A method for layered and staged casting of recycled block-aggregate concrete floor slabs

Abstract

This application relates to the technical field of floor slab casting, and in particular to a method for layered and multi-stage casting of recycled block-aggregate concrete floor slabs, comprising the following steps: S1: Erecting supports and prefabricated assembled frame modules, wherein the frame modules are integrally formed with floor slab reinforcement mesh, including bottom and top reinforcement mesh; S2: Pouring the first layer of recycled aggregate concrete and vibrating it to evenly cover the entire frame module with the first layer of recycled aggregate concrete; S3: Placing the recycled blocks; S4: Pouring the second layer of recycled aggregate concrete, which should be completed before the initial setting of the first layer of recycled aggregate concrete; S5: Concrete curing. This application has the effect of improving the quality and efficiency of floor slab casting.

Description

Technical Field

[0001] This application relates to the technical field of floor slab casting, and in particular to a method for casting recycled block-aggregate concrete floor slabs in layers and stages. Background Technology

[0002] In modern construction engineering, recycled aggregate concrete technology has been increasingly widely used to promote the resource utilization of construction waste, reduce engineering costs, and achieve green construction. One common technique is to use recycled aggregate concrete and larger recycled blocks (made from crushed waste concrete) in the floor slab structure to form a so-called recycled block-aggregate concrete floor slab.

[0003] In existing technologies, for floor slabs with relatively short thicknesses (e.g., typically within 250mm), the common practice is to mix the recycled blocks and recycled aggregate concrete in one go before pouring, or to lay the recycled blocks first and then pour the recycled aggregate concrete. However, these methods have revealed some insurmountable drawbacks in practice. When using a one-time mixing and pouring method, due to the difference in density and flowability between the recycled blocks and recycled aggregate concrete, the recycled blocks tend to sink to the bottom of the floor slab under gravity, directly contacting the formwork. Similarly, when using the lay-then-pour method, the recycled blocks are also placed directly on the formwork.

[0004] In both of the above scenarios, if the subsequent vibration work is insufficient or there are blind spots in the operation, the cement slurry in the recycled aggregate concrete will have difficulty flowing completely beneath the recycled blocks, failing to effectively coat the bottom of the blocks. This will result in the outline of the recycled blocks being directly exposed on the bottom surface of the slab after demolding, forming "imprints" that severely affect the structural appearance quality. More seriously, the gaps between the blocks and the formwork may not be filled by the slurry, leading to localized structural defects such as honeycombing, pitting, or even holes on the bottom of the slab. These defects not only affect the appearance but also reduce the effective cross-section of the slab, affect the thickness of the concrete cover for the reinforcing steel, weaken the load-bearing capacity and durability of the structure, and pose safety hazards. Summary of the Invention

[0005] In order to improve the quality and efficiency of floor slab casting, this application provides a method for casting recycled block-aggregate concrete floor slabs in layers and stages.

[0006] This application provides a method for layered and multi-stage casting of recycled block-aggregate concrete floor slabs, employing the following technical solution:

[0007] A method for layered and staged casting of recycled block-aggregate concrete floor slabs includes the following steps:

[0008] S1: Erect a support frame and prefabricated assembled frame modules. The frame modules are integrally formed with floor slab steel mesh, which includes bottom and top steel bars.

[0009] S2: Pour the first layer of recycled aggregate concrete and vibrate it to ensure that the first layer of recycled aggregate concrete is evenly spread throughout the entire frame module.

[0010] S3: Place the regenerated blocks;

[0011] S4: Pour the second layer of recycled aggregate concrete. The pouring of the second layer of recycled aggregate concrete should be completed before the initial setting of the first layer of recycled aggregate concrete.

[0012] S5: Concrete curing.

