High-uniformity red-mud-based curing agent for roadbed soil and construction method of high-uniformity red-mud-based curing agent

Abstract

The invention relates to the technical research field of civil engineering materials, in particular to a high-uniformity red-mud-based curing agent for roadbed soil and a construction method thereof.The high-uniformity red-mud-based curing agent for the roadbed soil comprises, by mass, 50-100 parts of treatment-free liquid red mud and 5-30 parts of a water-based curing agent, and aims to develop the high-uniformity red-mud-based curing agent for the roadbed soil and the construction method of the high-uniformity red-mud-based curing agent for the roadbed soil. The red mud can be used as a roadbed soil curing agent after being scientifically treated and cured, the roadbed performance and the water stability are improved by adding the solid waste material, the improved roadbed soil has certain strength and stability, the bearing capacity of a roadbed can be effectively improved, the service life of a road is prolonged, and the roadbed soil has a good application prospect. And the curing agent is a liquid curing agent, has good permeability, good workability with soil, convenience in construction operation and good spreading uniformity in construction, can effectively absorb a large amount of red mud and reduce environmental pollution, and has important social benefits and economic benefits.

Description

Technical Field

[0001] The invention belongs to the field of civil engineering material technology research, and in particular is a high-uniformity red mud-based curing agent for roadbed soil and a construction method thereof. Background Art

[0002] With the rapid development of road traffic construction, roads are important channels connecting urban and rural areas and promoting economic development. The roadbed is the foundation of the road structure, and the quality of the roadbed is directly related to driving safety, road service life, and economic and social development. At present, due to the high cost of natural sand, cement, asphalt concrete, etc., their resources are limited, and excessive exploitation may cause damage to the environment. On the other hand, my country's modernization level is also constantly improving. The development of the aluminum industry is also accompanied by the generation of a large amount of industrial solid waste red mud. The aluminum industry solid waste red mud contains a variety of valuable components. Through reasonable recycling and utilization, it can replace some natural materials for roadbed construction, improve economic benefits and reduce costs, alleviate the shortage of natural materials for infrastructure, and promote the recycling of solid waste resources.

[0003] At present, the technology of roadbed soil curing agent has attracted the attention of many scholars. Although a large number of domestic and foreign studies have been conducted to improve it, there are still many problems that have not been solved. For example, although the current cement soil and lime soil curing agents have improved the strength and stability of the roadbed, some of the curing agents that have been used in roadbed construction can only make up for the problem of insufficient strength by increasing the amount of curing agents added, which increases the construction cost; and the existing curing agents have insufficient water stability and uniformity, which is more serious during the rainy season, thus affecting the stability and service life of the road; nowadays, domestic roadbed soil curing agents rely heavily on imports, resulting in high costs, which to a certain extent limits the widespread application and promotion of roadbed soil curing agents; currently, the roadbed soil curing agent products on the market lack innovative and high-performance products, and the types and quantities of environmentally friendly and solid waste resource recycling roadbed soil curing agents on the market are relatively small, which cannot meet market demand.

[0004] At the same time, red mud, as an industrial solid waste, will cause air, water and soil pollution if not properly handled. In addition, its storage not only requires the occupation of a large area of ​​land, but also consumes a lot of yard construction and maintenance costs. Red mud contains many valuable components such as SiO2, Al2O3, CaO, Fe2O3, etc., and irrational use will cause waste of resources. At present, the research on red mud at home and abroad mainly focuses on activation, modification and composite utilization with other materials, and industrial solid waste red mud has not been used in large quantities in road construction. At present, red mud-based curing agents are used in road construction, which have many advantages such as environmental friendliness, superior performance, significant economic benefits and environmental advantages. In the fields of civil engineering and road engineering, it has broad application prospects and important research value.

[0005] The existing technology still fails to solve the performance problems such as high uniformity of roadbed soil curing agents and the problem of red mud resource utilization. Therefore, it is urgently necessary to invent a high-uniformity red mud-based curing agent for roadbed soil and a construction method thereof. Summary of the invention

[0006] The purpose of the present invention is to provide a high-uniformity red mud-based curing agent for roadbed soil and a construction method thereof. The curing agent has excellent uniformity and curing effect, can effectively improve the strength and stability of roadbed soil, can realize the large-scale use of red mud and red mud-based curing agent on road subgrade, reduces the use of natural ore materials, saves costs and speeds up the construction cycle, achieves the effect of energy conservation and emission reduction, and effectively solves the problems of industrial solid waste red mud and roadbed soil performance defects, so as to achieve the recycling of solid waste resources, reduce pollution, and the strength of the curing agent made of red mud meets the standard, which is adapted to the current trend of technological development.

