scholarly journals Prediction models of mechanical properties for pet-mortar composite in sodium sulphateaggressive mediums

2018 ◽  
Vol 149 ◽  
pp. 01051 ◽  
Author(s):  
Nabil Kazi Tani ◽  
A.S. Benosman ◽  
Y. Senhadji ◽  
H. Taïbi ◽  
M. Mouli ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Portland Cement ◽  
Modulus Of Elasticity ◽  
Aggressive Medium ◽  
Young Modulus ◽  
Sodium Sulphate ◽  
Sulphate Attack ◽  
Volume Fractions ◽  
Resistance Coefficients

In this research, an investigation was carried out on the effect of sodium sulphate attack on the durability of composites produced with waste polyethylene terephthalate (PET). Experiments were accomplished on limestone sand and cement mortars where the blended Portland cement was partially replaced by various volume fractions of waste PET particles (6%, 12% and 17%). The test solutions used to supply the sulphate ions and cations were 5%sodium sulphate solution. Compressive strengths measured on specimens were used to assess the changes in the mechanical properties of PET-mortars exposed to sulphate attack at different ages, mainly the Young modulus of elasticity. Based on experimental compressive tests on PETMortar composite specimens and there densities, the evolution of Young modulus of elasticity has been analyzed in accordance with normative models given by (ACI-318) and (BS-8110) codes of practice. In addition, a comparative study has been carried out for corrosion resistance coefficients K of unmodified mortar to those modified with waste PET particles. It can be noticed that, for the composite immersed in a corrosive Na2SO4 solution, the corrosion resistance coefficients decrease with the increase of the immersion period. The corrosion sulphate resistance K based on Young modulus before and after immersion of PET-mortar composites is better than that of the control mortar. Therefore, for safety considerations of PET-mortar composites use, ACI 318 is recommended code for design and investigation works. Also, it can be concluded that adding waste PET by volume fractions (6%, 12% and 17%) to blend Portland cement renders this cement more resistant to the sodium sulphate aggressive medium. Therefore, composites materials based waste PET aare often presented as the materials of the future because of their potential for innovation and the advantages they offer. In fact, using waste PET as cement substitutes reduces the energy consumption. These modified mortars address problems related to environmental pollution by CO2 emissions, and are used to repair various reinforced concrete structures in sodium sulphate aggressive mediums.

scholarly journals MICRO-MECHANICAL PROPERTIES OF CEMENT AND SLAG COMPOSITES MEASURED BY NANOINDENTATION

2020 ◽  
Vol 26 ◽  
pp. 45-49
Author(s):  
Jiří Němeček ◽  
Jiří Němeček
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Modulus Of Elasticity ◽  
Volume Fraction ◽  
Blended Cement ◽  
Hydration Products ◽  
Granulated Blast Furnace Slag ◽  
The Difference ◽  
Portland Cement Paste ◽  
Furnace Slag

In this study, the micromechanical response of two cementitious composites was characterized by nanoindentation. Pure Portland cement paste and Portland cement with 50 vol. % replaced with granulated blast furnace slag (GBFS) paste were investigated at the age of 28 days. Grid nanoindentation, statistical deconvolution and scanning electron microscopy were used to characterize the main hydration products. Several grids with approximately 500 indents on each sample were performed to obtain modulus of elasticity, hardness and creep indentation parameter. Similar mechanical phases containing calcium silica hydrate, crystalline calcium hydroxide and un-hydrated clinker were found in both samples varying by volume fraction. Blended cement, moreover, contains a phase of slag hydration products with a significantly lower modulus of elasticity. This phase with a high portion of unreacted GBFS is mostly responsible for the difference of mechanical properties of the whole composite.

Influence of Portland Cement Addition in the Physical and Mechanical Properties of Epoxy Resin

2015 ◽  
Vol 1088 ◽  
pp. 411-414 ◽  
Author(s):  
Francisco Augusto Zago Marques ◽  
Carlos Eduardo G. da Silva ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr ◽  
Túlio Hallak Panzera ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Composite Material ◽  
Portland Cement ◽  
Physical Properties ◽  
Epoxy Resin ◽  
Modulus Of Elasticity ◽  
Epoxy Matrix ◽  
Physical And Mechanical Properties ◽  
Response Variable

