scholarly journals Compatibility of Plants with a Mineral Binder

2022 ◽  
Author(s):  
Sandrine Marceau ◽  
Lucie Lacour ◽  
Dinarzed Diafi ◽  
Fabienne Farcas
Keyword(s):  
Mechanical Properties ◽  
Reducing Sugars ◽  
Isothermal Calorimetry ◽  
High Variability ◽  
Hemp Shiv ◽  
Mineral Binder ◽  
Plant Compounds ◽  
Lack Of Knowledge

Hemp concretes are the most widely used biobased concretes in France. However, their growth is still limited by the lack of knowledge and high variability of the performances of biobased concretes, especially for their mechanical properties. These results are related to interactions between the mineral binder and plant compounds that modify the hydration of the cement. In this work, the interactions between cement and eight types of hemp shiv, and a flax shiv are studied by isothermal calorimetry. The setting delays observed in the presence of plants are interpreted by analyzing the molecules extracted from these plants in water. A link can be observed between the setting delay and the coloration of the extract solutions or their concentration in reducing sugars and in polyphenols. These results constitute a basis in the objective to define an indicator enabling to predict the compatibility between plants and mineral binders.

Comparing Mechanical Properties of Secondary Wall and Cell Corner Middle Lamella in Spruce Wood

IAWA Journal ◽  
1997 ◽  
Vol 18 (1) ◽  
pp. 77-88 ◽  
Author(s):  
Rupert Wimmer ◽  
Barry N. Lucas
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Secondary Wall ◽  
Young's Modulus ◽  
Middle Lamella ◽  
Axial Direction ◽  
High Variability ◽  
Spatially Resolved ◽  
Spruce Wood ◽  
Cell Corner

Mechanical characterizations of the S2 layers and the cell corner middle lamella in the axial direction were investigated in spruce wood, A mechanical properties microprobe capable of measuring hardness and Young's modulus on a spatially resolved basis similar to that of an electron beam microprobe was used. Hardness of the cell comer middle lamella was found to be almost as high as that of the secondary wall, but the Young's modulus of the cell corner middle lamella was 50% less than that of the S2' The S2 showed constant hardness over its range of Young's modulus, but the cell corner middle lamella exhibited a strong correlation (R2 = 0.55) between hardness and the Young's modulus. Further investigations are needed to directly combine chemical and micromechanical properties and also to investigate the mechanical effects of the high variability of cell corner middle lamella chemistry.

The Effect of Coke Quality on Blast Furnace Working

2012 ◽  
Vol 706-709 ◽  
pp. 2164-2169
Author(s):  
Anna Konstanciak
Keyword(s):  
Mechanical Properties ◽  
Blast Furnace ◽  
Coke Quality ◽  
High Variability ◽  
Blast Furnace Process ◽  
Furnace Process ◽  
University Of Technology ◽  
Chamber Model

The analysis of coke quality and the effect of coke quality on blast furnace process was presented in this paper. The mechanical properties of cokes was determined by the MICUM method, the same coke samples were hot tested in the blast-furnace pre-tuyère chamber model at the Department of the Extraction and Recycling of Metals of the Czestochowa University of Technology to determine their thermo-abrasiveness ξ. Moreover, the permeability of the column of materials in the blast furnace during the use of those cokes was determined. The permeability of the materials column characterizes the “quality” of the materials, including the coke. Separating the coke features in this characteristics is possible with the remaining charge and technological conditions being stabilized. However, the high variability of charge conditions in the blast-furnace under examination distorts the existing permeabilities. Nevertheless, the dependence of the permeability on thermo-abrasiveness was “physically” correct, i.e. it decreased with increasing thermo-abrasiveness ξ, despite the small value of the coefficient of significance of this relationship.

scholarly journals Understanding the Fracture Behaviors of Metallic Glasses—An Overview

2019 ◽  
Vol 9 (20) ◽  
pp. 4277 ◽  
Author(s):  
Guan-Nan Yang ◽  
Yang Shao ◽  
Ke-Fu Yao
Keyword(s):  
Mechanical Properties ◽  
Fracture Mechanics ◽  
Metallic Glasses ◽  
Strain Field ◽  
High Variability ◽  
Fracture Properties ◽  
Complex Fracture ◽  
Polycrystalline Alloys ◽  
Fracture Behaviors ◽  
Key Questions