[0007] The technical solution adopted by the present invention is:

[0008] A high-uniformity red mud-based curing agent for roadbed soil comprises the following components in parts by mass:

[0009] 50-100 parts of untreated liquid red mud;

[0010] 5-30 parts of water-based curing agent.

[0011] Furthermore, the total mass proportion of active ingredients of the untreated liquid red mud alkaline components Na2O, K2O, and Al2O3 is 24.1-32.9%, of which the Na2O content is 2.4-5.6%, the Al2O3 content is 20.5-25.8%, and the K2O content is 1.2-1.5%.

[0012] Furthermore, the untreated liquid red mud is subjected to water screening and filtration treatment, and the average particle size is no more than 200 meshes and the density is 2650-2870 kg / m 3 , the moisture content is 25-32%.

[0013] Furthermore, the untreated liquid red mud is prepared by screening and filtering untreated red mud to remove large impurities, mixing it with an appropriate amount of water, and formulating it into a slurry-like material with appropriate viscosity and fluidity. Then, filtering equipment is used to remove sand, gravel, impurities, etc. in the mud to obtain a relatively pure red mud slurry. Finally, as needed, water is added or part of the water is evaporated to adjust the water content of the red mud slurry to meet the requirements of subsequent construction.

[0014] Furthermore, the water-based curing agent comprises water, an alkaline compound and a calcium-rich substance, and its mass parts are as follows:

[0015] 5-12 parts water;

[0016] 3-5 parts of basic compound;

[0017] 2-4 portions of calcium-rich substances.

[0018] Furthermore, the alkaline compound is prepared by mixing sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder, and the mass fractions thereof are as follows:

[0019] 3-5 parts of sodium hydroxide liquid;

[0020] 2-4 parts of sodium oxide liquid;

[0021] 1-4 parts of calcium oxide solid powder.

[0022] Furthermore, the mass concentration of the mixed liquid of the sodium hydroxide liquid and the sodium oxide liquid is not less than 48%, and the mass accounts for not less than 32% of the total amount of the alkaline compounds.

[0023] Furthermore, the calcium content of the calcium oxide solid powder is not less than 85%, the impurity content of the powder is not more than 0.5%, and the powder particle size is not more than 0.070 mm.

[0024] Furthermore, the water-based curing agent has an admixture ratio ranging from 2% to 6% of the roadbed soil mass, and a pH value of not less than 8.

[0025] Furthermore, the calcium-rich material is obtained by crushing, screening and grinding waste concrete blocks, and its particle size range is no more than 0.145 mm. The main components include unhydrated calcium silicate, calcium hydroxide and silicon dioxide, and the total mass proportion of active ingredients is no less than 75%, and the calcium content is no less than 17%.

[0026] Furthermore, the calcium-rich substance and the untreated liquid red mud are mixed to form high-calcium red mud, and the high-calcium red mud forms hydration products such as hydrated sodium calcium silicate gel, hydrated silicon and hydrated calcium aluminate gel. The hydration products have high mechanical strength and stability, thereby improving the uniformity and strength of the red mud-based curing agent.

[0027] Furthermore, SiO2, Al2O3, etc. in the untreated liquid red mud can also be extracted and utilized under alkaline conditions, and by adjusting the type and concentration of the alkaline components, it can be suitable for use as a soil solidifier and improver. The properties of the red mud can also be changed to make it suitable for use in building materials, adsorption materials and other fields, providing a new way for resource utilization.

[0028] In addition, the present invention also provides a construction method of a high-uniformity red mud-based curing agent for roadbed soil, which specifically comprises the following steps:

[0029] a) The untreated liquid red mud is subjected to water screening and filtration to remove large impurities, and a detailed chemical composition analysis is performed to determine its water content, the total mass percentage of active ingredients of alkaline components, and the precise contents of Na2O, Al2O3 and K2O;

[0030] b) preparing the alkaline compound: putting sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder into a stirring pot in a certain proportion and stirring evenly for 10-15 minutes at a stirring rate of 40-60 r / min to obtain the alkaline compound;

[0031] c) Preparation of water-based curing agent: accurately calculate and weigh the required water, alkaline compound and calcium-rich substance, put them into a high-speed stirrer in a certain proportion for mixing, the stirring rate is 200-300r / min, and the stirring time is 15-25 minutes, so as to obtain the water-based curing agent;

[0032] d) preparing a red mud-based curing agent: mixing the untreated liquid red mud and the water-based curing agent in a high-speed stirrer in a certain proportion at a stirring rate of 250-300 r / min for 20-25 minutes until a uniform slurry is formed, thereby obtaining a red mud-based curing agent;

[0033] e) Construction method: Mix the prepared red mud-based curing agent with the roadbed soil according to the mixing ratio range, and spray it with a sprayer at a spraying rate of 0.5-1kg / m 2 The travel speed of the spreader is 50-60m / min. After the spraying operation is completed, the construction is completed by using a grader to dig and mix and a roller to compact.

