A high-efficiency construction method for rapidly repairing a cement concrete bridge deck by using UHPC

Abstract

The application relates to a kind of high-efficiency construction methods for rapidly repairing cement concrete bridge deck with UHPC, and belongs to the technical field of bridge repair, comprising the following steps: step one: damage assessment, judging damage condition according to bridge deck damage range and depth; step two: surface treatment, dust removal, decontamination and cleaning of boundary crack area not connected with the center of damaged area using tools to make the boundary crack area connected with the center of damaged area, forming a complete repair surface; step three: data recording of cleaned damage range and depth; step four: UHPC material preparation, preparing raw materials and making according to the data recorded in step three; step five: pouring the prepared UHPC material into the center of damaged area, and thin rod is needed to guide the boundary crack area; step six: after repair is completed, covering the damaged area with film for wet curing, which can improve construction efficiency, relieve traffic pressure, shorten repair period and reduce maintenance cost.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of bridge repair, and particularly relates to a high-efficiency construction method for rapidly repairing a cement concrete bridge deck by using UHPC. BACKGROUND

[0002] As a new type of high-performance concrete material, UHPC has the characteristics of high strength, high toughness, and high durability. The compressive strength and tensile strength of UHPC are much higher than those of ordinary concrete, and UHPC has excellent wear resistance and corrosion resistance, so that UHPC has a significant advantage in bridge deck repair. In addition, UHPC also has good fluidity and self-compacting property, which can effectively fill cracks and holes and improve the repair quality.

[0003] With the continuous acceleration of infrastructure construction, the cement concrete bridge deck is increasingly frequently used, so the demand for bridge deck damage repair is increasingly urgent. The traditional repair method often has problems such as long construction period and unsatisfactory repair effect, and cannot meet the demand of modern rapid construction.

[0004] Part of the bridge deck needs to bear a large amount of traffic as the main artery of the city, but for the construction and repair on the bridge, the construction area needs to be divided to ensure the safety of construction personnel during repair, which causes the vehicles to be unable to normally pass through, resulting in a large traffic pressure of the entire city. Therefore, the construction efficiency during the repair of the bridge deck needs to be improved to restore the normal operation of the bridge deck and speed up the time for the vehicles to normally pass through. In addition, the durability of the repair needs to be ensured and the quality of the bridge deck needs to be improved as the bridge deck bears a large amount of traffic.

[0005] In the existing construction method for repairing the bridge deck, a transport vehicle is usually needed to transport repair materials to the repair area. In order to ensure the safety of the construction personnel, the entire bridge deck or even the entire lane needs to be divided into a construction area to interrupt the traffic on the bridge deck. In addition, the repair of the bridge deck involves complicated procedures such as bridge deck evaluation, modification, cleaning, maintenance, and acceptance, and the complicated construction process seriously affects the traffic.

[0006] Therefore, there is an urgent need to develop a new type of high-efficiency bridge deck repair method. SUMMARY

[0007] To solve the above problems in the prior art, the application provides a high-efficiency construction method for rapidly repairing a cement concrete bridge deck by using UHPC, which solves the problems of complicated construction process, low efficiency, and increased traffic pressure of the existing repair method.

[0008] The object of the application can be achieved by the following technical solutions.

[0009] An efficient construction method for rapid repair of cement concrete bridge decks using UHPC includes step one: damage assessment, which determines the extent and depth of damage to the bridge deck.

[0010] Step 2: Surface treatment. If the damage is localized and large, remove dust and dirt from the damaged surface and use tools to clean the boundary crack areas that are not connected to the center of the damaged area, so that the boundary crack areas are connected to the center of the damaged area to form a complete repair surface.

[0011] Step 3: Record the extent and depth of damage after cleaning;

[0012] Step 4: UHPC material preparation, based on the data recorded in Step 3, prepare and manufacture the raw materials;

[0013] Step 5: Pour the prepared UHPC material into the center of the damaged area. The boundary crack area needs to be guided by a thin rod to fill the boundary crack area with UHPC material.

[0014] Step Six: After the repair is completed, cover the damaged area with a film for wet curing.

[0015] Preferably, in step two, the individually split regions are connected to each other through openings, and the opening of the crack region near the center of the damaged region is connected to the center of the damaged region.

