scholarly journals Mixing Ratios and Cementing Mechanism of Similar Silty Mudstone Materials for Model Tests

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Hong-Yuan Fu ◽  
Shuang-Xing Qi ◽  
Zhen-Ning Shi ◽  
Ling Zeng
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Water Content ◽  
Uniaxial Compressive Strength ◽  
Dominant Factor ◽  
Similar Material ◽  
Silty Mudstone ◽  
Mixing Ratios ◽  
Similar Materials

The similarity model test is one of the important means to study the engineering properties of soft rock. This study aims to develop similar materials for silty mudstone, which has characteristics of low strength and water expansion, based on traditional materials including gypsum, barite powder, clay minerals, and distilled water. The orthogonal design method was used to determine the mixing ratios of the similar materials. The density, uniaxial compressive strength, tensile strength, elastic modulus, and Poisson’s ratio were selected as control indicators of the similar materials. The results show that the water content is the dominant factor for the density, tensile strength, elastic modulus, and Poisson’s ratio of the similar materials of silty mudstone, while the gypsum content is the dominant factor for the uniaxial compressive strength. The physical and mechanical properties of the similar material samples with water content of 19%, barite powder ratio of 32%, and gypsum mass of 250 g show good similarity to those of the raw silty mudstone. The water absorption and expansibility of similar materials with clay mineral ratio of 12% are consistent with those of the raw silty mudstone. The scanning electron microscopy (SEM) observation indicates that the similar material with optimal mixing ratios exhibits a similar microstructure to that of silty mudstone.

scholarly journals Experimental Development Process of a New Cement and Gypsum-Cemented Similar Material considering the Effect of Moisture

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Qi Liu ◽  
Shaojie Chen ◽  
Shuai Wang ◽  
Jing Chai ◽  
Dingding Zhang
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Moisture Content ◽  
Uniaxial Compressive Strength ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Mass Ratio ◽  
Similar Material ◽  
Residual Moisture ◽  
Similar Materials

A new type of similar material considering water characteristics is developed through orthogonal experiments. The similar material is composed of river sand, barite powder, cement, gypsum, and water. We determine the best test development process. First, the proportion test scheme is designed based on the orthogonal test. Then, the effects of the moisture content, mass ratio of aggregate to binder and other components on the density, uniaxial compressive strength, elastic model, and Poisson’s ratio of similar materials are analyzed by range analysis. Finally, the multiple linear regression equation between the parameters and the composition of similar materials is obtained, and the optimal composition ratio is determined according to the relationship between the test’s influencing factors and the mechanical properties of similar materials. The results show that the selected raw materials and their proportioning method are feasible. The content of barite powder plays a major role in controlling the density and Poisson’s ratio of similar materials. The mass ratio of aggregate to binder is the main factor that affects the uniaxial compressive strength and elastic modulus of similar materials, while the moisture content has the second largest effect on the density, uniaxial compressive strength, elastic modulus, and Poisson’s ratio of similar materials. When the residual moisture content increased from 0 to 4%, the uniaxial compressive strength and elastic modulus of similar materials decrease by 49.5% and 53.3%, respectively, and Poisson’s ratio increases by 54.8%. Determining the residual moisture content that matches the design of similar material model tests is critical to improving the test accuracy and provides a reference to prepare similar materials with different requirements.

scholarly journals The Effects of Different Nanoadditives on the Physical and Mechanical Properties of Similar Silty Mudstone Materials

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Ji-jing Wang ◽  
Zhen-ning Shi ◽  
Ling Zeng ◽  
Shuang-xing Qi
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Water Absorption ◽  
Natural Water ◽  
Physical And Mechanical Properties ◽  
Mechanical Parameters ◽  
Similar Material ◽  
Silty Mudstone ◽  
Similar Materials ◽  
Softening Coefficient