[0034] The beneficial effects produced by the present invention are as follows:

[0035] (1) A high-uniformity red mud-based solidifying agent for roadbed soil and a construction method thereof. Red mud is an industrial waste. Reasonable use can reduce the exploitation of natural resources and the damage to the environment. The red mud-based solidifying agent is made through a reasonable preparation process. It has good environmental performance and will not cause secondary pollution to the environment. It can reduce the cost of projects such as road construction and improve economic benefits.

[0036] (2) Red mud-based curing agent can significantly improve the curing effect of roadbed soil, can replace cement to stabilize the crushed stone subbase, effectively improve the uniformity and other properties of the cured soil, thereby improving the overall stability and deformation resistance of the roadbed, enhancing the stability of the project, and at the same time can meet the bearing requirements of roadbeds of different grades, with potential technical and economic advantages;

[0037] (3) The construction method of red mud-based solidifying agent is simple, easy to operate, and has high early strength. Vehicles can pass through after the construction is completed, shortening the construction period. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The present invention provides a preparation process and construction flow chart of a high-uniformity red mud-based curing agent for roadbed soil;

[0039] Figure 2 The present invention is a preparation flow chart of a high-uniformity red mud-based curing agent for roadbed soil;

[0040] Figure 3 The present invention is a construction drawing of a high-uniformity red mud-based curing agent for roadbed soil. DETAILED DESCRIPTION

[0041] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be pointed out that the embodiments described below are intended to facilitate the understanding of the present invention and do not have any limiting effect on the present invention.

[0042] Example 1

[0043] A high-uniformity red mud-based curing agent for roadbed soil comprises the following components in parts by mass: 50 parts of untreated liquid red mud and 5 parts of a water-based curing agent.

[0044] The total mass proportion of active ingredients of untreated liquid red mud alkaline components Na2O, K2O and Al2O3 is 24.1%, of which the content of Na2O is 2.4%, the content of Al2O3 is 20.5% and the content of K2O is 1.2%.

[0045] The untreated liquid red mud is screened and filtered with water, and the average particle size is 165 mesh and the density is 2650kg / m 3 , the moisture content is 25%.

[0046] The water-based curing agent is composed of water, alkaline compounds and calcium-rich substances, and its mass parts are as follows:

[0047] 5 parts water;

[0048] 3 parts of basic compound;

[0049] 2 parts of calcium-rich substances.

[0050] The alkaline compound is obtained by compounding sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder, and its mass parts are as follows:

[0051] 3 parts of sodium hydroxide liquid;

[0052] 2 parts of sodium oxide liquid;

[0053] 2 parts of calcium oxide solid powder.

[0054] The mass concentration of the mixed liquid of sodium hydroxide liquid and sodium oxide liquid is 48%, and the mass accounts for 32% of the total amount of alkaline compounds.

[0055] The calcium oxide solid powder has a calcium content of 85%, an impurity content of 0.5%, and a powder particle size of 0.070 mm.

[0056] The proportion of water-based curing agent is 2% of the roadbed soil mass, and the pH value is 8.

[0057] The calcium-rich material is obtained by crushing, screening and grinding waste concrete blocks, with a particle size range of 0.145 mm. The main components include unhydrated calcium silicate, calcium hydroxide and silicon dioxide, and the total mass proportion of active ingredients is 75%, and the calcium content is 17%.

[0058] The above-mentioned high-uniformity red mud-based curing agent for roadbed soil and the construction method thereof, the steps are as follows:

[0059] a) The untreated liquid red mud was subjected to water screening and filtration to remove large impurities and a detailed chemical composition analysis was performed, the water content was 25%, the total mass proportion of active components of alkaline components was 24.1%, the Na2O content was 2.4%, the Al2O3 content was 20.5% and the K2O content was 1.2%;

[0060] b) preparing the alkaline compound: putting sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder into a stirring pot in a mass ratio of 1.5:1:1 and stirring evenly for 10 minutes at a stirring rate of 40 r / min to obtain the alkaline compound;

[0061] c) Preparation of water-based curing agent: accurately calculate and weigh the required water, alkaline compound and calcium-rich substance, put them into a high-speed stirrer in a mass ratio of 2.5:1.5:1 for mixing, with a stirring rate of 200 r / min and a stirring time of 15 minutes to obtain a water-based curing agent;

[0062] d) preparing a red mud-based curing agent: mixing the untreated liquid red mud and the water-based curing agent in a high-speed stirrer at a mass ratio of 10:1, at a stirring rate of 250 r / min, for 20 minutes, until a uniform slurry is formed, thereby obtaining the red mud-based curing agent described in Example 1;

[0063] e) Construction method: Mix the prepared red mud-based curing agent with the roadbed soil according to the mixing ratio range, and spray it with a sprayer at a spraying rate of 0.5kg / m 2 The travel speed of the spreader is 50m / min. After the spraying operation is completed, the construction is completed by using a grader to dig and mix and a roller to compact.