[0016] Preferably, step four includes:

[0017] S401, Selection and preparation of raw materials, including cement, ultrafine powder, fine aggregate and fine sand, steel fiber and chemical additives.

[0018] S402, the raw material ratio is determined, wherein the ratio of cement, ultrafine powder, fine aggregate, fine sand and steel fiber is 1:1:1:2.5;

[0019] S403 uses a high-speed mixer to ensure that the raw materials are mixed evenly.

[0020] Preferably, the water-to-binder ratio of the UHPC material is between 0.15 and 0.25.

[0021] Preferably, the chemical additive is a water-reducing agent, and the dosage of the water-reducing agent is 4%.

[0022] Preferably, when the damaged area is located on a steep slope of the bridge, a positioning mechanism is installed in the damaged area, and the positioning mechanism is covered with a membrane. The steep slope extends from bottom to top, and the membrane covers 2 / 3 of the damaged area and adheres to the bridge surface.

[0023] Preferably, the positioning mechanism comprises two horizontal assemblies and two vertical assemblies; the two ends of any horizontal assembly are detachably connected with the vertical assemblies; the horizontal assemblies and the vertical assemblies are of the same structure, the horizontal assembly comprises a fixed segment and a telescopic segment, the telescopic segment is sleeved on the fixed segment and is in sliding connection with the fixed segment.

[0024] Preferably, the positioning mechanism further comprises a horizontal adjusting member and a vertical adjusting member, the horizontal adjusting member and the vertical adjusting member are both mounted on the side of the fixed segment of the respective assembly close to the telescopic segment; the horizontal adjusting member is used for adjusting the length of the horizontal assembly, the vertical adjusting member is used for adjusting the width of the vertical assembly, the horizontal adjusting member and the vertical adjusting member are of the same structure, the horizontal adjusting member comprises a gear and a rack, the gear is mounted in the fixed segment and is provided with a rotating member extending out of the fixed segment, the rotating member is used for rotating the gear, the rack is mounted on the telescopic segment and is in meshing connection with the gear in the fixed segment.

[0025] Preferably, the positioning mechanism further comprises a bolt, the fixed segment is further provided with a bolt hole, the bolt is matched with the bolt hole to position the length and the width of the positioning mechanism.

[0026] The present application has the following beneficial effects:

[0027] The damaged area has similar load-carrying capacity and service life to the original bridge deck, and the use life of the bridge deck is prolonged and the frequency of maintenance and reconstruction is reduced, thereby reducing the long-term maintenance cost. BRIEF DESCRIPTION OF DRAWINGS

[0028] For the convenience of those skilled in the art, the present application will be further described below with reference to the accompanying drawings.

[0029] Fig. 1 The schematic diagram of the positioning mechanism installation structure provided in an embodiment of the present application is shown in the figure;

[0030] Fig. 2 The schematic diagram of the positioning mechanism installation structure provided in an embodiment of the present application is shown in the figure;

[0031] Fig. 3 The schematic diagram of the horizontal positioning assembly connection structure provided in an embodiment of the present application is shown in the figure;

[0032] Legend: 1, damaged area; 11, boundary crack area; 12, opening; 21, horizontal assembly; 22, vertical assembly; 211, fixed segment; 212, telescopic segment; 3, horizontal adjusting member; 31, gear; 32, rack. DETAILED DESCRIPTION

[0033] To further clarify the technical means and effects taken by the present application to achieve the predetermined inventive purpose, the specific embodiments, structures, features and effects thereof according to the present application are described in detail below in combination with the drawings and preferred embodiments.

[0034] As shown in the drawings, Figs. 1-3 An efficient construction method for rapidly repairing a cement concrete bridge deck with UHPC, comprising the following steps: Step 1: damage assessment, determining whether it is crack damage or local area damage according to the damage range and depth of the bridge deck; On a certain cement concrete bridge deck, a local damage area 1 with an area of 2 square meters and a depth of about 5 centimeters is found, accompanied by several small cracks; After evaluation, it is determined that the area is a local area damage, which needs to be rapidly repaired;

[0035] Step 2: surface treatment, if it is a local large range damage, the damaged surface is dusted, decontaminated, and the boundary crack area 11 not connected with the damaged area 1 is cleaned with a tool to make the boundary crack area 11 connected with the damaged area 1, forming a complete repair surface; high-pressure air gun is used to clean the damaged area 1, and cleaning agent is used to remove oil stains and other impurities; Then, a special tool such as a chisel is used to process the opening 12 of the boundary crack area 11 not connected with the damaged area 1, until the crack is connected with the center of the damaged area 1, forming a smooth and continuous repair surface.

