scholarly journals Feasibility of a Polymer Foaming Agent as a Grouting Material for Broken Coal Masses

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Zhidong Sun ◽  
Junxiang Zhang ◽  
Yuning Sun
Keyword(s):  
Base Material ◽  
Reinforcement Effect ◽  
Foaming Agent ◽  
Low Viscosity ◽  
Grouting Material ◽  
Polymer Foaming ◽  
Amino Resin ◽  
Grouting Reinforcement ◽  
Excellent Adhesion ◽  
Grouting Materials

A new soluble polymer foaming (PF) grouting material was developed by using hydrophilic amino resin as the base material and adding other cross-linking, foam, foam stabilizing, toughening, and coupling agents. The PF material exhibited low viscosity, excellent adhesion, and strong penetration. The grouting reinforcement effect of the proposed PF material on broken coal masses was investigated and compared with that of traditional superfine cement (SC) through simulation experiments. Results showed that after grouting, fractures, joints, and other failure planes inside raw coal were filled and bonded, and the mechanical strength of the grout-coal concretion improved relative to the residual strength of raw coal. The average uniaxial compressive strength of SC specimens was 6.16 MPa, whereas that of PF specimens was 10.85 MPa. Moreover, the PF specimens presented an obvious characteristic of plastic strengthening. Analyzing the reinforcement effect of the grouting materials on the basis of single structural plane theory revealed that at the critical state, the average σ3 value of SC specimens was 1.43 MPa, whereas that of PF specimens was 3.09 MPa. In addition, coordination between the lateral and axial deformations of the PF specimens during compression promoted the formation of a bearing structure that can adapt to deformation. This structure is crucial for the safe operation of coal mines.

scholarly journals Development of Modified Grouting Material and Its Application in Roadway Repair Engineering

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yang Yu ◽  
Zhengyuan Qin ◽  
Xiangyu Wang ◽  
Lianying Zhang ◽  
Dingchao Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surrounding Rock ◽  
Engineering Practice ◽  
Mass Ratio ◽  
Control Effect ◽  
Grouting Pressure ◽  
Grouting Material ◽  
Wide Range ◽  
Grouting Reinforcement ◽  
Grouting Materials

It is very extraordinary for the success of coal mine roadway grouting with the following factors of high early strength, good fluidity, and convenient pumping, but the existing grouting materials make it difficult to achieve the above characteristics at the same time. Therefore, a modified grouting material is developed, which is composed of two kinds of dry materials A and B, which are mixed with water and in equal amounts. The physical and mechanical properties of modified grouting materials under different ratios were tested by laboratory orthogonal test, and the optimal ratio of grouting materials and additives was obtained: (1) the water-cement ratio is 0.8 : 1; (2) base material: the mass ratio of cement, fly ash, bentonite, and water is 1 : 0.3 : 0.1 : 1.44; (3) admixture: the mass ratio of water reducer C, accelerator D, and retarder E is 1.5% : 0.05% : 0.3%. The basic properties of the modified grouting materials were studied from the aspects of slurry flow state, diffusion range, and grouting parameters by using the numerical simulation method, and the reinforcement mechanism of slurry to the broken surrounding rock properties of the roadway was revealed: (1) the grouting pressure is the main factor affecting the slurry diffusion radius; (2) the mechanical properties of the roadway surrounding rock are improved, the plastic zone and deformation of surrounding rock are reduced, and the active support function of the anchor and cable is enhanced through grouting reinforcement; (3) the control effect of the roadway is improved, and the balanced bearing with anchorage structure of the roadway surrounding rock is realized through grouting reinforcement. On this basis, the modified grouting material is applied to roadway repair and reinforcement engineering practice. The field monitoring data show that the production practices were guided by roadway repair and reinforcement technology with the modified grouting material, as the core of the roadway surrounding rock control effect is good, and the modified grouting material has a wide range of application prospects.

scholarly journals A Novel Class F Fly Ash-Based Geopolymer and Its Application in Coal Mine Grouting

