scholarly journals Anisotropy of the Strength Properties of Clays of the North of Belarus

2016 ◽  
Author(s):  
Aliaksander Kremniou ◽  
Nikolai Vishniakov
Keyword(s):  
Uniaxial Compression ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Triaxial Tests ◽  
Experimental Investigations ◽  
Test Results ◽  
Glacial Origin ◽  
The North

This paper describes the results of experimental investigations anisotropic clay at triaxial tests and uniaxial compression. A band clay of glacial origin has been selected for the study widespread in the north of Belarus. Clays have layered texture due to the conditions of formation. Tests were carried out at different angles to the plane of soil stratification. Test results show significant differences in the values of strength characteristics of soils.

scholarly journals Research of the Behavior of Clay Materials with Double Porosity

2021 ◽  
Vol 13 (6) ◽  
pp. 3219
Author(s):  
Hynek Lahuta ◽  
Luis Andrade Pais
Keyword(s):  
Double Porosity ◽  
Strength Properties ◽  
Triaxial Tests ◽  
Building Structures ◽  
Foundation Soil ◽  
Problematic Use ◽  
The North ◽  
Static Liquefaction ◽  
Confinement Stress ◽  
Clay Materials

This contribution presents results from a series of compression and undrained triaxial tests to study the mechanical behavior of dump clay from the north of Bohemia. The use of these materials as a foundation for construction can’t be achieved without the adoption of some precautions. This comes from embankment, formed by digging the ground (altered claystone), up to the level of coal mining which is in a sub horizontal stratigraphic layer. A potential static liquefaction behavior was observed in undrained tests for high confinement stress. A structural collapse was noticed with the results obtained in the triaxial test. This collapse is characterized by an unexpected large decrease in deviator and mean effective stress. The soils formed have strength properties that are potentially dangerous. These concepts can improve the use of these kinds of soils in geotechnical engineering work. It continues and expands the results obtained in previous research, especially the future problematic use of these materials as the foundation soil for line or building structures.

scholarly journals The Effect of Calcium Carbonate Filler on Self-Compacting Concrete Using Different Aggregate Sizes

2019 ◽  
Vol 4 (9) ◽  
pp. 9-16
Author(s):  
Wasiu John ◽  
Agbawhe Okeoghene Oghenekume ◽  
Tuleun Lawrence Zahemen
Keyword(s):  
Calcium Carbonate ◽  
Coarse Aggregate ◽  
Rice Husk Ash ◽  
Research Work ◽  
Strength Properties ◽  
Limestone Powder ◽  
Experimental Investigations ◽  
Test Results ◽  
Self Compacting Concrete ◽  
Carbonate Filler

In this research work, the effect of Calcium Carbonate Filler was studied on the compressive strength and the workability of self-compacting Concrete (SCC) at different grades (M60, M65 and M70) and different coarse aggregate sizes (6.3mm, 10mm and 20mm). Calcium Carbonate Filler (Limestone powder) and Rice Husk Ash (RHA) were added in percentages of 2.5% and 5% to check its effect on the workability and strength properties of SCC and Normally Vibrated Concrete. Experimental investigations were carried out on SCC and normally vibrated concrete (NVC) samples of grade M60, M65 and M70 using different aggregate sizes of 6.3mm, 10mm and 20mm. The workability test results obtained showed values within specification.  The compressive and Tensile strengths for SCC (with powder and 2.5% RHA) are higher than that with powder and 5% RHA and NVC. Generally, the use of Calcium Carbonate Filler improved the strength and densities for SCC design mix and decreased its workability. It is concluded that the use of SCC with designed Fillers ratio and RHA (≤5%) will improve the strength properties of SCC.

scholarly journals Absorption and Strength Properties of Short Carbon Fiber Reinforced Mortar Composite

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 300
Author(s):  
Md. Safiuddin ◽  
George Abdel-Sayed ◽  
Nataliya Hearn
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Water Absorption ◽  
Carbon Fibers ◽  
Strength Properties ◽  
Fiber Content ◽  
Test Results ◽  
Air Content ◽  
Entrapped Air ◽  
Short Carbon

This paper presents the water absorption and strength properties of short carbon fiber reinforced mortar (CFRM) composite. Four CFRM composites with 1%, 2%, 3%, and 4% short pitch-based carbon fibers were produced in this study. Normal Portland cement mortar (NCPM) was also prepared for use as the control mortar. The freshly mixed mortar composites were tested for workability, wet density, and entrapped air content. In addition, the hardened mortar composites were examined for compressive strength, splitting tensile strength, flexural strength, and water absorption at the ages of 7 and 28 days. The effects of different carbon fiber contents on the tested properties were observed. Test results showed that the incorporation of carbon fibers decreased the workability and wet density, but increased the entrapped air content in mortar composite. Most interestingly, the compressive strength of CFRM composite increased up to 3% carbon fiber content and then it declined significantly for 4% fiber content, depending on the workability and compaction of the mortar. In contrast, the splitting tensile strength and flexural strength of the CFRM composite increased for all fiber contents due to the greater cracking resistance and improved bond strength of the carbon fibers in the mortar. The presence of short pitch-based carbon fibers significantly strengthened the mortar by bridging the microcracks, resisting the propagation of these minute cracks, and impeding the growth of macrocracks. Furthermore, the water absorption of CFRM composite decreased up to 3% carbon fiber content and then it increased substantially for 4% fiber content, depending on the entrapped air content of the mortar. The overall test results suggest that the mortar with 3% carbon fibers is the optimum CFRM composite based on the tested properties.

