performed to form a uniform, rough, shallow keyway. After cleaning, it is kept dry and clean, and a three-level acceptance is carried out. S2. Construction of the interface transition bonding layer: After the base layer passes the acceptance inspection, apply the interface agent, and then spread the polymer modified cement mortar transition layer with a thickness of 4-8mm. Short chopped fibers are added to the layer, and the layer is compacted and smoothed. S3. Preparation and Gradient Pouring of Steel Fiber Reinforced Concrete: The lower part of medium-strength steel fiber reinforced concrete and the upper part of high-strength steel fiber reinforced concrete are prepared separately. The steel fibers are precisely measured using a special electronic metering device. The process of dry mixing followed by wet mixing is adopted. The lower part of medium-strength concrete is poured first and vibrated to compact it. Then, the upper part of high-strength concrete is poured continuously to form the gradient main layer. Slump must be strictly controlled during transportation and pouring; substandard concrete must be removed from the site and adding water is strictly prohibited. S4. Surface preparation and polishing: The timing of polishing is determined by a penetration tester. The disc preparation and blade polishing are carried out in stages to form a dense and wear-resistant layer on the surface of the upper high-mixed area. The corners are polished manually. S5. Cutting and Filling Joints: Cut joints promptly after the concrete strength reaches the specified range. The depth of the cut joints shall not be less than 1 / 3 of the ground thickness. After cleaning, fill the joints with sealant according to structural requirements. S6. Curing and Finished Product Protection: After the polishing is completed, wet curing shall begin within the specified time. After the curing is completed, finished product protection measures shall be taken.

[0054] To address the existing problems of weak interfacial bonding, unreasonable functional zoning of steel fibers, and the resulting hollowness, cracks, and sanding in single-uniform steel fiber flooring, a composite structure is formed by sequentially implementing the preparation of the base bonding surface, wet bonding of the transition layer, gradient pouring, precise troweling, and timely cutting of joints. This results in a complete composite structure consisting of a dense and wear-resistant surface layer 1, a main steel fiber concrete layer 2, an interfacial transition bonding layer 3, and a base layer 4.

[0055] During application, each step is seamlessly integrated to ensure that the steel fibers are evenly distributed in the upper high-dosing zone 21 and the lower medium-dosing zone 22 according to the specified dosage. The interface transition bonding layer 3 forms a reliable bond with the base layer 4, the surface dense and wear-resistant layer 1 is solid and wear-resistant, and the slits 5 effectively release shrinkage stress. Compared with existing conventional construction methods, this method can significantly reduce the hollow rate and irregular cracks, improve the first-pass yield, and extend the service life of the ground.

[0056] Step S1, the base treatment, is further broken down into the following sub-steps: S11. Before construction, conduct a comprehensive inspection of the basement floor base, marking loose, sandy, and hollow areas, as well as the details such as inside and outside corners, construction joints, column bases, and equipment foundation bases that require special treatment.

[0057] S12. Use a high-pressure water gun with a pressure of 10-15 MPa to rinse the entire base surface, gradually moving from one end to the other to remove laitance, dust, oil stains, and loose concrete particles. For areas heavily contaminated with oil, first scrub with a neutral detergent solution, then rinse thoroughly with clean water.

[0058] S13. Use an electric hammer to remove the marked loose, sandy, and hollow areas to a depth of at least 5mm until a solid concrete base is exposed. After removal, use a wire brush to smooth the edges of the removed area and remove any remaining loose particles.

[0059] S14. Use an angle grinder equipped with diamond grinding discs to grind detailed areas such as inside and outside corners, construction joints, column bases, and equipment foundation bases, extending the grinding range 100mm beyond the edge of the detail. Simultaneously, achieve a uniform roughness according to design requirements, with a roughness Ra controlled between 1.5 and 3.0 mm; or use a light milling machine to create regular shallow keyways, with a keyway depth of 2–4 mm and a spacing of 80–150 mm, ensuring good mechanical interlocking conditions on the base surface.

[0060] S15. Use a high-powered industrial blower to remove water and dust from the substrate surface, ensuring it remains dry and clean. A three-tiered acceptance system is implemented: first, the construction team conducts a self-inspection; second, the project department's quality inspector conducts a re-inspection; and finally, the supervision unit conducts an acceptance inspection. Only after the inspection is passed and the acceptance record is signed can the next step be carried out.

[0061] Step S2, the construction of the interface transition adhesive layer, is further refined into the following sub-steps: S21. After the base layer passes the acceptance inspection, apply the special interface agent immediately. The application should be uniform, without any omissions or liquid accumulation. After the application is completed, proceed with the paving of the transition layer within the open time of the interface agent.

