scholarly journals Mortars prepared with mechanochemical treated asbestos-containing waste

2018 ◽  
Vol 251 ◽  
pp. 01009 ◽  
Author(s):  
Alexander Mezhov ◽  
Ekaterina Shokodko ◽  
Maria Kaddo
Keyword(s):  
Compressive Strength ◽  
Anionic Surfactant ◽  
Ball Mill ◽  
Experimental Results ◽  
Mechanochemical Treatment ◽  
Hydraulic Activity ◽  
Kinetics Of

The paper presents the results of recycling of asbestos-containing waste (ACW). It is shown that hydraulic activity of ACW is increased using mechanochemical treatment in the vibratory ball mill in presence of anionic surfactant. Experimental results show that substitution of 10% w.t. of cement on activated asbestos-containing waste leads to increasing of the compressive strength to 20%. Finally, the effect of the activated ACW on the hardening kinetics of mortars is examined.

scholarly journals Analysis of the Influencing Factors of FDM-Supported Positions for the Compressive Strength of Printing Components

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4008
Author(s):  
Zhengkai Feng ◽  
Heng Wang ◽  
Chuanjiang Wang ◽  
Xiujuan Sun ◽  
Shuai Zhang
Keyword(s):  
Compressive Strength ◽  
Stress Intensity ◽  
Influencing Factors ◽  
Fused Deposition Modeling ◽  
Experimental Results ◽  
Compression Tests ◽  
Suspended State ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
Reference Experiment

Fused deposition modeling (FDM) has the advantage of being able to process complex workpieces with relatively simple operations. However, when processing complex components in a suspended state, it is necessary to add support parts to be processed and formed, which indicates an excessive dependence on support. The stress intensity of the supported positions of the printing components can be modified by changing the supporting model of the parts, their density, and their distance in relation to the Z direction in the FDM printing settings. The focus of the present work was to study the influences of these three modified factors on the stress intensity of the supporting position of the printing components. In this study, 99 sets of compression tests were carried out using a position of an FDM-supported part, and the experimental results were observed and analyzed with a 3D topographic imager. A reference experiment on the anti-pressure abilities of the printing components without support was also conducted. The experimental results clarify how the above factors can affect the anti-pressure abilities of the supporting positions of the printing components. According to the results, when the supporting density is 30% and the supporting distance in the Z direction is Z = 0.14, the compressive strength of the printing component is lowest. When the supporting density of the printing component is ≤30% and the supporting distance in the Z direction is Z ≥ 0.10, the compressive strength of printing without support is greater than that of the linear support model. Under the same conditions, the grid-support method offers the highest compressive strength.

scholarly journals Cement-Based Renders Manufactured with Phase-Change Materials: Applications and Feasibility

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Luigi Coppola ◽  
Denny Coffetti ◽  
Sergio Lorenzi
Keyword(s):  
Compressive Strength ◽  
Phase Change ◽  
Phase Change Materials ◽  
Residential Buildings ◽  
Setting Time ◽  
Drying Shrinkage ◽  
Hydration Kinetics ◽  
Mechanical Performances ◽  
Entrapped Air ◽  
Kinetics Of

The paper focuses on the evaluation of the rheological and mechanical performances of cement-based renders manufactured with phase-change materials (PCM) in form of microencapsulated paraffin for innovative and ecofriendly residential buildings. Specifically, cement-based renders were manufactured by incorporating different amount of paraffin microcapsules—ranging from 5% to 20% by weight with respect to binder. Specific mass, entrained or entrapped air, and setting time were evaluated on fresh mortars. Compressive strength was measured over time to evaluate the effect of the PCM addition on the hydration kinetics of cement. Drying shrinkage was also evaluated. Experimental results confirmed that the compressive strength decreases as the amount of PCM increases. Furthermore, the higher the PCM content, the higher the drying shrinkage. The results confirm the possibility of manufacturing cement-based renders containing up to 20% by weight of PCM microcapsules with respect to binder.

Study on Waterproof and Water-Resistant Properties of Gypsum

2012 ◽  
Vol 476-478 ◽  
pp. 1585-1588
Author(s):  
Hong Pan ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Portland Cement ◽  
Water Absorption ◽  
Ordinary Portland Cement ◽  
Experimental Results ◽  
Softening Coefficient

The comprehensively modified effect of cement, VAE emulsion and self-made acrylic varnish on mechanical and water-resistant properties of gypsum sample was investigated and microstructure of gypsum sample was analyzed. Experimental results exhibit that absolutely dry flexural strength, absolutely dry compressive strength, water absorption and softening coefficient of gypsum specimen with admixture of 10% ordinary Portland cement and 6% VAE emulsion and acrylic varnish coated on its surface can respectively reach to 5.11MPa , 10.49 MPa, 8.32% and 0.63, respectively.

The Kinetics of Methyl Methacrylate Miniemulsion Polymerization Characterized through a Fluorescence Method

2012 ◽  
Vol 178-181 ◽  
pp. 609-612
Author(s):  
Hai Ke Feng ◽  
Hua Yu Qiu ◽  
Li Yuan Ding ◽  
Cun Jin Xu
Keyword(s):  
Methyl Methacrylate ◽  
Anionic Surfactant ◽  
Sodium Dodecyl Sulphate ◽  
Sodium Dodecyl ◽  
Miniemulsion Polymerization ◽  
Time Measurement ◽  
Fluorescence Method ◽  
Real Time Measurement ◽  
Measurement Results ◽  
Kinetics Of

In this paper, we followed the kinetics of methyl methacrylate (MMA) through a novel fluorescence method. The real-time measurement results show that in the regime of very low monomer contents, such as a solution containing 0.1 wt% of MMA with respect to water and with the anionic surfactant of sodium dodecyl sulphate (SDS), the kinetic of the miniemulsion could be followed by this embed fluorescence method. The processes of changing from emulsion to miniemulsion with different amount of surfactant and cosurfactant also have been monitored.

