A crack-resistant lightweight multi-layer structure manhole cover and its preparation method

Abstract

The present invention relates to the field of public facilities technology, and specifically to a crack-proof light multi-layer structure manhole cover and a preparation method thereof. The main body of the crack-proof light multi-layer structure manhole cover of the present invention is a cylindrical metal keel frame, and the metal keel frame is filled with the following structures from top to bottom: a cement layer, a shock-absorbing layer, a metal mesh layer, a composite rubber layer and a corrosion-resistant layer. The edge of the crack-proof light multi-layer structure manhole cover is encapsulated by a metal edging, and a water hole is provided on the manhole cover. While each layer of the crack-proof light multi-layer structure manhole cover of the present invention plays an independent role, adjacent layers also interact with each other, thereby improving the integrity of the manhole cover, avoiding damage caused by local stress concentration, reducing the probability of cracking, and improving the bearing capacity and service life of the manhole cover.

Description

Technical Field

[0001] The present invention relates to the technical field of public facilities, and in particular to a crack-resistant lightweight multi-layered manhole cover and a preparation method thereof. Background Art

[0002] Manhole covers, as a common municipal facility, play a crucial role in road planning. They not only bear the weight of vehicles and pedestrians but also provide access to the installation and maintenance of various underground facilities. Therefore, manhole covers must possess a range of excellent properties, including being lightweight, thin, strong, permeable, corrosion-resistant, and crack-resistant. Common manhole covers are often made of a single material, such as cast iron or cement. While these materials offer sufficient strength, their other advantages are limited.

[0003] Chinese patent CN212742633U discloses a crack-resistant plastic manhole cover for inspection wells. The cover is designed with a steel mesh, a fiber layer, and a rubber layer. The steel mesh is used to prevent cracking inside the cover, the fiber layer is used to prevent cracking outside the cover, and the rubber layer is used to prevent oxidation on the surface of the cover, thereby preventing the cover from cracking and extending its service life. Although the manhole cover of this patent adopts a fiber layer and rubber layer design, which reduces the overall quality while increasing the crack resistance, the structure of the manhole cover is that plastic is arranged around the steel mesh, a fiber layer is arranged around the plastic, and a rubber layer is arranged around the fiber layer. Each layer is stacked and performs its own function, resulting in poor integrity and limited crack resistance. Summary of the Invention

[0004] In response to the above problems, the first aspect of the present invention provides a crack-proof lightweight multi-layer manhole cover, whose main body is a cylindrical metal keel frame. The metal keel frame is filled with the following structures from top to bottom: a cement layer, a shock-absorbing layer, a metal mesh layer, a composite rubber layer and a corrosion-resistant layer. The edge of the crack-proof lightweight multi-layer manhole cover is encapsulated by a metal edging, and a water hole is provided on the crack-proof lightweight multi-layer manhole cover.

[0005] In the present invention, the thickness ratio of the cement layer, the shock absorbing layer, and the composite rubber layer is 1:(0.5-1.2):(1.5-3). The metal mesh layer and the corrosion-resistant layer are thin metal layers, so the cement layer, the shock absorbing layer, and the composite rubber layer are functional layers with obvious thickness requirements.

[0006] As the surface layer, the cement layer, similar to traditional reinforced cement, plays a role in bearing and resisting pressure. It can effectively disperse the pressure borne by the manhole cover and improve the bearing capacity of the manhole cover. The cement layer also has good wear resistance and weather resistance, can resist the erosion of the external environment, and extend the service life of the manhole cover.

[0007] The shock-absorbing layer is a mixture of lightweight porous particles and chemical fibers, wherein the lightweight porous particles are one of ultra-light expanded clay, volcanic rock particles or sodium bentonite particles, and the chemical fiber is one of regenerated nylon fiber, polyester fiber or recycled felt fiber. The lightweight porous particles in the shock-absorbing layer not only reduce the overall weight of the manhole cover but also play a role in energy absorption and shock absorption. The chemical fiber can reduce the displacement of the lightweight porous particles and increase the integrity of the shock-absorbing layer.

[0008] The metal mesh layer serves as a structural reinforcement, primarily enhancing the overall strength and toughness of the manhole cover. It is typically woven from high-strength steel or stainless steel wire to form a dense mesh structure. The presence of the metal mesh layer also ensures the manhole cover maintains good shape stability over long-term use, making it less susceptible to deformation and further extending its service life.

[0009] A second aspect of the present invention provides a method for preparing the aforementioned crack-resistant lightweight multi-layer manhole cover, comprising the following operations:

[0010] 1. Cut the aluminum alloy plate or stainless steel plate into the same shape as the metal keel frame and weld it to the bottom edge and crossbar of the metal keel frame to form the corrosion-resistant layer. Then, attach the metal edging along the side of the metal keel frame and weld it to the metal keel frame and the corrosion-resistant layer respectively.

