A substation column integrated fire-resistant and disassembly-free formwork and a construction method thereof

Abstract

This invention discloses an integrated fire-resistant, non-removable formwork for substation columns and its construction method, belonging to the field of substation building formwork technology. The integrated fire-resistant, non-removable formwork for substation columns includes a geopolymer formwork and bent anchor bars embedded in the geopolymer formwork. The geopolymer formwork is a hollow column or prism with open ends. One end of the bent anchor bar is embedded in the geopolymer formwork, and the other end faces the hollow interior. The geopolymer formwork is made of geopolymer concrete, which includes 0.5-1% carbon fiber by weight. During construction, this integrated fire-resistant, non-removable formwork for substation columns can serve as part of a permanent structural component, eliminating the need for dismantling. This avoids the cumbersome construction and labor costs associated with continuous formwork erection and dismantling during conventional wet concrete work. In later use, it shares the load with the main concrete structure, improving the structural bearing capacity. It is suitable for applications requiring high strength and high fire resistance in complex substation environments.

Description

Technical Field

[0001] This invention belongs to the field of substation building formwork technology, specifically relating to an integrated fire-resistant, non-removable formwork for substation columns and its construction method. Background Technology

[0002] High-strength concrete structures are mostly constructed using traditional casting methods, which involve complex construction processes, requiring on-site fabrication of wooden formwork, and then a complicated process of formwork erection and dismantling. The extensive use and wear and tear of wooden formwork not only leads to resource waste and environmental impact, but also results in frequent quality problems with the high-strength concrete after formwork removal. These problems include surface porosity, voids, honeycombing, and pitting, as well as the high-strength concrete's susceptibility to cracking when exposed to fire. These issues not only affect the structure's safety and durability but also increase the workload for subsequent repairs. Currently, there are also non-removable formwork options, such as the integrated formwork for fine steel fiber reinforced polymer concrete disclosed in Chinese utility model patent CN215760462U. This formwork includes several formwork components distributed vertically, with adjacent components detachably connected. The bottommost formwork component has a pre-embedded component fixed to its outer side. Each formwork component includes four vertically arranged planar and right-angled formworks, forming a square tubular structure. Adjacent planar formworks are detachably connected via the right-angled formworks. This integrated formwork does not need to be removed after pouring, forming a single unit with the concrete column, eliminating the need for post-pouring formwork removal and accelerating construction. However, this type of non-removable formwork suffers from complex construction processes and poor strength or fire resistance when applied to substations. Summary of the Invention

[0003] The technical problem to be solved by this invention is: how to provide an integrated, non-removable formwork for substation columns with good fire resistance, high compressive strength, and high flexural strength.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: an integrated fire-resistant and non-removable formwork for substation columns, comprising a geopolymer formwork and bent anchor steel bars pre-embedded in the geopolymer formwork; the geopolymer formwork is a column or prism with a hollow interior and open at both ends; one end of the bent anchor steel bar is pre-embedded in the geopolymer formwork, and the other end is set towards the hollow interior;

[0005] The geopolymer template is made of geopolymer concrete, which contains 0.5 to 1% carbon fiber by weight.

[0006] The above-mentioned construction method for integrated fire-resistant and non-removable formwork for substation columns includes the following steps: preparing polymer concrete in the workshop or production site according to the above-mentioned proportions, and using the polymer concrete in conjunction with bent anchor steel bars to pour the fire-resistant and non-removable formwork; the fire-resistant and non-removable formwork does not need to be removed after use.

[0007] The beneficial effects of this invention are as follows: The integrated fire-resistant, non-removable formwork for substation columns provided by this invention is formed by connecting polymer formwork through bent anchor steel bars. Because 0.5-1% carbon fiber is added to the polymer concrete used to make the formwork, the fire resistance, compressive strength, and flexural strength of the resulting polymer formwork are effectively improved. The resulting fire-resistant, non-removable formwork can not only serve as a permanent component without removal, avoiding the tedious construction process of continuous formwork erection and dismantling, but also shares the load with the main concrete structure during later use, significantly improving the structure's load-bearing capacity. It is particularly suitable for substations, which have high pressure and high fire resistance requirements. Attached Figure Description

[0008] Figure 1 This is a structural schematic diagram of the integrated fire-resistant and non-removable formwork for substation columns according to a specific embodiment of the present invention;

[0009] Figure 2 This is a structural schematic diagram of the integrated fire-resistant and non-removable formwork for substation columns, according to a specific embodiment of the present invention, from another angle.