[0036] Step 3: record the damage range and depth data after cleaning; record the damage range and depth after cleaning in detail as reference data for subsequent UHPC material preparation.

[0037] Step 4: UHPC material preparation, prepare and make raw materials according to the data recorded in step 3 to ensure that the repair material has excellent fluidity, adhesion and self-stability; According to the recorded damage range and depth data, calculate the volume of the repair space, and determine the corresponding raw materials according to the formula proportion of UHPC material, and ensure uniform mixing of the materials during stirring to obtain excellent fluidity, adhesion and self-stability.

[0038] Step 4: Pour the prepared UHPC material into the center of the damaged area 1, and use a thin rod to guide the boundary crack area to fill the UHPC material; The prepared UHPC material can completely fill the damaged area 1 and form a firm bond with the original bridge deck.

[0039] Step five: after the repair is completed, cover the damaged area 1 with a film for wet curing; immediately after the repair is completed, cover the damaged area 1 with a plastic film for wet curing, and periodically check the integrity of the film during the curing period to ensure that the damaged area 1 remains wet at all times. Wet curing can effectively promote the hardening and strength development of UHPC materials, ensuring that the damaged area 1 forms a solid whole with the original bridge deck.

[0040] Based on the above construction steps, compared with the existing bridge deck repair process, such as asphalt, the construction method is to cut off the damaged part with a cutting tool, clean the dust and debris, spray the adhesive layer of asphalt, evenly lay the good asphalt repair material on the damaged area 1, compact the asphalt, and maintain it; Among them, because the fluidity of asphalt is poor, in order to ensure the durability of asphalt, the damaged boundary crack area 11 needs to be completely removed until the dense concrete bridge deck is left, and after the boundary crack area 11 is removed, the concrete needs to be collected and cleaned, and the damaged area 1 is cleaned with a high-pressure water gun. Before laying the asphalt material, it also needs to be dried, and then the adhesive layer is brushed, so that the adhesion strength of the asphalt material to the bridge deck is high, which ensures the durability of the asphalt. It can be seen that the repair method of the asphalt material needs to use more tools, the construction process of the damaged area 1 is more and more complicated, and it takes a long time and is not efficient; However, if the bridge is the main artery of the city and needs to bear a large amount of traffic, the multi-lane bridge becomes a single-lane traffic due to repair, and if the bridge repair time is too long and the efficiency is too low, the vehicle cannot pass normally, resulting in that the original multi-lane can only realize single-lane traffic, causing the traffic pressure of the whole city to be large; Therefore, the application uses UHPC material as the repair material, controls the fluidity of UHPC by adjusting the ratio of UHPC, so that UHPC can automatically fill the edge crack area by itself during repair, and the crack area is open 12, which can ensure the repair effect of the boundary crack area 11, and the boundary crack area 11 does not need to be removed, which improves the construction efficiency and enters the curing stage as soon as possible. When in the curing stage, the damaged area 1 is surrounded, the construction area surrounded during construction is shortened, the space for vehicle traffic is increased, the time for normal vehicle traffic is accelerated, and the traffic pressure caused by bridge repair is reduced.

[0041] In summary, using UHPC material for repair can complete the repair work in a short time, reduce the impact on traffic, shorten the repair period, and UHPC material has excellent mechanical properties and durability, which can ensure that the damaged area 1 has similar load-carrying capacity and service life as the original bridge deck; Through rapid and efficient repair, the service life of the bridge deck can be prolonged, and the frequency of maintenance and reconstruction can be reduced, thereby reducing long-term maintenance costs.