[0062] S22. Polymer-modified cement mortar is used, with short-cut fibers of 6-12mm in length added, and the volumetric content is controlled at 0.5-1.5%. The mortar has low shrinkage characteristics and is prepared for use after being thoroughly mixed.

[0063] S23. Spread the prepared polymer-modified cement mortar evenly on the substrate that has been coated with the interface agent, with the thickness strictly controlled between 4 and 8 mm. Use a scraper and trowel to compact and smooth the transition layer, ensuring that it is in close contact with the substrate, has a smooth surface, and is free of hollow areas and cracks.

[0064] S24. Immediately after the transition layer is laid, organize the subsequent steel fiber reinforced concrete pouring to ensure that the transition layer and the upper concrete are bonded in a moist state to form a reliable wet interface.

[0065] Step S3, steel fiber reinforced concrete preparation and gradient pouring, is further refined into the following sub-steps: S31, steel fibers are quantitatively measured using a dedicated electronic metering device with an accuracy of ±0.5%. Two types of concrete are prepared separately: The amount of steel fiber added to the concrete in the lower part is 18-25 kg / m. 3 The upper part of the high-strength concrete contains 30-40 kg / m³ of steel fiber. 3The mixing process uses a forced mixer. First, the sand and gravel aggregates and steel fibers are added and dry-mixed for no less than 30 seconds to allow the steel fibers to be initially dispersed in the aggregates. Add the cementitious material and continue stirring; finally, add water and additives for wet mixing, which should last for at least 90 seconds, to ensure that the steel fibers are evenly dispersed and free of clumps.

[0066] S32. Optimize and adjust the water-cement ratio and admixture dosage based on the performance of raw materials and the ambient temperature during construction. The mixing plant will test the slump of each truckload of concrete before it leaves the factory; only those that pass the test can be shipped, and the slump value will be noted on the transport document.

[0067] S33. Concrete shall be transported using dedicated mixer trucks. During transportation, the mixing drum shall be rotated slowly at a speed of 2-4 r / min to prevent segregation. The feed inlet of the mixing drum shall be sealed immediately after the transport vehicle leaves the factory, and the addition of water during transportation is strictly prohibited. The transportation time should be controlled within 60 minutes.

[0068] S34. Upon arrival of concrete, a designated person shall test the slump of each truckload. Concrete that does not meet the slump requirements shall be strictly prohibited from being poured on site and shall be rejected immediately. At the same time, the chloride ion content of each truckload of concrete shall be tested, and test blocks cured under the same conditions shall be retained for acceptance by a three-party inspection involving the supervising engineer.

[0069] S35. The segmented casting method is adopted. The size of the segment is determined according to the ground design requirements and construction capabilities. The position of the segment joint is aligned with the structural column grid.

[0070] First, pour the lower part of the intermediate-mixed concrete to the design height, and then use an immersion vibrator to fully vibrate it. The insertion spacing of the vibrator should not be greater than 500mm, and the insertion depth should be 50mm below the surface of the base layer. Vibrate until the concrete surface is covered with slurry, no longer sinks, and no air bubbles emerge.

[0071] Immediately afterwards, the upper high-fiber concrete was poured continuously, with the thickness of the upper high-fiber zone controlled at 40-60mm. It was then vibrated to ensure compaction, so that the fiber content at the junction of the upper and lower zones would have a natural transition without obvious cold joints.

[0072] S36. After vibration, use a screed to level the concrete surface and remove laitance. Use the top surface of the compartment template as a reference to control the elevation and ensure that the pouring thickness is uniform with a deviation of no more than ±5mm.

[0073] S4. Surface preparation and polishing are further refined into the following sub-steps: S41. Use a concrete penetration tester to periodically test the surface hardness of concrete. Test once every 2 hours, and take no less than 3 points each time. Take the average value as the basis for judgment.

[0074] S42. When the concrete penetration reaches 3.0-3.5 MPa, perform the first pass of troweling. Use a disc trowel for grouting. The trowel travels in a crisscross pattern, making one pass in the longitudinal direction and one in the transverse direction. The travel speed is controlled at 3-5 m / min to form a uniform cement slurry layer on the surface of the upper high-mixed area and to promote the floating of some steel fibers and fine slurry.

[0075] S43. After the first pass of troweling is completed, wait for the moisture on the concrete surface to evaporate and the strength to increase further before performing the second pass of troweling.

[0076] A blade-type power trowel is used for finishing and polishing. The blade angle is adjusted appropriately and the speed is higher than that of the first pass. The surface is smoothed and compacted to eliminate trowel marks and sand holes, forming a dense and wear-resistant surface layer with a thickness of 3-8mm.

