CN114318990A - A method of recycling construction waste for road widening - Google Patents

Abstract

The invention discloses a construction waste recycling filling method for road widening, which comprises the following steps: building a building waste recycled aggregate concrete retaining wall on the outside of an old roadbed slope; digging steps on the old roadbed slope to form a step surface; construction waste A filling area is formed between the recycled aggregate concrete retaining wall and the step surface; the construction waste recycled filler is filled in layers in the filling area, and a layer of transverse reinforcement is laid after each layer is compacted. One end is fixed on the step surface, and the other end is stretched to the construction waste recycled aggregate concrete retaining wall, and then the construction waste recycled filler is turned up to form a turn-up reinforced soil; the above process is repeated until it is filled to the pavement structure layer. Next, complete the filling of the new roadbed; connect and reinforce anchor rods between the construction waste recycled aggregate concrete retaining wall and each layer of reinforced soil. Compared with the traditional gravity support structure, the present invention has the advantages of good seismic performance, less land occupation, wide application range, high construction efficiency, significant economic benefits and the like.

Description

A method of recycling construction waste for road widening

technical field

The invention relates to the technical field of road widening, in particular to a method for recycling construction waste for road widening.

Background technique

With the development of social economy and the increasing traffic flow, some of the original roads in our country can no longer meet the development and demand of modern transportation, and the widening and reconstruction of highways has become a hot issue in the current transportation field.

In the widening and reconstruction of existing roads, how to achieve a good combination of new and old roadbeds and reduce or even eliminate differential settlements while occupying as little land resources as possible is a key issue in road widening. Due to the limitations of design methods, construction machinery performance and construction technology, traditional methods often set up gravity-type support structures on the outside of the road. This method has high requirements on the bearing capacity of the original foundation, high consumption of building materials and poor seismic performance.

SUMMARY OF THE INVENTION

Aiming at the deficiencies in the prior art, the present invention provides a method for recycling construction waste for road widening.

The invention discloses a construction waste recycling filling method for road widening. The construction waste recycling filling method comprises:

Step S1, building a concrete retaining wall of recycled aggregate of construction waste on the outside of the old roadbed slope;

Step S2, excavating the old roadbed side slope that needs to widen the road to form a step surface; forming a filling area between the construction waste recycled aggregate concrete retaining wall and the step surface;

Step S3, in the filling area, the original foundation is cleared and compacted and then filled with a layer of construction waste recycled filler, after sufficient compaction, a layer of transverse reinforcement is laid on the surface, and a layer of transverse reinforcement is continued to be filled on the transverse reinforcement. layer of construction waste recycled filler, and behind the construction waste recycled aggregate concrete retaining wall, the construction waste recycled filler is turned over by the transverse reinforcement;

Step S4: Repeat the above step S3 until the construction waste recycled filler is filled below the pavement structure layer, and the filling of the new subgrade is completed, and the new subgrade and the old subgrade are connected through the step surface.

As a further improvement of the present invention, the width of the step surface is not less than 1m;

The horizontal steps face the old roadbed with an inward inclination preset gradient, and the gradient is not less than 2%.

As a further improvement of the present invention, the thickness of the construction waste recycled aggregate concrete retaining wall is not less than 15cm, and the slope of the thickness of the construction waste recycled aggregate concrete retaining wall is 1:0.5;

The grade strength of the construction waste recycled aggregate concrete retaining wall is not less than C25.

As a further improvement of the present invention, the construction waste recycled aggregate in the construction waste recycled aggregate concrete retaining wall is processed from one or more of concrete, mortar, stone and brick and tile in the construction waste.

As a further improvement of the present invention, the transverse reinforcement is a bidirectional geogrid;

One end of the two-way geogrid is fixed on the step surface by U-shaped steel nails, and the other end is stretched to the construction waste recycled aggregate concrete retaining wall, and then the construction waste recycled filler is turned over, and is combined with the construction waste recycled filler. The subgrade of the backfill layer is fixed with U-shaped steel nails.

As a further improvement of the present invention, the turn-back length of the turn-back package is not less than 2m;

Each layer of the two-way geogrid that is turned up contains construction waste fillers to form the turned-up reinforced soil.