This research evaluated, with the of the analyses of variance (ANOVA), a composite material based on epoxy matrix phase reinforced with Portland cement (CP-II) particles (0%wt [100%wt of resin], 20%wt, 40%wt, 60%wt). The response-variable investigated were modulus of elasticity (E) and compressive strength (S), bulk density (ρB), apparent density (ρA) and porosity (P). The highest values of the modulus of elasticity were provided from the composites manufactured with 40wt% of cement addition. The inclusion of 60% of cement implies in a reduction in the mechanical properties when compared with the results of the composite manufactured with 40% of cement. For the physical properties, the gradually inclusion of cement provides increasing in the density of the composites, and reduce the porosity of the materials manufactured.

scholarly journals RESISTÊNCIA A CORROSÃO EM DIFERENTES TRATAMENTOS DE SUPERFÍCIE SOBRE LIGAS DE ZINCO UTILIZADOS EM METAIS SANITÁRIOS

2019 ◽  
Vol 10 (2) ◽  
pp. 185
Author(s):  
Suzan Arnold ◽  
Sandra Raquel Kunst ◽  
Luciane Taís Fuhr ◽  
Cláudia Trindade Oliveira
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Lower Cost ◽  
Salt Spray ◽  
Aggressive Medium ◽  
Salt Spray Test ◽  
High Porosity ◽  
Ferrous Alloys ◽  
Copper Nickel

Entre as ligas não ferrosas, as ligas de zamac são as mais utilizadas para a fundição e vêm sendo aplicadas na substituição de peças de latão, utilizadas industrialmente em metais sanitários. O zamac apresenta propriedades mecânicas semelhantes às do latão, porém com custo inferior. Entretanto, a alta porosidade destas ligas, impede que tratamentos superficiais garantam bom acabamento e resistência à corrosão. Visando melhorar o desempenho, frente à corrosão de peças de zamac, o objetivo do presente trabalho é avaliar o processo de diferentes tratamentos de superfície dos metais sanitários produzidos em zamac. As amostras foram injetadas sobre pressão e submetidas a diferentes tratamentos superficiais (tratamento mecânico, tratamento químico, cobre alcalino, cobre ácido, níquel, cromo). Os corpos de prova foram expostos a um meio agressivo, por meio de nevoa salina a fim de analisar a resistência à corrosão das peças, além de análises de polarização, metalografia e microdureza. Observou-se que a maior incidência de corrosão ocorreu nas partes de injeção e solda da peça, as amostras tratadas com níquel e cromo demonstraram o melhor desemprenho frente a resistência a corrosão.Palavras-chave: Zamac. Metais sanitários. Corrosão.ABSTRACTAmong the non ferrous alloys, zamak are the most used for casting and have been applied to substitute brass parts, industrially utilized in sanitary metals. The zamak presents mechanical properties similar to brass, however with lower cost. Meanwhile, the high porosity of these alloys hinders the superficial treatments ensure good finishing and corrosion resistance. Aiming to improve the performance against corrosion of zamak parts, this work evaluates the process of different superficial treatments of sanitary metals produced with zamak. The samples were injected under pressure and submitted to different superficial treatments (mechanical, chemical, alkaline copper, acid copper, nickel and chromium). The specimens were exposed to an aggressive medium through salt spray test to evaluate the corrosion resistance, and the following analysis: polarization, metallography and microhardness. It was observed that the higher corrosion incidence occurred on the injection and weld regions. The samples treated with nickel and chromium demonstrated better performance of corrosion resistance. Keywords: Zamak. Sanitary materials. Corrosion.

scholarly journals Possibilities of using aluminate cements in high-rise construction

2018 ◽  
Vol 33 ◽  
pp. 02056
Author(s):  
Maria Kaddo
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Service Life ◽  
Portland Cement ◽  
Physical And Mechanical Properties ◽  
High Alumina ◽  
Corrosion Resistant ◽  
High Rise ◽  
Aluminate Cement

The article describes preferable ways of usage of alternative binders for high-rise construction based on aluminate cements. Possible areas of rational use of aluminate cements with the purpose of increasing the service life of materials and the adequacy of the durability of materials with the required durability of the building are analyzed. The results of the structure, shrinkage and physical and mechanical properties of concrete obtained from dry mixes on the base of aluminate cements for self-leveling floors are presented. To study the shrinkage mechanism of curing binders and to evaluate the role of evaporation of water in the development of shrinkage was undertaken experiment with simple unfilled systems: gypsum binder, portland cement and «corrosion resistant high alumina cement + gypsum». Principle possibility of binder with compensated shrinkage based on aluminate cement, gypsum and modern superplasticizers was defined, as well as cracking resistance and corrosion resistance provide durability of the composition.

scholarly journals Preparation and Properties of Ti-Y2O3 Composites for Implant Applications