Comparison of Test Results for Uniaxial Compression of Frozen Soil in Response to Constant Load and to Incremental Loading

2016 ◽  
Vol 53 (2) ◽  
pp. 91-97 ◽  
Author(s):  
V.I. Aksenov ◽  
A.V. Iospa ◽  
D.N. Krivov ◽  
K.V. Ozeritskii ◽  
V.V. Doroshin
Keyword(s):  
Uniaxial Compression ◽  
Constant Load ◽  
Frozen Soil ◽  
Test Results ◽  
Incremental Loading

General concept of determining the parameters of non-mining walls of ultra-deep diamond deposits development open pits

2021 ◽  
pp. 48-53
Author(s):  
I. V. Zyryanov ◽  
A. N. Akishev ◽  
I. B. Bokiy ◽  
N. M. Sherstyuk
Keyword(s):  
Rock Mass ◽  
Structural Relaxation ◽  
Slope Angle ◽  
Field Tests ◽  
Friction Angle ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Open Pit ◽  
Open Pit Mining ◽  
Relaxation Coefficient

A specific feature of open pit mining of diamond deposits in Western Yakutia is the construction of the open pits in the zone of negative ambient temperatures, which includes thick permafrost rock mass, and which is at the same time complicated by the influence of cryogenic processes on deformation of pit wall benches. The paper presents the comparative analysis of strength characteristics in frozen and thawed rocks, stability of benches during mining, the general geomechanical approach to the determination of parameters of non-mining walls of the ultra-deep open pit diamond mines, and the parameters of nonmining walls and benches. Optimization of open pit wall configuration should primarily be based on the maximum utilization of the strength properties of frozen rocks in combination with the development of new approaches, calculation schemes and methods for assessing stability of open pit walls and benches of unconventional design, including the non-mining vertical benches. The main design characteristic that determines the parameters of open pit walls is the structural tectonic relaxation coefficient, which specifies the calculated value of cohesion in rock mass. For the diamond deposits, the values of the structural relaxation coefficient were obtained in a series of field tests and back calculations. Full-scale tests were carried out both during exploration operations in underground mines and in open pits. The accuracy of determining the values of the structural relaxation coefficient in the range of 0.085–0.11 is confirmed by the parameters of non-mining walls in an open pit mine 385–640 m deep, with overall slope angles of 38–55° and a steeper H 0.35–0.5 lower part having the slope angle of up to 70° with average strength characteristics of 7.85–11.84 MPa and the internal friction angle of 28.1–37.4°. Using the natural load-bearing capacity of rock mass to the full advantage, which the values of the structural relaxation coefficient of deposits show, allows optimization of open pit wall slope design and minimization of stripping operations.

A Change of Undrain Shear Strength of Soft Ground during Consolidation Process

2014 ◽  
Vol 513-517 ◽  
pp. 269-272
Author(s):  
Yeong Mog Park ◽  
Ik Joo Um ◽  
Norihiko Miura ◽  
Seung Cheol Baek
Keyword(s):  
Shear Strength ◽  
Soft Clay ◽  
Confining Pressure ◽  
Triaxial Tests ◽  
Test Results ◽  
Exponential Equation ◽  
Consolidation Process ◽  
Degree Of Consolidation ◽  
Clay Ground ◽  
Strength Increment

The purpose of this study is to investigate the undrain shear strength increment during consolidation process of soft clayey soils. Thirty kinds of laboratory triaxial tests have been performed using undisturbed and remolded Ariake clay samples with different degree of consolidation and 5 kinds of confining pressure. Test results show that well known linear equation proposed by Yamanouchi et al.(1982) is overestimated the strength of undisturbed soft clay ground in the process of consolidation. A new simple and reasonable exponential equation proposed in this paper.

Weldability: Effect of Alloying Element Sc, Mn, and Zr on Alloys of the Al-Mg-Sc-Mn-Zr System

2019 ◽  
Author(s):  
V. I. Lukin
Keyword(s):  
Aluminum Alloys ◽  
Practical Importance ◽  
Strength Properties ◽  
Strength Characteristics ◽  
Mg Alloy ◽  
Alloying Element ◽  
Processing Properties ◽  
Alloys Of The Al ◽  
Effect Of Alloying

Scandium in aluminum alloys behaves as the most efficient modifier of the structure of the material and as an agent suppressing recrystallization. This unique behavior of scandium in alloys of the Al-Mg system greatly increases the strength characteristics, whilst retaining on a higher level the ductility and processing properties of deformed semi-finished products. This article describes the effect of complex alloying the Al-6.3% Mg alloy with scandium, manganese and zirconium on the weldability and strength properties of the material is of considerable scientific and practical importance.Investigations.

scholarly journals THE TEST RESULTS OF LOW-PERMEABILITY SHALE DEPOSITS WHEN DRILLING THE PRE-CRETACEOUS COMPLEX AT THE KARMALINOVSKOYE GAS CONDENSATE FIELD

2019 ◽  
pp. 45-58
Author(s):  
A. A. Zakharov ◽  
S. V. Korotkov ◽  
A. I. Gritsenko ◽  
R. A. Ivakin ◽  
V. G. Griguletsky
Keyword(s):  
Hydraulic Fracturing ◽  
Flow Rate ◽  
Gas Condensate ◽  
Low Permeability ◽  
Test Results ◽  
North West ◽  
The North ◽  
Exploratory Wells

The article reports the results of the analysis of the field prospecting activities of five exploratory wells at the Karmalinovskoye gas condensate field. We have found that the eastern part of the licensed area is characterized by the lack of fructuring in Paleozoic deposits, and the development of the productive deposit extends in the north-west direction. Hydraulic fracturing made it possible to get a stable gas and gas condensate flow rate in well № 4. This volume exceeds 3,8 times as large than flow rate in wells № 1 and № 2, which were tested after drilling without conducting hydraulic fracturing.

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