In order to analyze the influence of different nanoadditives on the physical and mechanical properties of similar silty mudstone materials, nano-TiO2 (NTi), nano Al2O3 (NAl), and nanobentonite (NBe) were added to improve the physical and mechanical properties of silty mudstone similar materials. The physical and mechanical parameters are more in line with silty rock. Finally, nanometer additives suitable for silty mudstone similar materials are determined by conducting density test, natural water absorption test, uniaxial compression test, splitting test, softening coefficient test, expansibility test, and microscopic test. The effects of adding NTi, NAl, and NBe on improving the physical and mechanical properties of silty mudstone similar materials were studied to analyze the influence law of different NTi, NAl, and NBe contents on similar material density, natural water absorption, uniaxial compressive strength, tensile strength, softening coefficient, expansion rate, and other physical and mechanical parameters. The microscopic morphology of similar materials was analyzed by scanning electron microscopy and the mechanism of influence of nanoadditives on the microscopic structure of samples was revealed. The results are as follows. (1) The density of similar materials of silty mudstone increases with the increase of the content of nanoadditive. The natural water absorption rate decreased first and then increased with the increase of the content of nanometer additives, while the softening coefficient decreased with the increase of the content of nanometer additives. The uniaxial compressive strength and tensile strength increased first and then decreased with the increase of the content of nanometer additives. This is due to the incorporation of the nanoadditive amount effective to promote the hydration reaction of gypsum and accelerate the production of cement, while a similar material may be filled in the pores, reducing the internal defects, a similar material to make denser; when excessive dosage, nanoadditives agglomeration occurs, resulting in deterioration of the effect, but will reduce the mechanical properties of similar materials. (2) When the content of NBe is 6%, the physical and mechanical parameters of similar materials can reach or be closer to the silty raw rock except uniaxial compressive strength. The failure mode of the uniaxial compression specimen is also the same as that of the original rock, which can be used as the best choice. The research results laid the foundation for further analysis of NBe application in similar materials.

Research on the Relation between the Mechanical Parameter and Water Content about the Synthetic Geotechnical Simulation Material

2011 ◽  
Vol 99-100 ◽  
pp. 982-987
Author(s):  
Chang Wu Liu ◽  
Shu Xin Liu ◽  
Yu Hang Xu
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Water Content ◽  
Physical Simulation ◽  
Experimental Finding ◽  
Mechanical Parameter ◽  
Similar Material ◽  
Synthetic Material ◽  
Simulation Test ◽  
The Ideal

The physical simulation test of similar material is one of the most common research techniques in the geotechnical domain. Because the experimental finding of physical simulation is directly affected by the physical mechanical property and stability of similar material, then selecting the fitting formulation, mixture ration and water content of the similar material for different investigated subjects to get the ideal similar material is the most attentive problem during the experiment. After researching the variational compressive strength and tensile strength with the water content of the synthetic material which is made of sand, cement, gesso with two mixed rations, the relation of second-degree parabola between the main mechanical parameter and the water content of the synthetic material is obtained, and the optimal rate of water content which can make the similar material reach the maximal compressive strength or tensile strength is obtained

scholarly journals Experimental Study on the Ratio Model of Similar Materials in the Simulation Test of Coal and Gas Outburst

2020 ◽  
Author(s):  
Peng Sun ◽  
Haitao Sun ◽  
Fujin Lin ◽  
Xuelin Yang ◽  
Wangang Jiang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Uniaxial Compressive Strength ◽  
Pulverized Coal ◽  
Ratio Model ◽  
River Sand ◽  
Adsorption And Desorption ◽  
Sodium Humate ◽  
Gas Outburst ◽  
Similar Materials

Abstract In order to obtain similar materials with specific physical and mechanical parameters and adsorption and desorption indexes used in coal and gas outburst simulation tests, pulverized coal was selected as aggregate, sodium humate as cementing agent and river sand as auxiliary materials. Based on this, an orthogonal test with 6 factors and 5 levels was designed, and the tests of weighing, uniaxial compression, firmness and adsorption and desorption were carried out. The parameters such as density, uniaxial compressive strength, elastic modulus, firmness coefficient and adsorption-desorption index of similar materials with different ratios were obtained, and the sensitivity of each factor was analyzed by range analysis. The influence law of various factors on the parameters of similar materials was studied, the ratio model of similar materials was obtained and the reliability of the model was verified, and a complete method for determining the ratio model of similar materials of outburst coal was put forward. The results show that the density of similar materials increases with the increase of river sand content, the uniaxial compressive strength and elastic modulus increase significantly with the increase of pulverized coal ratio and sodium humate content, and the firmness coefficient increases linearly with the increase of pulverized coal ratio. The adsorption constant an increases linearly with the increase of sodium humate content, while the adsorption constant b decreases linearly with the increase of sodium humate content. The initial elution rate △p of similar materials increases at first and then decreases with the increase of sodium humate content.