[0010] Figure 3 The diagram shows the compressive strength of carbon fiber geopolymer templates with different dosages in specific embodiments of the present invention.

[0011] Figure 4 The diagram shows the flexural strength of carbon fiber geopolymer templates with different dosages in specific embodiments of the present invention.

[0012] Label Explanation:

[0013] 1. Bent anchor steel bars; 2. Geopolymer formwork. Detailed Implementation

[0014] To explain in detail the technical content, objectives, and effects of the present invention, the following description is provided in conjunction with the embodiments and accompanying drawings.

[0015] Please refer to Figure 1 as well as Figure 2 A fire-resistant, non-removable formwork includes a geopolymer formwork and bent anchor bars embedded in the geopolymer formwork; the geopolymer formwork is a hollow column or prism with open ends; one end of the bent anchor bar is embedded in the geopolymer formwork, and the other end is set towards the hollow interior; the geopolymer formwork is integrally formed.

[0016] The geopolymer formwork is made by casting geopolymer concrete, which contains 0.5-1% carbon fiber by weight. Preferably, it contains 0.75-1%.

[0017] As described above, the beneficial effects of this invention are as follows: The integrated fire-resistant, non-removable formwork for substation columns provided by this invention can serve as a permanent component without the need for dismantling, avoiding the tedious construction process of constantly setting up and dismantling formwork. Furthermore, this integrated fire-resistant, non-removable formwork for substation columns shares the load with the main concrete structure during later use, improving the structure's load-bearing capacity. Due to the addition of a certain amount of carbon fiber and the integral structure of the geopolymer formwork, the formwork circumference of the substation column is seamless, preventing external corrosive media from penetrating and invading. This significantly improves the compressive strength, flexural strength, durability (including resistance to seawater corrosion), and fire resistance of the fire-resistant, non-removable formwork. Because of these characteristics, the fire-resistant, non-removable formwork provided by this invention is particularly suitable for the construction of substations, including those in coastal areas. It can meet the requirements of substations with larger upper loads due to electrical equipment, higher strength requirements for components, and higher fire resistance requirements due to the presence of oil-containing electrical equipment in the substation beam and column components.

[0018] The shape of the geopolymer formwork can be adjusted according to construction needs, such as cylindrical, triangular, square, and pentagonal prisms. The geopolymer formwork is integrally molded, meaning it is a one-piece formwork without seams, effectively resisting the intrusion of external corrosive media and improving the carbonation resistance and durability of the internal concrete.

[0019] Furthermore, geopolymer concrete includes granite powder, slag, metakaolin, melamine, water glass, sodium hydroxide, carbon fiber, river sand, and water.

[0020] Furthermore, the mass ratio of metakaolin to slag is 4:6, 5:5, or 3:7. Further, the water-cement ratio of the geopolymer concrete is 0.4–0.55, and the sand-cement ratio is 1.2–2.5, preferably 1.6–2.0. The mass ratio of water to slag and metakaolin is the water-cement ratio. The ratio of river sand to gel material is the sand-cement ratio.

[0021] Furthermore, the modulus of water glass is 1 to 1.6.

[0022] As described above, unlike the use of general building components, to meet the high strength and high fire resistance requirements of substations, granite powder is added, the water-cement ratio and sand-cement ratio are adjusted, and 0.5-1% carbon fiber is added to improve the strength, fire resistance, and durability of the geopolymer formwork. Due to the specific proportions of the geopolymer concrete in the geopolymer formwork of this invention, the addition of 0.5-1% carbon fiber is necessary to achieve a significant performance improvement.