[0013] By adopting the above technical solution, the first layer of recycled aggregate concrete is poured as a subbase, followed by the placement of the recycled blocks, and finally the second layer of recycled aggregate concrete is poured. This ensures that the bottom of the floor slab is formed by close contact between the recycled aggregate concrete and the formwork modules, fundamentally avoiding appearance and quality problems such as block imprints, honeycombing, and holes that may occur when the recycled blocks directly contact the formwork. At the same time, the recycled blocks are placed on the first layer of aggregate concrete before it has initially set, and their bottoms are fully wrapped with the concrete slurry, ensuring the bonding quality between the recycled blocks and the concrete. In addition, the use of prefabricated assembled frame modules simplifies the on-site formwork and rebar tying procedures, improving construction efficiency.

[0014] Optionally, the thickness of the first layer of recycled aggregate concrete is 40-50mm, and the first layer of recycled aggregate concrete covers the bottom reinforcement of the slab.

[0015] By adopting the above technical solution, the thickness of the first layer of recycled aggregate concrete is precisely controlled at 40-50mm. This ensures effective coverage of the bottom reinforcement of the slab, forming a reinforcement protective layer that meets the specifications. It also provides a suitable thickness and a grout-filled "bed" for the subsequently placed recycled blocks. This thickness is sufficient to fully enclose the bottom of the recycled blocks, ensuring a firm bond with the concrete matrix. At the same time, it avoids unnecessary self-weight and cost increases due to an excessively thick bedding layer, thus achieving a balance between structural reliability and economy.

[0016] Optionally, step S3 may further include the following steps:

[0017] S3.1: Prepare recycled blocks and place them after the first layer of recycled aggregate concrete is poured. The recycled blocks are evenly placed on the surface of the first layer of recycled aggregate concrete.

[0018] S3.2: The surface of the recycled block must be hard and clean, free of mud and loose debris;

[0019] S3.3: Before the recycled blocks are placed, they need to be sprayed with water to moisten them. The surface should be wet, but there should be no obvious water accumulation or water stains.

[0020] S3.4: Before the first layer of recycled aggregate concrete has set, place the recycled blocks evenly on the surface of the first layer of recycled aggregate concrete.

[0021] By adopting the above technical solutions and specifying the preparation and placement process of the recycled blocks in detail, the standardization of construction and the final molding quality are ensured. The recycled blocks are required to be clean and hard to avoid impurities affecting the interfacial bonding strength. Spraying water to moisten the blocks prevents the dry recycled blocks from instantly absorbing moisture from the first layer of recycled aggregate concrete, ensuring sufficient hydration reaction of the cement at the interface, thereby forming stronger bonding. The placement must be completed before initial setting to ensure that the upper and lower layers of concrete and the recycled blocks can form a seamless whole without construction cold joints, ensuring the integrity and structural safety of the floor slab.

[0022] Optionally, the preparation of the regenerated block in step S3.1 further includes the following steps:

[0023] S3.1.1: The concrete crusher shall be installed at the construction site;

[0024] S3.1.2: The construction site is divided into large block area, medium block area and small block area according to the specifications of the recycled blocks.

[0025] By adopting the above technical solution, and by setting up concrete crushers directly on the construction site and managing the recycled blocks in zones, the on-site resource utilization of construction waste is realized, reducing the cost and environmental impact of transporting waste and purchasing new materials. This not only improves construction efficiency but also conforms to the concept of green construction. At the same time, dividing the recycled blocks into zones according to specifications facilitates selection and uniform matching during construction, which helps control the uniformity of materials inside the floor slab, thereby ensuring the stability and reliability of the overall mechanical properties of the floor slab.

[0026] Optionally, step S4 may further include the following steps:

[0027] S4.1: Recycled concrete shall be pumped to the intended pouring location using a truck-mounted concrete pump.

[0028] S4.2: The second layer of recycled aggregate concrete is poured in stages along the span of the prefabricated frame module.

[0029] S4.3: When pouring the second layer of recycled aggregate concrete, vibrate while pouring. Use an immersion vibrator to fully vibrate the mixture of recycled blocks and new recycled aggregate concrete. The horizontal distance between adjacent insertion points should not exceed 500mm. The vibrator should be inserted to the bottom of the first layer of recycled aggregate concrete and pry the recycled blocks around to fully integrate the first and second layers of recycled aggregate concrete and to fully coat the recycled blocks with the concrete slurry.

