All-solid waste light foam soil, preparation method thereof and application of all-solid waste light foam soil in abutment back backfilling

Abstract

The invention discloses all-solid waste light foam soil, a preparation method thereof and application of the all-solid waste light foam soil in abutment back backfilling, and belongs to the technical field of pavement construction. The all-solid-waste light foam soil is prepared from the following components: an industrial solid waste cementing material, waste incineration ash, waste sintered bricks, an alkali activator, a water reducing agent, an expanding agent, a dense waterproof agent, regenerated plastic particles, anti-cracking fibers, an anti-freezing agent, a foaming agent, a foam stabilizer and water. The all-solid-waste light foam soil is used for forming an all-solid-waste light foam soil abutment back backfilling structure arranged between a roadbed and a bridge abutment, and through the structure, the problems that in the prior art, abutment back backfilling sedimentation is serious, cement consumption is too much, industrial solid waste is difficult to dispose, and pollution to the environment is too heavy are solved; the strength of the backfill material formed by the synergistic effect of the components is far higher than that of a common roadbed soil material, and the backfill material has the characteristics of low material consumption and light weight.

Description

Technical Field

[0001] This invention relates to the field of road construction technology, and in particular to a lightweight foamed soil made entirely of solid waste, its preparation method, and its application in backfilling of abutments. Background Technology

[0002] Lightweight foamed soil is a new type of lightweight thermal insulation material with a large number of pores. It is produced by fully foaming a foaming agent using an aeration machine, thoroughly mixing the foam with cement slurry, and then pouring it in place or molding it with molds, followed by natural curing. Its key feature is the formation of numerous foam pores within the structure, which makes the concrete lightweight.

[0003] Because the compaction area behind bridge abutments, especially on the inner side of the abutment wall, is limited and cannot accommodate high-pressure compaction equipment, it is difficult to achieve the required compaction degree. The compaction quality of the roadbed behind the abutments is inherently inferior to that of the open sections. After traffic begins, repeated loads can easily cause compressive settlement of the roadbed behind the abutments. Furthermore, the connection between the roadbed and the abutment involves a combination of rigidity and flexibility; the abutment is rigid, while the roadbed is flexible. The two structures have different bearing capacities and settlement rates, which will exacerbate uneven settlement. Uneven settlement will cause vehicle bouncing, affecting driving comfort and accelerating damage to the structure and pavement.

[0004] Lightweight foamed soil, used instead of backfill, reduces the load on the foundation, significantly mitigating the gradient of differential settlement between bridges (culverts) and the roadbed. This results in a slow and uniform change in differential settlement, fundamentally eliminating the problem of vehicle bouncing between bridges (culverts) and the roadbed in highways. Ordinary lightweight foamed soil primarily uses cement as its cementing material, leading to excessive consumption of cement raw materials. Cement production requires the mining of large quantities of limestone and clay, consuming significant energy. Replacing cement with waste materials solves problems related to carbon emissions, natural resource development, and waste disposal while ensuring material performance. Summary of the Invention

[0005] The purpose of this invention is to provide a lightweight foamed soil made entirely from solid waste, its preparation method, and its application in abutment backfilling, thereby solving the problems of severe settlement, excessive cement consumption, difficulty in disposing of industrial solid waste, and excessive environmental pollution caused by existing backfilling techniques.

[0006] To achieve the above objectives, the present invention provides a lightweight foamed soil made entirely from solid waste. The lightweight foamed soil made entirely from solid waste comprises the following raw materials in parts by weight: 100 parts of industrial solid waste cementitious material, 60-120 parts of waste incineration ash, 80-150 parts of waste sintered bricks, 2-4 parts of alkali activator, 1-2 parts of water-reducing agent, 0.5-1 part of expanding agent, 2-4 parts of dense waterproofing agent, 6-10 parts of recycled plastic granules, 1-3 parts of crack-resistant fiber, 2-3 parts of antifreeze agent, 10-20 parts of foaming agent, 1-3 parts of foam stabilizer, and 120-200 parts of water.

[0007] Preferably, the industrial solid waste cementing material comprises an activating material and a potential cementing material in a ratio of 1:1 to 1:2. The activating material is mainly composed of carbide slag, mixed with any one or two of cement and hydrated lime. The potential cementing material is any one or more of desulfurized gypsum, red mud, slag, and fly ash.