[0064] Example 2

[0065] A high-uniformity red mud-based curing agent for roadbed soil comprises the following components in parts by mass: 70 parts of untreated liquid red mud and 10 parts of a water-based curing agent.

[0066] The total mass proportion of active ingredients of untreated liquid red mud alkaline components Na2O, K2O and Al2O3 is 27.35%, of which the content of Na2O is 3.3%, the content of Al2O3 is 22.7% and the content of K2O is 1.35%.

[0067] The untreated liquid red mud is screened and filtered with water, and the average particle size is 175 mesh and the density is 2695kg / m 3 , the moisture content is 27%.

[0068] The water-based curing agent is composed of water, alkaline compounds and calcium-rich substances, and its mass parts are as follows:

[0069] 7 parts water;

[0070] 4 parts of a basic compound;

[0071] 3 parts of calcium-rich substances.

[0072] The alkaline compound is prepared by mixing sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder, and its mass parts are as follows:

[0073] 3 parts of sodium hydroxide liquid;

[0074] 3 parts of sodium oxide liquid;

[0075] 3 parts of calcium oxide solid powder.

[0076] The mass concentration of the mixed liquid of sodium hydroxide liquid and sodium oxide liquid is 51%, and the mass accounts for 33.5% of the total amount of alkaline compounds.

[0077] The calcium oxide solid powder has a calcium content of 87.5%, an impurity content of 0.45%, and a powder particle size of 0.060 mm.

[0078] The dosage of water-based curing agent is 4% of the roadbed soil mass, and the pH value is 9.

[0079] The calcium-rich material is obtained by crushing, screening and grinding waste concrete blocks. Its particle size range is 0.135mm. The main components include unhydrated calcium silicate, calcium hydroxide and silicon dioxide. The total mass of active ingredients accounts for 77%, and the calcium content is 19%.

[0080] The above-mentioned high-uniformity red mud-based curing agent for roadbed soil and the construction method thereof, the steps are as follows:

[0081] a) The untreated liquid red mud was subjected to water screening and filtration to remove large impurities and a detailed chemical composition analysis was performed, the water content was 27%, the total mass proportion of active components of alkaline components was 27.35%, of which the content of Na2O was 3.3%, the content of Al2O3 was 22.7% and the content of K2O was 1.35%;

[0082] b) preparing the alkaline compound: putting sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder into a stirring pot in a mass ratio of 1:1:1 and stirring evenly for 15 minutes at a stirring rate of 50 r / min to obtain the alkaline compound;

[0083] c) preparing a water-based curing agent: accurately calculating and weighing the required water, alkaline compound and calcium-rich substance, and mixing them in a high-speed stirrer at a mass ratio of 7:4:3, with a stirring rate of 260 r / min and a stirring time of 22 minutes to obtain a water-based curing agent;

[0084] d) preparing a red mud-based curing agent: mixing the untreated liquid red mud and the water-based curing agent in a high-speed stirrer at a mass ratio of 7:1 at a stirring rate of 250 r / min for 20 minutes until a uniform slurry is formed, thereby obtaining the red mud-based curing agent described in Example 2;

[0085] e) Construction method: Mix the prepared red mud-based curing agent with the roadbed soil according to the mixing ratio range, and spray it with a sprayer at a spraying rate of 0.5kg / m 2 The travel speed of the spreader is 50m / min. After the spraying operation is completed, the construction is completed by using a grader to dig and mix and a roller to compact.

[0086] Example 3

[0087] A high-uniformity red mud-based curing agent for roadbed soil comprises the following components in parts by mass: 80 parts of untreated liquid red mud and 15 parts of a water-based curing agent.

[0088] The total mass proportion of active ingredients of untreated liquid red mud alkaline components Na2O, K2O and Al2O3 is 28.5%, of which the content of Na2O is 3.75%, the content of Al2O3 is 23.4% and the content of K2O is 1.35%.

[0089] The untreated liquid red mud is screened and filtered with water, and the average particle size is 185 mesh and the density is 2735kg / m 3 , the moisture content is 29%.

