scholarly journals Experimental investigation of cracking behaviors of ductile and brittle rock-like materials

2021 ◽  
Vol 15 (56) ◽  
pp. 16-45
Author(s):  
Hao Bai ◽  
Wei Du ◽  
Yundong Shou ◽  
Lichuan Chen ◽  
Filippo Berto
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Axial Stress ◽  
Geotechnical Engineering ◽  
Cementitious Materials ◽  
Epoxide Resin ◽  
Application Range ◽  
Wide Range ◽  
Similar Materials ◽  
Cracking Characteristics

The cracking characteristics of ductile rocks were studied by similar materials with sand, barite, epoxide resin, polyamide, silicone rubber and alcohol, while the cracking characteristics of brittle rocks were investigated by similar material with sand, barite, rosin and alcohol. In this paper, to enhance the application range of the rock-like materials in the field of geotechnical engineering model tests, the values of the elastic modulus and the compressive strength of the artificial rock-like materials are changed in a wide range by adjusting the amount of cementitious materials (epoxide resin, polyamide, rosin, etc). The elastic modulus, compressive strength and cracking characteristics were obtained from the complete axial stress–strain curves of the specimens made of similar materials, which were cast using the different mixture ratios. These experimental data can provide quantitative investigation on mixture ratios of similar materials of rocks to model the geotechnical engineering. Furthermore, the effect of mixture ratios on mechanical properties and crack propagation pattern of specimens were also investigated by the specimens with pre-existing flaws under uniaxial compressive tests

Comparative Study on the Elastic Modulus of Polymer Concrete

2015 ◽  
Vol 1129 ◽  
pp. 145-150
Author(s):  
Kyu Seok Yeon ◽  
Kwan Kyu Kim ◽  
Chul Young Kim ◽  
Jae Heum Yeon
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Goodness Of Fit ◽  
Unsaturated Polyester ◽  
Acrylic Resin ◽  
Prediction Equation ◽  
Polymer Concrete ◽  
Wide Range ◽  
Structural Applications ◽  
Using Data

Polymer concrete is used for a wide range of precast structural applications and repair works for existing infrastructures. For these applications, one of the key mechanical propertiesthatneed to be consideredis the elastic modulus. In this study, the relationship between elastic modulus and compressive strength of polymer concrete made with three different types of resin (i.e., unsaturated polyester resin, acrylic resin, and epoxy resin) is comprehensively investigated using data sets available from previous studies in order to develop a prediction equation for elastic modulus that can be generally applied to polymer concrete. Results showed that the equation developed under this study can be reasonably adopted for the predictions of polymer concrete's elastic modulus as a function of compressive strength because the prediction equation has a high goodness of fit asrepresented by a R2 value of 0.77

scholarly journals The Influence of Fly Ash Content on the Compressive Strength of Cemented Sand and Gravel Material

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1426
Author(s):  
Qihui Chai ◽  
Fang Wan ◽  
Lingfeng Xiao ◽  
Feng Wu
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Construction Material ◽  
Cementitious Materials ◽  
Ash Content ◽  
Optimal Dosage ◽  
Design Strength ◽  
Cemented Sand ◽  
Wide Range ◽  
Sand And Gravel

Cemented sand and gravel (CSG) material is a new type of dam material developed on the basis of roller compacted concrete, hardfill, and ultra-poor cementing materials. Its main feature is a wide range of sources of aggregate (aggregate is not screened but by simply removing the large particles it can be fully graded on the dam filling) and low amounts of cementitious materials per unit volume. This dam construction material is not only economical and practical, but also green and environmentally friendly. There are many factors affecting the mechanical properties of CSG materials, such as aggregate gradation, sand ratio, water content, water–binder ratio, fly ash content, admixture content, etc. Based on the existing research results of the team, this paper focuses on the influence of fly ash content on the compressive strength of CSG materials. Through a large number of laboratory measured data, we found: (1) The compressive strength law of materials at different ages; the compressive strength of CSG material at age 90 d is generally 10~30% higher than that at 28 d, and it is proposed that 90 d or 180 d strength should be used as the design strength in the design of CSG material dam; (2) There is an optimal value of fly ash content in CSG materials: when the fly ash content is 50% of the total amount of cementitious materials (cement + fly ash), the fly ash content is defined as the optimal content, and the test data are verified by regression analysis. The discovery of an 'optimal dosage' of fly ash provides an important reference for the design and construction of CSG dams.

