Physical and mechanical properties of a compacted silty sand with low bentonite fraction

1998 ◽  
Vol 35 (6) ◽  
pp. 909-925 ◽  
Author(s):  
Filippo Santucci de Magistris ◽  
Francesco Silvestri ◽  
Filippo Vinale
Keyword(s):  
Mechanical Properties ◽  
Critical State ◽  
Physical And Mechanical Properties ◽  
Silty Sand ◽  
Granular Soils ◽  
Fine Grained ◽  
Optimum Water Content ◽  
Geotechnical Structures ◽  
Slurry Consolidation ◽  
Good Agreement

Compacted granular soils with small additions of bentonite have been used to build geotechnical structures such as impervious liners and cores of zoned earth dams. This paper presents a laboratory study showing how physical and mechanical characteristics of a silty sand are modified by a low percentage of bentonite. The effects of the addition of bentonite on the silty sand are reflected by an increase in the plasticity index, a reduction in maximum modified Proctor density, and a decrease in hydraulic conductivity. The most significant consequences on the mechanical properties are an increase of compressibility and secondary consolidation coefficients, and a reduction in shear strength. Different mixtures were either dynamically compacted at the optimum water content (compacted samples) or prepared after slurry consolidation from the minimum density (remoulded samples). Although the compacted and remoulded specimens show different isotropic compression lines, their critical-state lines in the v:p':q space are identical, where v is specific volume, p' is average effective stress, and q is deviator stress. Comparisons of the mechanical parameters with the existing literature database show that the compression coefficients of the remoulded mixtures are comparable to those of normally consolidated clayey soils of similar plasticity; nevertheless, those of the compacted mixtures are considerably lower. Also, the slopes of their critical-state lines in the q:p' plane are in good agreement with those predicted by empirical correlations for fine-grained soils.Key words: bentonite, silty sand, compaction, physical properties, compressibility, critical state.

Physical and Mechanical Properties of Fine-Grained Soil in the Zhejiang-Fujian Coastal Area, China

2011 ◽  
Vol 29 (4) ◽  
pp. 333-345 ◽  
Author(s):  
Yuan-Qin Xu ◽  
Pei-Ying Li ◽  
Ping Li ◽  
Le-Jun Liu ◽  
Cheng-Xiao Cao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Coastal Area ◽  
Physical And Mechanical Properties ◽  
Fine Grained ◽  
Fine Grained Soil

scholarly journals Mechanical and physical properties of fine-grained concrete for concrete additive manufacturing

2019 ◽  
Vol 91 ◽  
pp. 02041
Author(s):  
Sergey Udodov ◽  
Yuriy Galkin ◽  
Philip Belov
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Physical Properties ◽  
Crucial Role ◽  
Physical And Mechanical Properties ◽  
Concrete Composition ◽  
Fine Grained ◽  
Mechanical And Physical Properties ◽  
Time Periods

Additive manufacturing (3D printing) is becoming more and more common in the field of modern construction. However, for wider implementation of this technology, it is necessary to solve a number of material-oriented scientific problems related to development of concrete composition with targeted rheological, stress-strain, physical and mechanical properties. It has been established that time periods between successful applications of layers play the crucial role in ensuring monolithic features of the “printed” structures. Application of mathematics planning of the experiment allowed establishing the main principles of formation of basic physical and mechanical properties of fine-grained concrete depending on material composition.

Magnetic Pulse Compaction of Oxide Powders of the (ZrO2 – Y2O3) – Al2O3 System

2014 ◽  
Vol 1040 ◽  
pp. 819-823 ◽  
Author(s):  
Aleksander S. Ivashutenko ◽  
Nikita Martyushev ◽  
Igor G. Vidayev
Keyword(s):  
Mechanical Properties ◽  
Sintering Temperature ◽  
Physical And Mechanical Properties ◽  
Operating Principle ◽  
Magnetic Pulse ◽  
Fine Grained ◽  
Oxide Powders ◽  
Fine Grained Structure ◽  
Ampere’S Law ◽  
Ampère’S Law

Technology for manufacturing products by magnetic pulse compaction from oxide powders of the (ZrO2 – Y2O3) – Al2O3 system is presented in the paper. Diagram of the magnetic-pulse press with its operating principle being based on Ampere's law is given. Physical and mechanical properties of the obtained compacts are determined. The main feature of the designed technology is the reduced sintering temperature (200 °С) and the acquired fine-grained structure of the products. Another significant advantage achieved by applying the technology is the possibility for manufacturing fine-grained structure ceramic products with high mechanical properties.