[0008] Preferably, the red mud is sintered red mud that has not been calcined, dried at 105°C for at least 48 hours, and then crushed and sieved.

[0009] Preferably, the waste incineration ash is the bottom ash portion after waste incineration. After crushing, 3 wt‰ of COF material is added and mixed evenly; the COF material is a terpyridine covalent organic framework material.

[0010] Preferably, the waste sintered bricks are processed into powder material through crushing and other processes.

[0011] Preferably, the alkali activator is Na2SiO3 powder with a modulus of 3.0; the water-reducing agent is one or a combination of polycarboxylate water-reducing agent and naphthalene-based water-reducing agent; and the expanding agent is one or a combination of magnesium oxide and calcium sulfoaluminate.

[0012] Preferably, the anti-cracking fiber is one or a combination of two or more of basalt fiber, polyester fiber, and glass fiber; the organic antifreeze agent is one or a combination of glycerol, triethanolamine, glucose, urea, and ethylene glycol.

[0013] Foamed lightweight soil has a high drying shrinkage problem, making it prone to drying shrinkage cracks during the setting and hardening process. Using expansion agents and crack-resistant fibers can effectively reduce drying shrinkage.

[0014] Preferably, the foaming agent is any one of rosin-based foaming agents, anionic surfactants with tertiary amine side groups, protein-based foaming agents, and composite foaming agents; the foam stabilizer is any one of hydroxypropyl methylcellulose ether, calcium stearate, trisodium phosphate, and redispersible latex powder.

[0015] This invention also provides a method for preparing the above-mentioned lightweight foamed soil made entirely from solid waste, comprising the following steps:

[0016] S1. Mix the foaming agent and foam stabilizer to prepare foam for later use;

[0017] S2. Stir the industrial solid waste cementitious material, waste incineration ash, waste sintered bricks, alkali activator, water reducing agent, expansion agent, densifying and waterproofing agent, recycled plastic granules, crack-resistant fiber and antifreeze agent at a speed of 300-500 r / min for 3-4 min to form a uniform dry mixture. Then mix it with the remaining water evenly and stir for 60-90 s to obtain premixed lightweight foamed soil for later use.

[0018] S3. Mechanically mix the premixed lightweight foam soil with the foam for 90-150 seconds, then pour, solidify and cure to obtain the solid waste lightweight foam soil.

[0019] The lightweight foamed soil provided by this invention is used to form a lightweight foamed soil abutment backfill structure, which is set between the roadbed and the bridge abutment. The overlap between the roadbed and the lightweight foamed soil abutment backfill structure is excavated into an inclined step. The side of the lightweight foamed soil abutment backfill structure above the roadbed is a cement-stabilized crushed stone base course, and the side of the abutment is a concrete slab. Both the cement-stabilized crushed stone base course and the concrete slab are vertically cut into blocks, and the junction is a sloping cut with the concrete at the bottom. The cement-stabilized crushed stone base course and the concrete slab are waterproof layers, which overlap to the abutment cap. Asphalt concrete is laid on top of the waterproof layer.

[0020] Preferably, the all-solid-waste lightweight foam soil backfill structure is divided into longitudinal blocks and connected horizontally and longitudinally using bamboo reinforcement.

[0021] Lightweight foamed soil is used for backfilling abutments. The strength of the backfill material is much higher than that of ordinary subgrade soil materials, and it has the characteristics of low material consumption and light weight.

[0022] Therefore, the present invention, employing the above-mentioned lightweight foamed soil made entirely from solid waste, its preparation method, and its application in abutment backfilling, has the following beneficial effects:

