A method for quickly constructing an upper cone slope of a silo funnel

Abstract

This invention discloses a rapid construction method for the upper conical slope of a silo hopper, belonging to the field of silo construction technology. The method includes: prefabricating lightweight aggregate concrete slabs with grooved edges, embedded exposed reinforcing bars, and roughened lifting rings on the slab surface; installing L-shaped angle steel on the bottom slab of the hopper layer; fixing the bottom prefabricated slab to the bottom slab of the hopper layer using the L-shaped angle steel; pouring cast-in-place concrete between the prefabricated slab and the silo wall; splicing the upper prefabricated slabs layer by layer, with the upper and lower layers interlocked by grooved joints and reinforced with steel pipes passing through the lifting rings; repeating the pouring and splicing process to the designed height; and finally, installing anchor bolts to fix the top slab on the top layer of the silo inner wall. This invention uses prefabricated lightweight aggregate concrete slabs as a non-removable formwork, achieving coordinated prefabrication and cast-in-place construction, significantly improving construction efficiency, reducing labor and turnover material costs, and producing a high-quality conical slope.

Description

Technical Field

[0001] This invention relates to the field of silo construction technology, and in particular to a silo construction method, specifically a rapid construction method for the upper cone slope of a silo hopper. Background Technology

[0002] As an important component of the silo, the stability and reliability of the funnel cone slope directly affect the overall performance and safety of the silo.

[0003] Currently, the construction of cone slopes for silo funnels in the industry generally adopts the following methods: one is to dry-lay autoclaved aerated concrete blocks to form a stepped cone. The other is to use autoclaved aerated concrete blocks as a formwork, pour foamed concrete, and then use traditional formwork pouring or the "slope shaping" process for the surface layer of the cone slope.

[0004] These construction methods have significant shortcomings in practical applications: Dry-laid autoclaved aerated concrete (AAC) blocks require a large amount of manual labor for material handling and construction, resulting in low efficiency. When using traditional formwork for pouring concrete onto cone-shaped slopes, the sloping structure makes formwork installation difficult, necessitating extensive steel scaffolding as a support system, leading to high material consumption and costs. While the "slope-forming" process eliminates the formwork installation step, the concrete forming quality is difficult to control, and surface flatness and slope accuracy are hard to guarantee, affecting the service life and safety performance of the cone-shaped slope structure.

[0005] Non-removable formwork is characterized by its simple operation, high plasticity, stable quality, and low cost, and is widely used in high-rise civil buildings, industrial buildings, and low-rise rural houses. During construction, the prefabrication and positioning installation of non-removable formwork have a significant impact on the quality of concrete molding.

[0006] Therefore, it is necessary to study the various technical parameters of the construction of formwork that does not require removal, improve the accuracy of splicing and installation positioning, and improve construction efficiency, thereby shortening the construction period.

[0007] In summary, there is an urgent need in this field to develop a construction method for the cone slope of silo funnels to meet the engineering requirements for the long-term stable operation of silo construction systems. Summary of the Invention

[0008] To address the challenges of template size and precision control, as well as positioning and installation, in existing silo funnel cone slope construction, where the accuracy of splicing and installation directly impacts construction efficiency and final quality, this invention provides a rapid construction method for the upper cone slope of a silo funnel.