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 Post-irradiation effects on Nylon-fibers reinforced concretes

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Gonzalo Martínez-Barrera ◽  
Carmina Menchaca-Campos ◽  
Enrique Vigueras- Santiago ◽  
Witold Brostow
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Gamma Radiation ◽  
Elasticity Modulus ◽  
Silica Sand ◽  
Irradiation Effects ◽  
Application Range ◽  
Second Stage ◽  
Long Storage

AbstractFiber-reinforced concretes (FRCs) have a wider application range than ordinary concretes. Properties of FRCs necessarily depend on the characteristics of the aggregates used. We have studied first effects of gamma radiation on mechanical properties of hydraulic concretes containing Portland cement, silica sand, marble, water and Nylon fibers. Compressive strength and dynamic elasticity modulus are of particular importance. In the second stage we have analyzed the changes in these mechanical properties after storage of our concretes for three years. The long storage results in a 97 % of increment in the compressive strength and simultaneous lowering by 35 % of the dynamic elastic modulus. We find a larger influence of the Nylon fibers than those of silica sand and marble on mechanical properties of the concretes.

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.

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.

Compression Testing and Microstructure of Heat-Treatable Aluminum Periodic Cellular Metal

2006 ◽  
Vol 929 ◽  
Author(s):  
B. A. Bouwhuis ◽  
G. D. Hibbard
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Energy Density ◽  
Sheet Metal ◽  
Mechanical Performance ◽  
Weight Ratio ◽  
Resistance Mechanisms ◽  
Confined Compression ◽  
Wide Range ◽  
Out Of Plane

ABSTRACTPeriodic cellular metals (PCMs) can offer higher specific strengths and stiffnesses than conventional (i.e. stochastic) metallic foams. This study examines the effects of PCM microstructure and loading conditions on the mechanical performance.PCM cores with 95% open porosity were constructed from perforated 6061 aluminium alloy sheets using a perforation-stretching method. This method places planar, periodically-perforated sheet metal in an alternating-pin jig. The pins apply force out-of-plane, plastically deforming the sheet metal into a truss-like array of struts (i.e. metal supports) and nodal peaks (i.e. strut intersections). Micro-hardness profiles were taken in the PCM struts to investigate microstructural evolution during fabrication and after heat treatment.Truss cores were tested in two limiting uniaxial compression conditions. In the first, the PCM cores are placed between smooth compression platens where the nodes are laterally free and compressive forces are resisted through PCM node-bending (i.e. free compression). In the second, the PCM cores were placed between plates where the nodes are laterally confined and compressive forces are resisted through PCM beam-buckling (i.e. confined compression). Compression response was analyzed in terms of peak compressive strength, elastic modulus, and energy density absorbed upon densification; response values were used to illustrate the effect of compression test conditions. In addition, PCM cores were tested in the age-hardened state and annealed state to determine microstructural effects on compressive response.Analysis of PCM response in free- and confined-compression conditions indicates a greater force resistance in beam-buckling over node-bending resistance mechanisms. The compressive strength, elastic modulus, and energy density of heat-treatable AA6061 PCMs are be found to respond: 1) over a wide range of value, dependent on the microstructure; 2) over a wide range of value, dependent on the PCM compression conditions; and 3) equally, if not more repeatable and with higher compressive strength-to-weight ratio than conventional metal foams.

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.

ZYMAXX

Alloy Digest ◽  
1991 ◽  
Vol 40 (10) ◽  
Keyword(s):  
Fracture Toughness ◽  
Compressive Strength ◽  
Corrosion Resistance ◽  
Creep Resistance ◽  
Chemical Processing ◽  
Industrial Equipment ◽  
Automotive Applications ◽  
Adverse Conditions ◽  
Chemical Inertness ◽  
Wide Range

Abstract ZYMAXX provides outstanding compressive creep resistance, toughness and chemical inertness at high temperatures and pressures and under adverse conditions. They have a wide range of uses beyond chemical processing, including aerospace and automotive applications, general industrial equipment, home appliances, farm and construction equipment. This datasheet provides information on physical properties, hardness, tensile properties, and compressive strength as well as fracture toughness and creep. It also includes information on corrosion resistance. Filing Code: Cp-18. Producer or source: E. I. Dupont de Nemours & Company Inc..

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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