2017 ◽  
Vol 62 (2) ◽  
pp. 663-666
Author(s):  
G. Adamek ◽  
J. Jakubowicz ◽  
M. Dewidar
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Corrosion Resistance ◽  
Mechanical Alloying ◽  
Size Structure ◽  
Young Modulus ◽  
Argon Atmosphere ◽  
New Materials ◽  
High Corrosion Resistance ◽  
Metallic Biomaterials

AbstractThe paper presents the preparation of Ti-(1-30wt.%)Y2O3composites using the mechanical alloying process. Ti based materials are the best metallic biomaterials because of their excellent properties: biocompatibility, low Young moduli and high corrosion resistance. Pure Ti and Y2O3powders were alloyed under argon atmosphere in shaker type mill (Spex 8000) followed by pressing and sintering.The ultra-low grain size structure improves the mechanical properties and hardness of the new materials in comparison to microcrystalline Ti-based sinters. However, because of the porosity of approx. 20-30%, a decrease in the Young modulus is observed. Moreover, the new composites show good tendency towards covering by Ca-P compounds during soaking in SBF.

scholarly journals Coal ash Portland Cement Mortars Sulphate Resistance

2021 ◽  
Vol 7 (1) ◽  
pp. 98-106
Author(s):  
Esperanza Menéndez ◽  
Cristina Argiz ◽  
Miguel Ángel Sanjuán
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Coal Fly Ash ◽  
Electrical Power ◽  
Bottom Ash ◽  
Coal Ash ◽  
Sodium Sulphate ◽  
Sulphate Attack ◽  
Coal Bottom Ash ◽  
Cement Mortars

Coal fly ash (CFA), coal bottom ash (CBA) are residues produced in thermo-electrical power stations as result of the coal combustion in the same boiler. Therefore, some characteristics of the coal fly ash (CFA) are comparable with those of the coal bottom ash (CBA). Nevertheless, coal bottom ash size is larger than coal fly ash one. Consequently, it was found that it is necessary to grind the coal bottom ash (CBA) to reach a similar size to that one of the CFA. The objective of this paper is to evaluate the performance of Portland cement mortars made with coal fly ash (CFA), coal bottom ash (CBA) or mixes (CFA+CBA), against sulphate attack. The methodology is based on the expansion of slender bars submerged in a sodium sulphate solution (5%) according to the ASTM C-1012/C1012-13 standard. It has been found that mortars elaborated with CEM I 42.5 N (without ashes) presented the largest expansion (0.09%) after a testing period of 330 days. Mortars made with CEM II/A-V exhibited lower expansion (0.03%). Summing up, it can be established that mortar expansion decreases when the coal ash amount increases, independently of the type of coal ash employed. The novelty of this paper relies on the comparison between the performances of Portland cement mortars made with coal fly ash (CFA) or coal bottom ash (CBA) exposed to external sulphate attack. Doi: 10.28991/cej-2021-03091640 Full Text: PDF

Elasticity of Calcium Silicate Brick Masonry Wall Due to Sulphate Attack

2010 ◽  
Vol 133-134 ◽  
pp. 195-200
Author(s):  
Ibrahim Mohamad H. Wan ◽  
B.H. Abu Bakar ◽  
M.A. Megat Johari ◽  
P.J. Ramadhansyah
Keyword(s):  
Relative Humidity ◽  
Modulus Of Elasticity ◽  
Calcium Silicate ◽  
Masonry Wall ◽  
Sodium Sulphate ◽  
Brick Masonry ◽  
Sulphate Solution ◽  
Masonry Structures ◽  
Sulphate Attack ◽  
Sulphate Concentration

The aim of this study is to investigate the behaviour of the calcium silicate brick masonry wall exposed to sulphate condition. This paper presents some result about the effect of sodium sulphate attack on the elasticity of the calcium silicate brick masonry structures. All specimens were cured under polythene sheet for 14 days in environmental controlled room with temperature of 25± 2°C and 80 ± 5% relative humidity. After curing, the specimens were exposed to sodium sulphate solution before tested at 14, 28, 56 and 180 days respectively. As a result, the modulus of elasticity of the calcium silicate brick masonry wall reduces with the increase of sulphate concentration.