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Luchang Xiong ◽  
Zhijun Wan ◽  
Shubing Qin ◽  
Peng Shi ◽  
Junhui Wang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Solid Waste ◽  
Surrounding Rock ◽  
Reinforcement Effect ◽  
Grouting Material ◽  
Grouting Reinforcement ◽  
Optimal Material ◽  
Class F Fly Ash ◽  
Class F

The novel class F fly ash-based geopolymer, largely made of fly ash from the coal solid waste, was used as a kind of grouting material in the coal and electricity-integrated mine from which the solid waste comes, for the purpose of in situ utilization of fly ash. The ratio experiment of material, designed through the orthogonal method, was used to study material properties such as fluidity and strength which are important to the application of mine grouting, and the optimal material proportioning scheme for Green Fly Ash-based grouting material is determined. It has been found out that there was serious rib spalling, roof deformation, obvious floor heave, crack development, and some water seepage in the permanent refuge chamber of the mine. Therefore, to solve these problems, a specific scheme of grouting reinforcement for the surrounding rocks of the permanent refuge chamber and roadway in this mine was designed. Through an analysis of the reinforcement effect of the cementation of surrounding rock after the grouting process, it can be concluded that the green fly ash-based polymer as grouting material can well penetrate into the cracks of the broken surrounding rock and get fully cemented with the surrounding rock and that it can reduce the deformation of the surrounding rock effectively, increase the integrity, and improve the carrying capacity of the surrounding rock. Besides, the grouting reinforcement effect of surrounding rock was verified through numerical simulation, and the grouting process design of green fly ash-based polymer mine was discussed. This study can provide a green and economical approach to the in situ utilization of fly ash which is a kind of coal solid waste.

Study on Properties of Grouting Materials and Reinforcement Effect in Coal Roadways Influenced by Dynamic Pressure

2019 ◽  
Vol 37 (4) ◽  
pp. 3329-3342
Author(s):  
Zeng-qiang Yang ◽  
Chang Liu ◽  
Yun Dong ◽  
Lin-ming Dou ◽  
Jing-ke Wu
Keyword(s):  
Dynamic Pressure ◽  
Reinforcement Effect ◽  
Grouting Materials

Study of Rheological Properties of Carbon Nanotube-Reinforced Ultrafine Cement Grouting Materials

2021 ◽  
pp. 1-44
Author(s):  
Yunxiao Liu ◽  
Jiahang Zhang ◽  
Yinyin Chi
Keyword(s):  
Carbon Nanotubes ◽  
Rheological Properties ◽  
Polyvinyl Pyrrolidone ◽  
Cement Grouting ◽  
Grouting Material ◽  
Multi Walled Carbon Nanotubes ◽  
Different Diameters ◽  
Grouting Materials ◽  
Walled Carbon Nanotubes ◽  
Ultrafine Cement

In this study, three different diameters of multi-walled carbon nanotubes (MWCNTs) dispersed by polyvinyl pyrrolidone (PVP) were used to reinforce superfine cement grouting materials. The effect of MWCNTs and polyvinyl pyrrolidone (PVP) on the rheological properties of grouting material were accordingly studied. It was found that the yield stress (τ0) and plastic viscosity (η) were slightly decreased when PVP content was low and increased when the PVP content increased. The effect of MWCNT diameter on τ0 was not found to be clear but was more significant on η. The smaller MWCNT diameter was, the more quickly η increase. It was also found that the thixotropic ring area was increased as the MWCNTs content increased. The addition of PVP and MWCNTs caused an increase in the number of entanglement points in different scales, which was the main reason for the viscosity and thixotropy increase. Therefore, the rheological properties of superfine cement grouting material should be adjusted when MWCNTs were added as a reinforcing component. Due to the wrapping of PVP on cement particles which isolates the contacting part between the water and the cement particles, it slows down the cement's hydration rate thus slows down the fluidity loss of the slurry.