[0090] The water-based curing agent is composed of water, alkaline compounds and calcium-rich substances, and its mass parts are as follows:

[0091] 8 parts water;

[0092] 5 parts of basic compound;

[0093] 2 parts of calcium-rich substances.

[0094] The alkaline compound is prepared by mixing sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder, and its mass parts are as follows:

[0095] 4 parts of sodium hydroxide liquid;

[0096] 2 parts of sodium oxide liquid;

[0097] 2 parts of calcium oxide solid powder.

[0098] The mass concentration of the mixed liquid of sodium hydroxide liquid and sodium oxide liquid is 52.5%, and the mass accounts for 34% of the total amount of alkaline compounds.

[0099] The calcium oxide solid powder has a calcium content of 89.5%, an impurity content of 0.42%, and a powder particle size of 0.055 mm.

[0100] The proportion of water-based curing agent is 5% of the roadbed soil mass, and the pH value is 10.

[0101] The calcium-rich material is obtained by crushing, screening and grinding waste concrete blocks, and has a particle size range of 0.130 mm. The main components include unhydrated calcium silicate, calcium hydroxide and silicon dioxide, and the total amount of active ingredients is 79%, and the calcium content is 22%.

[0102] The above-mentioned high-uniformity red mud-based curing agent for roadbed soil and the construction method thereof, the steps are as follows:

[0103] a) The untreated liquid red mud was subjected to water screening and filtration to remove large impurities and a detailed chemical composition analysis was performed, and the water content was 29%, the total mass percentage of active components of alkaline components was 28.5%, the Na2O content was 3.75%, the Al2O3 content was 23.4% and the K2O content was 1.35%;

[0104] b) preparing the alkaline compound: putting sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder into a stirring pot in a mass ratio of 2:1:1 and stirring evenly for 12 minutes at a stirring rate of 40 r / min to obtain the alkaline compound;

[0105] c) Preparation of water-based curing agent: accurately calculate and weigh the required water, alkaline compound and calcium-rich substance, put them into a high-speed stirrer in a mass ratio of 4:2.5:1, mix them at a stirring rate of 250 r / min and a stirring time of 20 minutes, and then obtain a water-based curing agent;

[0106] d) preparing a red mud-based curing agent: mixing the untreated liquid red mud and the water-based curing agent in a high-speed stirrer at a mass ratio of 16:3, at a stirring rate of 300 r / min, for 25 minutes, until a uniform slurry is formed, thereby obtaining the red mud-based curing agent described in Example 3;

[0107] e) Construction method: Mix the prepared red mud-based curing agent with the roadbed soil according to the mixing ratio range, and spray it with a sprayer at a spraying rate of 0.65kg / m 2 The travel speed of the spreader is 54m / min. After the spraying operation is completed, the construction is completed by using a grader to dig and mix, and a roller to compact and shape.

[0108] Example 4

[0109] A high-uniformity red mud-based curing agent for roadbed soil comprises the following components in parts by mass: 90 parts of untreated liquid red mud and 20 parts of a water-based curing agent.

[0110] The total mass proportion of active ingredients of untreated liquid red mud alkaline components Na2O, K2O and Al2O3 is 28.75%, of which the content of Na2O is 3.25%, the content of Al2O3 is 24.1% and the content of K2O is 1.4%.

[0111] The untreated liquid red mud is screened and filtered with water, and the average particle size is 160 mesh and the density is 2635kg / m 3 , the moisture content is 30.5%.

[0112] The water-based curing agent is composed of water, alkaline compounds and calcium-rich substances, and its mass parts are as follows:

[0113] 8 parts water;

[0114] 4 parts of a basic compound;

[0115] 3 parts of calcium-rich substances.

[0116] The alkaline compound is obtained by compounding sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder, and its mass parts are as follows:

[0117] 4 parts of sodium hydroxide liquid;

[0118] 3 parts of sodium oxide liquid;

[0119] 1 part of calcium oxide solid powder.

[0120] The mass concentration of the mixed liquid of sodium hydroxide liquid and sodium oxide liquid is 53%, and the mass accounts for 34.5% of the total amount of alkaline compounds.

[0121] The calcium oxide solid powder has a calcium content of 90.5%, an impurity content of 0.4%, and a powder particle size of 0.050 mm.

[0122] The proportion of water-based curing agent is 5.5% of the roadbed soil mass, and the pH value is 12.5.

[0123] The calcium-rich material is obtained by crushing, screening and grinding waste concrete blocks. Its particle size range is 0.126mm. The main components include unhydrated calcium silicate, calcium hydroxide and silicon dioxide. The active ingredients account for 80.5% of the total amount, and the calcium content is 23.5%.