Effects of differences in mineralization on the mechanical properties of bone

1984 ◽  
Vol 304 (1121) ◽  
pp. 509-518 ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Volume Fraction ◽  
Young Modulus ◽  
Compact Bone ◽  
Work Of Fracture ◽  
Very High

There is a considerable variation in the mineralization of bone; normal, non-pathological compact bone has ash masses ranging from 45 to 85% by mass. This range of mineralization results in an even greater range of mechanical properties. The Young modulus of elasticity can range from 4 to 32 GPa, bending strength from 50 to 300 MPa, and the work of fracture from 200 to 7000 Jm -2 . It is not possible for any one type of bone to have high values for all three properties. Very high values of mineralization produce high values of Young modulus but low values of work of fracture (which is a measure of fracture toughness). Rather low values of mineralization are associated with high values of work of fracture but low values of Young modulus and intermediate values of bending strength. The reason for the high value for the Young modulus associated with high mineralization is intuitively obvious, but has not yet been rigorously modelled. The low fracture toughness associated with high mineralization may be caused by the failure of various crack-stopping mechanisms that can act when the mineral crystals in bone have not coalesced, but which become ineffective when the volume fraction of mineral becomes too high. The adoption of different degrees of mineralization by different bones, leading to different sets of mechanical properties, is shown to be adaptive in most cases studied, but some puzzles still remain.

scholarly journals Influence of Environmental Humidity on Mechanical Properties of Natural and Recycled Unbound Materials

2015 ◽  
Vol 63 (2) ◽  
pp. 405-409 ◽  
Author(s):  
Aleš Florian ◽  
Lenka Ševelová ◽  
Jaroslav Žák
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Cyclic Load ◽  
Young Modulus ◽  
Testing Procedure ◽  
Test Method ◽  
State Of Stress ◽  
Low Volume Roads ◽  
Low Volume ◽  
Materials Used

Low volume roads are widely used all over the world. To improve their quality a FEM computer simulation of their behavior is proposed. The input information about mechanical properties of individual materials is crucial for obtaining results as exact as possible. Among others, the mechanical properties are generally dependent on the state of stress and on humidity conditions. For this purpose the cyclic-load triaxial machine testing of cyclic-load performance of materials seems to be a promising test method. The test specimens can be prepared with different amounts of water. Thus modulus of elasticity (Young modulus) of different materials including recycled ones can be measured under the different conditions of horizontal and vertical stresses and under the different humidity conditions. Using the proposed testing procedure the modulus of elasticity of materials used in the newly built low volume road is obtained under the different state of stress as well as humidity conditions set to standard, dry and fully saturated level. Also recycled materials which are able to replace the traditional materials in the pavement are tested. Obtained values of modulus of elasticity can be used in a FEM study of the newly built road.

Mechanical Properties of Cementitious and Non-Cementitious System After Ageing Tests for Well Abandonment Cementing Operations

2019 ◽  
Author(s):  
Ingrid Ezechiello da Silva ◽  
Vivian Karla Castelo Branco Louback Machado Balthar ◽  
Romildo Dias Toledo Filho ◽  
Gabriella de Medeiros de Sá Cavalcante ◽  
Robert Lucian de Lima dos Santos
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Portland Cement ◽  
Epoxy Resin ◽  
Modulus Of Elasticity ◽  
Thermal Bath ◽  
Strength Tests ◽  
Well Abandonment

The plug and Abandonment (P&A) are the final stage of the life cycle of an oil well. This implies that the plugging material must withstand the chemicals, temperature and well pressure to ensure its long-term integrity. Portland cement is the most used material as a safety barrier in P&A operations. However, the extreme conditions of the well have challenged the mechanical properties of Portland Cement. In this context, the present work aims to identify the adequate systems as permanent plugging material and to characterize them with a qualification process based on international references and experimental validation. Hence, four systems were tested for plug cementing operation with composition variations under pre-defined ageing conditions. Class G Portland cement slurry was used as reference to allow comparison of mechanical properties (compressive strength and tensile strength) between flexible cement paste, a system containing a mixture of Class G Portland Cement with epoxy resin and finally a system with epoxy resin only. Samples containing Class G Portland Cement were cured for 14 days under well bottom conditions (3000 psi and temperature of 174 degrees Fahrenheit) and cured for 14 days at well temperature (using a thermal bath). Samples containing resin were cured for 14 days under well bottom conditions (3000 psi and temperature of 150 degrees Fahrenheit) and cured for 14 days at well temperature (using a thermal bath). Finally, the samples were aged for 60 days in a thermal bath at well temperature and exposed to the brine which is the completion fluid composition which will be above and below in contact with the well barrier in a P & A operation. The results of the compressive strength tests of the samples aged in brine showed tha in some systems tested the reduction of the modulus of elasticity occurred, however, it was also observed the increase of the modulus of elasticity in another system. The same was true of the results of tensile strength tests of aged samples, the increase of rupture loading in some systems and reduction in the other ones were observed. The mechanical tests of the samples before and after ageing were performed to define the best system to be used in a well abandonment operation aiming for long-term integrity.

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