[0030] The vibrator should be inserted in a row-and-column or staggered manner, and the vibration time at each point should be no less than 30 seconds, until the concrete surface no longer sinks significantly, no more air bubbles appear, and mortar appears on the surface.

[0031] When vibrating, insert the vibrator quickly and pull it out slowly, and move the vibrator up and down slightly to ensure uniform vibration.

[0032] S4.4: For structural embedded parts and reserved holes, dense reinforcement and other special parts, measures should be formulated in advance, and vibration should be strengthened during construction to ensure that vibration is not missed.

[0033] S4.5: To control the elevation and flatness of the slab surface, use short steel bars to mark the elevation of the slab surface;

[0034] S4.6: After concrete is poured, water bleeding is likely to occur on the surface. Therefore, the concrete surface should be repeatedly rubbed with a wooden scrubbing board during the later stage of concrete vibration.

[0035] By adopting the above technical solution and through meticulous process control of the entire process of pouring and vibrating the second layer of recycled aggregate concrete, the density and uniformity of the final floor slab were ensured. In particular, the key operation of inserting the vibrator to the bottom of the first layer of recycled aggregate concrete and prying the recycled blocks effectively eliminated the potential interface between the two layers of concrete, promoting their complete integration into a whole. At the same time, it drove the grout to coat all sides and top surfaces of the recycled blocks, eliminating voids around the blocks. Strict steps such as vibration, finishing, and grinding further ensured the density of the concrete, controlled the flatness of the slab surface, and effectively prevented surface shrinkage cracks, comprehensively improving the structural strength and durability of the floor slab.

[0036] Optionally, when pouring the second layer of recycled aggregate concrete, the second layer of recycled aggregate concrete is formed with a fluid inclined surface under the action of fluid gravity, and a vibrator is inserted into the fluid inclined surface to vibrate the second layer of recycled aggregate concrete poured each time.

[0037] By adopting the above technical solution, vibration is applied to the naturally formed fluid slope during continuous concrete pouring. Compared with vibration on the top surface of the second recycled aggregate concrete, this method not only increases the vibration area but also ensures that the newly poured concrete and the previously placed concrete are fully vibrated and compacted at the joint. This effectively eliminates air at the joint and avoids construction cold joints caused by discontinuous placement. This method ensures the continuity and homogeneity of the entire floor slab at the same elevation level and improves construction quality.

[0038] Optionally, step S5 may further include the following steps:

[0039] S5.1: Water curing shall begin 4-6 hours after pouring, with watering no less than 7 times a day and curing time no less than 14 days.

[0040] S5.2: Within 24 hours after the concrete is poured, it is strictly forbidden for people to walk on it. Within 36 hours after the concrete is poured, except for testing temperature measuring equipment and covering for insulation, it is forbidden for people to walk on it and for construction materials to be piled up.

[0041] S5.3: For parts that cannot be continuously covered by the frame module, cut and fill with insulation felt to avoid cold bridging.

[0042] By adopting the above technical solutions and formulating strict and comprehensive curing measures, the recycled block-aggregate concrete was ensured to obtain the necessary moisture and stable temperature environment during the hardening process. Timely watering curing ensured full hydration of cement, which is conducive to the normal development of concrete strength and durability and effectively inhibits shrinkage cracks. Strict restrictions on early access and loads protected the structure from damage before it reached sufficient strength. Thermal insulation measures for weak points avoided temperature stress cracks caused by excessive local temperature differences, thus ensuring the safety and final quality of the entire floor slab structure during the curing period.

[0043] Optionally, the frame module includes a UHPC base plate, UHPC side plates are provided around the periphery of the UHPC base plate, the UHPC base plate is provided with a connecting mechanism for fixing the UHPC side plates, and the floor slab steel mesh is integrally formed and provided on the top surface of the UHPC base plate.