Dimethyl Hydantoin Formaldehyde: A new Water-soluble Resin for Use as a Mounting Medium

1958 ◽  
Vol s3-99 (48) ◽  
pp. 451-452
Author(s):  
H. F. STEEDMAN
Keyword(s):  
Water Soluble ◽  
Formaldehyde Resin ◽  
High Solubility ◽  
Solubility In Water ◽  
Low Viscosity ◽  
Excellent Adhesion

Dimethyl hydantoin formaldehyde resin dissolved in water or in 70 ml ethyl slcohol+30 ml wster is put forward as a solution suitsble for the mounting of insects, smsll crustacea, &c. Its chief advantage over other water-soluble resins is its high solubility in water, its excellent adhesion to glass, its low viscosity even in high per-centage solutions, snd its hsrdness on drying.

scholarly journals Polyurethane/Red Mud Composites with Flexibility, Stretchability, and Flame Retardancy for Grouting

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 906 ◽  
Author(s):  
Chunjing Zhang ◽  
Bo Shuai ◽  
Xuefeng Zhang ◽  
Xinxin Hu ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Flame Retardancy ◽  
Red Mud ◽  
Three Dimensional ◽  
Engineering Application ◽  
Synergistic Interactions ◽  
Grouting Material ◽  
Dimensional Network ◽  
Grouting Materials ◽  
Inorganic Composite

Flexibility, stretchability, and flame retardancy are of ever increasing importance in constructing grouting materials. Herein, a simple and effective strategy to make organic-inorganic composite grouting material in a “flexible, stretchable, and flame retardant” way was based on the excellent synergistic interactions among polyurethane prepolymer, red mud, polyethylene glycol, and trimethylolpropane. The resultant polyurethane/red mud composite grouting material with three-dimensional network structure presented a favorable flexibility, desirable compressive strength of 29.2 MPa at 50% compression state, and a good elongation at 15.1%. The grouting material was mainly composed of amorphous polyurethane and crystalline red mud, and its probable formation mechanism was reaction of prepolymer with H2O, polyethylene glycol and trimethylolpropane under vigorous stirring in the presence of catalyst. Furthermore, the grouting material possessed favorable thermal stability, flame retardancy and repairment performance for roadway cracks. This work may open a simple and convenient avenue for the massive engineering application of red mud and preparation of flexible organic-inorganic hybrid grouting material.

Study on Microfine Cement Grouting Material for Silty Fine Sand Stratum

2013 ◽  
Vol 838-841 ◽  
pp. 1457-1462
Author(s):  
Chun Lei Xia ◽  
Ying Ye ◽  
Guan Ming Wang ◽  
Li Cui
Keyword(s):  
Portland Cement ◽  
Particle Diameter ◽  
Fine Sand ◽  
Cement Grouting ◽  
Grouting Material ◽  
Soluble Glass ◽  
Microfine Cement ◽  
Sand Flow ◽  
Sand Stratum ◽  
Grouting Materials

Silty fine sand is the second smallest sand with a particle diameter ranging from 0.0625 to 0.120 mm.This kind of sand exists in a large amount in Beijing subway excavation project. Due to the poor self-stabilization of this stratum,seeping , sand flow and collapse take place frequently. Grouting materials such as Portland cement and soluble glass (also called sodium silicate) are employed in most of excavation projects to reinforce this sand stratum. However, the reinforcement is not effective, leading to a large amount of accidents in the process of construction. The reason may be attributed to the fact that Portland cement is unable to penetrate into the stratum and the strength of soluble glass (0.6MPa) is too weak to resist the stratum pressure. To solve this problem, a modified microfine cement grouting material able to penetrate into silty fine sand stratum is developed in this paper. A combination of suspension and diluent is used to increase the penetration extension of the grouts,and the experimental results reveal that the addition of the mixture of suspension and diluent in microfine cement grouting materials improves the penetration property substantially.

