A gallery structure of an engineered cementitious composite material and a construction method thereof
By using hollow PVC plastic rods and steel wire mesh skeleton frames in ECC concrete structures, combined with the connection between prestressed tendons and cement paste, the problem of deformation incompatibility between ECC concrete and traditional steel mesh structures was solved, and the toughness and ductility of the materials were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- POWERCHINA HUADONG ENG CORP LTD
- Filing Date
- 2023-03-16
- Publication Date
- 2026-06-16
AI Technical Summary
When ECC concrete is used in combination with traditional steel reinforcement, it is prone to cracking at weak points due to its high drying shrinkage rate, leading to problems of inconsistent deformation.
Hollow PVC plastic rods and steel wire mesh structures are used to replace traditional steel mesh to build a skeleton frame. Prestressed tendons are inserted into the prestressed tendon ducts and filled with cement paste to form a connection between the prestressed tendons and ECC concrete, reducing the constraint of drying shrinkage deformation.
It effectively overcomes the problem of deformation incompatibility between ECC concrete and traditional steel mesh structures, avoids fractures in weak parts, and improves the toughness and ductility of the material.
Smart Images
Figure CN116378471B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of concrete engineering technology, and in particular to a corridor structure made of engineering cement-based composite material and its construction method. Background Technology
[0002] With the development of society and economy and the progress of science and technology, engineering structures are developing towards higher quality, longer service life, and stronger durability. In order to effectively improve the shortcomings of traditional concrete in terms of low tensile strength and deformation resistance, ECC concrete has emerged. ECC (Engineered Cementitious Composite) is an engineering cement-based composite material first successfully developed by Professor Victor C. Li of the University of Michigan in the 1990s. It is a functional fiber-reinforced cement-based composite material. It generally uses cement, fly ash and other cementitious materials and fine aggregates as the matrix, and incorporates short fibers with a volume ratio not exceeding 2.5% for mixing and molding. After hardening, the fiber-reinforced cement-based composite material produces multiple fine cracks under tensile load, exhibiting a unique strain-hardening phenomenon. This ECC concrete has high toughness and ductility as well as excellent crack control ability, which is conducive to solving a series of engineering problems caused by the high brittleness, easy cracking and uncontrollable crack width after cracking, poor durability and ductility of concrete structures in my country.
[0003] Traditional corridor structures are made of reinforced concrete and are constructed following the steps of rebar tying, formwork erection, concrete pouring, formwork removal, and curing. To ensure the compactness of the concrete, special attention must be paid to the quality of the concrete mix. Layered pouring and vibration with a vibrator are typically used. The vibration spacing and time are controlled according to the concrete's fluidity, workability, and the availability of the vibrating equipment to ensure that the concrete is neither under-vibrated nor over-vibrated, and to remove air bubbles from the concrete.
[0004] ECC concrete is based on a microscopic fiber reinforcement mechanism, using extremely fine high-performance fibers. It reinforces cement mortar using material micromechanical design theory and technology, enabling it to bend rather than fracture under immense pressure (structural model such as...). Figure 1 (As shown), because the fibers move within them; the fibers are somewhat similar to ligaments in the human body, providing flexible connections and thus greatly improving tensile strength.
[0005] Despite its many advantages, ECC concrete, which uses cement, fly ash, and other binders and fine aggregates as its matrix and lacks coarse aggregates, exhibits, according to test results, the same characteristics as ordinary concrete: high early plastic shrinkage and significant drying shrinkage, with a drying shrinkage rate significantly higher than that of ordinary concrete. Figure 2As shown, for a fixed maximum sand particle size, the lower the water-cement ratio and the more adhesive used, the greater the drying shrinkage rate of the ECC specimen. When this material is used in combination with traditional steel reinforcement to cast corridor structures, the use of steel reinforcement, due to its larger elastic modulus, limits the drying shrinkage deformation of ECC concrete to some extent, making ECC concrete prone to fracture at weak points. This problem remains to be solved. Summary of the Invention
[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing an engineering cement-based composite material corridor structure and its construction method to overcome the problems of large material shrinkage and incompatibility with steel reinforcement deformation.
[0007] The technical objective of this invention is achieved as follows: a corridor structure made of engineering cement-based composite material, wherein the bottom of the corridor structure is cup-shaped, and above the cup-shaped opening is the main body of the corridor cast using engineering cement-based composite material. The main body of the corridor has an internal corridor in the form of a city gate. The main body of the corridor has two skeleton frames, inner and outer, between its outer wall and the internal corridor. The skeleton frames are constructed of hollow PVC plastic rods arranged in a crisscross pattern. A layer of wire mesh is fixed to the outer side of each skeleton frame, and the inner side has crisscrossing prestressing tendon channels. Prestressing tendons are placed in the prestressing tendon channels and filled with cement slurry. The two ends of the prestressing tendons are fixedly connected to the anchoring structure, and the anchoring structure is fixed to the skeleton frame.