[0044] By adopting the above technical solution, UHPC, named Ultra-High Performance Concrete, combines the traditional bottom and side formwork with the structural layer of the floor slab by using a frame module composed of a UHPC base plate and side plates. The high strength and high durability of UHPC material make this module not only a formwork that does not need to be removed, improving construction efficiency, but also a permanent component of the floor slab, enhancing the load-bearing capacity and service life of the entire floor slab. The reinforcing bars are prefabricated on the UHPC base plate in the factory, which greatly reduces the amount of on-site reinforcing bar tying work, ensures the accuracy of the reinforcing bar position, and realizes the assembly and high quality of floor slab construction.

[0045] Optionally, the connecting mechanism includes a connector and a U-shaped component. The connector is integrally formed on the inner side of the UHPC side plate, and the U-shaped component is disposed on the top surface of the UHPC base plate. The UHPC base plate is provided with a fixing component for fixing the U-shaped component. The connector is placed on the top surface of the U-shaped component, and the connector and the U-shaped component are tied together.

[0046] By adopting the above technical solution, the prefabrication of UHPC base plate and UHPC side plate in the factory can improve the efficiency of frame module assembly. When the frame module needs to be assembled, the UHPC side plate is first built on the periphery of the UHPC base plate, and then the U-shaped piece is fixed to the top surface of the UHPC base plate by fixing components. At this time, the connector is placed on the top surface of the U-shaped piece, and finally the connector and the U-shaped piece are tied together with wire. At this time, the UHPC side plate and the UHPC base plate are fixed together, which helps to improve the connection quality of the frame module assembly.

[0047] Optionally, the fixing component includes an embedded cylinder, which is embedded in the UHPC base plate. The top end of the embedded cylinder extends outside the top surface of the UHPC base plate. The U-shaped member is inserted into the embedded cylinder, and the embedded cylinder is provided with a pin for fixing the U-shaped member.

[0048] By adopting the above technical solution, when it is necessary to bind the connectors and U-shaped parts, the U-shaped parts are first inserted into the embedded cylinder. Then, the height of the U-shaped parts is adjusted according to the position of the connectors so that the U-shaped parts and the connectors overlap. Finally, the U-shaped parts are fixed by the pins. This helps to reduce the installation error of the connectors during the prefabrication process, allows the U-shaped parts to adapt to connectors of different heights, ensures that the U-shaped parts and the connectors overlap, and thus improves the applicability of the U-shaped parts.

[0049] In summary, this application includes the following beneficial technical effects:

[0050] By first pouring a first layer of recycled aggregate concrete as a base layer, then placing the recycled blocks, and finally pouring a second layer of recycled aggregate concrete, it is ensured that the bottom of the floor slab is formed by close contact between the recycled aggregate concrete and the formwork modules. This fundamentally avoids appearance and quality problems such as block imprints, honeycombing, and holes that may occur when the recycled blocks directly contact the formwork. At the same time, the recycled blocks are placed on the first layer of aggregate concrete before it has initially set, and their bottoms can be fully wrapped with the concrete slurry, ensuring the bonding quality between the recycled blocks and the concrete. In addition, the use of prefabricated assembled frame modules simplifies the on-site formwork and rebar tying procedures, improving construction efficiency. Attached Figure Description

[0051] Figure 1 This is a structural diagram of the second layer of recycled aggregate concrete poured in stages according to this application;

[0052] Figure 2 This is a simplified diagram of the method steps for layered and multi-stage pouring of recycled block-aggregate concrete floor slabs as described in this application;

[0053] Figure 3 This is a cross-sectional view of the frame module of this application;

[0054] Figure 4 yes Figure 3 An enlarged view of part A.