THE EFFECT OF POROSITY ON ENGINEERING PROPERTIES OF VESICULAR AMYGDALOIDAL BASALTS

2021 ◽  
Vol 5 (11) ◽  
Author(s):  
P .S.K.Murthy ◽  
Sachin Gupta ◽  
Dhirendra Kumar ◽  
Mahabir Dixit
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Uniaxial Compressive Strength ◽  
Modulus Of Elasticity ◽  
Poisson’S Ratio ◽  
Central India ◽  
Poisson's Ratio ◽  
Engineering Properties ◽  
Secondary Minerals

The interconnection of vesicles in basaltic flows greatly affects the engineering properties such as uniaxial compressive strength, modulus of elasticity, Poisson’s ratio, tensile strength and sonic velocities. Sometimes these vesicles are filled with secondary minerals such as quartz/olivine/calcite form as amygdules (which are impermeable). In the present study, to understand effect of porosity, vesicular and amygdular basaltic flows collected from central and west-central India were investigated for these engineering properties and correlated with apparent porosity of core samples. It is observed that a good level of correlation is obtained for uniaxial compressive strength (UCS), elastic modulus (E) and Poisson’s ratio in vesicular basalts when porosity >8-10%. In case of Brazilian strengths a linearly downward trend is observed with the increase in porosity values. And, no significant correlation is observed for waves’ velocities in both variants of basalts.

scholarly journals Influence of Water Content on the Mechanical Parameters of the Intact Rock and Rock Mass

2018 ◽  
Author(s):  
Balázs Vásárhelyi ◽  
Morteza Davarpanah
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Rock Mass ◽  
Internal Friction ◽  
Water Content ◽  
Uniaxial Compressive Strength ◽  
Water Saturation ◽  
Friction Angle ◽  
Intact Rock ◽  
Mechanical Parameters

The goal of this paper is to present the influence of the water saturation of the intact rock on different mechanical parameters, such as internal friction angle, cohesion, Hoek-Brown constant (mi ). Analyzing the previously published results, it was found that due to water saturation both the uniaxial compressive strength and tensile strength decrease similarly, i.e. the ratio of these two values is constant, thus the internal friction angle does not change but only the cohesion. Likewise, Hoek-Brown constant (mi ) remains constant; it is independent on the moisture content.The ratio of the elastic modulus and the uniaxial compressive strength of the intact rock is also calculated. According to the laboratory results, this ratio (namely modulus ratio) is also independent on the water content.It is shown that the mechanical parameters of the rock mass (such as compressive strength, tensile strength, deformation modulus) similarly depend on the water content than the intact rock.

scholarly journals Experimental development process of similar material of water resisting layer in physical model test

2021 ◽  
Vol 303 ◽  
pp. 01012
Author(s):  
Qi Liu ◽  
Shaojie Chen ◽  
Shuai Wang ◽  
Jing Chai ◽  
Dingding Zhang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Uniaxial Compressive Strength ◽  
Poisson’S Ratio ◽  
Silicone Oil ◽  
Poisson's Ratio ◽  
Mass Ratio ◽  
Similar Material ◽  
River Sand ◽  
Similar Materials ◽  
The Stability

