scholarly journals Effects of Coal Gangue on Cement Grouting Material Properties

Author(s):  
J Y Liu ◽  
H X Chen
2021 ◽  
pp. 1-44
Author(s):  
Yunxiao Liu ◽  
Jiahang Zhang ◽  
Yinyin Chi

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.


2013 ◽  
Vol 838-841 ◽  
pp. 1457-1462
Author(s):  
Chun Lei Xia ◽  
Ying Ye ◽  
Guan Ming Wang ◽  
Li Cui

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.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6144
Author(s):  
Jiaolong Ren ◽  
Zedong Zhao ◽  
Yinshan Xu ◽  
Siyuan Wang ◽  
Haiwei Chen ◽  
...  

Cement grouting material is one of the most important materials in civil construction at present, for seepage prevention, rapid repair, and reinforcement. To achieve the ever-increasing functional requirements of civil infrastructures, cement grouting materials must have the specific performance of high fluidization, early strength, and low shrinkage. In recent years, nanomaterials have been widely used to improve the engineering performance of cement grouting materials. However, the mechanisms of nanomaterials in grouting materials are not clear. Hence, a high-fluidization, early strength cement grouting material, enhanced by nano-SiO2, is developed via the orthogonal experimental method in this study. The mechanisms of nano-SiO2 on the microstructure and hydration products of the HCGA, in the case of different curing ages and nano-SiO2 contents, are analyzed through scanning electron microscopy tests, X-ray diffraction tests, differential scanning calorimetry tests, and Fourier transform infrared spectroscopy tests.


2017 ◽  
Vol 29 (2) ◽  
pp. 54-62 ◽  
Author(s):  
Guijin Zhang ◽  
Jie Liu ◽  
Yi Li ◽  
Jingwei Liang

2021 ◽  
Vol 1036 ◽  
pp. 319-326
Author(s):  
Hao Ran Duan ◽  
Peng Zhao ◽  
Lei Qin ◽  
Feng Jiao Shi

The engineering practice shows that the application of grouting technology to treat underground engineering has strong applicability and is one of the most commonly used technical means at present. Based on the underground engineering, this paper introduces the research achievements of grouting materials in recent years, including cement-based grouting materials, mixed grouting materials, anti-scouring grouting materials, and ultra-fine cement grouting materials. Current demand of grouting materials in underground engineering, there exists large dosage of cement, high content, high cost, serious environmental pollution problems, such as looking for alternatives or mixed with other raw materials for preparation of cementation material become the development trend, compared with the cement grouting material, chemical grouting material with higher performance, but in smaller projects within the scope of application. How to reduce the production cost of chemical grouting materials, simplify the production process, overcome the existing toxicity, reduce environmental pollution and improve the durability of solidified body has become the bottleneck of its popularization and application. Some achievements have been made in the modification of cement or chemical materials by nanometer components, but there is still a long way to go before the large-scale application of grouting engineering.


2021 ◽  
Vol 14 (1) ◽  
pp. 399
Author(s):  
Luchang Xiong ◽  
Zhaoyang Zhang ◽  
Zhijun Wan ◽  
Yuan Zhang ◽  
Ziqi Wang ◽  
...  

As a solid waste produced by coal combustion, fly ash will cause serious environmental pollution. However, it can be considered as a sustainable and renewable resource to replace partial cement in grouting materials. Fly ash grouting materials re-cement the broken rock mass and improve the mechanical properties of the original structure. It can reinforce the broken surrounding rock of mine roadway. The utilization of fly ash also reduces environmental pollution. Therefore, this paper establishes a new material mixture ratio optimization model to meet the requirement of material property through combining the methods of experimental design and numerical analysis. Based on the Box–Behnken design with 3 factors and 3 levels, a mathematical model is constructed to fit the nonlinear multiple regression functions between material properties and raw materials ratios. The influence of raw materials is analyzed on material properties (the material’s 7-day uniaxial compressive strength, initial setting time, and slurry viscosity). Then, 80 Pareto solutions are obtained through NASG-II algorithm which takes the regression functions as the objective functions for multi-objective optimization of the grouting material ratio. Finally, the best ratio solution of water-cement ratio—0.71, silica fume content—1.73%, and sodium silicate content—2.61% is obtained through the NNRP-TOPSIS method.


2014 ◽  
Vol 507 ◽  
pp. 300-305
Author(s):  
Chang Zheng Sun ◽  
Xiao Ping Zhang ◽  
Hai Nan Zhao ◽  
Qiang Gao

The gradation of coarse sand, medium sand and fine sand on fluidity initial, final setting time, flexural strength, compressive strength, and other properties and structure, of ultra early strength grouting material, was explored. The quartz sand gradation of cement sand ratio 1.0 was systematically studied. The results showed that, the coarse sand, medium sand and fine sand mixed according to the reasonable distribution, when glue sand ratio was 1.0-1.5, ultra-early-strength grouting material, with final setting time for 50-60(min), the initial fluidity greater than 320(mm), 0.5h fluidity greater than 280(mm), 2h compressive strength of 35.6(MPa), 1d flexural strength greater than 13(MPa), 28d compressive strength over 93(MPa), achieved the free vibration.


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