[0008] Preferably, the anchoring structure includes an anchor plate, reinforcing bars, and a pad. The reinforcing bars are located at the four corners on the back of the anchor plate. The anchor plate has through holes that pass through its front and back sides. A positioning tube corresponding to the hole is fixed on the back of the anchor plate. The positioning tube is connected to the prestressing tendon duct. The prestressing tendon in the prestressing tendon duct passes through the positioning tube and the through hole and is fixed on the pad.
[0009] Preferably, the wire mesh is kept at a distance from the frame.
[0010] This invention also provides a construction method for a corridor structure made of engineering cement-based composite materials, comprising the following steps:
[0011] S1. Use plastic rods to build the skeleton frame of the corridor structure (5);
[0012] S2. Fix the wire mesh (1) to one side of the frame (5);
[0013] S3. On the other side of the skeleton frame (5), the embedded pipe is laid, and the anchor plate (31), reinforcing bar (32) and positioning pipe (35) of the anchoring structure (3) are placed. The inner and outer templates of the corridor structure are built.
[0014] S4. When pouring cement-based composite materials, ensure that the upper and lower layers are mixed evenly during the pouring process to prevent uneven fiber distribution.
[0015] S5. After the engineering cement-based composite material is poured and the concrete is collected, and after the engineering cement-based composite material has set, the inner formwork support is appropriately relaxed to reduce the constraint of the inner formwork on the shrinkage deformation of the engineering cement-based composite material.
[0016] S6. After the engineering cement-based composite material is poured and reaches 30-50% of the design strength, the embedded pipe is removed to form prestressed tendon ducts (6).
[0017] S7. Insert prestressing tendons (2) into the prestressing tendon duct (6), tension the prestressing tendons (2), fix the anchor head of the prestressing tendons (2) on the pad (33), and after fixing, grout the entire prestressing tendon duct (6) through the grouting pipe (34). The grout is a cement paste one grade higher than that of the engineering cement-based composite material.
[0018] S8. After grouting is completed, the anchor head is treated, coated with anti-rust paint, and then sealed with pre-shrink mortar.
[0019] S9. Remove the inner and outer formwork in a timely manner according to the hardening condition of the cement-based composite material.
[0020] Preferably, in step S1, the plastic rod is a PVC rod with a diameter of 10 to 20 mm.
[0021] Preferably, in steps S3 and S6, the pre-embedded pipe is a PVC thin-walled corrugated pipe with a diameter of 3 to 10 cm.
[0022] The beneficial effects of this invention are as follows: This invention uses wire mesh instead of traditional steel mesh, reducing the elastic modulus to overcome the problem of deformation incompatibility between the engineering cement-based composite material and the traditional steel mesh structure, thus preventing ECC concrete from breaking at weak points. The hollow PVC plastic rods serve to fix the wire mesh structure. Furthermore, the modulus of the hollow PVC plastic rods is lower than that of steel bars (steel bars have a modulus of 2000 MPa, while PVC has a modulus of 1400 MPa). The hollow PVC plastic rods have better deformation capacity than steel bars and are better able to adapt to the high initial drying shrinkage of ECC concrete. After the engineering cement-based composite material is poured and the formwork is closed, and after the final setting of the composite material, the internal formwork support is appropriately relaxed to reduce the constraint of the internal formwork on the shrinkage deformation of the engineering cement-based composite material, thus preventing ECC concrete from breaking at weak points. The effect of prestressing tendons inserted into the prestressing tendon ducts is to replace the tensile stress reinforcement in traditional concrete structures, overcoming the problem of deformation incompatibility between the engineering cement-based composite material and the traditional steel mesh structure, and preventing ECC concrete from breaking at weak points. Attached Figure Description
[0023] Figure 1 This is a schematic diagram of the structural model of ECC concrete.
[0024] Figure 2 This is a schematic diagram showing the trend of drying shrinkage deformation of ECC concrete with different water-cement ratios over time.
[0025] Figure 3 This is a cross-sectional schematic diagram of the corridor structure in an embodiment of the present invention.
[0026] Figure 4 This is a schematic diagram of the arrangement of the skeleton frame, wire mesh, prestressing tendons, and prestressing tendon ducts in an embodiment of the present invention.
[0027] Figure 5 This is a schematic diagram of the anchoring structure in an embodiment of the present invention.
[0028] Figure 6 This is a schematic diagram of the structure of the wire mesh in an embodiment of the present invention.