[0009] This invention is achieved using the following technical solution: A rapid construction method for the upper cone slope of a silo hopper includes the following steps: a) Precast lightweight aggregate concrete slab The precast lightweight aggregate concrete slab has a size of 1200mm×2400mm×150mm. The edges of the slab are provided with grooves for splicing, with a groove width of 30mm and a groove depth of 20mm. Parallel Φ16 pre-embedded steel bars are embedded in the slab, with a spacing of 200mm between two adjacent pre-embedded steel bars. One end of the pre-embedded steel bar is exposed to cooperate with the adjacent lightweight aggregate concrete slab to form a structural reinforcement at the splice joint. The exposed length is 300mm. A lifting ring is pre-embedded on one side of the slab surface, and the other side is roughened to form a roughened surface. The roughened surface faces the cast-in-place concrete layer to enhance the adhesion between the lightweight aggregate concrete slab and the cast-in-place concrete layer. After curing to the design strength, the formwork is removed and the equipment is transported to the construction site for use. b. Installation of L-shaped angle steel L-shaped angle steel is installed on the bottom plate of the funnel layer along the circumference of the inner wall of the silo. One side of the L-shaped angle steel is attached to the bottom plate of the funnel layer and fixed by angle steel fixing bolts. The L-shaped angle steel and the inner wall of the silo enclose the filling area. c. Installation of the bottom lightweight aggregate concrete slab The prefabricated bottom lightweight aggregate concrete slab is fixed to the bottom plate of the funnel layer using the L-shaped angle steel described in step b, so that the edge of the lightweight aggregate concrete slab abuts against the lower edge of the L-shaped angle steel, and the slope of the lightweight aggregate concrete slab is adjusted to be consistent with the design slope of the cone slope. Specifically, lightweight aggregate mortar is filled into the contact joint between the L-shaped angle steel and the edge of the bottom lightweight aggregate concrete slab to form a mortar filling layer, which seals the gap between the L-shaped angle steel and the precast slab. Specifically, the exposed embedded steel bars on the side of the slab are lapped and fixed to connect adjacent precast slabs into a whole; Preferably, two adjacent lightweight aggregate concrete slabs are reinforced by using reinforcing steel pipes passing through the pre-embedded lifting rings on the slab surface to reinforce the two adjacent bottom lightweight aggregate concrete slabs. d. Cast-in-place concrete layer pouring Cast-in-place concrete is poured in the filling area between the bottom lightweight aggregate concrete slab and the inner wall of the silo to form a cast-in-place concrete layer. e. Assemble lightweight aggregate concrete slabs and install reinforcing steel pipes. A layer of lightweight aggregate concrete slab is spliced ​​on top of the bottom lightweight aggregate concrete slab, and the upper and lower adjacent precast slabs are joined by tongue and groove joints. Preferably, reinforcing steel pipes are used to pass through the pre-embedded lifting rings on the precast slab surface to reinforce the two adjacent layers of precast slabs, and anchor bolts are used to reinforce the junctions between the two sides and the silo. f, casting and splicing Repeat steps d and e, following a bottom-up order, to repeatedly pour and splice lightweight aggregate concrete slabs layer by layer until the design height of the cone slope is reached. g. Install anchor bolts Install inner wall anchors on the top layer of the silo's inner wall, with a spacing of 800mm between two adjacent inner wall anchors, to connect and fix the top layer of lightweight aggregate concrete slab to the inner wall of the silo.

[0010] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a rapid construction method for the upper cone slope of a silo hopper, which uses precast lightweight aggregate concrete slabs instead of autoclaved aerated concrete blocks as a formwork that does not need to be removed, resulting in significant improvements in all aspects.

[0011] Precast slabs, produced in a factory, have higher dimensional accuracy than on-site dry-laid aerated concrete blocks, improving the surface flatness and slope accuracy of the conical slope. Based on actual construction calculations, the traditional method requires a 40-day construction period, 10 workers per day, totaling 400 man-days. Using this method, the construction period is reduced to only 30 days, saving 10 days. Labor input is reduced from 10 people per shift (including material transport) to 6 people per shift, saving approximately 40% in labor costs, an estimated reduction of 280 man-days, and approximately 98,000 yuan in labor costs. The rental of steel pipe scaffolding for reusable materials is reduced from 10 tons to 3 tons (only for protective erection), saving approximately 70% in reusable material costs and 100% in autoclaved aerated concrete block costs, reducing reusable material and autoclaved aerated concrete block costs by approximately 32,000 yuan. In summary, this invention saves approximately 130,000 yuan and shortens the construction period by 10 days. Attached Figure Description

[0012] Figure 1 is a schematic vertical cross-sectional view of the present invention; Figure 2 is a schematic diagram of the single-unit planar structure of the lightweight aggregate concrete slab of the present invention; Figure 3 is a schematic cross-sectional view of the connection node between the precast lightweight aggregate concrete slab and the inner wall of the silo according to the present invention. Figure 4 This is a schematic diagram of the splicing of the precast lightweight aggregate concrete slab of the present invention.