Experimental Study on the Failure Criterion for Brittle Materials in Compression

2011 ◽  
Vol 320 ◽  
pp. 259-262
Author(s):  
Xu Ran ◽  
Zhe Ming Zhu ◽  
Hao Tang
Keyword(s):  
Thin Film ◽  
Experimental Study ◽  
Compressive Strength ◽  
Fracture Mechanics ◽  
Failure Criterion ◽  
Brittle Materials ◽  
Experimental Results ◽  
Experiment Study ◽  
Confining Stress ◽  
Theoretical Results

The mechanical behavior of multi-cracks under compression has become a very important project in the field of fracture mechanics and rock mechanics. In this paper, based on the previous theoretical results of the failure criterion for brittle materials under compression, experiment study is implemented. The specimens are square plates and are made of cement, sand and water, and the cracks are made by using a very thin film (0.1 mm). The relations of material compressive strength versus crack spacing and the lateral confining stress are obtained from experimental results. The experimental results agree well with the failure criterion for brittle materials under compression, which indicates that the criterion is effective and applicable.

scholarly journals Investigation of cultivated lavender (Lavandula officinalis L.) extraction and its extracts

2014 ◽  
Vol 20 (1) ◽  
pp. 71-86 ◽  
Author(s):  
Vesna Nadjalin ◽  
Zika Lepojevic ◽  
Mihailo Ristic ◽  
Jelena Vladic ◽  
Branislava Nikolovski ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Essential Oil ◽  
Experimental Results ◽  
Flame Ionisation Detector ◽  
Main Components ◽  
Lavandula Officinalis ◽  
Physical And Chemical ◽  
Kinetics Of ◽  
Flame Ionisation ◽  
Ionisation Detector

In this study essential oil content was determined in lavender flowers and leaves by hydrodistillation. Physical and chemical characteristics of the isolated oils were determined. By using CO2 in supercritical state the extraction of lavender flowers was performed with a selected solvent flow under isothermal and isobaric conditions. By the usage of gas chromatography in combination with mass spectrometry (GC/MS) and gas chromatography with flame ionisation detector (GC/FID) the qualitative and quantitative analysis of the obtained essential oil and supercritical extracts (SFE) was carried out. Also, the analysis of individual SFE extracts obtained during different extraction times was performed. It turned out that the main components of the analysed samples were linalool, linalool acetate, lavandulol, caryophyllene oxide, lavandulyl acetate, terpinen-4-ol and others. Two proposed models were used for modelling the extraction system lavender flower - supercritical CO2 on the basis of experimental results obtained by examining the extraction kinetics of this system. The applied models fitted well with the experimental results.

Etude par spectrométrie infrarouge de l'action de solvants aprotiques sur l'association ester–eau et ester–Ba2+. Discussion du rôle catalytique du solvant et de l'ion Ba2+ dans l'hydrolyse alcaline du propionate de methyle

1979 ◽  
Vol 57 (4) ◽  
pp. 400-403 ◽  
Author(s):  
Anne Le Narvor ◽  
Pierre Saumagne
Keyword(s):  
Ir Spectra ◽  
Charge Density ◽  
Carbonyl Group ◽  
Alkaline Hydrolysis ◽  
Experimental Results ◽  
Methyl Propionate ◽  
Orbital Control ◽  
Different Types ◽  
Kinetics Of ◽  
Better Than

The ir spectra of mixtures of methyl propionate/water and methyl propionate/Ba2+ in dimethylsulfoxide and in acetonitrile have been recorded in the region of the νCO mode of the ester. Evidence is presented to indicate the presence of different types of complexes; their concentration was determined as a function of the composition of the medium. The spectroscopic results are compared to those from the kinetics of the alkaline hydrolysis in the same conditions. It is demonstrated that the orbital control explains the experimental results better than does the charge density on the carbon of the carbonyl group. [Journal translation]

scholarly journals Comparison of Analytical Approaches Predicting the Compressive Strength of Fibre Reinforced Polymers

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2517 ◽  
Author(s):  
Christian Leopold ◽  
Sergej Harder ◽  
Timo Philipkowski ◽  
Wilfried Liebig ◽  
Bodo Fiedler
Keyword(s):  
Compressive Strength ◽  
Prediction Accuracy ◽  
Volume Fraction ◽  
Fibre Volume Fraction ◽  
Experimental Results ◽  
Analytical Models ◽  
Reinforced Polymers ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Analytical Approaches

Common analytical models to predict the unidirectional compressive strength of fibre reinforced polymers are analysed in terms of their accuracy. Several tests were performed to determine parameters for the models and the compressive strength of carbon fibre reinforced polymer (CFRP) and glass fibre reinforced polymer (GFRP). The analytical models are validated for composites with glass and carbon fibres by using the same epoxy matrix system in order to examine whether different fibre types are taken into account. The variation in fibre diameter is smaller for CFRP. The experimental results show that CFRP has about 50% higher compressive strength than GFRP. The models exhibit significantly different results. In general, the analytical models are more precise for CFRP. Only one fibre kinking model’s prediction is in good agreement with the experimental results. This is in contrast to previous findings, where a combined modes model achieves the best prediction accuracy. However, in the original form, the combined modes model is not able to predict the compressive strength for GFRP and was adapted to address this issue. The fibre volume fraction is found to determine the dominating failure mechanisms under compression and thus has a high influence on the prediction accuracy of the various models.

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