[0077] S44. For areas where a power trowel cannot operate, such as column bases, wall corners, and the area around equipment foundations, use a wooden trowel and a steel trowel for manual polishing. First, use a wooden trowel to smooth the surface, and then use a steel trowel to press it smooth, ensuring that the edges and corners are flat and smooth and blend seamlessly with the main surface.

[0078] S45. During the troweling process, use a 2m straightedge to check the flatness of the floor at any time. The flatness deviation should not exceed 3mm. Any areas that exceed the flatness standard should be repaired in time with a trowel or manually.

[0079] Step S5, cutting and filling the joints, is further broken down into the following sub-steps: S51. When the concrete strength reaches 8-12 MPa, slitting operations shall be carried out. The slitting depth shall not be less than 1 / 3 of the ground thickness, the slitting width shall be 10-20 mm, the slitting position shall be aligned with the structural columns and walls, and the longitudinal and transverse slitting spacing shall be determined according to the design requirements, generally not exceeding 6 m.

[0080] S52. Use a road cutting machine to move forward at a constant speed along the marked ink line, with the speed controlled at 1-2 m / min, to ensure consistent cutting depth and neat edges.

[0081] S53. After cutting the seam, use a high-pressure water gun to clean the dust and debris inside the seam, and wait for the seam to dry completely.

[0082] S54. First, fill the lower part of the seam with foam rod 51, then inject elastic sealant. The sealant filling should be full, dense, and smooth, adhering firmly to the seam wall. Before filling, masking tape can be pasted on both sides of the seam wall to prevent contamination. After filling, use a scraper to smooth and clean the residue.

[0083] Step S6, Maintenance and Finished Product Protection, is further broken down into the following sub-steps: S61. Curing shall begin within 12 to 24 hours after the floor is smoothed.

[0084] S62. Use water spraying or geotextile covering for curing. When using water spraying, spray water no less than 4 times a day to keep the ground surface moist at all times; When using geotextile for curing, the geotextile should completely cover the ground, with an overlap width of not less than 200mm, and the geotextile should be kept moist at all times. The curing time should be no less than 7 days, and may be extended to 14–21 days for important parts or in low-temperature environments.

[0085] Where d is the number of days.

[0086] S63. Management during maintenance: During the maintenance period, walking on the ground, piling up items or carrying out other operations are strictly prohibited. Warning signs should be set up at the entrance of the maintenance area and special personnel should be assigned to patrol.

[0087] S64. After curing, lay a protective film or cardboard on the ground surface to protect the finished product. The overlap of the protective film should be no less than 100mm and secured with tape. For areas where subsequent construction is required, lay cardboard or rubber mats on top of the protective film to prevent construction tools and materials from scratching or contaminating the ground. During the finished product protection period, arrange for dedicated personnel to patrol and replace any damaged protective materials promptly.

[0088] This is for the construction of an underground parking garage floor. After base treatment, a rough surface with a thickness of approximately 2.0 mm (Ra) is formed. A 6 mm thick interface transition bonding layer 3 is applied. The lower layer contains medium-strength concrete with a steel fiber content of 22 kg / m³, while the upper layer contains high-strength concrete with a steel fiber content of 35 kg / m³. The upper high-strength zone 21 has a thickness of 50 mm. Dry mixing takes 35 seconds, followed by wet mixing takes 100 seconds, resulting in a slump of 160–180 mm at site. When the penetration reaches 3.2 MPa, a disc-type slurry raising process is performed, followed by blade finishing to form a dense, wear-resistant surface layer 1. When the strength reaches 10 MPa, slits are cut, and after 14 days of curing, a PE protective film is laid.

[0089] This is for the construction of the equipment room floor. Due to the large load, the steel fiber content in the upper high-dosage zone 21 is adjusted to 38kg / m³, the interface transition bonding layer 3 is 7mm thick, the base layer 4 uses regular shallow keyways with a depth of 3mm and a spacing of 100mm, the slit spacing is 5m, the curing time is extended to 21 days, and rubber pads are used for finished product protection.

[0090] When constructing on the ground in a civil defense area, the upper high-fiber mortar zone should have a steel fiber content of 32 kg / m³. 3 The interface transition bonding layer 3 uses polymer mortar with better sealing performance. The cuts avoid the joints of the civil defense structure and use civil defense special sealant. Electric welding and gas cutting operations are strictly prohibited during the curing period. Multi-layer board is used for finished product protection.