Fracture properties are crucial for the applications of structural materials. The fracture behaviors of crystalline alloys have been systematically investigated and well understood. The fracture behaviors of metallic glasses (MGs) are quite different from that of conventional crystalline alloys and have drawn wide interests. Although a few reviews on the fracture and mechanical properties of metallic glasses have been published, an overview on how and why metallic glasses fall out of the scope of the conventional fracture mechanics is still needed. This article attempts to clarify the up-to-date understanding of the question. We review the fracture behaviors of metallic glasses with the related scientific issues including the mode I fracture, brittle fracture, super ductile fracture, impact toughness, and fatigue fracture behaviors. The complex fracture mechanism of MGs is further discussed from the perspectives of discontinuous stress/strain field, plastic zone, and fracture resistance, which deviate from the classic fracture mechanics in polycrystalline alloys. Due to the special deformation mechanism, metallic glasses show a high variability in fracture toughness and other mechanical properties. The outlook presented by this review could help the further studies of metallic glasses. The review also identifies some key questions to be answered.

Direct Reinforcement of Natural Rubber Latex Mixes

1951 ◽  
Vol 24 (3) ◽  
pp. 649-661 ◽  
Author(s):  
Jean Le Bras ◽  
Ivan Piccini
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Natural Rubber ◽  
Natural Rubber Latex ◽  
Operating Conditions ◽  
Rubber Latex ◽  
Resorcinol Formaldehyde ◽  
Molecular Ratio ◽  
Direct Reinforcement ◽  
Lack Of Knowledge

Abstract The direct utilization of latex has up to the present time been limited to a relatively small number of applications because of lack of knowledge of how to communicate to articles sufficient hardness, modulus, resistance to tearing, and resistance to abrasion. It is possible to obtain such properties by combining the molding of latex (thermosensitized by the action of trypsin) with the addition of partially condensed resins. Numerous types of resins can be utilized, but the best results have been obtained by resorcinol-formaldehyde resins. The mechanical properties of vulcanizates thus prepared are extremely high—for example, the tensile strength may reach 7500 pounds per square inch (with an elongation of 700 per cent), and the resistance to tearing 900 pounds per inch. Operating conditions that must be observed for the formation of the resin are described in detail, as well as the influence on the properties of vulcanizates of different factors: length of condensation of the resin, conditions of vulcanization, proportion of catalyst, molecular ratio of constituents, conditions of drying, etc. A new way is opened for obtaining vulcanizates of natural rubber of outstanding mechanical propoerties.

scholarly journals Micro-Mechanical Properties of Expanded Clay Particles

2019 ◽  
Vol 8 (11) ◽  
pp. 840-844
Keyword(s):  
Mechanical Properties ◽  
Power Law ◽  
High Variability ◽  
Compression Tests ◽  
Clay Particles ◽  
High Dependency ◽  
Crushing Force ◽  
Clay Aggregates ◽  
Force Displacement ◽  
Highly Porous

The aim of this paper is to study the micro-mechanical behavior of an industrial crushable and highly porous granular material. Lightweight Expanded Clay Aggregates (LECA) was selected in this research for testing thanks to its brittle nature and highly porous character which makes it easier to study the crushable behavior of this material. LECA’s micro-mechanical properties were identified to understand the parameters that affect particle’s crushing. Uniaxial compression tests, consisting on compressing the particles between two rigid platens, were made on a set of single LECA’s particles to investigate the force displacement response and the Hertzian behavior was identified as the contact law. The particles’ strengths were determined for tested granules using the crushing force and grains’ Young moduli were calculated using the suggested contact law. Due to their high variability, the particles’ crushing stress and their Young moduli were related to particle’s dimension using a suggested power law to predict these mico-mechanical properties. Results have shown a high dependency between the particle’s micro-mechanical properties and their dimensions.

scholarly journals Reactivity and Microstructure of Metakaolin Based Geopolymers: Effect of Fly Ash and Liquid/Solid Contents

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3485 ◽  
Author(s):  
Vogt ◽  
Ukrainczyk ◽  
Ballschmiede ◽  
Koenders
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Isothermal Calorimetry ◽  
Bound Water ◽  
Silicate Solution ◽  
X Ray Diffraction ◽  
Solid Ratio ◽  
Potassium Silicate Solution ◽  
Dissolution Tests ◽  
Strength Tests

Geopolymers are inorganic binders based on mixtures of an aluminosilicate powder with an alkali-silicate solution. Properties of geopolymers are strongly determined by the type of reactive solid, the liquid/solid ratio of paste and, amongst others, the Si/Al ratio of the formed geopolymer network. In this study, fly ash blended metakaolin based geopolymers with varying liquid/solid ratios (l/s), activated by potassium silicate solution, are investigated. Reactivity of metakaolin and fly ash was investigated by powder X-ray diffraction (XRD) and dissolution tests. Reactivity, mechanical properties and microstructure of hardened pastes were analyzed by setting and compressive strength tests, mercury intrusion porosimetry (MIP), capillary water absorption tests, thermogravimetric analysis-differential scanning calorimeter (TGA-DSC), isothermal calorimetry and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). The results show that substitution of metakaolin by fly ash as well as variation of l/s brings advantages up to a certain degree, but also has a considerable influence on the pore size distribution, mechanical properties, Si/Al ratio of the geopolymer network and the content of bound water.

