scholarly journals Effect of Dolomite Powder on Mechanical Properties of M40 Grade Concrete When Cement was Partially Replaced

2019 ◽  
Vol 8 (12) ◽  
pp. 3510-3513
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Flexural Strength ◽  
Mineral Deposit ◽  
Partial Substitution ◽  
Huge Amount ◽  
Substitution Rates ◽  
Cement Production ◽  
The Cost

Cement is one of the most significant constituents of concrete. Most of the properties of concrete depend on cement. By calcining argillaceous and calcareous material at a high temperature in cement production. During this procedure, huge amount of Co2 is discharged into the air. India is the second biggest manufacturer of cement on the planet. It is assessed that the generation of one tonne of cement brings about discharge of 0.8 tonne of Co2 . The decline in the utilization of cement will lessen the cost of concrete and outpouring of Co2 . Dolomite powder acquired by pulverizing rock forming mineral deposit of dolostone can be utilized as a trade material for cement in concrete up to certain percentage. Dolomite powder has a few comparative attributes of cement. Utilizing dolomite powder in cement can diminish the expense of cement and may expand the solidarity somewhat. Dolomite powder is a pozzolonic material which will improve not only the density but also strengthen the hardness of concrete. This paper inspects the likelihood of utilizing dolomite powder as partial substitution material to cement. The substitution rates attempted were 0 to 25% at a regular interval of 5% by weight of cement. The outcome demonstrates that substituting of cement with dolomite powder improves the compressive, split tensile and flexural strength of concrete.

scholarly journals Experimental study on high temperature mechanical properties of aluminate cement mortar mixed with fiber

2021 ◽  
Vol 25 (6 Part B) ◽  
pp. 4441-4448
Author(s):  
Ping Xu ◽  
Dong Han ◽  
Jian-Xin Yu ◽  
Yu-Hao Cui ◽  
Min-Xia Zhang
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Flexural Strength ◽  
Volume Fraction ◽  
Cement Mortar ◽  
Steel Fibers ◽  
Basalt Fibers ◽  
High Temperature Mechanical Properties ◽  
Micro Structures ◽  
Aluminate Cement

The aim of the present paper is to study the mechanical properties of aluminate cement mortar mixed with different chopped fibers under high temperature. The specimens with a size of 40 mm ? 40 mm ? 160 mm is treated at various tempera?tures of 25?C, 200?C, 400?C, 600?C, and 800?C. The compressive and flexural strength of the aluminate cement mortar and its micro-structures are tested. The results show that the chopped steel fibers and basalt fibers are effective in improv?ing the high temperature mechanical properties of aluminate cement mortar. When the volume fraction of chopped steel fibers is 2%, the compressive strength and flexural strength of the test block treated at the temperature of 800?C increase by 18.3% and 128.6%, respectively.

Microstructure and Mechanical Properties of SiC Whisker-Reinforced ZrB2 Ultra-High Temperature Ceramic

2008 ◽  
Vol 368-372 ◽  
pp. 1730-1732 ◽  
Author(s):  
Ping Hu ◽  
Xing Hong Zhang ◽  
Jie Cai Han ◽  
Song He Meng ◽  
Bao Lin Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Temperature ◽  
Flexural Strength ◽  
Hot Pressing ◽  
Room Temperature ◽  
Pressing Temperature ◽  
Sintering Time ◽  
Microstructure And Mechanical Properties ◽  
Ultra High Temperature

SiC whisker-reinforced ZrB2 matrix ultra-high temperature ceramic were prepared at 2000°C for 1 h under 30MPa by hot pressing and the effects of whisker on flexural strength and fracture toughness of the composites was examined. The flexural strength and fracture toughness are 510±25MPa and 4.05±0.20MPa⋅m1/2 at room temperature, respectively. Comparing with the SiC particles-reinforced ZrB2 ceramic, no significant increase in both strength and toughness was observed. The microstructure of the composite showed that the SiC whisker was destroyed because the SiC whisker degraded due to rapid atom diffusivity at high temperature. The results suggested that some related parameters such as the lower hot-pressing temperature, a short sintering time should be controlled in order to obtain SiC whiskerreinforced ZrB2 composite with high properties.