[0013] In the picture: 1. Silo body; 2. Cast-in-place concrete layer; 3. Lightweight aggregate concrete slab; 4. Inner wall anchors; 5. L-shaped angle steel; 6. Groove; 7. Lifting ring; 8. Embedded steel bars; 9. Mortar filling layer; 10. Reinforcing steel pipe; 11. Funnel layer bottom plate; 12. Roughened surface; 13. Angle steel fixing bolts. Detailed Implementation

[0014] Specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0015] A rapid construction method for the upper conical slope of a silo hopper, taking the upper conical slope section (+1.900m~+7.854m) of the raw coal silo hopper layer at the Boli Coal Mine of Yangquan Coal Industry Group as an example, shows that the conical slope forms a 60° angle with the horizontal direction, with a maximum thickness of 3.44m and a maximum height of 5.95m. Figures 1-4 As shown: Includes the following steps: a) Precast lightweight aggregate concrete slab The dimensions and splicing method of the precast lightweight aggregate concrete slab 3 are designed based on geometric relationships. Based on the cone slope height of 5.95m, maximum thickness of 3.44m, cone slope angle of 60°, and silo diameter of 22m, the calculated cone slope height is 6.87m. Each silo contains 4 cone slopes, with a total bottom depth of 55.3m. The lightweight aggregate concrete is divided into blocks of 1200mm×2400mm×150mm, with 23 blocks circumferentially and 6 layers longitudinally. The maximum weight of a single block is controlled at 388kg, which meets the lifting requirements.

[0016] The precast lightweight aggregate concrete slab 3 has grooves 6 on its edges for splicing. The grooves are 30mm wide and 20mm deep. Parallel Φ16 pre-embedded steel bars 8 are embedded in the slab. The spacing between two adjacent pre-embedded steel bars 8 is 200mm. One end of the pre-embedded steel bar 8 is exposed, with an exposed length of 300mm. A Φ60 lifting ring 7 is embedded on one side of the slab surface. The other side is roughened using a wire rake to form a roughened surface 12. The roughened surface 12 accounts for ≥80% of the area, and the local depression depth is ≥2mm. 3 out of every 50 slabs are taken to test whether the interface roughness Ra≥1.5mm is met.

[0017] After curing to a strength of 20MPa, the formwork is removed and the product is transported to the construction site for use.

[0018] Preferably, in this embodiment, a forklift is used for transportation, and the equipment is vertically fixed to prevent damage.

[0019] b. Installation of L-shaped angle steel An L-shaped angle steel is installed on the bottom plate 11 of the funnel layer along the circumference of the inner wall of the silo. The L-shaped angle steel has a specification of 50×5mm. One side of the L-shaped angle steel is attached to the bottom plate 11 of the funnel layer and is fixed by angle steel fixing bolts 13. The L-shaped angle steel and the inner wall of the silo enclose the filling area.

[0020] c. Installation of the bottom lightweight aggregate concrete slab The precast lightweight aggregate concrete slab 3 is hoisted into place using lifting rings 7. After hoisting, it is fixed with temporary supports. The precast lightweight aggregate concrete slab 3 is then fixed to the funnel-shaped bottom plate 11 using the L-shaped angle steel described in step b, so that the edges of the lightweight aggregate concrete slab 3 abut against the upper edge and lower part of the L-shaped angle steel. The slope of the lightweight aggregate concrete slab 3 is adjusted to match the designed slope of the cone slope. In this embodiment, the designed inclination angle is 60°±0.5°. A total station is used to check the inclination angle of each precast slab to ensure that the deviation is within the allowable range.

[0021] Lightweight aggregate mortar is filled into the contact joint between the L-shaped angle steel and the three edges of the bottom lightweight aggregate concrete slab to form a mortar filling layer 9, which seals the gap between the L-shaped angle steel and the precast slab.

[0022] The pre-embedded steel bars 8 exposed on the side of the slab are lapped and fixed to connect adjacent precast slabs into a whole.

[0023] The two adjacent lightweight aggregate concrete slabs 3 are reinforced by reinforcing steel pipes 10 passing through the pre-embedded lifting rings 7 on the slab surface.

[0024] d. Cast-in-place concrete layer pouring C25 concrete is poured in layers in the filling area between the bottom lightweight aggregate concrete slab 3 and the inner wall of the silo, with each layer ≤500mm, forming the cast-in-place concrete layer 2; the temporary support is removed after the cast-in-place concrete layer 2 is poured.

[0025] e. Assemble lightweight aggregate concrete slabs and install reinforcing steel pipes. A layer of lightweight aggregate concrete slab 3 is spliced ​​on top of the bottom lightweight aggregate concrete slab 3, and the two adjacent layers of precast slabs are joined together by a tongue and groove joint 6.