[0023] (1) In the vertical direction from the abutment to the roadbed, the thickness of the lightweight foamed soil decreases sequentially, and the overall strength shows a decreasing trend. Above the lightweight foamed soil, a concrete slab, a concrete slab-stabilized crushed stone base transition zone, and a stabilized crushed stone base are successively adopted to achieve a smooth transition from the abutment to the roadbed. The lightweight foamed soil material is used in small quantities and is lightweight, which effectively reduces the compression on the underlying structure and greatly slows down the settlement phenomenon. The porous structure of the material greatly increases the permeability of the abutment backfill. Recycled plastic particles are dispersed in the grid and form an insulation layer in the lightweight foamed soil, which significantly improves the insulation effect of the lightweight concrete and gives the lightweight foamed soil abutment backfill structure good frost resistance. The lightweight foamed soil backfill, the cement-stabilized crushed stone base course, and the concrete slab above the abutment are all vertically segmented into block structures, eliminating the traditional overall settlement of bridge approach slabs. Furthermore, bamboo reinforcement is used for horizontal longitudinal connection, forming a flexible structure. Settlement in some areas causes slight deformation of the surrounding block structures, creating a transition zone between the settled and intact areas, effectively reducing vehicle accidents caused by bridge approach slab slabs. The roadbed steps are vertically slightly inclined, causing the lightweight foamed soil blocks to tend to move towards the abutment, effectively reducing compression on the relatively low-strength roadbed and minimizing roadbed deformation.

[0024] (2) Using waste incineration ash and waste sintered bricks as aggregates in lightweight foamed soil can fully utilize their lightweight aggregate characteristics. Lightweight foamed soil can replace backfill soil in construction to reduce the load on the foundation, which can greatly alleviate the gradient of differential settlement between bridge (culvert) and roadbed, making the differential settlement between bridge foundations slow and uniform. Using industrial solid waste cementing materials to replace cement, and waste incineration ash and waste sintered bricks to replace raw soil, achieves the synergistic utilization of multiple solid wastes, eliminates the use of cement and raw soil, improves the utilization rate of industrial solid waste, greatly reduces the production cost and energy consumption of foamed lightweight soil, saves natural resources, and protects the environment. At the same time, waste incineration ash and waste sintered bricks have certain potential cementing activity, which plays a role in improving mechanical strength. The low degree of hydration of industrial solid waste in the early stage and the slow strength formation, combined with the grid structure formed by anti-cracking fibers, helps to alleviate the problem of drying shrinkage cracks. The tripyridine covalent organic framework material can coordinate and adsorb metal ions, which greatly alleviates the problem of heavy metal pollution of the surrounding land by waste incineration ash.

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a lightweight foamed soil backfill structure for solid waste according to an embodiment of the present invention;

[0027] Figure label:

[0028] 1. Roadbed; 2. Steps; 3. Cement-stabilized crushed stone base course; 4. Lightweight concrete made entirely of solid waste; 5. Concrete slab; 6. Main beam; 7. Abutment cap; 8. Bridge abutment; 9. Bamboo reinforcement; 10. Waterproof layer; 11. Asphalt concrete. Detailed Implementation

[0029] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0030] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] In the description of this invention, it should be understood that the terms "center", "around", "lateral", "longitudinal", "length", "thickness", "angle", "up", "down", "left", "right", etc., which indicate the orientation or location, are limited to simplifying the description of this invention and are not specific locations or orientations. The above terms are not intended to limit this invention.

[0033] The specific connection methods of each part in this invention all adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment all adopt conventional models in the prior art. In addition, the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0034] Example 1

[0035] This embodiment provides a lightweight foamed soil made entirely from solid waste, comprising the following components by weight: 100 parts industrial solid waste cementitious material, 90 parts waste incineration ash, 120 parts waste sintered bricks, 3 parts alkali activator, 1.5 parts water-reducing agent, 1 part expanding agent, 3 parts dense waterproofing agent, 8 parts recycled plastic granules, 2 parts crack-resistant fiber, 2 parts antifreeze agent, 15 parts foaming agent, 2 parts foam stabilizer, and 160 parts water.

[0036] Industrial solid waste cementing materials consist of activating materials and potential cementing materials in a ratio of 1:1.5. The activating material is carbide slag, and the potential cementing materials are slag and fly ash.

[0037] The waste incineration ash is the bottom ash after waste incineration. After crushing, 3 wt‰ of COF material is added and mixed evenly. The COF material is a tripyridine covalent organic framework material.

[0038] The alkali activator is Na2SiO3 powder with a modulus of 3.0; the water-reducing agent is polycarboxylate water-reducing agent; and the expanding agent is magnesium oxide and calcium sulfoaluminate.

[0039] The crack-resistant fiber is basalt fiber; the organic antifreeze agents are glycerol and triethanolamine.