[0023] Furthermore, by weight percentage, geopolymer concrete contains 0.3 to 0.6% melamine.

[0024] As can be seen from the above description, melamine is mainly used as a water-reducing agent, while also improving frost resistance, reducing construction difficulty, and increasing construction efficiency.

[0025] Furthermore, by weight percentage, geopolymer concrete contains 6-10% sodium hydroxide.

[0026] Furthermore, by weight percentage, the geopolymer concrete includes 0.2 to 0.5% granite powder.

[0027] Furthermore, carbon fiber can be any finished product available on the market, such as the various types of carbon fiber produced by Toray Industries.

[0028] The above-mentioned construction method for the integrated fire-resistant and non-removable formwork for substation columns includes the following steps: preparing polymer concrete in the workshop or production site according to the above-mentioned proportions, and using the polymer concrete in conjunction with bent anchor steel bars to pour the integrated fire-resistant and non-removable formwork for substation columns; this integrated fire-resistant and non-removable formwork for substation columns is used as the formwork for pouring high-strength reinforced concrete substation columns and does not need to be removed after use.

[0029] Please refer to Figures 1-2 Embodiment 1 of the present invention is as follows:

[0030] A fire-resistant, non-removable formwork for substation columns includes a cuboid geopolymer formwork and bent anchor bars embedded in the geopolymer formwork; the geopolymer formwork is a cuboid with a hollow interior and open at both ends; one end of the bent anchor bar is embedded in the geopolymer formwork, and the other end is set towards the hollow interior.

[0031] Geopolymer formwork is made of geopolymer concrete;

[0032] By weight percentage, the geopolymer concrete consists of the following components: 0.2% granite powder, 0.48% slag, 0.32% metakaolin, 0.3% melamine, water glass with a modulus of 1.6, 6% sodium hydroxide, 0.75% carbon fiber (Toray T700), river sand, and water; the water-cement ratio of the geopolymer concrete is 0.45, and the sand-cement ratio is 1.8; the mass ratio of metakaolin to slag is 4:6.

[0033] The above-mentioned construction method for fire-resistant, non-removable formwork includes the following steps: preparing polymer concrete in the workshop or production site according to the above proportions, and using the polymer concrete in conjunction with bent anchor steel bars to pour the fire-resistant, non-removable formwork; the fire-resistant, non-removable formwork does not need to be removed after use.

[0034] Embodiment 2 of the present invention is as follows:

[0035] The only difference between Example 2 and Example 1 is that the amount of carbon fiber added is 0.5%.

[0036] Embodiment 3 of the present invention is as follows:

[0037] The only difference between Example 3 and Example 1 is that the amount of carbon fiber added is 1%.

[0038] Embodiment four of the present invention is as follows:

[0039] The only difference between Example 4 and Example 1 is that the amount of carbon fiber added is 1.5%.

[0040] Embodiment five of the present invention is as follows:

[0041] The difference between Example 5 and Example 1 lies in the composition of the geopolymer concrete. The geopolymer concrete in Example 5, by weight percentage, consists of the following components: 0.3% granite powder, 0.48% slag, 0.32% metakaolin, 0.6% melamine, water glass with modulus 1, 10% sodium hydroxide, 1% carbon fiber (Toray T700), river sand, and water. The water-cement ratio of the geopolymer concrete is 0.5, the sand-cement ratio is 1.8, and the mass ratio of metakaolin to slag is 5:5.

[0042] Embodiment six of the present invention is as follows:

[0043] The difference between Example 6 and Example 1 lies in the composition of the geopolymer concrete. The geopolymer concrete in Example 5, by weight percentage, consists of the following components: 0.5% granite powder, 0.48% slag, 0.32% metakaolin, 0.5% melamine, water glass with a modulus of 1.2, 8% sodium hydroxide, 0.8% carbon fiber (Toray T700), river sand, and water. The water-cement ratio of the geopolymer concrete is 0.55, the sand-cement ratio is 1.8, and the mass ratio of metakaolin to slag is 3:7.