[0124] The above-mentioned high-uniformity red mud-based curing agent for roadbed soil and the construction method thereof, the steps are as follows:

[0125] a) The untreated liquid red mud was screened and filtered to remove large impurities, and a detailed chemical composition analysis was performed, showing that the water content was 30.5%, the total mass proportion of active components of alkaline components was 28.75%, the Na2O content was 3.25%, the Al2O3 content was 24.1% and the K2O content was 1.4%;

[0126] b) preparing the alkaline compound: putting sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder into a stirring pot in a mass ratio of 4:3:1 and stirring evenly for 14 minutes at a stirring rate of 40 r / min to obtain the alkaline compound;

[0127] c) Preparation of water-based curing agent: accurately calculate and weigh the required water, alkaline compound and calcium-rich substance, put them into a high-speed stirrer in a mass ratio of 2:1:0.75, mix them at a stirring rate of 200 r / min and a stirring time of 15 minutes, and then obtain a water-based curing agent;

[0128] d) preparing a red mud-based curing agent: mixing the untreated liquid red mud and the water-based curing agent in a high-speed stirrer at a mass ratio of 4.5:1, at a stirring rate of 280 r / min, for 24 minutes, until a uniform slurry is formed, thereby obtaining the red mud-based curing agent described in Example 4;

[0129] e) Construction method: Mix the prepared red mud-based curing agent with the roadbed soil according to the mixing ratio range, and spray it with a sprayer at a spraying rate of 0.7kg / m 2 The travel speed of the spreader is 53m / min. After the spraying operation is completed, the construction is completed by using a grader to dig and mix, and a roller to compact and shape.

[0130] Example 5

[0131] A high-uniformity red mud-based curing agent for roadbed soil comprises the following components in parts by mass: 100 parts of untreated liquid red mud and 30 parts of a water-based curing agent.

[0132] The total mass proportion of active ingredients of untreated liquid red mud alkaline components Na2O, K2O and Al2O3 is 32.9%, of which the content of Na2O is 5.6%, the content of Al2O3 is 25.8% and the content of K2O is 1.5%.

[0133] The untreated liquid red mud is screened and filtered with water, and the average particle size is 200 mesh and the density is 2870kg / m 3 , the moisture content is 32%.

[0134] The water-based curing agent is composed of water, alkaline compounds and calcium-rich substances, and its mass parts are as follows:

[0135] 12 parts water;

[0136] 5 parts of basic compound;

[0137] 4 parts of calcium-rich substances.

[0138] The alkaline compound is prepared by mixing sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder, and its mass parts are as follows:

[0139] 5 parts of sodium hydroxide liquid;

[0140] 4 parts of sodium oxide liquid;

[0141] 4 parts of calcium oxide solid powder.

[0142] The mass concentration of the mixed liquid of sodium hydroxide liquid and sodium oxide liquid is 58%, and the mass accounts for 36.5% of the total amount of alkaline compounds.

[0143] The calcium oxide solid powder has a calcium content of 94.5%, an impurity content of 0.35%, and a powder particle size of 0.045 mm.

[0144] The proportion of water-based curing agent is 6% of the roadbed soil mass, and the pH value is 11.

[0145] The calcium-rich material is obtained by crushing, screening and grinding waste concrete blocks. Its particle size range is 0.120 mm. The main components include unhydrated calcium silicate, calcium hydroxide and silicon dioxide. The total mass of active ingredients accounts for 84.5%, and the calcium content is 25%.

[0146] The above-mentioned high-uniformity red mud-based curing agent for roadbed soil and the construction method thereof, the steps are as follows:

[0147] a) The untreated liquid red mud was subjected to water screening and filtration to remove large impurities and a detailed chemical composition analysis was performed, the water content was 32%, the total mass proportion of active components of alkaline components was 32.9%, the Na2O content was 5.6%, the Al2O3 content was 25.8% and the K2O content was 1.5%;

[0148] b) preparing the alkaline compound: putting sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder into a stirring pot at a mass ratio of 1.25:1:1 and stirring evenly for 15 minutes at a stirring rate of 60 r / min to obtain the alkaline compound;

[0149] c) preparing a water-based curing agent: accurately calculating and weighing the required water, alkaline compound and calcium-rich substance, and mixing them in a high-speed stirrer at a mass ratio of 3:1.25:1, with a stirring rate of 300 r / min and a stirring time of 25 minutes to obtain a water-based curing agent;

[0150] d) preparing a red mud-based curing agent: mixing the untreated liquid red mud and the water-based curing agent in a high-speed stirrer at a mass ratio of 10:3, at a stirring rate of 300 r / min, for 25 minutes, until a uniform slurry is formed, to obtain the red mud-based curing agent described in Example 5;

[0151] e) Construction method: Mix the prepared red mud-based curing agent with the roadbed soil according to the mixing ratio range, and spray it with a sprayer at a spraying rate of 0.85kg / m 2 The travel speed of the spreader is 57m / min. After the spraying operation is completed, the construction is completed by using a grader to dig and mix, and a roller to compact and shape.