[0029] Attached reference numerals: 1. Wire mesh; 2. Prestressed tendon; 3. Anchoring structure; 31. Anchor plate; 32. Reinforcing bar; 33. Pad plate; 34. Grouting pipe; 35. Positioning pipe; 4. Engineering cement-based composite material; 5. Skeleton frame; 6. Prestressed tendon duct; 7. Cup-shaped opening; A1. Main corridor body; A2. Internal corridor; A3. Detailed Implementation
[0030] To enable those skilled in the art to more clearly understand the purpose, technical solution and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments, but the present invention is not limited to the following embodiments.
[0031] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0032] like Figure 3As shown, this invention provides a corridor structure made of engineering cement-based composite material. The bottom of the corridor structure is a cup-shaped opening A1, and above the cup-shaped opening A1 is the main corridor body A2. The main corridor body A2 has an internal corridor A3 in the form of a city gate, and is constructed using engineering cement-based composite material (ECC concrete). Within the engineering cement-based composite material 4 between the outer wall of the main corridor body A2 and the internal corridor A3, there are two skeleton frames 5, one inner and one outer. The skeleton frames 5 are constructed from hollow PVC plastic rods arranged in a crisscross pattern. A layer of wire mesh 1 is fixed approximately 10cm from the outer side of each skeleton frame 5, and the inner side has crisscrossing prestressing tendon channels 6. Prestressing tendons 2 are installed in the prestressing tendon channels 6 and filled with cement grout. The two ends of the prestressing tendons 2 are fixedly connected to an anchoring structure 3, which is fixed to the skeleton frames 5.
[0033] like Figure 5 As shown, the anchoring structure 3 includes an anchor plate 31, reinforcing bars 32, and a pad 33. The reinforcing bars 32 are located at the four corners on the back of the anchor plate 31 and are anchored into the engineering cement-based composite material 4. The anchor plate 31 has through holes that pass through its front and back sides. A positioning tube 35 corresponding to the through hole is fixed on the back of the anchor plate 31. The positioning tube 35 is connected to the prestressing tendon channel 6. The prestressing tendon 2 in the prestressing tendon channel 6 passes through the positioning tube 35 and the through hole and is fixed on the pad 33.
[0034] Example 1:
[0035] Taking a certain project as an example, the corridor structure is as follows: Figure 3 As shown, the corridor is 5.5m wide, the main body of the corridor A2 above the bottom cup-shaped opening A1 is 7m high, the internal corridor A3 is in the form of a 2.5m × 3.5m city gate, and the longitudinal length of each compartment is 5m. It is cast using engineering cement-based composite material (ECC concrete).
[0036] Taking a typical cross-section of the structure as an example, a wire mesh 1 is installed 10cm away from the surface of the skeleton frame 5, such as... Figure 6 As shown, the wire mesh 1 is made of high-strength steel wire with a diameter of 5mm, which is bent and woven together, with the upper and lower wires intertwined to form a sheet-like structure.
[0037] Closely attached to the skeleton frame 5, prestressing tendons 2 are arranged at 30cm intervals in both the longitudinal and transverse directions. These prestressing tendons 2 are low-relaxation prestressing tendons with the following technical parameters: 6×37M+FC, diameter 15mm, fpk=1770MPa, Ep=1.95×105MPa, and tensile strength at break 122kN. Before use, the grease on the surface of the prestressing tendons 2 should be removed to increase the bond strength between the prestressing tendons 2 and the cement grout after subsequent grouting.
[0038] Anchorage structure 3 is provided at the anchorage location of prestressed tendon 2. The anchorage structure is as follows: Figure 5As shown, anchor plate 31 is a 10cm×10cm×1cm steel plate, with reinforcing ribs 32 at its four corners. Pad plate 33 is a 6cm×6cm×1cm steel plate. After the anchor plate 31 is perforated, the prestressing tendon 2 is tensioned, and the anchor head of the prestressing tendon 2 is fixed to the pad plate 33 using clamps. After fixing, grouting is performed through grouting pipe 34 to fill the entire prestressing tendon duct. The grout is a cement paste one grade higher than that used in ECC concrete. Positioning pipe 35 is connected to a pre-embedded PVC thin-walled corrugated pipe used to form the prestressing tendon duct.
[0039] The construction method for the cement-based composite material corridor structure of the above-mentioned project is also provided, which shall be implemented according to the following steps:
[0040] S1. Use hollow PVC plastic rods with a diameter of 15mm to build the skeleton frame of the corridor structure 5;
[0041] S2. Fix the wire mesh 1 to one side of the frame 5;
[0042] S3. On the other side of the skeleton frame 5, a pre-embedded pipe is laid. The pre-embedded pipe is a thin-walled corrugated PVC pipe with a diameter of 5cm. At the same time, the anchor plate 31, reinforcing bar 32 and positioning pipe 35 of the anchoring structure 3 are fixed, and the inner and outer templates of the corridor structure are built.