As a further improvement of the present invention, the construction waste recycled filler adopts a layered filling method;

The full width of the roadbed of the same horizontal layer shall use the same material source and the same batch of regenerated fillers.

As a further improvement of the present invention, the construction waste recycled filler is made by mixing one or more of bricks, concrete blocks, blocks and mortar particles;

The organic matter content in the construction waste regeneration filler is not more than 5%, the content of light impurities is not more than 0.1%, the non-uniformity coefficient is not more than 5%, and the content of soluble salt is not more than 0.3%.

As a further improvement of the present invention, the light-duty support method further includes:

Step S5, after filling the construction waste recycled filler, drive an oblique reinforcing anchor rod into each layer of the turn-up reinforced soil;

One end of each of the reinforcing anchor rods is placed in the turn-up reinforced soil, and the other end obliquely passes through the corresponding concrete retaining wall of recycled construction waste.

As a further improvement of the present invention, the reinforcement anchor rod is a steel rod anchor rod, and the steel rod anchor rod adopts HRB335 grade steel bars;

The diameter of the HRB335 steel bar is not less than 20mm.

Compared with the prior art, the beneficial effects of the present invention are:

The method of the invention has simple and clear structure, clear thinking for solving problems, and can effectively solve the problems of large land occupation, large amount of masonry work and poor seismic performance during road widening and subgrade filling.

The invention can effectively reduce the land resources and economic waste required for garbage disposal by using the construction waste regenerated filler and the construction waste regenerated aggregate concrete retaining wall. And reduce the loss of natural resources, relieve the huge pressure brought by the massive consumption of natural stone.

Compared with the traditional gravity retaining structure, the light retaining structure has the advantages of good seismic performance, less land occupation, wide application range, high construction efficiency, significant economic benefits and the like.

Description of drawings

Fig. 1 is a method flow chart of a method for recycling construction waste for road widening disclosed in the present invention;

FIG. 2 is a schematic structural diagram of a method for recycling construction waste for road widening disclosed in the present invention.

In the picture:

1. Old roadbed; 1-1. Step surface; 2. New roadbed; 3. Construction waste recycled filler; 4. Reinforced soil with reverse wrapping; 5. Construction waste recycled aggregate concrete retaining wall; 6. Reinforced anchor rod; 7. Two-way geogrid.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments These are some embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation or a specific orientation. construction and operation, and therefore should not be construed as limiting the invention. Furthermore, the terms "first", "second", and "third" are used for descriptive purposes only and should not be construed to indicate or imply relative importance.

In the description of the present invention, it should also be noted that, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection or a connectable connection. Detachable connection, or integral connection; may be mechanical connection or electrical connection; may be direct connection, or indirect connection through an intermediate medium, or internal communication between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

Below in conjunction with accompanying drawing, the present invention is described in further detail:

As shown in FIG. 1 , the present invention discloses a method for recycling construction waste for road widening. The method for recycling construction waste includes:

Step S1, building a concrete retaining wall 5 of recycled aggregates of construction waste on the outside of the slope of the old roadbed 1;

Step S2, excavating the side slope of the old roadbed 1 that needs to widen the road, and then forming a step surface 1-1; a filling area is formed between the construction waste recycled aggregate concrete retaining wall 5 and the step surface 1-1;

Step S3, in the filling area, clear and compact the original foundation and then fill with a layer of construction waste recycled filler 3, after fully compacting, lay a layer of transverse reinforcement on the surface, and continue to fill a layer of construction waste on the transverse reinforcement Recycled filler 3, and behind the construction waste recycled aggregate concrete retaining wall 5, the construction waste recycled filler 3 is reversely wrapped through transverse reinforcement;

Step S4: Repeat the above step S3 until the construction waste regenerated filler 3 is filled below the pavement structure layer, the filling of the new roadbed 2 is completed, and the new roadbed 2 and the old roadbed 1 are connected by the step surface 1-1.

The method of the invention has simple and clear structure, clear thinking for solving problems, and can effectively solve the problems of large land occupation, large amount of masonry work and poor seismic performance during road widening and subgrade filling.