[0042] In an embodiment, in step two, the openings 12 between the separately cracked areas are connected to each other, and the openings 12 of the boundary crack areas 11 closer to the edge of the damaged area 1 are connected to the center of the damaged area 1; UHPC material is known for its excellent fluidity, which can fill small gaps and holes. By connecting the dispersed crack openings 12 and connecting them to the damaged area 1, it can be ensured that the UHPC material can flow smoothly into each boundary crack area 11 when pouring, so as to fully utilize the fluidity characteristics of the material; in the traditional repair method, it may be necessary to first chisel or clean the edge cracks and integrate them with the damaged area 1, which is easier to fill; however, this method increases the complexity and time cost of construction operation, and in this embodiment, according to the fluidity characteristics of UHPC, the edge cracks are not chiseled but directly connected by openings 12, which not only simplifies the construction steps, but also improves the construction efficiency; in addition, by connecting the multiple dispersed crack openings 12 and connecting them to the damaged area 1, a continuous damaged area 1 can be formed; in this way, when the UHPC material is filled and hardened, a more solid overall structure will be formed, thereby improving the strength and durability of the damaged area 1. When pouring the repair material, it can also be distributed and operated, first, the UHPC material is poured in the crack area, so that the crack area is not filled through the opening 12, but the UHPC material poured in the crack area penetrates from the crack area to the center of the damaged area 1, and then the main UHPC material is poured in the center of the damaged area 1, so that the repair material poured in the crack edge is fully integrated with the repair material poured in the center of the damaged area 1; at the same time, connecting the crack openings 12 and connecting them to the damaged area 1 can disperse stress and reduce the occurrence of stress concentration, thereby improving the overall stability of the bridge deck. By making full use of the fluidity characteristics of UHPC material for efficient repair, the long-term maintenance cost of the bridge can be reduced, because the continuous structure formed by the damaged area 1 has high strength and durability, which can reduce future repair and reinforcement work due to damage.

[0043] In summary, according to the fluidity characteristics of UHPC, the strategy of directly connecting the edge cracks by openings 12 without chiseling can fully utilize the performance characteristics of the material, improve the repair efficiency and quality, and reduce the construction cost and maintenance cost.

[0044] In an embodiment, step four includes:

[0045] S401, selection and preparation of raw materials, including cement, ultra-fine powder, fine aggregate and fine sand, steel fiber and chemical additives; wherein for the selection of raw materials, ultra-fine powder uses ultra-fine mineral powder with high activity, such as silica fume, slag powder, etc., for improving the microstructure and mechanical properties of the material; select fine aggregate and fine sand with reasonable particle size distribution and stable quality to provide the skeleton and filling effect required by UHPC material; add appropriate steel fiber to increase the tensile strength and toughness of UHPC, and improve the overall performance of the repair layer;

[0046] S402, determination of raw material ratio, wherein the ratio of cement, ultra-fine powder, fine aggregate, fine sand and steel fiber is 1:1:1:2.5; according to the actual situation of bridge damage and the performance requirements of UHPC material, the ratio of raw materials is determined, the ratio of cement, ultra-fine powder, fine aggregate, fine sand and steel fiber is 1:1:1:2.5, which can provide excellent fluidity, adhesion and self-stability, and is suitable for rapid repair of bridge deck.

[0047] S403, using high-speed mixer for stirring to ensure uniform mixing of raw materials; put the prepared raw materials into the high-speed mixer according to the determined ratio. Because steel fiber plays a crucial role, it is necessary to ensure that the steel fiber is evenly distributed in the UHPC material, so that the repaired bridge deck has strong compressive and tensile properties; turn on the mixer, adjust the stirring speed and time to ensure that the raw materials are fully mixed and uniformly dispersed; add an appropriate amount of water or other liquid additives during stirring to adjust the consistency and fluidity of UHPC; after stirring is completed, the prepared UHPC material is transported to the construction site to prepare for subsequent repair work.

[0048] In an embodiment, the water-binder ratio of UHPC material is between 0.15-0.25, which means that the amount of mixing water required per part of cement is low, which helps to reduce the porosity of concrete and improve the density, thereby enhancing the strength and durability of concrete; due to the low water-binder ratio, the porosity of concrete is reduced, which helps to reduce the possibility of harmful ion and gas penetration and improve the impermeability of concrete.

[0049] In an embodiment, the chemical additive is a water reducing agent, and the dosage of the water reducing agent is 4%; the addition of water reducing agent can effectively improve the fluidity of UHPC, making it easier to pour, reducing the construction difficulty, and the addition of water reducing agent also helps to reduce the pores and cracks in the concrete, further improving its durability and impermeability.