[0091] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A basement pin-milling steel fiber wear-resistant floor, characterized by: From top to bottom, it includes a dense wear-resistant surface layer, a main steel fiber reinforced concrete layer, an interface transition bonding layer, and a base layer; The main body steel fiber concrete layer is composed of an upper high-mixing area and a lower middle-mixing area 3 , the milling pin type steel fiber mixing amount of the upper high-mixing area is 30-40 kg / m 3 ; the milling pin type steel fiber mixing amount of the lower middle-mixing area is 18-25 kg / m The interface transition bonding layer is a polymer-modified cement mortar layer with a thickness of 4-8 mm, containing short-cut fibers. The base surface has uniform, rough, shallow keyways after treatment.

2. The milled steel fiber wear-resistant floor for basements according to claim 1, characterized in that: The surface dense wear-resistant layer has a thickness of 3-8 mm and is formed by high-doping zone on the upper part of the main steel fiber concrete layer through slurry raising and calendering. The surface is rich in milled steel fibers and fine slurry.

3. The milled steel fiber wear-resistant floor for basements according to claim 1, characterized in that: The upper high-doping zone has a thickness of 40-60 mm, and the lower medium-doping zone has a thickness equal to the remaining main layer thickness; the fiber doping content at the junction of the upper high-doping zone and the lower medium-doping zone exhibits a transitional distribution.

4. The milled steel fiber wear-resistant floor for basements according to claim 1, characterized in that: The short-cut fibers incorporated into the interface transition bonding layer have a length of 6–12 mm and a volume content of 0.5–1.5%; the polymer-modified cement mortar has low shrinkage characteristics.

5. The milled steel fiber wear-resistant floor for basements according to claim 1, characterized in that: The surface roughness Ra of the base layer is 1.5 to 3.0 mm; or the depth of the regular shallow keyway is 2 to 4 mm and the spacing is 80 to 150 mm.

6. The milled steel fiber wear-resistant floor for basements according to claim 1, characterized in that: A layer of galvanized steel wire mesh or synthetic fiber mesh is provided in the lower part of the intermediate mixing zone of the main steel fiber concrete layer.

7. The milled steel fiber wear-resistant floor for basements according to claim 1, characterized in that: The ground is provided with a cut, the depth of which is not less than 1 / 3 of the ground thickness. The cut is aligned with the structural columns and walls. The lower part of the cut is filled with foam rods, and the upper part is filled with elastic sealant.

8. A construction method for a milled steel fiber wear-resistant floor in a basement as described in any one of claims 1 to 7, characterized in that: Includes the following steps: S1. The basement floor base is washed with a high-pressure water gun, loose parts are removed and fine grinding is performed to form a uniform, rough, shallow keyway. After cleaning, it is kept dry and clean, and a three-level acceptance is carried out. S2. After the base layer passes the acceptance inspection, apply the interface agent, and then spread the polymer modified cement mortar transition layer with a thickness of 4-8mm. Short chopped fibers are added to the mortar, and then compact and smooth it. S3. Prepare the lower part of medium-strength steel fiber reinforced concrete and the upper part of high-strength steel fiber reinforced concrete respectively, using a dry-mixing and then wet-mixing process, and form a gradient main layer after pouring. S4. Perform disc slurry lifting and blade finishing in stages to form a dense and wear-resistant layer on the surface of the upper high-mixing zone; S5. Cut joints promptly after the concrete strength reaches the specified range. The depth of the joints should not be less than 1 / 3 of the ground thickness. After cleaning, fill with sealant. S6. After the smoothing is completed, wet curing shall begin within the specified time. After curing is completed, protective measures shall be taken for the finished product.

9. The construction method for a milled steel fiber wear-resistant floor in a basement according to claim 8, characterized in that: In step S1, the chiseling depth is not less than 5mm; the shallow keyway formed by grinding or light milling has a depth of 2-4mm and a spacing of 80-150mm; the roughness Ra is controlled at 1.5-3.0mm. In step S2, the interface transition bonding layer is laid within the open time and connected with the subsequent concrete pouring to ensure wet bonding; the short chopped fiber length is 6-12mm and the volume content is 0.5-1.5%.

10. A construction method for a milled steel fiber wear-resistant floor in a basement according to claim 8, characterized in that: The sandstone aggregate and steel fiber are dry mixed for not less than 30 seconds in the step S3, and then the cementing material is added and wet mixed for not less than 90 seconds; the steel fiber content in the lower mixed concrete is 18-25 kg / m 3 The steel fiber content in the upper mixed concrete is 30-40 kg / m 3 The thickness of the upper high-mixing area is controlled to be 40-60 mm during pouring. In step S4, when the concrete penetration reaches 3.0 to 3.5 MPa, the first round of disc grouting is performed, with the walking path being crisscrossed; subsequently, when the penetration further increases, the second round of blade finishing is performed, with the blade-type grouting machine rotating at a higher speed than the first round.

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