CN111827465A - A kind of reinforced rockfill concrete structure and construction method thereof - Google Patents

Abstract

The invention discloses a reinforced rockfill concrete structure and a construction method thereof. The reinforced rockfill concrete structure comprises rockfill concrete and steel bars arranged at the bottom, surrounding, top and interior of the rockfill concrete silo surface according to design requirements. The construction method includes: after laying the bottom steel bars and vertical steel bars according to the design requirements, pouring self-compacting concrete that can completely cover the bottom steel bars and the thickness of the excess steel bars is not less than 150mm to 300mm; The blocks with the required particle size are thrown into the self-compacting concrete containing coarse aggregate; continue to follow the riprap type rockfill concrete process or use the ordinary rockfill concrete construction process, continue to construct to the top surface of the structure, and complete the pouring process. The invention combines rockfill concrete and reinforced concrete, and is suitable for large-volume concrete structures requiring reinforcement at the bottom, surrounding, top and interior, and has the advantages of less cement consumption, low hydration temperature rise, easy continuous construction and the like.

Description

A kind of reinforced rockfill concrete structure and construction method thereof

technical field

The invention relates to a concrete structure and a construction method, in particular to a large-volume concrete structure with design requirements for peripheral reinforcement and a small amount of internal reinforcement, and a matching construction method.

Background technique

Mass concrete is a very important part of concrete engineering. In actual engineering, there are often reinforcement requirements for mass concrete to form a mass reinforced concrete structure. This structure is widely used in bridges, sluices, subways, high-rise buildings and other projects. However, the traditional mass concrete construction method has high cement consumption and difficult temperature control, which makes the mass reinforced concrete structure easy to crack and the cost is high.

Rockfill concrete (Jin Feng, An Xuehui, Construction method of rockfill concrete dam, ZL03102674.5) uses a large number of large-diameter blocks or pebbles, which not only saves cement consumption and costs, but also greatly reduces hydration heat and simplifies temperature. It has been widely used in dam projects. Rockfill concrete construction technology can be divided into ordinary rockfill concrete construction method (Jin Feng, An Xuehui, Xiaoyuan Xiaozhi, etc. Ordinary rockfill concrete construction method, ZL200710100315.3) and riprap rockfill concrete construction method (An Xue Hui, Jin Feng, Xiaoyuan Xiaozhi, etc. Construction method of riprap type rockfill concrete, ZL200710121791.3). Ordinary rockfill concrete first transports the rockfill that meets the requirements to the warehouse surface for natural accumulation, and then uses the self-compacting concrete that meets the requirements to pour from the surface of the rockfill body. High strength rockfill concrete. The riprap type rockfill concrete is to pour the self-compacting concrete with excellent segregation resistance and good plasticity into the silo, and then throw the boulders or pebbles into the poured self-compacting concrete by mechanical or manual methods. Form a complete and dense rockfill concrete. Rockfill concrete simplifies the construction process and required equipment, and the construction speed is greatly improved; using a large number of blocks and pebbles, only 40-50% of the concrete is needed for each square of rockfill concrete, which effectively reduces the cost of concrete by more than 30% and effectively solves the problem. The heat of hydration problem of mass concrete. However, rockfill concrete is currently only used in large-volume concrete structures such as dams. When large-volume reinforced concrete is used, it is necessary to arrange steel bars at the bottom or inside of the silo surface. The technology cannot be directly applied to large-volume reinforced concrete structures.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the deficiencies of the prior art, propose a reinforced rockfill concrete structure and a construction method thereof, and apply the advantages of the rockfill concrete technology to contain reinforcement requirements, especially with peripheral reinforcement and a small amount of internal reinforcement. In the mass concrete projects required by the reinforcement design, the application scope of rockfill concrete is widened to solve the difficult temperature control and high cost of mass reinforced concrete in bridges, sluices, subways, high-rise buildings and other projects.