[0040] The foaming agent is a composite foaming agent; the foam stabilizer is hydroxypropyl methylcellulose ether.

[0041] This embodiment provides a method for preparing the above-mentioned lightweight foamed soil made entirely from solid waste, including the following steps:

[0042] S1. Mix the foaming agent, foam stabilizer and water according to the above weight proportions to prepare foam for later use.

[0043] S2. Weigh the industrial solid waste cementitious material, waste incineration ash, waste sintered bricks, alkali activator, water-reducing agent, expansion agent, densifying and waterproofing agent, recycled plastic granules, crack-resistant fiber and antifreeze agent according to the above weight parts, stir at a speed of 300-500 r / min for 3-4 min to form a uniform dry mixture, then mix it evenly with the remaining water and stir for 60-90 s to obtain premixed lightweight foamed soil for later use.

[0044] S3. Mechanically mix the premixed lightweight foam soil with the foam for 90-150 seconds, then pour, solidify and cure to obtain the solid waste lightweight foam soil.

[0045] Example 2

[0046] This embodiment provides a lightweight foamed soil made entirely of solid waste. The preparation method and raw materials are basically the same as those in Example 1. The difference from Example 1 is that the industrial solid waste cementing material is replaced with all cement.

[0047] Example 3

[0048] This embodiment provides a lightweight foamed soil made entirely from solid waste. The preparation method and raw materials are basically the same as those in Embodiment 1. The difference from Embodiment 1 is that COF material is not added after the waste incineration ash is crushed.

[0049] Example 4

[0050] This embodiment provides a lightweight foamed soil made entirely from solid waste. The preparation method and raw materials are basically the same as those in Example 1. The difference from Example 1 is that it does not contain anti-cracking fibers.

[0051] Example 5

[0052] This embodiment provides a lightweight foamed soil made entirely from solid waste. The preparation method and raw materials are basically the same as those in Example 1. The difference from Example 1 is that the waste incineration ash and waste sintered bricks are replaced with fine sand and sandy soil.

[0053] The performance of the foamed lightweight soil materials prepared in Examples 1-5 of this invention was verified, and the performance test results are shown in Table 1.

[0054] Table 1 Performance Test Data

[0055]

[0056] Example 6

[0057] As attached Figure 1 As shown, this embodiment provides a backfill structure for an abutment prepared from lightweight foamed soil made entirely from solid waste, including a roadbed 1 and an abutment 8. The bottom of the pile foundation of the abutment 8 is located in the natural foundation, and a cap 7 is provided on the top of the abutment 8. A main beam 6 is provided in front of the cap 7. Lightweight foamed soil 4 made entirely from solid waste is filled between the roadbed 1 and the abutment 8. The overlap between the roadbed 1 and the lightweight foamed soil 4 is excavated into a step 2, which is inclined. The lightweight foamed soil 4 backfill is cut into longitudinal blocks and connected horizontally and longitudinally by bamboo reinforcement 9. A cement-stabilized crushed stone base course 3 is placed on the side of the roadbed 1 above the foamed lightweight soil 4, and a concrete slab 5 is placed on the side of the abutment 8. The cement-stabilized crushed stone base course 3 and the concrete slab 5 are also cut into blocks vertically, with the concrete slab at the bottom of the intersection. The cement-stabilized crushed stone base course 3 and the concrete slab 5 are waterproof layers 10, which overlap to the cap 7. Asphalt concrete 11 is laid on top of the waterproof layer 10. The roadbed 1 and lightweight foamed soil 4 are dynamic compaction foundations. The waterproof layer 10 is laid up to the cap 7, completely enclosing the backfill structure behind the abutment.

[0058] Therefore, the present invention provides a lightweight foamed soil made entirely from solid waste, its preparation method, and its application in abutment backfilling, which solves the problems of severe settlement, excessive cement consumption, difficulty in disposing of industrial solid waste, and excessive environmental pollution caused by existing backfilling techniques. The backfill material formed by the synergistic effect of the components has a strength far higher than that of ordinary roadbed soil materials, and has the characteristics of low material usage and light weight.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A lightweight foamed soil made entirely from solid waste, characterized in that, The composition of the all-solid-waste lightweight foamed soil includes the following raw materials in parts by weight: 100 parts of industrial solid waste cementitious material, 60-120 parts of waste incineration ash, 80-150 parts of waste sintered bricks, 2-4 parts of alkali activator, 1-2 parts of water-reducing agent, 0.5-1 part of expanding agent, 2-4 parts of dense waterproofing agent, 6-10 parts of recycled plastic granules, 1-3 parts of crack-resistant fiber, 2-3 parts of antifreeze agent, 10-20 parts of foaming agent, 1-3 parts of foam stabilizer, and 120-200 parts of water.