[0055] Explanation of reference numerals in the attached drawings: 1. Frame module; 2. Floor slab reinforcement mesh; 3. Bottom reinforcement of slab; 4. Top reinforcement of slab; 5. First layer of recycled aggregate concrete; 6. Recycled block; 7. Second layer of recycled aggregate concrete; 8. Fluid inclined surface; 9. UHPC bottom plate; 10. UHPC side plate; 11. Connector; 12. U-shaped piece; 13. Embedded cylinder; 14. Pin. Detailed Implementation

[0056] The following is in conjunction with the appendix Figure 1-4 This application will be described in further detail.

[0057] See Figure 1-4 A method for layered and multi-stage casting of recycled block-aggregate concrete floor slabs includes the following steps:

[0058] S1: Construction Preparation and Formwork System Erection

[0059] First, construction preparation work is carried out, such as erecting a floor slab support system that meets the requirements for load-bearing capacity and flatness at the predetermined location, such as the construction site. Then, the prefabricated assembled frame module 1 is hoisted and installed. In this embodiment, the frame module 1 serves as a non-removable template, and it is prefabricated in the factory using UHPC (ultra-high performance concrete) material.

[0060] See Figure 1-3The frame module 1 includes a UHPC base plate 9 and four UHPC side plates 10. An integrally formed floor slab steel mesh 2 is pre-embedded on the top surface of the UHPC base plate 9. The floor slab steel mesh 2 includes bottom steel bars 3 and top steel bars 4, and the position and spacing of the floor slab steel mesh 2 have been precisely controlled in the factory.

[0061] See Figure 3 and Figure 4 Four UHPC side panels 10 are installed on the periphery of the UHPC base plate 9, and the UHPC base plate 9 is equipped with a connecting mechanism for fixing the four UHPC side panels 10 to the periphery of the UHPC base plate 9. The connecting mechanism includes connectors 11 and U-shaped members 12. In this embodiment, the connectors 11 are steel bars, and there are multiple connectors 11, which are integrally formed on the inner side of the UHPC side panel 10. The U-shaped members 12 are also steel bars, and the number of U-shaped members 12 is the same as the number of connectors 11. Since the height position of the connectors 11 is prone to construction errors during the pre-embedding process, in order to facilitate the adjustment of the height of the U-shaped members 12 and ensure that the connectors 11 are placed on the top surface of the U-shaped members 12, the U-shaped members 12 are moved and installed on the top surface of the UHPC base plate 9, and the connectors 11 are placed on the top surface of the U-shaped members 12, and the connectors 11 and U-shaped members 12 are tied together.

[0062] Furthermore, to facilitate the fixing of the height of the U-shaped component 12, a fixing assembly is installed on the UHPC base plate 9. The fixing assembly includes embedded cylinders 13. Each U-shaped component 12 is provided with two embedded cylinders 13. The embedded cylinders 13 are integrally formed within the UHPC base plate 9, and the top of the embedded cylinders 13 extends beyond the top surface of the UHPC base plate 9. The two ends of the U-shaped component 12 are respectively inserted into the two embedded cylinders 13. The side wall of the U-shaped component 12 has through holes, and the embedded cylinders 13 are inserted with pins 14 for fixing the U-shaped component 12 through the insertion holes.

[0063] When prefabricating the frame module 1, first insert the U-shaped part 12 into the embedded cylinder 13, then pre-install the UHPC side plate 10 on the periphery of the UHPC base plate 9, then move and adjust the height of the U-shaped part 12 until the connector 11 overlaps the top surface of the U-shaped part 12, then insert the pin 14 into the top of the embedded cylinder 13 and the U-shaped part 12 in sequence, and finally tie the U-shaped part 12 and the connector 11 together with steel bars to enhance the stability of the connection between the two.

[0064] See Figure 2 S2: Pouring the first layer of recycled aggregate concrete 5:

[0065] After the frame module 1 is installed, the first layer of recycled aggregate concrete 5 is poured. The recycled aggregate concrete is pumped into the frame module 1 using a concrete pump, and the pouring thickness is strictly controlled to be 40-50mm. The thickness of the first layer of recycled aggregate concrete 5 covers the bottom reinforcement 3 on the UHPC base plate 9 and forms a uniformly thick concrete cushion layer.