To achieve the above object, the present invention adopts the following technical solutions:

A reinforced rockfill concrete structure proposed by the present invention is characterized in that it includes steel bars or their substitutes and rockfill concrete; the steel bars or their substitutes are steel bars or their substitutes arranged according to design requirements, and are arranged on the warehouse surface. Bottom, surrounding, top and interior; the rockfill concrete includes rockfill and self-compacting concrete, wherein, the rockfill is made of boulders or pebbles, and its saturated compressive strength should exceed the compressive strength requirements of large-volume reinforced concrete. The minimum particle size of the rockfill mentioned above is 50mm; when using riprap type rockfill concrete, the maximum particle size of the rockfill used shall not exceed 500mm; when using ordinary rockfill concrete, the maximum particle size of the rockfill used shall not exceed that of the construction machinery. The transportation capacity is less than 1/8~1/4 of the structure size or the thickness of the pouring layer; the self-compacting concrete contains coarse aggregate, and the maximum particle size of the coarse aggregate is 10mm~20mm, and the performance of the self-compacting concrete meets the requirements of large Design requirements for volumetric reinforced concrete; the self-compacting material with a thickness of not less than 150mm to 300mm in excess of the thickness of the corresponding steel bar or its substitute by pouring steel bars or their substitutes at the bottom and inside of the silo surface The concrete forms a protective layer; the self-compacting concrete that can completely cover the steel bar or its substitute and reach the design height of the top of the silo surface is poured at the place where the steel bar or its substitute is laid on the top of the silo surface.

The present invention also proposes a construction method for the above-mentioned reinforced rockfill concrete structure, which is characterized by comprising the following steps:

1) Arrange bottom steel bars or their substitutes and surrounding steel bars or their substitutes for the silo surface where the rockfill concrete needs to be poured, and set up formwork or formwork substitutes;

2) The bottom of the warehouse surface shall be constructed by using the riprap type rockfill concrete construction method. First pour the self-compacting concrete that can completely cover the bottom steel bar or its substitute and whose thickness exceeds the steel bar or its substitute by not less than 150mm to 300mm. Then the rockfill with a particle size of 50mm to 500mm is evenly thrown into the self-compacting concrete;

3) Continue to rip rock into the silo surface and pour self-compacting concrete at the same time, and continue to carry out riprap type rockfill concrete construction until the silo surface is poured; After the rockfill concrete is constructed, continue to dump and fill the rockfill with a particle size of 50mm to 500mm to the set height, adopt the ordinary rockfill concrete process, and pour the self-compacting concrete to fill the rockfill voids in the formwork or its substitute until it reaches the set height. Design height for pouring to the top of the silo face.

Further, when it is necessary to lay steel bars or their substitutes inside the warehouse surface according to the design requirements, step 3) is replaced by the following steps: first, the rockfill concrete is constructed to below the height of the internal steel bars or their substitutes, and then the steel bars are laid out. or its substitute; then pour the self-compacting concrete that completely covers the steel bar or its substitute and the thickness of the steel bar or its substitute is not less than 150mm to 300mm, and then adopts the construction of riprap type rockfill concrete The process is to throw the rockfill into the poured self-compacting concrete evenly; continue to rip rock into the silo surface and pour the self-compacting concrete at the same time, and continue to carry out the riprap type rockfill concrete construction until the silo surface is poured.

Further, when the steel bar or its substitute needs to be laid on the top of the warehouse surface according to the design requirements, step 3) also includes the following steps: when the rockfill concrete is constructed to the design height of the steel bar or its substitute on the top of the warehouse surface, the top is laid. The rebar or its substitute; pour the self-compacting concrete that can completely cover the top rebar or its substitute and reach the design height of the top of the silo surface.

The invention proposes a reinforced rockfill concrete structure and a construction method by combining the rockfill concrete and the reinforced concrete on the basis of the existing rockfill concrete structure and construction method. Compared with the existing large-volume concrete structure and construction method, the present invention has the following advantages: 1. Compared with the existing rockfill concrete structure, the bottom, surrounding, top and interior of the poured silo surface of the structure of the present invention can be arranged 2. Compared with ordinary mass concrete, the present invention pours rockfill concrete in the middle of the silo surface, and the actual field test verification shows that the rockfill rate can reach 50% during construction, and the cement consumption is greatly reduced. Reduce the heat of concrete hydration, thereby canceling the temperature control measures such as burying cooling water pipes; 3. The present invention adopts the self-compacting concrete poured first during construction of the riprap type rockfill concrete, which can protect the steel bars and prevent the rockfill from smashing the steel bars; ④ The present invention adopts the throwing The combination of rock-type rockfill concrete and ordinary rockfill concrete construction methods can further reduce the requirements for construction equipment, speed up the construction process, and reduce construction costs.