High Temperature Mechanical Properties of Ni-YSZ Cermets for SOFC Anode

2010 ◽  
Author(s):  
Fumitada Iguchi ◽  
Hiromichi Kitahara ◽  
Hiroo Yugami
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Flexural Strength ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Strain Diagram ◽  
Thermal Cycles ◽  
High Temperature Mechanical Properties ◽  
Sofc Anode ◽  
The Difference

The mechanical properties of Ni-YSZ cermets at high temperature in reduction atmosphere were evaluated by the four points bending method. We studied the influences of reduction and thermal cycles, i.e. a cycle from R.T. to 800°C, to flexural strength and Young’s modulus. The flexural strength of Ni-YSZ at room temperature was lower than that of NiO-YSZ by about 10 to 20% mainly caused by the increment of porosity. But, the flexural strength of Ni-YSZ at 800°C was drastically decreased by an half of that at R.T. In addition, the stress–strain diagram of Ni-YSZ at 800°C indicated that it showed weak ductility. The maximum observed strain was over 0.5% at 30MPa. On the contrary, NiO-YSZ showed only brittlely at 800°C. The difference was caused by Ni metal in the Ni-YSZ cermets. Therefore, it was expected that Ni-YSZ is easily deformed in operation, though residual stress between an anode and an electrolyte was low. The influence of thermal cycles to flexural strength and Young’s modulus was not observed clearly. At the same time, the differences of microstructure were not observed. Therefore, it was concluded that the cycle does not change mechanical properties significantly.

Effect of the Sintering Additives on the Microstructure and the Properties of Textured Silicon Nitride

2005 ◽  
Vol 287 ◽  
pp. 242-246
Author(s):  
Dong Soo Park ◽  
Y.M. Kim ◽  
Byung Dong Hahn ◽  
Chan Park
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Flexural Strength ◽  
Room Temperature ◽  
Sintering Additives ◽  
Significant Difference ◽  
Grain Width

Silicon nitride samples without and with 3 wt% of the aligned b-silicon nitride whisker seeds were prepared with 8.2 wt% Er2O3 and 1.9 wt% AlN. After sintering at 2148 K for 4h, the samples exhibited densities higher than 99.5% TD. The microstructures and properties of the samples were compared with those of the samples sintered with 4.8 wt% Y2O3 and 2.2 wt% Al2O3 at 2273 K for 4h. For samples without the whiskers, the sample with 4.8 wt% Y2O3 + 2.2 wt% Al2O3 had coarser microstructures than those with with 8.2 wt% Er2O3 + 1.9 wt% AlN. However, the samples with the whisker seeds, the former sample appeared to have only slightly larger grains than the latter sample in spite of the significant difference in the sintering temperatures. For the samples without the whisker seeds, the room temperature flexural strength was higher for the sample with Er2O3 + AlN. However, for the samples with the aligned whisker seeds, the sample with Y2O3 + Al2O3 exhibited higher room temperature flexural strength than that with Er2O3 + AlN although the average grain width of the former sample was larger than that of the latter sample. In case of the high temperature flexural strength at 1673 K, the flexural strengths of the samples with the whisker seeds were higher than double the strengths of the samples without the whisker seeds. For samples without the whisker seeds, the sample with Er2O3 + AlN exhibited better mechanical properties than that with Y2O3 + Al2O3. However, for the samples with the aligned whisker seeds, the sample with Y2O3 + Al2O3 exhibited better mechanical properties than those with Er2O3 + AlN. The results were explained in terms of the microstructures of the samples.