[0050] In an embodiment, when the damaged area 1 is located on the steep slope section of the bridge, the damaged area 1 is installed with a positioning mechanism, and the positioning mechanism is installed with a film. From bottom to top, the film covers 2 / 3 of the damaged area 1 and adheres to the bridge deck, ensuring that the damaged area 1 located on the upper steep slope area can be fully filled with UHPC material. Due to gravity and the high flowability of UHPC material, the material is prone to flow to the low place on the steep slope section. By covering the damaged area 1 with a film of 2 / 3, the excessive flow of UHPC material to the low place can be effectively prevented, ensuring the full repair of the high area. Due to the effect of the film, the damaged area 1 located on the upper steep slope area can be fully filled with UHPC material, ensuring the integrity and strength of the damaged area 1. This is crucial for restoring the structural integrity and safety of the bridge.

[0051] In an embodiment, the positioning mechanism includes two horizontal components 21 and two vertical components 22. Either end of the horizontal component 21 is detachably connected to the vertical component 22. The horizontal component 21 and the vertical component 22 have the same structure, and the horizontal component 21 includes a fixed section 211 and a telescopic section 212. The telescopic section 212 is sleeved on the fixed section 211 and is in sliding connection with the fixed section 211. The structure of the horizontal component 21 and the vertical component 22 is consistent, and both are composed of a fixed section 211 and a telescopic section 212. The telescopic section 212 is sleeved on the fixed section 211 and is in sliding connection with the fixed section 211. This design allows the positioning mechanism to be adjusted according to the size of the damaged area 1. When the size of the positioning mechanism needs to be adjusted, the length of the telescopic section 212 can be changed by sliding it, thereby adapting to different sizes of the damaged area 1. In actual operation, first, the size of the positioning mechanism is determined according to the specific size of the damaged area 1 of the bridge. Then, the length of the horizontal component 21 and the vertical component 22 is adjusted by sliding the telescopic section 212, so that they match the damaged area 1. Next, the two ends of the horizontal component 21 are detachably connected to the vertical component 22 to form a complete positioning mechanism. Finally, the positioning mechanism is placed on the damaged area 1 to ensure that it closely adheres to the bridge deck, providing stable support for subsequent UHPC material repair. The horizontal component 21 and the vertical component 22 of the positioning mechanism both use telescopic sections 212, so they can be adjusted according to the size of the damaged area 1, have strong adaptability, and can be widely used in the repair work of various damaged areas 1 of bridges, improving their value and practicality. The horizontal component 21 and the vertical component 22 of the positioning mechanism are detachably connected, so that the positioning mechanism can be disassembled for cleaning and maintenance after completing a repair work, ready for the next use.

[0052] In an embodiment, the positioning mechanism further comprises a horizontal adjusting member 3 and a vertical adjusting member, both of which are mounted on the fixed section 211 of the respective assembly near the telescopic section 212; the horizontal adjusting member 3 is used to adjust the length of the horizontal assembly 21, and the vertical adjusting member is used to adjust the width of the vertical assembly 22; the horizontal adjusting member 3 and the vertical adjusting member have the same structure, and the horizontal adjusting member 3 comprises a rotating gear 31 and a rack 32; the gear 31 is mounted in the fixed section 211 and is provided with a rotating member extending out of the fixed section 211, the rotating member is used to rotate the gear 31, and the rack 32 is mounted on the telescopic section 212 and is engaged with the gear 31 in the fixed section 211; when it is necessary to adjust the length or width of the horizontal assembly 21 or the vertical assembly 22, the gear 31 is driven to rotate by rotating the rotating member, and the rotation of the gear 31 drives the rack 32 engaged therewith to move linearly, thereby pushing the telescopic section 212 to slide in the fixed section 211; by controlling the rotating direction and rotating amount of the gear 31, the extension or retraction length of the telescopic section 212 can be accurately adjusted, and the length or width of the entire assembly is adjusted; by adjusting the length and width of the horizontal assembly 21 and the vertical assembly 22, the positioning mechanism can adapt to damaged areas 1 of different sizes and shapes, and the application range and flexibility thereof are improved.