[0043] S4. When pouring cement-based composite materials (ECC concrete), ensure that the upper and lower layers are mixed evenly during the pouring process to prevent uneven fiber distribution.
[0044] S5. After the engineering cement-based composite material is poured and the concrete is collected, and after the engineering cement-based composite material has set, the inner formwork support is appropriately relaxed to reduce the constraint of the inner formwork on the shrinkage deformation of the engineering cement-based composite material.
[0045] S6. After the engineering cement-based composite material is poured and reaches 30-50% of the design strength, use tools to remove the embedded pipe to form the prestressed tendon duct 6.
[0046] S7. Insert prestressing tendons 2 into the prestressing tendon duct, tension the prestressing tendons 2, and fix the anchor heads of the prestressing tendons 2 to the pad 33 by means of clamp fixing. After fixing, grout the entire prestressing tendon duct through the grouting pipe 34. The grout is a cement paste of a higher grade than that of engineering cement-based composite materials.
[0047] S8. After grouting is completed, the anchor head is treated by applying anti-rust paint and then sealing the hole with pre-shrink mortar.
[0048] S9. Remove the inner and outer formwork in a timely manner according to the hardening condition of the cement-based composite material.
[0049] The above description is merely a preferred embodiment of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A corridor structure made of engineering cement-based composite material, wherein the bottom of the corridor structure is a cup-shaped opening (A1), and above the cup-shaped opening (A1) is a corridor body (A2) cast using engineering cement-based composite material, and the corridor body (A2) has an internal corridor (A3) in the form of a city gate, characterized in that: The main body of the corridor (A2) has two skeleton frames (5) between its outer wall and the inner corridor (A3). The skeleton frames (5) are constructed from hollow PVC plastic rods arranged in a crisscross pattern. Each skeleton frame (5) has a layer of wire mesh (1) fixed on its outer side and crisscross prestressed tendon channels (6) on its inner side. The prestressed tendon channels (6) contain prestressed tendons (2) and are filled with cement grout. The two ends of the prestressed tendons (2) are fixedly connected to the anchoring structure (3). The anchoring structure (3) is fixed to the skeleton frame (5). The anchoring structure (3) includes an anchor plate (31), reinforcing bars (32) and a pad plate (33). The reinforcing bars (32) are located at the four corners on the back of the anchor plate (31). The anchor plate (31) has through holes that pass through its front and back sides. A positioning tube (35) corresponding to the hole is fixed on the back of the anchor plate (31). The positioning tube (35) is connected to the prestressing tendon channel. The prestressing tendon (2) in the prestressing tendon channel passes through the positioning tube (35) and the through hole and is fixed on the pad plate (33).
2. The corridor structure of engineering cement-based composite material according to claim 1, characterized in that: The wire mesh (1) is kept at a distance from the skeleton frame (5).
3. The construction method of the corridor structure of the engineering cement-based composite material as described in any one of claims 1 to 2, characterized in that... Includes the following steps: S1. Use plastic rods to build the skeleton frame of the corridor structure (5). S2. Fix the wire mesh (1) to one side of the frame (5); S3. On the other side of the skeleton frame (5), the embedded pipe is laid, and the anchor plate (31), reinforcing bar (32) and positioning pipe (35) of the anchoring structure (3) are placed. The inner and outer templates of the corridor structure are built. S4. When pouring cement-based composite materials, ensure that the upper and lower layers are mixed evenly during the pouring process to prevent uneven fiber distribution. S5. After the engineering cement-based composite material is poured and the concrete is collected, and after the engineering cement-based composite material has set, the inner formwork support is appropriately relaxed to reduce the constraint of the inner formwork on the shrinkage deformation of the engineering cement-based composite material. S6. After the engineering cement-based composite material is poured and reaches 30-50% of the design strength, the embedded pipe is removed to form prestressed tendon ducts (6). S7. Insert prestressing tendons (2) into the prestressing tendon duct (6), tension the prestressing tendons (2), fix the anchor head of the prestressing tendons (2) on the pad (33), and after fixing, grout the entire prestressing tendon duct (6) through the grouting pipe (34). The grout is a cement paste one grade higher than that of the engineering cement-based composite material. S8. After grouting is completed, the anchor head is treated, coated with anti-rust paint, and then sealed with pre-shrink mortar. S9. Remove the inner and outer formwork in a timely manner according to the hardening condition of the cement-based composite material.
4. The construction method as described in claim 3, characterized in that: In step S1, the plastic rod is a hollow PVC rod with a diameter of 10~20mm.
5. The construction method as described in claim 4, characterized in that: In steps S3 and S6, the pre-embedded pipe is a PVC thin-walled corrugated pipe with a diameter of 3 to 10 cm.