The present invention can effectively reduce the land resources and economic waste required for garbage disposal by using the construction waste recycled filler 3 and the construction waste recycled aggregate concrete retaining wall 5 . And reduce the loss of natural resources, relieve the huge pressure brought by the massive consumption of natural stone.

Compared with the traditional gravity retaining structure, the light retaining structure has the advantages of good seismic performance, less land occupation, wide application range, high construction efficiency, significant economic benefits and the like.

specific:

As shown in Figure 2, the width of the step surface in the present invention is not less than 1m; the horizontal step faces the old roadbed with an inward inclination preset gradient, and the gradient is not less than 2%; the width of the step surface in the present invention is preferably 1m; the horizontal step faces the old roadbed The preset gradient of inclination is preferably 2%. It can effectively strengthen the connection between the old subgrade 1 and the new subgrade 2.

Further, the thickness of the construction waste recycled aggregate concrete retaining wall 5 in the present invention is not less than 15cm, and the gradient of the thickness of the construction waste recycled aggregate concrete retaining wall 5 is 1:0.5; the grade of the construction waste recycled aggregate concrete retaining wall 5 The strength is not less than C25.

Due to the demolition of a large number of protective, drainage facilities, bridges and culverts and other structures in the road widening, a large number of high-quality building masonry materials such as mortar blocks and concrete blocks are formed. The source of such materials is clear, the composition is single, and the strength is relatively large. It is a source of high-quality recycled materials. The part of the masonry materials can be classified and crushed to form building aggregates, which can replace part of the natural aggregates and be used in concrete retaining walls. According to the feedback from existing indoor tests and engineering practice, the proportion of building materials in retaining wall structures can reach 30-50%.

Therefore, in the present invention, the recycled aggregate of construction waste in the concrete retaining wall 5 is made from one or more of concrete, mortar, stone and bricks and tiles in the construction waste. The construction waste recycled aggregate concrete retaining wall 5 in the present invention is to add a certain proportion of construction waste recycled aggregate to concrete instead of conventional coarse and fine aggregates to form a masonry support structure with a certain level of strength. The confinement of the clad reinforced soil 4 to the land improves the self-support of the structure, and according to the mechanical analysis, the lateral pressure of the soil after filling is smaller. Therefore, compared with the gravity retaining wall, its size is greatly reduced, and a steeper slope can be set to reduce the footprint.

Further, the construction waste recycled aggregate in the construction waste recycled aggregate concrete retaining wall 5 in the present invention has undergone processes such as crushing, impurity removal, and shaping by professional manufacturers, and the particle shape is polyhedron. From the analysis of the existing indoor test and engineering practice, in the concrete structure of the expressway, the recycled aggregate of construction waste can replace not more than 50% of the aggregate, and its mechanical properties can be basically the same as the conventional concrete. The strength of the construction waste recycled aggregate concrete retaining wall is above C25. According to the filling height and engineering conditions, it can be prefabricated in the factory and assembled on site to reduce environmental pollution during on-site construction and enhance construction efficiency.

Further, the transverse reinforcement in the present invention is a bidirectional geogrid 7; one end of the bidirectional geogrid 7 is fixed on the step surface 1-1 by U-shaped steel nails, and the other end is stretched to the construction waste recycled aggregate concrete retaining wall. After 5 places, the construction waste regenerated filler 3 is turned upside down, and is fixed with U-shaped steel nails with the compacted roadbed of the filling layer, that is, one end of the two-way geogrid 7 in the present invention is fixed on the step surface 1-1, and the other end is fixed on the step surface 1-1. It is fixed inside the layer of compacted roadbed after being turned upside down.

Further, the turn-back length of the turn-up in the present invention is not less than 2m; each layer of turn-up bidirectional geogrid contains construction waste fillers to form turn-up reinforced soil 4 . The turn-back reinforced soil 4 in the present invention improves the deformation conditions of the soil body and improves the engineering performance of the soil body by utilizing the interaction with the soil, thereby achieving the purpose of stabilizing the soil body.