Description of drawings

FIG. 1 is a schematic diagram of a reinforced rockfill concrete structure according to an embodiment of the present invention.

Figures 2, 3, and 4 are schematic diagrams of the construction process of a reinforced rockfill concrete structure with bottom horizontal steel bars, surrounding vertical steel bars and top horizontal steel bars;

Figures 5 and 6 are schematic diagrams of the construction process of setting internal horizontal steel bars in a reinforced rockfill concrete structure.

Figures 7 and 8 are schematic diagrams of the construction process of the reinforced rockfill concrete structure with reinforcement requirements in the interior and the top;

FIG. 9 is a structural schematic diagram of the completion of pouring of reinforced rockfill concrete with internal reinforcement.

Reference number:

1: Bottom horizontal rebar; 2: All around vertical rebar; 3: Formwork or formwork substitute; 4: Self-compacting concrete; 5: Rockfill; 6: Top horizontal rebar; 7: Internal horizontal rebar; 8: Protective layer.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, and do not limit the protection scope of the present invention.

In order to better understand the present invention, an application example of a reinforced rockfill concrete structure and a construction method thereof proposed by the present invention will be described in detail below.

In the present invention, steel bar configuration is introduced on the basis of the existing rockfill concrete technology, and construction is carried out through the combination of riprap type rockfill concrete and ordinary rockfill concrete construction methods, and finally a complete and dense structure that can meet the requirements of structural reinforcement is formed. Reinforced rockfill concrete structure. The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings:

A reinforced rockfill concrete structure of the present invention, referring to FIG. 1, includes steel bars (1, 2, 6, 7) or their substitutes (such as steel plates, steel trusses, prestressed steel strands) located in the formwork or its substitutes 3 line, etc.) and rockfill concrete. The reinforcing bars or their substitutes are laid out according to the design requirements, and can be laid on the bottom, surrounding, top and interior of the warehouse surface (as shown in Figure 1, bottom horizontal reinforcing bars 1, surrounding vertical reinforcing bars 2, top horizontal reinforcing bars 6 and internal horizontal reinforcing bars are shown in Figure 1). 7). The rockfill concrete includes: rockfill 5 and self-compacting concrete 4, wherein the rockfill 5 is made of boulders or pebbles, and its saturated compressive strength should exceed the compressive strength requirements of large-volume reinforced concrete, with a minimum particle size of 50 mm; The maximum particle size of rockfill used in riprap type rockfill concrete shall not exceed 500mm; when ordinary rockfill concrete is used, the maximum particle size of rockfill shall not exceed the transportation capacity of construction machinery, and be smaller than the size of the reinforced rockfill concrete structure. 1/8～1/4 or pouring layer thickness. The self-compacting concrete 4 contains a certain amount of coarse aggregate, and the maximum particle size of the coarse aggregate is 10 mm to 20 mm. Meet the design requirements of large-volume reinforced concrete. The self-compacting concrete 4 (the self-compacting concrete) that can completely cover the corresponding steel bar or its substitute and the thickness exceeding the corresponding steel bar or its substitute is not less than 150mm to 300mm by pouring the steel bar or its substitute at the bottom and inside of the silo. It is required to have excellent anti-segregation performance and good plastic retention performance) to form the protective layer 8, and then proceed with the construction of the remaining steel bars and rockfill concrete.