[0152] Example 6

[0153] A high-uniformity red mud-based curing agent for roadbed soil comprises the following components in parts by mass: 85 parts of untreated liquid red mud and 15 parts of a water-based curing agent.

[0154] The total mass proportion of active ingredients of untreated liquid red mud alkaline components Na2O, K2O and Al2O3 is 29.12%, of which the content of Na2O is 3.12%, the content of Al2O3 is 24.68% and the content of K2O is 1.32%.

[0155] The untreated liquid red mud is screened and filtered with water, and the average particle size is 186.5 mesh and the density is 2740kg / m 3 , the moisture content is 29.5%.

[0156] The water-based curing agent is composed of water, alkaline compounds and calcium-rich substances, and its mass parts are as follows:

[0157] 9 parts water;

[0158] 3 parts of basic compound;

[0159] 4 parts of calcium-rich substances.

[0160] The alkaline compound is obtained by compounding sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder, and its mass parts are as follows:

[0161] 3 parts of sodium hydroxide liquid;

[0162] 2 parts of sodium oxide liquid;

[0163] 4 parts of calcium oxide solid powder.

[0164] The mass concentration of the mixed liquid of sodium hydroxide liquid and sodium oxide liquid is 53%, and the mass accounts for 34.5% of the total amount of alkaline compounds.

[0165] The calcium oxide solid powder has a calcium content of 90%, an impurity content of 0.4%, and a powder particle size of 0.050 mm.

[0166] The proportion of water-based curing agent is 5% of the roadbed soil mass, and the pH value is 10.5.

[0167] The calcium-rich material is obtained by crushing, screening and grinding waste concrete blocks, with a particle size range of 0.127 mm. The main components include unhydrated calcium silicate, calcium hydroxide and silicon dioxide, and the total mass proportion of active ingredients is 79.5%, and the calcium content is 22.5%.

[0168] The above-mentioned high-uniformity red mud-based curing agent for roadbed soil and the construction method thereof, the steps are as follows:

[0169] a) The untreated liquid red mud was screened and filtered to remove large impurities, and a detailed chemical composition analysis was performed, showing that the water content was 29.5%, the total mass proportion of active components of alkaline components was 29.12%, of which the content of Na2O was 3.12%, the content of Al2O3 was 24.68% and the content of K2O was 1.32%;

[0170] b) preparing the alkaline compound: putting sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder into a stirring pot in a mass ratio of 1.5:1:2 and stirring evenly for 15 minutes at a stirring rate of 50 r / min to obtain the alkaline compound;

[0171] c) preparing a water-based curing agent: accurately calculating and weighing the required water, alkaline compound and calcium-rich substance, and mixing them in a high-speed stirrer at a mass ratio of 2.25:0.75:1, with a stirring rate of 200 r / min and a stirring time of 20 minutes to obtain a water-based curing agent;

[0172] d) preparing a red mud-based curing agent: mixing the untreated liquid red mud and the water-based curing agent in a high-speed stirrer at a mass ratio of 17:3 at a stirring rate of 250 r / min for 20 minutes until a uniform slurry is formed, thereby obtaining the red mud-based curing agent described in Example 6;

[0173] e) Construction method: Mix the prepared red mud-based curing agent with the roadbed soil according to the mixing ratio range, and spray it with a sprayer at a spraying rate of 1kg / m 2 The travel speed of the spreader is 60m / min. After the spraying operation is completed, the construction is completed by using a grader to dig and mix and a roller to compact.

