Influence of High-Calcium Ash Composition on the Composite Binders’ Properties

2021 ◽  
Vol 316 ◽  
pp. 1019-1024
Author(s):  
O. A. Ignatova ◽  
A. A. Dyatchina
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Cement Stone ◽  
Normal Density ◽  
Fine Aggregate ◽  
Equivalent Amount ◽  
High Calcium ◽  
Composition Structure ◽  
Kinetics Of ◽  
Positive Effect

The paper presents the studies’ results of chemical composition, structure, and physico-mechanical properties of high-calcium ashes from the Kansk-Achinsk coals (2017-2019 selection). It was found that ash has a complex poly-mineral composition and contains hydraulically active minerals and oxides of СаОfr, β-C2S, CA, C3A, C4AF, C2F, CaSO4. According to the content of CaOfr, MgO does not meet standards’ requirements. The uniformity of the volume change is maintained by the composition with 50% of cement. The structure and hardening kinetics of ash and ash-cement stone compositions, obtained from the test of normal density, were analyzed. It was established that the hardening of compositions with ash from the Kansk-Achinsk coals was largely influenced by ash minerals. An equivalent amount of cement in composite binders cannot be replaced. In order to obtain a positive effect, compositions with ash instead cement of no more than 30% and a part of fine aggregate, without exceeding the ratio of ash: cement = 1: 1, should be used.

scholarly journals Composition, Structure and Mechanical Properties of Industrially Sputtered Ta–B–C Coatings

Coatings ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 853
Author(s):  
Michael Kroker ◽  
Pavel Souček ◽  
Pavol Matej ◽  
Lukáš Zábranský ◽  
Zsolt Czigány ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Protective Coatings ◽  
Multilayered Structure ◽  
Number Density ◽  
Substrate Rotation ◽  
Industrial Batch ◽  
Axis Rotation ◽  
Composition Structure ◽  
Sputter Deposited

Ta–B–C coatings were non-reactively sputter-deposited in an industrial batch coater from a single segmented rotating cylindrical cathode employing a combinatorial approach. The chemical composition, morphology, microstructure, mechanical properties, and fracture resistance of the coatings were investigated. Their mechanical properties were linked to their microstructure and phase composition. Coatings placed stationary in front of the racetrack of the target and those performing a 1-axis rotation around the substrate carousel are compared. Utilization of the substrate rotation has no significant effect on the chemical composition of the coatings deposited at the same position compared to the cathode. Whereas the morphology of coatings with corresponding chemical composition is similar for stationary as well as rotating samples, the rotating coatings exhibit a distinct multilayered structure with a repetition period in the range of nanometers despite utilizing a non-reactive process and a single sputter source. All the coatings are either amorphous, nanocomposite or nanocrystalline depending on their chemical composition. The presence of TaC, TaB, and/or TaB2 phases is identified. The crystallite size is typically less than 5 nm. The highest hardness of the coatings is associated with the presence of larger grains in a nanocomposite structure or formation of polycrystalline coatings. The number, density, and length of cracks observed after high-load indentation is on par with current optimized commercially available protective coatings.

scholarly journals Determination of the physical-mechanical properties of a permeable block

2021 ◽  
Vol 2139 (1) ◽  
pp. 012016
Author(s):  
H Y Jaramillo ◽  
J A Gómez-Camperos ◽  
N Quintero-Quintero
Keyword(s):  
Mechanical Properties ◽  
Polyethylene Terephthalate ◽  
Physical And Mechanical Properties ◽  
Normal Density ◽  
Fine Aggregate ◽  
High Permeability ◽  
Good Resistance ◽  
Standard Procedures ◽  
Concrete Blocks

Abstract This study aims to analyze the influence of the incorporation of crushed polyethylene terephthalate as a substitute for fine aggregate in percentages of 10%, 15%, and 20% for the elaboration of concrete blocks. The methodology used is experimental quantitative approach, where the influence of the addition of crushed polyethylene terephthalate as a substitute for fine aggregate for the elaboration of concrete blocks was analyzed to identify the variation in the physical and mechanical properties of samples elaborated under different substitutions and in this way compare with the Colombian standard procedures. The results found in this study indicated that the blocks with the different percentages of polyethylene terephthalate presented a good resistance compared to the block without polyethylene terephthalate, which presented a resistance of 8 MPa. The blocks with polyethylene terephthalate at 10%, 15%, and 20% presented an average resistance of 6.36 MPa, 3.58 MPa, and 4.63 MPa, respectively. Finally, it was analyzed that the blocks with 10% aggregate are waterproof with normal density. In comparison, the blocks with 15% and 20% polyethylene terephthalate have high permeability, with the ability to drain 1 liter of water in 105 s and 38 s, respectively.