[0011] Second, evenly spray a mixture of recycled rubber particles and low-melting-point polymer particles onto the surface of the flattened non-woven fiber cloth, stack it multiple times, and repeatedly roll it with a hot roller to the required thickness. After cooling and shaping, cut it and lay it on the corrosion-resistant layer to form the composite rubber layer. Cut the metal mesh into a suitable size and lay it on the composite rubber layer. Then weld the edge to the inner wall of the metal edging to form the metal mesh layer.

[0012] 3. Mix the lightweight porous particles and chemical fibers evenly according to the weight ratio and fill them on the metal mesh layer to the required thickness to form the shock absorbing layer. Then pour cement slurry on the shock absorbing layer and form a cement layer after solidification.

[0013] 4. Drill a hole vertically on the cement layer and install a corrosion-resistant metal ring in the hole to form a water hole. Seal the water hole and both sides of the manhole cover.

[0014] While each layer of the anti-cracking lightweight multi-layer structure manhole cover of the present invention plays an independent role, adjacent layers also interact with each other to improve the integrity of the manhole cover, which is specifically manifested as follows: the corrosion-resistant layer is tightly combined with the composite rubber layer, and the solid support of the corrosion-resistant layer provides a stable base for the composite rubber layer, and the elasticity of the composite rubber layer effectively alleviates the rigid impact of the corrosion-resistant layer when subjected to force; both the composite rubber layer and the shock-absorbing layer are made of fiber products, and the fibers at the interface will be entangled with each other, reducing the dislocation between layers, and the seismic and crack-proof performance is improved. The metal mesh layer and metal edging between the two can play a skeleton support role after welding; the cement layer will infiltrate into the surface layer of the shock-absorbing layer after pouring, thereby more quickly transmitting and dispersing the impact received by the cement layer, avoiding damage caused by local stress concentration, reducing the chance of cracking of the cement layer, and improving the bearing capacity and service life of the manhole cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the crack-proof lightweight multi-layer manhole cover of the present invention.

[0016] Figure 2 Schematic diagram of the metal keel frame.

[0017] The parts are numbered as follows: 1. Metal keel frame, 2. Cement layer, 3. Shock-absorbing layer, 4. Metal mesh layer, 5. Composite rubber layer, 6. Corrosion-resistant layer, 7. Metal edging, 8. Water hole. DETAILED DESCRIPTION

[0018] The present invention is described below with reference to examples, which are only used to explain the present invention and are not used to limit the scope of the present invention. Example 1

[0019] A crack-proof lightweight multi-layer structure manhole cover with a thickness of 5 cm and a diameter of 40 cm, such as Figure 1 and Figure 2 As shown, the main body is a cylindrical metal keel frame 1, which is filled with the following structure from top to bottom: a cement layer 2, a shock-absorbing layer 3, a metal mesh layer 4, a composite rubber layer 5, and a corrosion-resistant layer 6. The edge of the crack-proof lightweight multi-layer manhole cover is enclosed by a metal edging 7, and the crack-proof lightweight multi-layer manhole cover is provided with a water hole 8. The shock-absorbing layer 3 is a mixture of ultra-light ceramsite and recycled nylon fiber in a weight ratio of 1:3; the composite rubber layer 5 is a composite material of 3mm rubber particles uniformly filled between multiple layers of non-woven polyethylene fiber cloth; the corrosion-resistant layer 6 is an aluminum alloy plate. The thicknesses of the cement layer 2, shock-absorbing layer 3, and composite rubber layer 5 are 1.2 cm, 1.4 cm, and 2.2 cm, respectively. Example 2

[0020] A crack-proof lightweight multi-layer structure manhole cover with a thickness of 7 cm and a diameter of 80 cm, such as Figure 1and Figure 2 As shown, the main body is a cylindrical metal keel frame 1, which is filled with the following structure from top to bottom: a cement layer 2, a shock-absorbing layer 3, a metal mesh layer 4, a composite rubber layer 5, and a corrosion-resistant layer 6. The edge of the crack-proof lightweight multi-layer manhole cover is enclosed by a metal edging 7, and the crack-proof lightweight multi-layer manhole cover is provided with a water hole 8. The shock-absorbing layer 3 is a mixture of sodium bentonite particles and recycled felt fibers in a weight ratio of 1:4; the composite rubber layer 5 is a composite material of 5mm-diameter rubber particles uniformly filled between multiple layers of non-woven polyethylene fiber cloth; the corrosion-resistant layer 6 is a stainless steel plate. The thicknesses of the cement layer 2, shock-absorbing layer 3, and composite rubber layer 5 are 2.5cm, 1.25cm, and 3.1cm, respectively. Example 3

[0021] A crack-proof lightweight multi-layer structure manhole cover with a thickness of 9 cm and a diameter of 100 cm, such as Figure 1 and Figure 2 As shown, the main body is a cylindrical metal keel frame 1, which is filled with the following structure from top to bottom: a cement layer 2, a shock-absorbing layer 3, a metal mesh layer 4, a composite rubber layer 5, and a corrosion-resistant layer 6. The edge of the crack-proof lightweight multi-layer manhole cover is enclosed by a metal edging 7, and the crack-proof lightweight multi-layer manhole cover is provided with a water hole 8. The shock-absorbing layer 3 is a mixture of volcanic rock particles and polyester fiber in a weight ratio of 1:5; the composite rubber layer 5 is a composite material of 6mm rubber particles uniformly filled between multiple layers of non-woven polyethylene fiber cloth; the corrosion-resistant layer 6 is an aluminum alloy plate. The thicknesses of the cement layer 2, shock-absorbing layer 3, and composite rubber layer 5 are 3cm, 2cm, and 4cm, respectively.