Further, due to the interaction between the reinforced soil bar and the fill, the mechanical properties of the soil are improved. This improvement is reflected in the mutual friction constraint between the geogrid and the fill, which inhibits the deformation of the fill and bears tensile stress. Or withstand shearing and bending to improve the strength and stability of the soil. Therefore, the choice of reinforcement is very important. Geogrids and similar geosynthetic materials can be used as reinforcement materials. Such products are rich in categories. In the present invention, high-strength bidirectional geogrids 7 with high strength, small tensile strain, good aging resistance and small creep deformation are preferably used.

Further, as shown in Table 1 and Table 2, the construction waste regeneration filler 3 in the present invention adopts the layered filling method to fill; because the construction waste is relatively complicated, it is necessary to classify, clean, and crush the construction waste. After the process, it is used as a roadbed filler, and the construction waste recycled filler 3 in the present invention is preferably made by mixing one or more of bricks, concrete blocks, blocks and mortar particles; and the construction waste recycled filler used for roadbed fillers The particle size of 3 should be less than 37.5mm, and the paving thickness of roadbed filling, optimal water content, loose paving coefficient and mechanical combination should be applied according to actual engineering requirements. Since concrete blocks, masonry, mortar blocks, etc. have different water absorption and strengths, the same material source and the same batch of recycled filler should be used for the full width of the subgrade of the same horizontal layer. When rolling in layers, each layer of construction waste filling should be flat and dense, and meet the requirements for the compaction degree of conventional roadbed filling.

Further, the organic matter content in the construction waste regeneration filler 3 in the present invention is not more than 5%, the content of light impurities is not more than 0.1%, the non-uniformity coefficient is not more than 5%, and the content of soluble salt is not more than 0.3%.

Further, according to different project scales and grades, the index requirements for construction waste are different. Taking highway construction waste recycling filler as an example, it can meet the following requirements. Recycled filler mainly refers to the recycled building materials formed after construction waste is crushed, screened and sorted by special equipment. Recycled materials should be sampled and tested before use, and can only be used after passing the test. Recycled materials of the same source and specification at the construction site are tested and stored as the same batch of materials. Different batches of recycled materials should be sampled and tested separately. The particle size of the recycled material for filling the embankment should not be greater than 150mm, and the particle size of the recycled material for filling the road bed should not be larger than 60mm.

Table 1 Requirements for the gradation of recycled materials

Table 2 Technical requirements for recycled materials

Note: Light impurities refer to impurity materials with low density that are not suitable for roadbed filling (such as plastics, wood blocks, cloth pieces, paper scraps, foam particles, etc.).

Further, construction parameters such as compaction power, rolling speed, compaction times, and paving layer thickness of the construction waste recycled filler 3 in the present invention should be determined according to actual engineering conditions and conform to corresponding standards.

Further, as shown in FIG. 1 , the light-duty support method of the present invention further includes:

Step S5, after filling the construction waste regeneration filler 3, drive an oblique reinforcement anchor rod 6 into each layer of the turn-up reinforced soil 4; one end of each reinforcement anchor rod 6 is placed in the turn-up type reinforcement In the reinforcement soil 4, the other end obliquely passes through the corresponding construction waste recycled aggregate concrete retaining wall 5, and the setting of the reinforcement anchor rod 6 is mainly its anchoring effect. The diameter of the HRB33-grade steel bar; the diameter of the HRB335-grade steel bar is not less than 20 mm, and the diameter of the HRB335-grade steel bar in the present invention is preferably 20 mm.

Further, during actual construction, the construction points of the present invention include:

1. The subgrade filling should be mechanized;

2. During the construction of the roadbed, the light debris mixed in the recycled materials should be collected again manually;

3. Recycled materials from different sources and batches should be layered horizontally, filled in sections, and compacted in layers. The full width of the subgrade of the same horizontal layer shall use the same material source and the same batch of recycled materials, and shall not be mixed and filled;

4. When laying the bars, make sure that the bars are flat and straight, and use U-shaped steel nails to fix the bars when they overlap to ensure that the bars are not wrinkled or twisted;