The present invention also proposes a construction method for the above-mentioned reinforced rockfill concrete structure, which can reinforced the mass concrete structure according to the design requirements, and carry out construction according to the following steps:

1) Referring to Figure 2, according to the design requirements in the large-volume reinforced concrete, the bottom horizontal steel bar 1 and the surrounding vertical steel bars 2 are arranged for the silo surface where the rockfill concrete needs to be poured, and the formwork or formwork substitute 3 is set;

2) The bottom of the silo surface is constructed by the riprap type rockfill concrete construction method. First pour the self-compacting concrete 4 that can completely cover the bottom horizontal steel bar 1 and exceed the bottom horizontal steel bar with a thickness of not less than 150mm to 300mm to form a protective layer 8 for the bottom steel bar , see Figure 2, and then throw the rockfill 5 with a particle size of 50mm to 500mm into the self-compacting concrete 4 that has been poured evenly, see Figure 3; the performance requirements of the self-compacting concrete should meet: slump 250mm ~ 290mm, Expansion 500mm～700mm and V-shaped funnel passing time 5s～30s;

3) Continue to rip rock into the silo surface and pour self-compacting concrete 4 at the same time, and continuously carry out the construction of riprap type rockfill concrete (the thickness of the self-compacting concrete poured at one time is determined according to the riprap speed, and the performance loss of the self-compacting concrete to be poured is required. Complete the riprap work before exceeding the lower limit standard) until the silo surface pouring is completed, see Figure 4; or only use riprap rockfill concrete at the bottom of the silo surface, and continue to fill 150mm after the riprap rockfill concrete construction is completed. ～1200mm of rockfill to the set height (this height is related to the construction capacity, the riprap type rockfill concrete can be continuously constructed for several tens of meters as long as the construction capacity meets the requirements; when the warehouse surface is large, the pouring speed must ensure that the concrete cannot be initially constructed. Then, using the ordinary rockfill concrete construction technology, pour the self-compacting concrete 4 to fill and compact the rockfill voids in the formwork or formwork substitute 3 until it is poured to the design height of the top of the silo surface. The performance requirements of self-compacting concrete used in ordinary rockfill concrete construction should meet: slump 250mm-290mm, expansion 600mm-800mm, V-shaped funnel passing time 5s-30s.

Further, referring to Fig. 5 and Fig. 6, when the inner horizontal steel bar 7 needs to be laid according to the design requirements, first the rockfill concrete is constructed to below the design height of the inner horizontal steel bar 7, and then the inner horizontal steel bar 7 is laid out, and then the pouring can completely cover. Self-compacting concrete with internal horizontal steel bar 7 and the thickness exceeding the steel bar is not less than 150mm~300mm, which plays the role of cushion and protects the steel bar from being damaged by riprap. Throw it into the poured self-compacting concrete, and then pour it to the design height of the top of the silo surface according to the operation of step 3).

Further, referring to Figures 7 to 9, when the top horizontal steel bar 6 needs to be laid according to the design requirements, the rockfill concrete is first constructed to below the design height of the top horizontal steel bar 6, and then the top horizontal steel bar 6 is laid; Self-compacting concrete 4 covering the top horizontal steel bar 6 and reaching the design height of the top of the silo face.

Further, when the silo surface is large or needs to reach a certain height inside the silo surface (such as below the height of the internal horizontal steel bars), the pouring stop time exceeds the initial setting time of the self-compacting concrete, and the top surface of the self-compacting concrete where the pouring stops should be low. To ensure that part of the rockfill is exposed to the top of the self-compacting concrete and to ensure the bonding strength of the upper and lower layers of concrete.

Further, the top surface of the self-compacting concrete that has been stopped for pouring should be maintained, and after the concrete strength reaches 2.5MPa, the construction of the upper layer of self-compacting concrete can be carried out; In order to meet the impermeability requirements or strength requirements of reinforced rockfill concrete structures.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand: it can still be Modifications are made to the technical solutions described in the foregoing embodiments, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (6)