[0022] The preparation method of the crack-resistant lightweight multi-layer structure manhole cover of Examples 1 to 3 comprises the following steps:

[0023] 1. Cut the aluminum alloy plate or stainless steel plate into the same shape as the metal keel frame 1 and weld it to the bottom edge and crossbar of the metal keel frame 1 to form the corrosion-resistant layer 6. Then, attach the metal edging 7 along the side of the metal keel frame 1 and weld it to the metal keel frame 1 and the corrosion-resistant layer 6 respectively.

[0024] Second, evenly spray a mixture of recycled rubber particles and low-melting-point polymer particles onto the surface of the laid-flat fiber cloth. After stacking multiple times, repeatedly roll it with a hot roller to the desired thickness. After cooling and shaping, cut it and lay it on the corrosion-resistant layer 6 to form the composite rubber layer 5. Cut the metal mesh into a suitable size and lay it on the composite rubber layer 5. Then weld the edge to the inner wall of the metal edging 7 to form the metal mesh layer 4.

[0025] 3. Mix the lightweight porous particles and chemical fibers evenly according to the weight ratio and fill them on the metal mesh layer 4 to the required thickness to form the shock absorbing layer 3. Then pour cement slurry on the shock absorbing layer 3 and form the cement layer 2 after solidification.

[0026] Fourth, vertically drill a hole in the cement layer 2, install a corrosion-resistant metal ring in the hole, which is the water hole 8, and seal the water hole 8 and both sides of the manhole cover.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A crack-proof lightweight multi-layer structure manhole cover, characterized in that: The main body of the anti-cracking light multi-layer structure manhole cover is a cylindrical metal keel frame (1), and the metal keel frame (1) is filled with the following structures in order from top to bottom: a cement layer (2), a shock-absorbing layer (3), a metal mesh layer (4), a composite rubber layer (5) and a corrosion-resistant layer (6). The edge of the anti-cracking light multi-layer structure manhole cover is encapsulated by a metal edging (7), and the anti-cracking light multi-layer structure manhole cover is provided with a water hole (8); The shock absorbing layer (3) is a mixture of lightweight porous particles and chemical fibers; the lightweight porous particles are one of ultra-light ceramsite, volcanic rock particles or sodium bentonite particles, and the chemical fibers are one of regenerated nylon fibers and polyester fibers; The aluminum alloy plate or the stainless steel plate is cut into the same shape as the metal keel frame (1) and welded to the bottom edge and the cross bar of the metal keel frame (1) to form the corrosion-resistant layer (6). Then, the metal edging (7) is attached along the side of the metal keel frame (1) and welded to the metal keel frame (1) and the corrosion-resistant layer (6) respectively.

2. The anti-cracking lightweight multi-layer structure manhole cover according to claim 1 is characterized in that: The thickness ratio of the cement layer (2), the shock absorbing layer (3) and the composite rubber layer (5) is 1:(0.5-1.2):(1.5-3).

3. The crack-proof lightweight multi-layer structure manhole cover according to claim 2 is characterized in that: The composite rubber layer (5) is a composite material in which rubber particles are evenly filled between multiple layers of non-woven fiber cloth.

4. A method for preparing the crack-resistant lightweight multi-layer manhole cover according to claim 3, characterized in that: The following steps are involved:

1. Cut the aluminum alloy plate or stainless steel plate into the same shape as the metal keel frame (1), and weld it to the bottom edge and crossbar of the metal keel frame (1) to form the corrosion-resistant layer (6). Then, attach the metal edging (7) along the side of the metal keel frame (1) and weld it to the metal keel frame (1) and the corrosion-resistant layer (6) respectively.

2. Evenly spray the mixture of recycled rubber particles and low-melting-point polymer particles onto the surface of the flattened non-woven fiber cloth, stack it multiple times, and repeatedly roll it with a hot roller to the required thickness. After cooling and shaping, cut it and lay it on the corrosion-resistant layer (6), which is the composite rubber layer (5). Cut the metal mesh into a suitable size and lay it on the composite rubber layer (5), and weld the edge to the inner wall of the metal edging (7), which is the metal mesh layer (4); 3. Mixing the lightweight porous particles and chemical fibers uniformly according to weight ratio, and filling the metal mesh layer (4) to a desired thickness, which is the shock absorbing layer (3), and then pouring cement slurry onto the shock absorbing layer (3), and forming a cement layer (2) after solidification; Fourth, vertically drill a hole on the cement layer (2), install a corrosion-resistant metal ring in the hole, which is the water hole (8), and seal the water hole (8) and the manhole cover on both sides.

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