Development of Superfine Spherical Silica Grout as an Alternative Grouting Material for the Geological Disposal of Long-Lived Radioactive Waste

2010 ◽  
Author(s):  
Morimasa Naito ◽  
Hirokazu Kishi ◽  
Naomi Fukuoka ◽  
Tsutomu Yamada ◽  
Hideaki Ishida
Keyword(s):  
Radioactive Waste ◽  
Calcium Hydroxide ◽  
Cementitious Materials ◽  
Geological Disposal ◽  
Grouting Material ◽  
Spherical Silica ◽  
Geological Repository ◽  
Binder Ratio ◽  
Grouting Materials ◽  
Term Performance

As an alternative grouting material for the geological repository of long-lived radioactive waste, the “Superfine Spherical silica Grout” (SFSG) material is developed using a fine spherical silica and a fine calcium hydroxide. The developed SFSG material takes an advantage of its smaller particle size distribution (max. ∼1 micron or less) than those of the cementitious materials, and also provides a low alkaline environment so as to reduce unfavorable effects on the long-term performance of geological disposal system. The SFSG is a mixture of the “super fine silica powder”, the superfine calcium hydroxide and additives such as superplasticizer. Presently, the mixture being investigated for grouting materials is focused on water/binder ratio (W/B) of 1.2. Some preliminary laboratory experiments were carried out to characterize its fundamental properties from the viewpoint of practical use for geological disposal, which is required to be equivalent with the conventional cementitious materials in terms of penetrability, strength, pH performance and workability. From a series of experiments, it was concluded that SFSG is expected to become an alternative grouting material for a geological repository.

scholarly journals A More Realistic Study on the Mechanical Properties of CFRC Composite Grouting Material under a Long-Term Water Immersion Process

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Yao Xiao ◽  
Huafeng Deng ◽  
Jianlin Li ◽  
Eleyas Assefa
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Fiber ◽  
Water Immersion ◽  
Fiber Content ◽  
Grouting Material ◽  
Bonding Properties ◽  
Grouting Materials ◽  
Dam Foundations

The long-term effect of water immersion on the mechanical properties of CFRC composite grouting materials was studied by using five different carbon fiber contents (0, 0.25%, 0.50%, 0.75%, and 1.00%). The direct shear and long-term immersion tests were performed based on the specified and optimum values of carbon fiber content, respectively. The results showed the following: (1) the application of carbon fiber significantly improved the shear resistance of CRFC composite grouting material by using “reinforcing” and “anchoring” actions. The shear strength of the specimen was increasing by 5.66%∼43.41% when the carbon fiber content increased from 0.25% to 1.00%. After a comprehensive analysis, the optimum carbon fiber content was found to be 0.75%. (2) The degradation in the compressive and tensile strength of CRFC composite specimens exhibited a consistent trend (i.e., a steep gradient was gradually followed by a gentle slope) under a long-term water immersion process. About 90% of the total degradation in the compressive and tensile strength has occurred in 90 immersion days (i.e., 16.05% and 18.45%, respectively). In comparison, the degradation in the tensile strength (20.05%) was slightly higher than the compressive strength (18.16%). (3) Under the long-term water immersion process: the properties of the specimens were gradually deteriorating, the carbon fibers were gradually reaching a fatigue stage, and the bonding properties of carbon fiber was decreasing, which resulted in a reduction in the compressive and tensile strength. The uniaxial compression failure mode changed from brittle to ductile, and the development of local failure was very noticeable. Based on the findings of this paper, groundwater has a significant impact on the mechanical properties of grouted rock mass such as dam foundations and abutments. Therefore, the degradation in the grouting materials has to be considered in practical cases.

Preliminary Study on Nanometer Grouting Materials

2011 ◽  
Vol 418-420 ◽  
pp. 139-142
Author(s):  
Li Guo ◽  
Bing Xie ◽  
Hong Fang Li
Keyword(s):  
Solid Particle ◽  
Underground Engineering ◽  
Water Shutoff ◽  
Grouting Material ◽  
Molecular Dimension ◽  
Particle Dimension ◽  
Preliminary Study ◽  
Grouting Materials ◽  
The Cost ◽  
Cost Of Construction

The application of grouting technology in the reinforcement and water shutoff of underground engineering is very extensive. The grouting technology mainly includes two aspects: grouting process and grouting material. The grouting material is a vital link in grouting. It affects the cost of construction directly, and determines the success or failure of the engineering. The smaller the molecular dimension of solution or solid particle dimension, the greater the scope that the grout can be injected into. And it is beneficial to the grouting effect. With the development of nanotechnology, the development of nanometer grouting materials is feasible, and is also a great breakthrough for the grouting technique.

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