[0066] It is worth noting that during the construction process, an immersion vibrator was used to initially vibrate the first layer of recycled aggregate concrete 5 to ensure that it was compacted and fully wetted and in contact with the surface of the UHPC base plate 9, without any gaps.

[0067] See Figure 2 S3: Preparation and placement of regenerated block 6:

[0068] Specifically, the steps are as follows: S3.1: When the first layer of recycled aggregate concrete 5 is poured and remains in a plastic state (i.e. before initial setting), the recycled blocks 6 are placed immediately.

[0069] The preparation steps for the regenerated block 6 also include the following:

[0070] S3.1.1: Preparations for recycled block 6 are completed on the construction site: a concrete crusher is set up;

[0071] S3.1.2: Crush the construction waste concrete blocks on site into recycled blocks 6 of different sizes, and divide them into three block areas of large, medium and small according to size, so as to facilitate subsequent use as needed.

[0072] S3.2: Before placement, the screened recycled blocks 6 are processed: First, remove the mud, oil and loose debris from the surface of the recycled blocks 6 to ensure that the surface of the recycled blocks 6 is hard and clean.

[0073] S3.3: Then, spray water onto the surface of the recycled block 6 using a sprayer until the surface is evenly moistened, but be careful not to have any running water or water stains. This helps prevent the dried recycled block 6 from over-absorbing moisture from the first layer of recycled aggregate concrete 5, ensuring the quality of the interface bonding;

[0074] S3.4: Construction workers will evenly and manually place the treated recycled blocks 6 onto the surface of the moist first layer of recycled aggregate concrete 5, ensuring that appropriate gaps are left between the recycled blocks 6 to avoid concentrated accumulation and to ensure that the entire slab surface is basically evenly covered. The recycled blocks 6 will sink slightly under their own weight, and their bottoms will be able to fully contact and be wrapped with the slurry of the first layer of recycled aggregate concrete 5.

[0075] See Figure 1 and Figure 2 S4: Pour the second layer of recycled aggregate concrete and vibrate it as a whole.

[0076] After all the recycled blocks 6 have been placed, and before the first layer of recycled aggregate concrete 5 has set, the second layer of recycled aggregate concrete 7 should be poured immediately.

[0077] Specifically, the steps include: S4.1: Using a truck-mounted concrete pump to deliver the concrete to the pouring location;

[0078] S4.2: To ensure the quality of the pouring, the concrete is poured in stages using a stepped approach along the span of frame module 1. Under gravity, the concrete will naturally form a fluid inclined surface 8.

[0079] S4.3: While pouring the second layer of recycled aggregate concrete 7, the construction workers use an immersion vibrator to thoroughly compact the mixture of new and old concrete and recycled blocks 6. During vibration, the principle of "quick insertion and slow withdrawal" should be followed. The insertion points of the vibrator should be arranged in rows or staggered patterns, with a horizontal spacing not exceeding 500mm. Crucially, the vibrator must be inserted vertically and penetrate the second layer of recycled aggregate concrete 7 until its end enters approximately 5-10cm into the first layer of recycled aggregate concrete 5 below.

[0080] During the vibration process, the construction workers need to gently pry the vibrator around to help break up any potential cross-sections that may exist between the upper and lower layers of concrete, drive the grout to flow, and make it completely cover all sides and top surfaces of the recycled block 6 and fill all gaps.

[0081] The vibration time at each point shall not be less than 30 seconds, until the concrete surface stops significantly settling, no more air bubbles emerge, and a uniform layer of mortar appears on the surface. In particular, the vibration operation shall be concentrated on the aforementioned fluid inclined surface 8 to ensure that the interface between the old and new concrete is effectively vibrated each time.

[0082] S4.4: For areas with dense reinforcement, embedded parts and reserved holes, etc., strengthen vibration and prevent missed vibration;

[0083] S4.5: After compaction, use a long scraper to level the floor slab surface according to the pre-set elevation control points, and then use a wooden washboard for the first sanding.