1. a reinforced rockfill concrete structure, is characterized in that, comprises reinforcing bar or its substitute and rockfill concrete; Described reinforcing bar or its substitute is the reinforcing bar or its substitute that is laid out according to design requirements, and is arranged at the bottom of warehouse surface, Surroundings, tops and interiors; the rockfill concrete includes rockfill and self-compacting concrete, wherein the rockfill is made of boulders or pebbles, and its saturated compressive strength should exceed the compressive strength requirements of large-volume reinforced concrete. The minimum particle size of the rock is 50mm; when using riprap type rockfill concrete, the maximum particle size of the rockfill used shall not exceed 500mm; when using ordinary rockfill concrete, the maximum particle size of the rockfill used shall not exceed the transportation capacity of the construction machinery , and less than 1/8-1/4 of the structure size or the thickness of the pouring layer; the self-compacting concrete contains coarse aggregate, and the maximum particle size of the coarse aggregate is 10mm-20mm, and the performance of the self-compacting concrete meets the requirements of large-volume steel bars Concrete design requirements; the self-compacting concrete is formed by pouring the self-compacting concrete that can completely cover the corresponding steel bar or its substitute and the thickness exceeding the corresponding steel bar or its substitute is not less than 150mm to 300mm at the bottom and inside of the warehouse surface where steel bars or their substitutes are laid. Protective layer; pour the self-compacting concrete that can completely cover the steel bar or its substitute and reach the design height of the top of the silo surface at the place where the steel bar or its substitute is laid on the top of the silo surface. 2. a construction method of reinforced rockfill concrete structure according to claim 1, is characterized in that, comprises the following steps: 1) Arrange bottom steel bars or their substitutes and surrounding steel bars or their substitutes for the silo surface where the rockfill concrete needs to be poured, and set up formwork or formwork substitutes; 2) The bottom of the warehouse surface shall be constructed by using the riprap type rockfill concrete construction method. First pour the self-compacting concrete that can completely cover the bottom steel bar or its substitute and whose thickness exceeds the steel bar or its substitute by not less than 150mm to 300mm. Then the rockfill with a particle size of 50mm to 500mm is evenly thrown into the self-compacting concrete; 3) Continue to rip rock into the silo surface and pour self-compacting concrete at the same time, and continue to carry out riprap type rockfill concrete construction until the silo surface is poured; After the rockfill concrete is constructed, continue to dump and fill the rockfill with a particle size of 50mm to 500mm to the set height, adopt the ordinary rockfill concrete process, and pour the self-compacting concrete to fill the rockfill voids in the formwork or its substitute until it reaches the set height. Design height for pouring to the top of the silo face. 3. according to the construction method of the described reinforced rockfill concrete structure of claim 2, it is characterized in that, when needing to lay reinforcement or its substitute in the interior of the warehouse surface according to the design requirement, step 3) is replaced by the following steps: Concrete is constructed to below the height of the internal steel bar or its substitute, and then the steel bar or its substitute is laid out; then the self-compacting concrete is poured to completely cover the steel bar or its substitute and the thickness beyond the steel bar or its substitute is not less than 150mm～300mm of self-compacting concrete, and then adopt the construction technology of rockfill type rockfill concrete to evenly throw the rockfill into the poured self-compacting concrete; continue to rip rock into the silo surface and pour the self-compacting concrete at the same time. The riprap type rockfill concrete is constructed until the silo surface is poured. 4. according to the construction method of the described reinforced rockfill concrete structure of claim 2 or 3, it is characterized in that, when needing to lay reinforcement or its substitute on the top of the warehouse surface according to the design requirement, step 3) also comprises the following steps: When the stone concrete is constructed to the design height of the rebar or its substitute at the top of the silo surface, the rebar on the top or its substitute shall be laid; concrete. 5. according to the construction method of the described reinforced rockfill concrete structure of claim 4, it is characterized in that, when the warehouse surface is larger or other reasons reach the set height in the warehouse, the pouring stop time exceeds the initial setting time of the self-compacting concrete , and the top surface of the self-compacting concrete when the pouring stops should be lower than the rockfill, so as to ensure that some of the rockfill is exposed on the top of the self-compacting concrete and ensure the bonding strength of the upper and lower layers of concrete. 6. the construction method of the reinforced rockfill concrete structure according to claim 5, is characterized in that, the self-compacting concrete top surface of the pouring stop should be maintained, and after the concrete strength reaches 2.5MPa, the upper concrete construction is carried out; The top surface of the suspended self-compacting concrete is chiseled or punched to meet the impermeability or strength requirements of the reinforced rockfill concrete structure.

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