2. The all-solid-waste lightweight foamed soil backfill structure according to claim 1, characterized in that, The industrial solid waste cementitious material comprises an activating material and a potential cementitious material, with a mass ratio of 1:1 to 1:

2. The main component of the activating material is carbide slag, mixed with one or two of cement and hydrated lime. The potential cementitious material is one or more of desulfurized gypsum, red mud, slag, and fly ash.

3. The lightweight foamed soil for solid waste as described in claim 2, characterized in that, The red mud is sintered red mud that has not been calcined, and is dried at 105°C for at least 48 hours, and then crushed and sieved.

4. The lightweight foamed soil for solid waste as described in claim 1, characterized in that, The waste incineration ash is the bottom ash portion after waste incineration. After crushing, 3 wt‰ of COF material is added and mixed evenly. The COF material is a tripyridine covalent organic framework material.

5. The lightweight foamed soil for solid waste as described in claim 1, characterized in that, The alkali activator is Na2SiO3 powder with a modulus of 3.0; the water-reducing agent is one or a combination of polycarboxylate water-reducing agent and naphthalene-based water-reducing agent; the expanding agent is one or a combination of magnesium oxide and calcium sulfoaluminate; the waste sintered bricks are processed into powder material through a crushing process.

6. The lightweight foamed soil for solid waste as described in claim 1, characterized in that, The anti-cracking fiber is one or a combination of two or more of basalt fiber, polyester fiber, and glass fiber; the organic antifreeze agent is one or a combination of glycerol, triethanolamine, glucose, urea, and ethylene glycol.

7. The lightweight foamed soil for solid waste as described in claim 1, characterized in that, The foaming agent is any one of rosin-based foaming agents, anionic surfactants with tertiary amine side groups, protein-based foaming agents, and composite foaming agents; the foam stabilizer is any one of hydroxypropyl methylcellulose ether, calcium stearate, trisodium phosphate, and redispersible latex powder.

8. A method for preparing a lightweight foamed soil for solid waste as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. Mix the foaming agent, foam stabilizer and water to make foam, and set aside. S2. Stir the industrial solid waste cementitious material, waste incineration ash, waste sintered bricks, alkali activator, water reducing agent, expansion agent, densifying and waterproofing agent, recycled plastic granules, crack-resistant fiber and antifreeze agent at a speed of 300-500 r / min for 3-4 min to form a uniform dry mixture. Then mix it with the remaining water evenly and stir for 60-90 s to obtain premixed lightweight foamed soil for later use. S3. Mechanically mix the premixed lightweight foam soil with the foam for 90-150 seconds, then pour, solidify and cure to obtain the solid waste lightweight foam soil.

9. An application of a lightweight foamed soil containing solid waste as described in any one of claims 1-7, characterized in that, The lightweight foamed soil is used to form a lightweight foamed soil abutment backfill structure, which is set between the roadbed and the bridge abutment. The overlap between the roadbed and the lightweight foamed soil abutment backfill structure is excavated into an inclined step. The side of the lightweight foamed soil abutment backfill structure adjacent to the roadbed is a cement-stabilized crushed stone base course, and the side adjacent to the bridge abutment is a concrete slab. Both the cement-stabilized crushed stone base course and the concrete slab are vertically cut into blocks, and the junction is a sloping cut with the concrete at the bottom. The cement-stabilized crushed stone base course and the concrete slab are waterproof layers, which overlap to the abutment cap. Asphalt concrete is laid on top of the waterproof layer.

10. The application of a lightweight foamed soil for solid waste as described in claim 9, characterized in that, The solid waste lightweight foam soil backfill structure is divided into longitudinal blocks and connected horizontally and longitudinally using bamboo reinforcement.

Images