Performance of ilmenite concrete at sustained elevated temperatures

1988 ◽  
Vol 15 (5) ◽  
pp. 776-783
Author(s):  
H. S. Wilson
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperature ◽  
Flexural Strength ◽  
Key Words ◽  
Elevated Temperatures ◽  
Cement Ratio ◽  
Nondestructive Tests ◽  
High Temperature Mechanical Properties ◽  
Curing Period

Two similar mixes were made with cement contents of about 350 kg/m3 and a water–cement ratio of 0.50. The concrete specimens, moist cured for 7 days, were cured in air for 28 and 120 days, respectively, prior to heating. The exposure temperatures were 75, 150, 300, and 450 °C. The periods of exposure at each temperature were 2, 30, and 120 days.The compressive strengths, before heating, of the specimens cured for 35 and 120 days were 41.0 and 46.2 MPa, respectively, and the flexural strengths were 4.9 and 5.8 MPa. Compared with those strengths, the strengths of the specimens heated for 30 days or more increased at 75 °C but decreased at higher temperatures. The losses increased with increase in temperature, reaching about 30% at 450 °C.The flexural strength of the concrete cured in air for 28 days was more adversely affected than was the compressive strength. The flexural and compressive strengths of the concrete cured in air for 120 days were affected to about the same degree. The longer curing period had little effect on the relative losses in compressive strength, but the longer curing period reduced the loss in flexural strength. In most applications, the loss in strength could be compensated by proportioning the mix to overdesign for strength. Key words: high-density concrete, ilmenite, aggregates, high temperature, mechanical properties, nondestructive tests.

Properties of High Temperature Sintered Clay Ceramic Added with Multi-Wire Sawn Granite Waste

2014 ◽  
Vol 775-776 ◽  
pp. 69-74 ◽  
Author(s):  
Monica Castoldi Borlini Gadioli ◽  
Mariane Costalonga de Aguiar ◽  
Carlos Maurício Fontes Vieira ◽  
Verônica Scarpini Candido ◽  
Sérgio Neves Monteiro
Keyword(s):  
High Temperature ◽  
Melting Point ◽  
Flexural Strength ◽  
Water Absorption ◽  
Linear Shrinkage ◽  
Huge Amount ◽  
Ornamental Stones ◽  
The World ◽  
Alkaline Oxides

Brazil is currently one of the world leading producers and exporters of ornamental stones. The increasing production also generates a proportionally huge amount of wastes. Depending on stones such as granite, these wastes may be composed of relatively high content of alkaline oxides. This is a low melting point flux with advantage for a potential addition of the waste into common clay ceramic. Thus, the present work investigated the addition of a granite waste, generated during the sawing stage using the multi-wire technology, into clayey ceramics fired at 1200oC. This ceramic added with up to 30 wt% waste were evaluated in terms of linear shrinkage, water absorption and flexural strength. It was found that the waste fluxing compounds promoted a reduction in water absorption and increase in strength that are associated with an improved clayey ceramic.

scholarly journals High-temperature Mechanical Properties and Their Influence Mechanisms of ZrC-Modified C-SiC Ceramic Matrix Composites up to 1600 °C

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1581 ◽  
Author(s):  
Jianjun Sha ◽  
Shouhao Wang ◽  
Jixiang Dai ◽  
Yufei Zu ◽  
Wenqiang Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Flexural Strength ◽  
Residual Stresses ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Thermally Induced ◽  
High Temperature Mechanical Properties ◽  
Sic Ceramic

In order to understand the influence of the mechanisms of ZrC nanoparticles on the high-temperature mechanical properties of C-SiC ceramic matrix composites, the mechanical properties were measured from room temperature (RT) to 1600 °C under vacuum. The microstructures features were characterized by scanning electron microscopy. In comparison with the composites without ZrC nanoparticles, the ZrC-modified composite presented better mechanical properties at all temperatures, indicating that the mechanical properties could be improved by the ZrC nanoparticles. The ZrC nanoparticles could reduce the residual silicon and improve the microstructure integrity of composite. Furthermore, the variation of flexural strength and the flexural modulus showed an asynchronous trend with the increase of temperature. The flexural strength reached the maximum value at 1200 °C, but the highest elastic modulus was obtained at 800 °C. The strength increase was ascribed to the decrease of the thermally-induced residual stresses. The degradation of mechanical properties was observed at 1600 °C because of the microstructure deterioration and the formation of strongly bonded fiber–matrix interface. Therefore, it is concluded that the high temperature mechanical properties under vacuum were related to the consisting phase, the matrix microstructure, and the thermally-induced residual stresses.

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