[0084] S4.6: After the concrete surface has stopped bleeding and before it has initially set, use a wooden washboard to repeatedly rub and polish it a second time to eliminate surface micro-cracks and improve surface smoothness and density.

[0085] By meticulously controlling the entire process of pouring and vibrating the second layer of recycled aggregate concrete 7, the density and uniformity of the final floor slab were ensured. In particular, the key operation of inserting the vibrator to the bottom of the first layer of recycled aggregate concrete 5 and prying the recycled blocks 6 effectively eliminated the potential interface between the two layers of concrete, promoting their complete integration into a whole. At the same time, it drove the grout to coat all sides and top surfaces of the recycled blocks 6, eliminating voids around the blocks. Strict steps such as vibration, finishing, and grinding further ensured the density of the concrete, controlled the flatness of the slab surface, and effectively prevented surface shrinkage cracks, comprehensively improving the structural strength and durability of the floor slab.

[0086] See Figure 2 S5: Concrete curing:

[0087] Specifically, the steps are as follows: S5.1: After concrete pouring and surface treatment are completed, the curing stage begins. Approximately 4-6 hours after pouring, when the concrete surface has reached a certain strength, water curing begins. This is done by covering the concrete with plastic film or geotextile and continuously sprinkling water to keep the concrete surface constantly moist. Watering should be done at least 7 times per day, for a total curing time of at least 14 days.

[0088] S5.2: During the curing period, the floor slab shall be strictly protected: within 24 hours after the completion of the pouring, no one is allowed to walk on it; within 36 hours, except for necessary temperature measurement and curing work, no one is allowed to walk on it and no construction materials are allowed to be piled up.

[0089] S5.3: For areas of the frame module 1 that are difficult to cover continuously, such as the corners and wall column reinforcing bars, local insulation is reinforced by cutting and filling with insulation felt to prevent temperature cracks caused by excessive local heat dissipation forming "cold bridges". The entire maintenance process is handled by designated personnel in shifts, and detailed maintenance records are kept.

[0090] By implementing strict and comprehensive curing measures, the recycled block-aggregate concrete was ensured to obtain the necessary moisture and stable temperature environment during the hardening process. Timely watering curing ensured full cement hydration, which helped the normal development of concrete strength and durability and effectively inhibited shrinkage cracks. Strict restrictions on early access and loads protected the structure from damage before it had reached sufficient strength. Insulation measures for weak points prevented temperature stress cracks caused by excessive local temperature differences, thus ensuring the safety and final quality of the entire floor structure during the curing period.

[0091] After the above steps, a recycled block-aggregate concrete floor slab with a flat and smooth bottom, no quality defects, good structural integrity, and excellent appearance quality can be obtained.

[0092] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method of constructing a floor slab of recycled aggregate concrete in layers and lifts, characterized in that, Includes the following steps: S1: Erect a support frame and a prefabricated assembled frame module (1). The frame module (1) is integrally formed with a floor slab steel mesh (2). The floor slab steel mesh (2) includes bottom steel bars (3) and top steel bars (4). S2: Pour the first layer of recycled aggregate concrete (5) and vibrate it to make the first layer of recycled aggregate concrete (5) evenly spread throughout the entire frame module (1); S3: Place the regenerated blocks (6); S4: Pour the second layer of recycled aggregate concrete (7). The pouring of the second layer of recycled aggregate concrete (7) should be completed before the initial setting of the first layer of recycled aggregate concrete (5). S5: Concrete curing; The frame module (1) includes a UHPC base plate (9), and a UHPC side plate (10) is provided on the periphery of the UHPC base plate (9). The UHPC base plate (9) is provided with a connecting mechanism for fixing the UHPC side plate (10). The floor slab steel mesh (2) is integrally formed and provided on the top surface of the UHPC base plate (9). The connecting mechanism includes a connector (11) and a U-shaped component (12). The connector (11) is integrally formed and disposed on the inner side of the UHPC side plate (10). The U-shaped component (12) is disposed on the top surface of the UHPC base plate (9). The UHPC base plate (9) is provided with a fixing component for fixing the U-shaped component (12). The connector (11) is placed on the top surface of the U-shaped component (12). The connector (11) and the U-shaped component (12) are tied together. The fixing component includes a pre-embedded cylinder (13), which is pre-embedded in the UHPC base plate (9). The top end of the pre-embedded cylinder (13) extends outside the top surface of the UHPC base plate (9). The U-shaped piece (12) is inserted into the pre-embedded cylinder (13). The pre-embedded cylinder (13) is provided with a pin (14) for fixing the U-shaped piece (12).