[0174] In order to detect the road performance of a high-uniformity red mud-based curing agent for roadbed soil, its various key technical indicators were tested, and the results are shown in Tables 1, 2, and 3:

[0175] Table 1 Roadbed deflection value detection

[0176]

[0177] Table 2 Roadbed strength test

[0178] Rebound modulus(Mpa) California load factor (%) Shear strength(Kpa) Example 1 30.2 30.259 144.9 Example 2 34.6 33.254 150.8 Example 3 34.9 33.587 151.2 Example 4 36.7 33.932 154.6 Example 5 33.8 32.761 148.7 Example 6 37.3 34.209 159.3 Acceptance Criteria ≥30Mpa 8％-50％ 140Kpa-200Kpa

[0179] Table 3 Roadbed compaction test

[0180]

[0181] It can be concluded from Tables 1, 2, and 3 that the deflection value, compaction degree, and strength of the roadbed are higher than the standard control standards; the deviation of each test index is small and tends to be stable, which can meet the bearing requirements of roadbeds of different grades. In addition, the present invention realizes the efficient utilization of liquid red mud and the stable combination with roadbed soil by accurately calculating the raw material composition and optimizing the preparation process. The curing agent not only has excellent curing effect, but also shows good environmental adaptability and durability, providing a new solution for the reinforcement and stabilization of roadbed soil. At the same time, the curing agent preparation process of the present invention is simple, the cost is low, and it has broad application prospects and market potential.

[0182] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A high uniformity red mud-based curing agent for roadbed soil, characterized in that: The composition includes the following components in parts by weight: 50-100 parts of untreated liquid red mud; 5-30 parts of water-based curing agent; The untreated liquid red mud is screened and filtered with water, and the average particle size is no more than 200 meshes, and the density is 2650-2870 kg / m 3 , moisture content is 25-32%; The water-based curing agent comprises water, alkaline compounds and calcium-rich substances, and its mass parts are as follows: 5-12 parts water; 3-5 parts of basic compound; 2-4 parts of calcium-rich substances; The alkaline compound is prepared by mixing sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder, and its mass parts are as follows: 3-5 parts of sodium hydroxide liquid; 2-4 parts of sodium oxide liquid; 1-4 parts of calcium oxide solid powder.

2. The high-uniformity red mud-based curing agent for roadbed soil according to claim 1, characterized in that: The total mass proportion of active ingredients of the untreated liquid red mud alkaline components Na2O, K2O and Al2O3 is 24.1-32.9%, of which the content of Na2O is 2.4-5.6%, the content of Al2O3 is 20.5-25.8%, and the content of K2O is 1.2-1.5%.

3. The high uniformity red mud-based curing agent for roadbed soil according to claim 1, characterized in that: The mass concentration of the mixed liquid of the sodium hydroxide liquid and the sodium oxide liquid is not less than 48%, and the mass accounts for not less than 32% of the total amount of the alkaline compounds.

4. The high uniformity red mud-based curing agent for roadbed soil according to claim 1, characterized in that: The calcium oxide solid powder has a calcium content of not less than 85%, an impurity content of not more than 0.5%, and a powder particle size of not more than 0.070 mm.

5. The high uniformity red mud-based curing agent for roadbed soil according to claim 1, characterized in that: The water-based curing agent has a dosage ratio ranging from 2% to 6% of the roadbed soil mass, and a pH value of not less than 8.

6. The high-uniformity red mud-based curing agent for roadbed soil according to claim 1, characterized in that: The calcium-rich material is obtained by crushing, screening and grinding waste concrete blocks, and its particle size range is no more than 0.145 mm. The main components include unhydrated calcium silicate, calcium hydroxide and silicon dioxide, and the total mass proportion of active ingredients is no less than 75%, and the calcium content is no less than 17%.

7. A construction method of a high-uniformity red mud-based curing agent for roadbed soil according to any one of claims 1 to 6, characterized in that: The following steps are involved: a) The untreated liquid red mud is subjected to water screening and filtration to remove large impurities, and a detailed chemical composition analysis is performed to determine its water content, the total mass percentage of active ingredients of alkaline components, and the precise contents of Na2O, Al2O3 and K2O; b) preparing the alkaline compound: putting sodium hydroxide liquid, sodium oxide liquid and calcium oxide solid powder into a stirring pot in a certain proportion and stirring evenly for 10-15 minutes at a stirring rate of 40-60 r / min to obtain the alkaline compound; c) Preparation of water-based curing agent: accurately calculate and weigh the required water, alkaline compound and calcium-rich substance, put them into a high-speed stirrer in a certain proportion for mixing, the stirring rate is 200-300r / min, and the stirring time is 15-25 minutes, so as to obtain the water-based curing agent; d) preparing a red mud-based curing agent: mixing the untreated liquid red mud and the water-based curing agent in a high-speed stirrer in a certain proportion at a stirring rate of 250-300 r / min for 20-25 minutes until a uniform slurry is formed, thereby obtaining a red mud-based curing agent; e) Construction method: Mix the prepared red mud-based curing agent with the roadbed soil according to the mixing ratio range, and spray it with a sprayer at a spraying rate of 0.5-1kg / m 2 The travel speed of the spreader is 50-60m / min. After the spraying operation is completed, the construction is completed by using a grader to dig and mix and a roller to compact.

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