[0053] In an embodiment, the positioning mechanism further comprises a latch, and the fixed section 211 and the telescopic section 212 are further provided with latch holes, and the latch is matched with the latch holes to position the length and width of the positioning mechanism; after the positioning mechanism is adjusted to a suitable position, the telescopic section 212 is fixed on the fixed section 211 by the latch, so that the positioning mechanism can be stably maintained at the required position, and the insertion and extraction operation of the latch is simple and convenient, and the positioning and releasing operations can be quickly performed.

[0054] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Although the present application has been disclosed as above with reference to the preferred embodiment, it is not intended to limit the present application, and any person skilled in the art can make some changes or modifications to the above disclosed technical content to obtain equivalent embodiments with equivalent changes, without departing from the technical solution of the present application. Any modification, change, equivalent change and modification of the above embodiment based on the technical essence of the present application are still within the scope of the technical solution of the present application.

Claims

1. A high-efficiency construction method for rapidly repairing a cement concrete bridge deck with UHPC, characterized in that, The method comprises the following steps: step one: damage assessment, judging the damage condition according to the damage range and depth of the bridge deck; Step two: surface treatment, if the damage is in a large local range, the damaged surface is cleaned, the dirt is removed, and the boundary crack area not connected with the center of the damaged area is cleaned to make the boundary crack area connected with the center of the damaged area, forming a complete repair surface; in step two, the mutually opened areas between the separately cracked areas are connected, and the opening of the boundary crack area close to the center of the damaged area is connected with the center of the damaged area; Step three: recording the data of the cleaned damage range and depth; Step four: UHPC material preparation, preparing and producing the raw materials according to the data recorded in step three; S401, selecting and preparing the raw materials, the raw materials including cement, superfine powder, fine aggregate and fine sand, steel fiber and chemical additives; S402, determining the proportion of the raw materials; S403, stirring by using a high-speed mixer to ensure that the raw materials are uniformly mixed; Step five: pouring the UHPC material in the boundary crack area, so that the boundary crack area is not filled through the opening, but the UHPC material poured in the boundary crack area penetrates from the boundary crack area to the center of the damaged area, and then the main UHPC material is poured in the center of the damaged area, so that the repair material poured in the crack edge is fully fused with the repair material poured in the center of the damaged area; Step six: after the repair is completed, covering the damaged area with a film for wet curing; the water-binder ratio of the UHPC material is between 0.15 and 0.25; when the damaged area is located in the steep slope section of the bridge, the damaged area is provided with a positioning mechanism, the positioning mechanism is provided with a film, the steep slope is from bottom to top, and the film covers 2 / 3 of the damaged area and is attached to the bridge deck. 2.The high-efficiency construction method for rapidly repairing a cement concrete bridge deck with UHPC according to claim 1, characterized in that, The chemical additive is a water reducing agent, and the mixing amount of the water reducing agent is 4%.

3. The high-efficiency construction method for rapidly repairing a cement concrete bridge surface with UHPC according to claim 1, characterized in that, The positioning mechanism comprises two horizontal assemblies and two vertical assemblies; the two ends of any horizontal assembly are respectively detachably connected with the vertical assemblies; the horizontal assembly and the vertical assembly are identical in structure, the horizontal assembly comprises a fixed section and an extension section, and the extension section is sleeved on the fixed section and is in sliding connection with the fixed section.

4. The high-efficiency construction method for rapidly repairing a cement concrete bridge surface with UHPC according to claim 3, characterized in that, The positioning mechanism further comprises a horizontal adjusting member and a vertical adjusting member, the horizontal adjusting member and the vertical adjusting member are installed on the side of the fixed section of each assembly close to the extension section; the horizontal adjusting member is used for adjusting the length of the horizontal assembly, the vertical adjusting member is used for adjusting the width of the vertical assembly, the horizontal adjusting member and the vertical adjusting member are identical in structure, the horizontal adjusting member comprises a rotating gear and a rack, the gear is installed in the fixed section and is provided with a rotating member extending out of the fixed section, the rotating member is used for rotating the gear, and the rack is installed on the extension section and is in meshing connection with the gear in the fixed section.

5. The high-efficiency construction method for rapidly repairing a cement concrete bridge surface with UHPC according to claim 4, characterized in that, The positioning mechanism further comprises a bolt, the fixed section is further provided with a bolt hole, and the bolt is matched with the bolt hole to position the length and width of the positioning mechanism.

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