5. Technical measures should be taken to reduce slump loss and prevent segregation during transportation of recycled aggregate concrete. When the slump loss of the recycled aggregate concrete mixture is large due to transportation or waiting for a long time for pouring, it can be mixed with an appropriate amount of water reducing agent determined by the technical plan before unloading, but it is strictly forbidden to add water.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. The construction waste recycling filling method for road widening is characterized by comprising the following steps:

step S1, building a construction waste recycled aggregate concrete retaining wall on the outer side of the old roadbed side slope;

step 2, digging steps on the old roadbed slope of the road needing to be widened, and further forming a step surface; a filling area is formed between the construction waste recycled aggregate concrete retaining wall and the step surface;

step S3, filling a layer of construction waste regeneration filler after the surface of the original foundation is cleaned and compacted in the filling area, paving a layer of transverse reinforcement on the surface after the foundation is fully compacted, continuously filling a layer of construction waste regeneration filler on the transverse reinforcement, and reversely wrapping the construction waste regeneration filler through the transverse reinforcement behind the construction waste regeneration aggregate concrete retaining wall;

and S4, repeating the step S3 until the construction waste regenerated filler is filled below the pavement structure layer, and completing filling of a new roadbed, wherein the new roadbed is connected with the old roadbed through the step surface.

2. The resource filling method of construction waste for road widening according to claim 1, wherein the width of the step surface is not less than 1 m;

the horizontal step faces the old roadbed and inclines inwards by a preset gradient which is not less than 2%.

3. The resource filling method of the construction waste for road widening according to claim 1, wherein the thickness of the construction waste recycled aggregate concrete retaining wall is not less than 15cm, and the gradient of the thickness of the construction waste recycled aggregate concrete retaining wall is 1: 0.5;

the grade strength of the construction waste recycled aggregate concrete retaining wall is not less than C25.

4. The resource filling method of construction waste for road widening according to claim 3, wherein the construction waste recycled aggregate in the construction waste recycled aggregate concrete retaining wall is processed by one or more of concrete, mortar, stone and tiles in the construction waste.

5. The resource reclamation filling method of the construction waste for road widening as recited in claim 1, wherein the transverse reinforcement is a bidirectional geogrid;

one end of the bidirectional geogrid is fixed on the step surface through a U-shaped steel nail, and the other end of the bidirectional geogrid extends to the rear of the construction waste regeneration aggregate concrete retaining wall, the construction waste regeneration filler is reversely wrapped and fixed with a filling layer lamination roadbed through the U-shaped steel nail.

6. The resource reclamation filling method of construction waste for road widening according to claim 5, wherein the turning length of the turn-up is not less than 2 m;

and each layer of the reverse-wrapped bidirectional geogrid contains building garbage fillers to form the reverse-wrapped reinforced soil.

7. The resource filling method of the construction waste for road widening according to claim 1, characterized in that the construction waste regenerated filler adopts a layered filling method;

the full width of the roadbed at the same horizontal layer adopts the same material source and the same batch of regenerated fillers.

8. The resource filling method of the construction waste for road widening according to claim 7, wherein the construction waste recycled filler is prepared by mixing one or more of bricks, concrete blocks, building blocks and mortar particles;

the content of organic matters in the building garbage regenerated filler is not more than 5%, the content of light impurities is not more than 0.1%, the non-uniformity coefficient is not more than 5%, and the content of soluble salts is not more than 0.3%.

9. The resource reclamation filling method for the construction waste for road widening as recited in claims 1 to 7, wherein the light retaining method further comprises:

step S5, after the construction waste is filled to regenerate the filler, an oblique reinforcing anchor rod is driven into each layer of the reverse wrapped reinforced soil;

one end of each reinforcing anchor rod is arranged in the reverse-wrapped reinforced soil, and the other end of each reinforcing anchor rod penetrates through the corresponding construction waste recycled aggregate concrete retaining wall in an inclined mode.

10. The resource filling method of the construction waste for road widening according to claim 9, wherein the reinforcing anchor is a steel bar anchor, and the steel bar anchor adopts HRB335 grade steel bars;

the diameter of the HRB335 grade steel bar is not less than 20 mm.

Images