The stability evaluation of water resisting layer in the process of coal mining is the key to study the law of water and soil loss and prevent the loss of water resources. The development and proportioning of similar materials are the basis to study the stability of water resisting layer by physical simulation. A new type of similar material considering water characteristics was developed through orthogonal experiments. The similar material was composed of river sand, bentonite, silicone oil, vaseline, and water. Determine the best test development process. First of all, the proportion test scheme is designed based on the orthogonal test. Then, the influence of cement concentration, mass ratio of silicone oil to vaseline and other components on the density, uniaxial compressive strength, elastic model and Poisson’s ratio of similar materials was analyzed by range analysis. Finally, the multiple linear regression equation between the parameters and the composition of similar materials for water resisting layer is obtained, and the optimal composition ratio is further determined according to the relationship between the test influencing factors and the mechanical properties of similar materials. The results show that the selected raw materials and their proportioning method are feasible. The content of river sand plays a major role in controlling the density and Poisson’s ratio of similar materials. The mass ratio of aggregate to binder is the main factor affecting the uniaxial compressive strength and elastic modulus of similar materials, while the cementing concentration has the second largest influence on the density, uniaxial compressive strength, elastic modulus and Poisson’s ratio of similar materials. Determining the cementing concentration that matches the design of similar material model tests is critical to improving test accuracy and provides a reference for the preparation of similar materials for water resisting layer under different requirements during the development of similar materials.

scholarly journals Experimental study on the ratio model of similar materials in the simulation test of coal and gas outburst

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Peng Sun ◽  
Haitao Sun ◽  
Fujin Lin ◽  
Xuelin Yang ◽  
Wangang Jiang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Uniaxial Compressive Strength ◽  
Pulverized Coal ◽  
Ratio Model ◽  
River Sand ◽  
Adsorption And Desorption ◽  
Sodium Humate ◽  
Gas Outburst ◽  
Similar Materials

AbstractTo obtain the similar materials with specific physical and mechanical parameters and adsorption and desorption indexes used in coal and gas outburst simulation tests, pulverized coal was selected as aggregate, and sodium humate was selected as cementing agent and river sand was selected as auxiliary materials. Based on this, orthogonal tests with 6 factors and 5 levels were designed, and the tests of weighing, uniaxial compression, firmness, adsorption and desorption were carried out. The parameters such as density, uniaxial compressive strength, elastic modulus, firmness coefficient and adsorption–desorption index of similar materials with different ratios were obtained, and the sensitivity of each factor was analyzed by range analysis. The influence of various factors on the similar materials was studied, and the ratio model of similar materials was obtained. The reliability of the model was verified, and a complete method for determining the ratio model of similar materials of outburst coal was put forward. The results show that the density of the similar materials increases with the river sand content, and the uniaxial compressive strength and elastic modulus increase significantly with the pulverized coal ratio and sodium humate content, and the firmness coefficient increases linearly with the pulverized coal ratio. The adsorption constant increases linearly with the sodium humate content, while the adsorption constant b decreases linearly with the sodium humate content. The initial elution rate Δp of similar materials increases at first and then decreases with the increase of sodium humate content.

scholarly journals Experimental Analysis of the Mechanical Properties and Resistivity of Tectonic Coal Samples with Different Particle Sizes

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2303
Author(s):  
Congyu Zhong ◽  
Liwen Cao ◽  
Jishi Geng ◽  
Zhihao Jiang ◽  
Shuai Zhang
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Uniaxial Compressive Strength ◽  
Coalbed Methane ◽  
Coal Sample ◽  
Fine Particles ◽  
Particle Sizes ◽  
Tectonic Coal

Because of its weak cementation and abundant pores and cracks, it is difficult to obtain suitable samples of tectonic coal to test its mechanical properties. Therefore, the research and development of coalbed methane drilling and mining technology are restricted. In this study, tectonic coal samples are remodeled with different particle sizes to test the mechanical parameters and loading resistivity. The research results show that the particle size and gradation of tectonic coal significantly impact its uniaxial compressive strength and elastic modulus and affect changes in resistivity. As the converted particle size increases, the uniaxial compressive strength and elastic modulus decrease first and then tend to remain unchanged. The strength of the single-particle gradation coal sample decreases from 0.867 to 0.433 MPa and the elastic modulus decreases from 59.28 to 41.63 MPa with increasing particle size. The change in resistivity of the coal sample increases with increasing particle size, and the degree of resistivity variation decreases during the coal sample failure stage. In composite-particle gradation, the proportion of fine particles in the tectonic coal sample increases from 33% to 80%. Its strength and elastic modulus increase from 0.996 to 1.31 MPa and 83.96 to 125.4 MPa, respectively, and the resistivity change degree decreases. The proportion of medium particles or coarse particles increases, and the sample strength, elastic modulus, and resistivity changes all decrease.

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