CN-122010483-A - Alkali residue-gangue-gas slag concrete for hardening coal mine tunnel floor and paving method thereof

CN122010483ACN 122010483 ACN122010483 ACN 122010483ACN-122010483-A

Abstract

The invention belongs to the technical field of underground engineering of coal mines, and particularly discloses alkali residue-gangue-coal gasification residue concrete for hardening a coal mine tunnel bottom plate and a paving method thereof, wherein the concrete comprises, by weight, 2.5-4.5 parts of fine aggregate, 4-7 parts of coarse aggregate, 1-3 parts of cement, 0.5-1.5 parts of water and alkali residue, the alkali residue is 0-9% of the cement in mass, the fine aggregate consists of coal gasification coarse residue and yellow sand, the mass ratio of coal gasification residue to yellow sand is 1:1-2, the coarse aggregate consists of gangue and broken stone, and the waste stone accounts for 0-30% of the coarse aggregate in mass. According to the invention, the reasonable gangue substitution rate is determined by preparing gangue-gas-slag concrete with different gangue substitution rates and testing the compressive strength, and the compressive strength and the flexural strength of the alkaline residue-gangue-gas-slag concrete are further improved by doping alkaline residues, so that the concrete hardening and paving process is provided, and the essential transition from passive repair to active guarantee is realized for constructing a high-strength, smooth and durable roadway foundation.

Inventors

WANG HUI
ZHANG RAN
YIN WEI
ZHANG FENGRUI
ZHU JUN
JIANG HAOPENG
XU LINSHENG
Yi Mengwei
WAN CHENKUN
Jiang Haohui
XUE JIANGMING

Assignees

淮阴工学院

Dates

Publication Date: 20260512
Application Date: 20260106

Claims (5)

1. The alkali residue-gangue-gas slag concrete for hardening the floor of the coal mine tunnel is characterized by comprising, by weight, 2.5-4.5 parts of fine aggregate, 4-7 parts of coarse aggregate, 1-3 parts of cement, 0.5-1.5 parts of water and alkali residue, wherein the dosage of the alkali residue is 0-9% of the cement mass, the fine aggregate consists of gas slag and yellow sand, the mass ratio of the gas slag to the yellow sand is 1:1-2, the coarse aggregate consists of gangue and broken stone, and the dosage of the gangue is 0-30% of the mass of the coarse aggregate.
2. The alkali residue-gangue-coal gasification residue concrete for hardening the floor of the coal mine tunnel is characterized by comprising, by weight, 3.065 parts of fine aggregate, 5.69 parts of coarse aggregate, 2 parts of cement, 1 part of water and alkali residue, wherein the alkali residue is 3-9% of the cement in mass, the fine aggregate consists of coal gasification residue and yellow sand, the mass ratio of the coal gasification residue to the yellow sand is 1:1.5, the coarse aggregate consists of gangue and broken stone, and the amount of the gangue is 10-30% of the mass of the coarse aggregate.
3. The alkali residue-gangue-gas slag concrete for hardening coal mine tunnel floor according to claim 1, wherein the amount of the alkali residue is 6% of the mass of cement, and the amount of the gangue is 30% of the mass of coarse aggregate.
4. The alkaline residue-gangue-coal gasification slag concrete for hardening the floor of the coal mine tunnel according to claim 1 is characterized in that the particle size of the alkaline residue is 2-3 mm, the particle size of the coal gasification coarse residue is 4-5 mm, and the grading of the gangue is 9.5-13.2 mm, 13.2-16 mm and 16-19 mm.
5. The method for paving the alkali residue-gangue-gas slag concrete for hardening the floor of the coal mine tunnel according to claim 1, which is characterized by comprising the following steps: (1) Mixing and transporting, namely adopting a movable concrete mixer for coal mines, wherein the distance between the mixer and a hardening and bottoming place is 5-10 m, weighing various raw materials according to a proportion, sequentially adding cement, broken stone, gangue, yellow sand, alkaline residue and coal gas slag into the mixer, starting the mixer, uniformly mixing the raw materials, adding water at a uniform speed in the mixing process, continuously mixing after adding all the water, and selecting an underground mining explosion-proof material carriage with a self-discharging function to transport to a roadway hardening place in time; (2) Cleaning and leveling the bottom plate, namely cleaning sundries in a roadway before paving, removing floating coal and broken stone on the unpaved bottom plate, and leveling the severely uneven area of the bottom plate; (3) The steel templates are respectively arranged at two sides of the width of the hardened pavement of the bottom plate, the distance between the steel templates at two sides is the width of the hardened pavement, and the height of the steel templates is the same as the thickness of the hardened pavement; (4) Discharging mixed concrete, namely when the lateral steel template of the working unit is installed, spraying water to the bottom plate of the roadway and the inner side of the steel template for full wetting treatment, and uniformly discharging the ash and gangue-based full-solid waste cement concrete uniformly mixed by a mixer in the working unit from inside to outside according to the retreating direction by using a transport vehicle with no accumulated water as a standard; (5) The concrete artificial distribution, namely after the unloading of the transport vehicle is finished, dismantling steel drills on the inner side of the steel template, inserting the steel drills into gaps of the bottom plate for filling by using concrete, and adopting an artificial shovel to approximately level; (6) The intensive vibration discharging primary leveling is that after the artificial material distribution of the concrete in the length of the hardening unit of the roadway floor is finished, the vibration operation is started after the row type inserting material distribution depth is regulated, and the row type vibrator continuously drags and shakes; (7) Leveling the paver, namely performing leveling operation of the paver within 15min after the operation unit is vibrated by the paver; (8) After finishing the facing, when the concrete surface is sunk at about 5mm under the slight pressure of fingers, transversely roughening the bridge surface by adopting a plastic brush, wherein the roughening requires uniform lines and the depth is controlled to be 2-3 mm; (9) The transverse construction of the kerf, namely starting the kerf operation when the surface of the concrete slab is hardened enough to bear the kerf equipment, constructing the transverse kerf at intervals of 5-10 m according to the width of the concrete pavement in an operation unit, removing saw dust and sundries after the kerf operation is completed, and caulking by using a caulking material; (10) Concrete curing, namely covering geotextiles after the concrete is finally set or when no trace exists on the surface of the concrete, and curing in a wet state; (11) And filling side ditches on two sides of the hardened pavement, namely removing steel templates on two sides of the pavement after the hardened pavement of the roadway is finally solidified, paving the concrete slab of the hardened pavement and the residual width parts left on two sides of the roadway completely by adopting a manual filling mode, and paving according to a designed broadband and depth vertical die if a roadway drainage ditch is required to be reserved.

