Sort by:
Publication Type:
Open access:
Publication Date:
Periodicals:
Search results
Online since: December 2019
Authors: Alexander I. Nikulin, Al-Khawaf Ali Fadhil Qasim
Diagrams of non-uniform compression and concrete tension (a) and the reinforcement deformation with the physical yield point (b):
The unknown parameters of concrete deformation diagrams for non-uniform compression and tension (refer with Fig. 2a) are obtained by transforming the original (reference) diagrams using a number of new hypotheses and assumptions [8]:
– for the ultimate stage of concrete deformation under non-uniform compression (which corresponds to the cross-sectional area of the compressed element in step exhaustion of its strength at normal section), the fiber deformation passing through the gravity center of the compressive stressing diagram is equal to the concrete ultimate deformation under central compression ebR;
– the exhaustion criterion in the carrying capacity of an eccentrically compressed reinforced concrete element is achieved by the fiber grains of this element compressed zone to the ultimate value of the relative deformation ebu with the concrete resistance
Since a number of dependencies in the system is non-linear, their numerical implementation is performed using the iterative methods.
The calculations made it possible to reveal the influence of a number of factors on the bearing capacity of eccentrically compressed reinforced concrete elements: – with an increase in the concrete class calculated, the bearing capacity (Nu) of the samples increases; the greatest growth is observed in the elements where the process of crack formation has received a slight development; in particular, for the samples with an estimated length of 2.0 m, a reinforcement content of 2.0% and a relative eccentricity of 0.45 increase in value Nu turned out to be the greatest and made +47 % and +85 %, respectively, for concrete В40 and В60 compared with В20; with a relative load eccentricity e0/h = 1,0 the corresponding excess load capacity decreased significantly and amounted, respectively, +14 % and +23 %, which is explained by the presence of a more extensive crack zone in such samples; – the raise in the reinforcement ratio of the cross section increases the samples carrying capacity; the
Since a number of dependencies in the system is non-linear, their numerical implementation is performed using the iterative methods.
The calculations made it possible to reveal the influence of a number of factors on the bearing capacity of eccentrically compressed reinforced concrete elements: – with an increase in the concrete class calculated, the bearing capacity (Nu) of the samples increases; the greatest growth is observed in the elements where the process of crack formation has received a slight development; in particular, for the samples with an estimated length of 2.0 m, a reinforcement content of 2.0% and a relative eccentricity of 0.45 increase in value Nu turned out to be the greatest and made +47 % and +85 %, respectively, for concrete В40 and В60 compared with В20; with a relative load eccentricity e0/h = 1,0 the corresponding excess load capacity decreased significantly and amounted, respectively, +14 % and +23 %, which is explained by the presence of a more extensive crack zone in such samples; – the raise in the reinforcement ratio of the cross section increases the samples carrying capacity; the
Online since: June 2025
Authors: Hiroki Saito, Yuji Ichikawa, Jiyuan Cui, Kazuhiro Ogawa, Makoto Nakashima, Atsushi Suzuki, Fumio Sato
In addition, Fig. 5 shows a large number of microcracks generated at the interface.
Additionally, a large number of vertical cracks were observed near the interface, indicating that the interface is a relatively weak region.
Conversely, in addition to the release of residual stresses at the interface, Fig. 6(b) shows a significant number of cracks at the interface, indicating that the degradation of the top coat near the interface may also contribute to the observed behavior.
Trice, Grain-Boundary Grooving of Plasma-Sprayed Yttria-Stabilized Zirconia Thermal Barrier Coatings, J.
Additionally, a large number of vertical cracks were observed near the interface, indicating that the interface is a relatively weak region.
Conversely, in addition to the release of residual stresses at the interface, Fig. 6(b) shows a significant number of cracks at the interface, indicating that the degradation of the top coat near the interface may also contribute to the observed behavior.
Trice, Grain-Boundary Grooving of Plasma-Sprayed Yttria-Stabilized Zirconia Thermal Barrier Coatings, J.
Online since: January 2019
Authors: Phayao Yongsiriwit, Chanyut Fongsuwan, Murnee Daoh, Pitchpilai Khoonphunnarai
It is difficult to determine the number of units installed and amount of hot water used.
Radioactivity measurement First, start with cracking the rock samples into fine grain, Furthermore, use 2 mm grille to sieve fine rock samples, and put into plastic bowl with dimension 6.5 cm x 7.5 cm.
This is because the number of granite outcrops are too few.
The major product from this type of alteration [14] is that high 40K content in granite may be because the number of samples from the outcrops is too few.
Radioactivity measurement First, start with cracking the rock samples into fine grain, Furthermore, use 2 mm grille to sieve fine rock samples, and put into plastic bowl with dimension 6.5 cm x 7.5 cm.
This is because the number of granite outcrops are too few.
The major product from this type of alteration [14] is that high 40K content in granite may be because the number of samples from the outcrops is too few.
Online since: May 2020
Authors: Viktor Malau, Adji Swandito
Brine composition analysis was carried out to determine anions and cations number.
Whereas the pearlite grains are visible only in smaller areas.