[0026] The reinforcing steel pipe 10 is passed through the pre-embedded lifting ring 7 on the precast slab surface to reinforce the interlayer of the two adjacent precast slabs.

[0027] f, casting and splicing Repeat steps d and e, following a bottom-up order, to pour and splice the cast-in-place concrete layer 2 and the lightweight aggregate concrete slab 3, splicing and reinforcing them until the design height of the cone slope is reached.

[0028] g. Install anchor bolts Install inner wall anchor bolts 4 on the top layer of the inner wall of the silo to connect and fix the top layer of lightweight aggregate concrete slab 3 to the inner wall of the silo.

[0029] The scope of protection claimed by this invention is not limited to the specific embodiments described above. Moreover, for those skilled in the art, this invention can have various modifications and alterations. Any modifications, improvements, and equivalent substitutions made within the concept and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for rapid construction of a silo funnel upper cone slope, characterized in that: Includes the following steps: a) Precast lightweight aggregate concrete slab The precast lightweight aggregate concrete slab (3) has grooves (6) for splicing on the edge of the slab, and parallel pre-embedded steel bars (8) are embedded in the slab. One end of the pre-embedded steel bars (8) is exposed. A lifting ring (7) is embedded on one side of the slab surface, and the other side is roughened to form a roughened surface (12). After curing to the design strength, the slab is demolded and transported to the construction site for use. b. Installation of L-shaped angle steel An L-shaped angle steel is installed on the bottom plate (11) of the funnel layer along the circumference of the inner wall of the silo. One side of the L-shaped angle steel is attached to the bottom plate (11) of the funnel layer and is connected and fixed by angle steel fixing bolts (13). The L-shaped angle steel and the inner wall of the silo enclose a filling area. c. Installation of the bottom lightweight aggregate concrete slab The prefabricated bottom lightweight aggregate concrete slab (3) is fixed to the bottom plate (11) of the funnel layer by the L-shaped angle steel described in step b, so that the edge of the lightweight aggregate concrete slab (3) abuts against the lower edge of the L-shaped angle steel, and the slope of the lightweight aggregate concrete slab (3) is adjusted to be consistent with the design slope of the cone slope. d. Cast-in-place concrete layer pouring Cast-in-place concrete is poured in the filling area between the bottom lightweight aggregate concrete slab (3) and the inner wall of the silo to form a cast-in-place concrete layer (2). e. Splicing lightweight aggregate concrete slabs A layer of lightweight aggregate concrete slab (3) is spliced ​​on top of the bottom lightweight aggregate concrete slab (3), and the two adjacent layers of precast slabs are joined by tenon joints through grooves (6); f, casting and splicing Repeat steps d and e, and in a bottom-up order, repeat the pouring and splicing of the cast-in-place concrete layer (2) and the splicing and reinforcement of the lightweight aggregate concrete slab (3) until the design height of the cone slope is reached. g. Install anchor bolts Install inner wall anchors (4) on the top layer of the inner wall of the silo to connect and fix the top layer of lightweight aggregate concrete slab (3) to the inner wall of the silo.

2. The method according to claim 1, characterized in that: In step c, lightweight aggregate mortar is filled into the contact joint between the L-shaped angle steel and the edge of the bottom lightweight aggregate concrete slab (3) to form a mortar filling layer (9), which seals the gap between the L-shaped angle steel and the precast slab.

3. The method according to claim 1, characterized in that: In step c, the pre-embedded steel bars (8) exposed on the side of the slab are lapped and fixed so that adjacent precast slabs are connected as a whole.

4. The method according to claim 1, characterized in that: In step c, two adjacent lightweight aggregate concrete slabs (3) are reinforced by reinforcing steel pipes (10) passing through the pre-embedded lifting rings (7) on the slab surface; anchor bolts are used to reinforce the junctions of the two sides with the silo. In step e, a reinforcing steel pipe (10) is used to pass through the pre-embedded lifting ring (7) on the precast slab surface to reinforce the two adjacent precast slabs.

5. The rapid construction method for the upper cone slope of a silo hopper according to claim 1, characterized in that: In step a, the exposed length of the pre-embedded steel bars (8) is 300mm and the horizontal spacing is 200mm.

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