Description

Alkali residue-gangue-gas slag concrete for hardening coal mine tunnel floor and paving method thereof Technical Field The invention belongs to the technical field of underground coal mine engineering, relates to a coal mine tunnel bottom plate hardening material, and in particular relates to alkali residue-gangue-gas slag concrete for coal mine tunnel bottom plate hardening and a paving method thereof. Background Gangue is a solid waste produced in the coal mining and washing processes, the annual emission is more than 7 hundred million tons, and the accumulation of the gangue occupies a large amount of land and can cause a series of environmental problems such as spontaneous combustion, soil pollution and water resource. The roadway tunneling amount in China reaches 15 ten thousand kilometers, the demand of the bottom plate concrete hardening on the gravel aggregate is huge, and the gravel resources are drastically reduced due to years of mining. The mineral components and properties of the gangue are similar to those of natural crushed stone, and the gangue is used for replacing crushed stone coarse aggregate to prepare gangue concrete, so that the gangue concrete becomes a research hot spot in the field of building materials in recent years, and the concrete prepared based on the gangue aggregate can not only reduce the problem of gangue accumulation, but also reduce the use amount of crushed stone, and has remarkable economic and environmental benefits. The first world of soda production in China adopts an ammonia soda process, about 0.6 ton of soda ash is discharged per 1 ton of soda produced by the ammonia soda process, the annual discharge amount exceeds 800 ten thousand tons, and hundreds of millions of tons are accumulated. The existing alkaline residue treatment mode mainly comprises clear liquid sea discharging, surface accumulation and the like, and serious water pollution and land salinization are caused. The proportion of soluble salt in the caustic sludge exceeds 20%, caCl 2 and NaCl chloride are mainly used, the content of Cl - is extremely high, the comprehensive utilization rate of the solid waste caustic sludge is less than 4% at present, and the requirement of the national bulk solid waste utilization rate is severely lower. Along with the increasingly strict regulation policy of solid waste treatment, a plurality of alkali-making enterprises are forced to stop production and close because alkali residues cannot be treated, and the reduction and resource utilization of the solid waste alkali residues are urgent. The paving of the roadway floor is a systematic engineering, and the quality of the roadway floor is directly related to the service life, the transportation efficiency and the operation safety of the roadway. The investigation finds that the bottom bulge is generated on the roadway bottom plate under the extrusion of high-level stress, the synchronous bottom bulge of the gangue concrete pavement is induced to be damaged, the bottom bulge of part of the pavement is up to more than 1.5m, the pavement is frequently repaired, the bottom is extremely difficult to start, and the underground driving safety and the production efficiency are seriously influenced. The stress characteristics and the environment determine that the core index of the pavement strength is the flexural strength, the compressive strength of the bottom plate pavement meets the requirements and even is rich, the pavement damage is mainly caused by insufficient flexural strength, and the high-level stress of the bottom drum puts forward higher requirements on the flexural strength of the gangue concrete pavement, so that the improvement of the flexural strength of the gangue concrete is a key for ensuring the long-term stability of the bottom plate pavement. The physical and mechanical performance indexes of the gangue are worse than those of broken stone, and the mechanical performance of the concrete is possibly reduced to different degrees when the gangue is used for preparing the concrete, and the strength degradation can be supplemented by adding alkaline residues. Therefore, in order to reduce the hardening cost of the roadway floor and simultaneously treat the solid waste gangue, the coal gasification coarse slag and the alkaline slag, the alkaline slag-gangue-coal gasification slag concrete for hardening the roadway floor of the coal mine and the paving method thereof are researched, and reference can be provided for the design of the mixing proportion of the solid waste concrete for the subsequent mine and the on-site construction. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide the alkaline residue-gangue-coal gasification residue concrete for hardening the bottom plate of the coal mine tunnel, which effectively utilizes the coal gangue and the alkaline residue, reduces the using amount of broken stone aggregate, improves the flexural strength and the compres