scholarly journals Modeling of proportions and prediction of properties of macadam and sand mixes stabilized with mineral binders with the ant additive

2018 ◽  
Vol 196 ◽  
pp. 04034
Author(s):  
Vakhtang Matua ◽  
Sergey Sizonets ◽  
Dmitry Stroev
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Principal Factor ◽  
Water Soluble ◽  
Prediction Of Properties ◽  
Mineral Additive ◽  
Amphoteric Surfactants ◽  
And Performance ◽  
The Mathematical Model ◽  
Mineral Binder

Optimization of the proportion and the properties of stabilized macadam and sand mixes (MSM) with introduction of the ANT additive was carried out by means of the mathematical designing of the experiment. This method allows a rather full and comprehensive assessment of the effect of the components on the properties of stabilized macadam and sand mixes (MSM), obtaining of the mathematical model of the process in graphic form, and obtaining of the theoretical model of assessment and prediction of the physical-mechanical and performance properties of the materials under study.At the first stage of the research percentages of a mineral binder, water and an additive were selected and the effect of the variability factor of these components on the mix’s physical-mechanical properties was studied. The following factors were selected as variates: X1 standing for quantity of water, %; X2 standing for the content of sulfate-resistant portland cement grade 500, %; X3 standing for the content of the ANT ionic stabilizer being essentially a water-soluble active organo-mineral additive containing amphoteric surfactants and microelements, %. The experimental design and the levels of the factors’ variability were specified on the basis of the test results.The principal factor exerting influence on the strength property of stabilized macadam and sand mixes is application of the ANT X3 ionic stabilizer.

Effect of Variability of Recycled Aggregate on Properties of Concrete

2012 ◽  
Vol 174-177 ◽  
pp. 1122-1132
Author(s):  
Chao Jun Wan ◽  
Xu Chen ◽  
Teng Li ◽  
Tai Zhong Huang ◽  
Tian Ming Deng
Keyword(s):  
Mechanical Properties ◽  
High Variability ◽  
Recycled Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Hardened Cement ◽  
Essential Factor ◽  
Hardened Cement Paste ◽  
Aggregate Concrete ◽  
Natural Aggregate

Low, medium and high variability of aggregates of concrete were designed and prepared and the influence of variability of recycled aggregates on the mechanical properties and durability of concretes was investigated. The experimental results indicated that the kinds of strengths, static compressive elastic modulus and durability of recycled concrete were decreased at engineering-acceptable level compared with natural aggregate concrete; the most properties of recycled concrete with high variability of recycled aggregates are not very different from that of recycled concrete with medium variability of recycled aggregates even that of natural aggregate concretes; however, the variability of properties of recycled concrete with high variability of recycled aggregates are much different from that of medium variability of recycled aggregates and more different from that of natural aggregate concretes, which means if only one or limited properties of recycled concrete were tested, the existing high variability of properties of concrete may not be revealed to a full enough extent, and the possible neglect of this high variability may result in potential engineering risk in application of high variability of recycled aggregate; the content of hardened cement paste and mortar attached to the recycled aggregate is found to be the essential factor to influence the properties of recycled concrete.

Production of Titanium Alloy Components by Semi-Solid Forming

2012 ◽  
Vol 192-193 ◽  
pp. 515-520 ◽  
Author(s):  
Levente Kertesz ◽  
Mathias Liewald
Keyword(s):  
Mechanical Properties ◽  
Metal Forming ◽  
Medical Engineering ◽  
High Variability ◽  
Development Work ◽  
Forming Process ◽  
Forming Technology ◽  
Semi Solid ◽  
New Research ◽  
The University

The relatively high costs of processing titanium alloys and the high variability in the products' quality currently represent the major economic obstacles to using such materials in either production or medical engineering. For this reason, new research and development work at the Institute for Metal Forming Technology of the University of Stuttgart is pursuing the objective of improving and enhancing pre-existing processes for these types of materials. In doing this, aspects are considered which specify definite mechanical properties during and after the forming process as well as reduce the costs by means of cutting the manufacturing times, increase the use of semi-finished products and minimise finishing operations.

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