2. The method of laying and casting regenerative block-aggregate concrete floor according to claim 1, characterized in that, The thickness of the first layer of recycled aggregate concrete (5) is 40-50mm, and the first layer of recycled aggregate concrete (5) is placed on the bottom reinforcement (3) of the slab.

3. The method for layered and multi-stage casting of recycled block-aggregate concrete floor slabs according to claim 1, characterized in that, Step S4 further includes the following steps: S4.1: Recycled concrete shall be pumped to the intended pouring location using a truck-mounted concrete pump. S4.2: The second layer of recycled aggregate concrete (7) is poured in stages along the span direction of the prefabricated frame module (1); S4.3: When pouring the second layer of recycled aggregate concrete (7), vibrate while pouring. Use an immersion vibrator to fully vibrate the mixture of recycled blocks (6) and new recycled aggregate concrete. The horizontal distance between adjacent insertion points should not exceed 500mm. The vibrator should be inserted to the bottom of the first layer of recycled aggregate concrete (5) and pry the recycled blocks (6) around to fully integrate the first layer of recycled aggregate concrete (5) and the second layer of recycled aggregate concrete (7) and to fully coat the recycled blocks (6) with the concrete slurry. The vibrator should be inserted in a row-and-column or staggered manner, and the vibration time at each point should be no less than 30 seconds, until the concrete surface no longer sinks significantly, no more air bubbles appear, and mortar appears on the surface. When vibrating, insert the vibrator quickly and pull it out slowly, and move the vibrator up and down slightly to ensure uniform vibration. S4.4: For structural embedded parts and reserved holes, dense reinforcement and other special parts, measures should be formulated in advance, and vibration should be strengthened during construction to ensure that vibration is not missed. S4.5: In order to control the elevation and flatness of the slab surface, use short steel bars to mark the elevation of the slab surface, then use a long scraper to smooth the slab surface, and then use a wooden washboard to perform the first grinding. S4.6: After concrete is poured, water bleeding is likely to occur on the surface. Therefore, during the later stage of concrete vibration, the concrete surface is repeatedly rubbed with a wooden washboard.

4. The method for layered and multi-stage casting of recycled block-aggregate concrete floor slabs according to claim 3, characterized in that, When the second layer of recycled aggregate concrete (7) is poured each time, the second layer of recycled aggregate concrete (7) is formed with a fluid inclined surface (8) under the action of fluid gravity. The vibrator is inserted into the fluid inclined surface (8) to vibrate the second layer of recycled aggregate concrete (7) poured each time.

5. The method for layered and multi-stage casting of recycled block-aggregate concrete floor slabs according to claim 1, characterized in that, Step S5 also includes the following steps: S5.1: Water curing shall begin 4-6 hours after pouring, with watering no less than 7 times a day and curing time no less than 14 days. S5.2: Within 24 hours after the concrete is poured, it is strictly forbidden for people to walk on it. Within 36 hours after the concrete is poured, except for testing temperature measuring equipment and covering for insulation, it is forbidden for people to walk on it and for construction materials to be piled up. S5.3: For parts that cannot be continuously covered by the frame module (1), cut and fill with insulation felt to avoid cold bridging.

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