[0044] Comparative Example 1 is:

[0045] The only difference between Comparative Example 1 and Example 1 is that the amount of carbon fiber added is 0%.

[0046] Comparative Example 2 is:

[0047] The only difference between Comparative Example 2 and Example 1 is that the amount of carbon fiber added is 0.25%.

[0048] The compressive strength and flexural strength of the geopolymer templates obtained in Examples 1-4, and Comparative Examples 1 and 2, were tested on the 7th, 14th, and 28th days after fabrication. The tests were conducted according to the "Standard for Test Methods of Physical and Mechanical Properties of Concrete" GB50081-2019, which specifies that the standard cube specimens for concrete compressive strength testing are 150mm × 150mm × 150mm, and the standard specimens for concrete flexural strength testing are 150mm × 150mm × 600mm. Three specimens were used for each group for both compressive and flexural strength. The results are shown in Tables 1 and 2, and... Figure 3 and Figure 4 As shown.

[0049] The temperature resistance test was conducted on the geopolymer template obtained in Example 1 on day 28 after its fabrication, and the results are shown in Table 3.

[0050] Table 1

[0051]

[0052] Table 2

[0053]

[0054] Table 3

[0055]

[0056] In summary, the integrated fire-resistant, non-removable formwork for substation columns provided by this invention has the following advantages:

[0057] (1) It is suitable for the construction of substation columns in substations, and has good high temperature resistance, high compressive strength and flexural strength;

[0058] (2) The template is an integral structure without joints, and there are no gaps around the template, so external corrosive media cannot easily penetrate or invade;

[0059] (3) No need to remove the formwork, it can be used as part of the permanent component and share the load with the main concrete structure, further increasing the load-bearing capacity of the structure; at the same time, it greatly reduces the construction difficulty and the various costs required for modeling and demolding, and improves the construction efficiency.

[0060] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent modifications made based on the content of the present invention specification and drawings, or direct or indirect applications in related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A substation column integrated fire resistant and non-removable formwork, characterized in that, It includes a geopolymer template and bent anchor bars embedded in the geopolymer template; the geopolymer template is a column or prism with a hollow interior and open at both ends; one end of the bent anchor bar is embedded in the geopolymer template, and the other end is set towards the hollow interior; the geopolymer template is a seamless integrated template; The geopolymer template is made of geopolymer concrete, which contains 0.5-1% carbon fiber by weight. The geopolymer concrete comprises granite powder, slag, metakaolin, melamine, water glass, sodium hydroxide, carbon fiber, river sand, and water; The geopolymer concrete comprises 0.2 to 0.5% granite powder by weight percentage.

2. The substation column integrated fire resistant and non-removable formwork according to claim 1, characterized in that, The mass ratio of metakaolin to slag is 4:6, 5:5, or 3:

7.

3. The substation column integrated fire resistant and non-removable formwork according to claim 1, characterized in that, The water-cement ratio of the geopolymer concrete is 0.4~0.

55.

4. The substation column integrated fire resistant and non-removable formwork according to claim 1, characterized in that, The modulus of the water glass is 1 to 1.

6.

5. The substation column integrated fire resistant and non-removable formwork according to claim 1, characterized in that, The mortar-binder ratio of the geopolymer concrete is 1.2 to 2.5 by weight percentage.

6. The substation column integrated fire resistant and non-removable formwork according to claim 1, characterized in that, The geopolymer concrete contains 0.3 to 0.6% melamine by weight percentage.

7. The substation column integrated fire resistant and non-removable formwork according to claim 1, characterized in that, The geopolymer concrete contains 6-10% sodium hydroxide by weight percentage.

8. A construction method of the substation column integrated fireproof and dismantling-free formwork according to any one of claims 1 to 7, characterized in that, The process includes the following steps: preparing geopolymer concrete in the workshop or production site according to the above proportions, and using the geopolymer concrete in conjunction with bent anchor steel bars to pour geopolymer formwork; the geopolymer formwork does not need to be removed after use.

Images