The Study of the Complex Mechanical Properties of Rolled Bars of VT6 Alloy as a Function of Chemical Composition and Structure Type

2020 ◽  
Vol 989 ◽  
pp. 283-289
Author(s):  
Yu.B. Egorova ◽  
L.V. Davydenko ◽  
I.M. Mamonov
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Statistical Tests ◽  
Structure Type ◽  
Strength Properties ◽  
Alloying Elements ◽  
Mean Values ◽  
Composition And Structure ◽  
Composition Structure ◽  
The Stability

This paper presents the results of statistical tests, carried out to identify the mechanical properties of Ø 16-150 mm VT6 titanium alloy bars, as a function of their post-annealing chemical composition and structure. It is shown that the high variation of mechanical properties may be, due to fluctuations in the grade composition and structure type. 50% to 60% of variations in strength properties are due to composition + structure co-effects. To improve the stability of such properties, the paper identifies maximum permissible total fluctuations in the chemical composition in terms of aluminum/molybdenum equivalents of alloying elements and impurities. The research team has fitted the regression dependencies for evaluating the mean values of the mechanical properties of Ø 16-60 mm VT6 bars, as a function of the structure type and aluminum/molybdenum equivalents of the alloying elements and impurities.

scholarly journals INFLUENCE OF THE CHEMICAL COMPOSITION AND METHOD OF SMELTING ON THE PROPERTIES OF THE METAL OF WELDED JOINTS OF ECONOMICALLY ALLOYED CHROMIUM-MANGANESE-NICKEL STEELS

2021 ◽  
pp. 69-73
Author(s):  
O. P. Bondareva ◽  
E. V. Sedov ◽  
O. B. Kryuchkov ◽  
I. L. Gonik
Keyword(s):  
Mechanical Properties ◽  
Phase Composition ◽  
Chemical Composition ◽  
Grain Growth ◽  
Base Metal ◽  
Welded Joints ◽  
Austenitic Steels ◽  
Welding Cycle ◽  
Thermal Welding ◽  
Positive Effect

The results of studies on the influence of the chemical composition on mechanical properties of the base metal and the metal of the near-seam zone of welded joints of ferrite-austenitic steels are presented. The positive effect of microalloying of steels with calcium and cerium on the resistance to embrittlement of the metal after exposure to the thermal welding cycle is shown. It is established that alloying ferrite-austenitic steels with molybdenum and vanadium reduces the tendency to grain growth during welding heating, and doping with nitrogen leads to the stabilization of the phase composition of steels under the influence of elevated welding and operating temperatures.

scholarly journals The Use of Borax in Deterring Flash Setting of High Calcium Fly Ash Based Geopolymer

2016 ◽  
Vol 857 ◽  
pp. 416-420 ◽  
Author(s):  
Antoni ◽  
Stephen Wibiatma Wijaya ◽  
Juan Satria ◽  
Agung Sugiarto ◽  
Djwantoro Hardjito
Keyword(s):  
Particle Size ◽  
Compressive Strength ◽  
Fly Ash ◽  
Chemical Composition ◽  
Setting Time ◽  
Chemical Properties ◽  
Physico Chemical ◽  
High Calcium ◽  
High Calcium Fly Ash ◽  
Positive Effect

Geopolymer that was made with high CaO content fly ash was found to have higher compressive strength than the low CaO fly ash, using the same mixture composition. This effect could be due to the physico-chemical properties of the fly ash, in respect to its particle size or the chemical composition. Although it was not widely published, the occurrence of flash setting of geopolymer was known to occur when using high CaO content fly ash as the precursor. Geopolymer paste may solidify within minutes after the addition of alkali activators, making it very difficult to cast in big volume. This paper investigate the effect of borax addition to the high calcium fly ash-based geopolymer mixture to reduce the occurrence of flash setting. It was found that the setting time can be extended significantly, with the addition of 5% borax, by mass, of fly ash. The addition of borax also have positive effect on increasing the compressive strength of geopolymer.

Sign in / Sign up

Export Citation Format

Share Document