Estimating compaction behavior of fine-grained soils based on compaction energy

2008 ◽  
Vol 45 (6) ◽  
pp. 877-887 ◽  
Author(s):  
Osman Sivrikaya ◽  
Ergun Togrol ◽  
Cafer Kayadelen
Keyword(s):  
Engineering Properties ◽  
Unit Weight ◽  
Fine Grained ◽  
Dry Unit Weight ◽  
Compaction Behavior ◽  
Optimum Water Content ◽  
Geotechnical Structures ◽  
Compaction Energy ◽  
Optimum Water

For successful designs of geotechnical structures, rational determination of the engineering properties of soils is an important process. In this context, compaction parameters, maximum dry unit weight (γdmax), and optimum water content (wopt) are required to be determined at various compaction energies. This paper proposes correlation equations that relate γdmax and wopt obtained from standard Proctor (SP) and modified Proctor (MP) tests to the index properties. To develop accurate relations, the data collected from the literature and the authors’ own database have been used. It has been found that while wopt has the best correlation with plastic limit (wp), γdmax can be estimated more accurately from wopt than it can from wp. In addition, the empirical methods including compaction energy (E) are described for estimating wopt and γdmax of fine-grained soils. The variables of the developed models for wopt and γdmax are wp, E, and wopt. It has been shown that the proposed correlations including the compaction energy will be useful for a preliminary design of a project where there is a financial constraint and limited time.

scholarly journals Effect of ion nitriding by glow discharge on the physical and mechanical properties of the plastically deformed tool steel R6M5

2021 ◽  
Vol 2064 (1) ◽  
pp. 012052
Author(s):  
R K Vafin ◽  
A V Asylbaev ◽  
D V Mamontov ◽  
I D Sklizkov ◽  
G I Raab ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Glow Discharge ◽  
Tool Steel ◽  
Physical And Mechanical Properties ◽  
Coarse Grained ◽  
Steel R6m5 ◽  
Ion Nitriding ◽  
Fine Grained ◽  
Fine Grained Structure

Abstract This work is devoted to the study of the effect of the duration of ion nitriding by glow discharge on the physical and mechanical properties of tool steel with different initial structure. We used specimens of R6M5 tool steel with a coarse-grained structure obtained after annealing at a temperature of 850°C and with a fine-grained structure obtained after severe plastic deformation by torsion discharge. With an increase in the duration of ion nitriding, the thickness of the hardened layer and wear resistance increase. The combination of plastic deformation with ion nitriding by glow discharge increases the adsorption and diffusion rate of the saturating element due to the creation of a highly fragmented and disoriented fine-grained structure and contributed to reduction in processing time.

scholarly journals Stabilization Characteristics of Different Loose Sandy Soils using Microbial-Induced Calcite Precipitation

2021 ◽  
Vol 18 (9) ◽  
Author(s):  
Naglaa MOHAMED ◽  
Nehad HAFEZ ◽  
Medhat EL-MAHLLAWY ◽  
Abbas SHARAKY
Keyword(s):  
Shear Strength ◽  
Physical And Mechanical Properties ◽  
Sandy Soils ◽  
Silty Sand ◽  
Soil Permeability ◽  
Calcite Precipitation ◽  
Precipitated Calcium Carbonate ◽  
Remarkable Effect ◽  
Geotechnical Structures ◽  
Low Shear

Loose sands (siliceous, silty, and calcareous classes) are extensively found near arid areas in Egypt. Furthermore, many geotechnical structures, like water channels and roads, may be constructed on weak or loose sand soils. The geotechnical behavior of loose sands is usually connected with different interdependent problems, such as high permeability, low shear strength, low bearing capacity, high seepage, and low stability. This work characterized the effect of stabilization of the siliceous, silty, and calcareous sandy soils via biocementation process using Sporosarcina pasteurii bacteria as a potential eco, commercial, and engineering solution. This was carried out using bacteria, fixation, and cementation solutions (BFC) at different times number additions. The results indicated that the addition times of solution have a remarkable effect on the physical and mechanical properties of sandy soils. The results also proved that the precipitation of calcite by the bacterial activity led to cohesion of soil grains, and this increased the resistance of soils to deterioration. In addition, the high content of the precipitated calcium carbonate enhanced the shear strength and the unconfined compressive strength and decreased the soil permeability. S. pasteurii bacteria can be used successfully and commercially in the biocementation process for siliceous sand, silty sand, and calcareous sandy soils in Egypt using the recommended conditions and mixes.

Modélisation du comportement du milieu granulaire en fonction de l'écrasement des grains

1998 ◽  
Vol 35 (3) ◽  
pp. 517-523
Author(s):  
Afif Rahma
Keyword(s):  
Mechanical Properties ◽  
Computer Simulations ◽  
Numerical Solutions ◽  
High Stress ◽  
Physical And Mechanical Properties ◽  
Plastic Work ◽  
Constitutive Law ◽  
Grain Crushing ◽  
Stress Levels ◽  
Good Agreement

The influence of grain crushing under high stress levels is introduced in the elasto-plastic constitutive law (Hujeux's model) using additional variables that change with the physical and mechanical properties of the grains. These variables are defined as functions of the amount of dissipated plastic work, which is proposed as a parameter for describing the material yield. The results of computer simulations along oedometric and triaxial paths indicate a very good agreement between the experimental curves and the numerical solutions. The proposed modifications are therefore validated.Key words: correlation, grain crushing, constitutive law, modelization, plastic work.[Journal translation]

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