Table 3 shows the results of hardness test resulting in a Vickers Hardness Number (VHN) of 204.
The number of iron ions decrease in the solution as showed in Fig.4 (a) due to blockage of the surface with the adsorbed inhibitor molecules.
Whereas the pearlite grains are visible only in smaller areas.
Table 3 shows the results of hardness test resulting in a Vickers Hardness Number (VHN) of 204.
The number of iron ions decrease in the solution as showed in Fig.4 (a) due to blockage of the surface with the adsorbed inhibitor molecules.
Online since: May 2010
Authors: Yu Liu, Xian Zheng Gong, Zhi Hong Wang, Bo Xue Sun, Zuo-Ren Nie
For the elements dissolved in the hydrosphere, the exergy of the elements is expressed as:
2
0 0 0 0
1
2.303 ( ) ln( )
2
qel fi i qH y qy n i n in i
y
Ex j G jz Ex j b Ex RT jz pH jRT m γ
= − ∆ + − − − ×
∑
(6)
Where j is the number of reference ions derived from one molecule of the element under consideration,
z is the charge of the reference ion present in seawater, by is the number of molecules of the additional
element y present in a molecule of the reference species in seawater, min is the molality under standard
condition, γi is the activity coefficient.
The chemical composition of pure mineral is unchangeable, so the calculation of the pure minerals' exergy can use the relation between compounds and elements, it is expressed as: [12] 0 0 , ch el ch el f el Ex n e G = + ∆∑ (9) Where Exch is the exergy of compounds, nel is the number of moles, ech is the exergy of elements, and ∆G is the standard mole Gibbs's free energy of formation of substance.
The thermodynamics states of minerals can be divided into two categories [14]: Regarding the natural minerals as ideal solid solution, the corresponding formula is: , 0 ln ch i ch i i i Ex n e RT n a = +∑ ∑ (10) Regarding the natural minerals as a mixture of separate grains, the corresponding formula is: , ch i ch i Ex n e= ∑ (11) Where ech,i is the exergy of compounds, ni is mole fractions of compounds, ai is the activity of substances, and for ideal solid solution ai is equal to ni.
As shown in table 2, to the non-aluminum-containing minerals, there is no distinct difference between the results based on Szargut's and Rivero's data of elements' exergy respectively, but to the aluminum-containing minerals especially for the minerals which contain a large number of aluminum, it will cause a significant difference on the results when using different models.
Considering both ideal solid solution model and separate grains model are the limit states of the pure minerals existing in natural minerals, the real state of pure minerals should between them, so select the average of the two outcomes as the final result will be more accurate.
The chemical composition of pure mineral is unchangeable, so the calculation of the pure minerals' exergy can use the relation between compounds and elements, it is expressed as: [12] 0 0 , ch el ch el f el Ex n e G = + ∆∑ (9) Where Exch is the exergy of compounds, nel is the number of moles, ech is the exergy of elements, and ∆G is the standard mole Gibbs's free energy of formation of substance.
The thermodynamics states of minerals can be divided into two categories [14]: Regarding the natural minerals as ideal solid solution, the corresponding formula is: , 0 ln ch i ch i i i Ex n e RT n a = +∑ ∑ (10) Regarding the natural minerals as a mixture of separate grains, the corresponding formula is: , ch i ch i Ex n e= ∑ (11) Where ech,i is the exergy of compounds, ni is mole fractions of compounds, ai is the activity of substances, and for ideal solid solution ai is equal to ni.
As shown in table 2, to the non-aluminum-containing minerals, there is no distinct difference between the results based on Szargut's and Rivero's data of elements' exergy respectively, but to the aluminum-containing minerals especially for the minerals which contain a large number of aluminum, it will cause a significant difference on the results when using different models.
Considering both ideal solid solution model and separate grains model are the limit states of the pure minerals existing in natural minerals, the real state of pure minerals should between them, so select the average of the two outcomes as the final result will be more accurate.
Online since: December 2013
Authors: Xiao Ning Zhang, Li Wen Zeng, Shun Xian Zhang
The particle area ratio is defined as the accumulated scanning section area of the coarse aggregate particles to the fan-shaped area, the first step calculates particle area size in each scan area respectively, and the second step is to evaluate the uniformity of asphalt mixture aggregate distribution through the statistical analysis of the grain area ratio.
The each cross section scanning results of core samples from specimens are shown in table 1, in this table, located in the central position of No 20 and located in number at the bottom of the 40th section scanning images and sector scan image are shown in figure 5 and figure 6.
Section scan results Section number particle size ratio quantity maximum minimum average standard deviation variable coefficient Section 1 24 0.682 0.445 0.572 0.085 0.164 Section 2 24 0.724 0.443 0.571 0.083 0.158 Section 3 24 0.733 0.439 0.573 0.080 0.152 … … … … … … … Section 39 24 0.485 0.268 0. 545 0.068 0.135 Section 40 24 0.535 0.351 0.529 0.070 0.140 (a) No.20 cross section image (b) Sector scan images Fig .5, No 20 cross section images and sector scan images (a)No 40 cross section image (b) sector scan images Figure. 6, No 40 cross section images and sector scan images Coarse aggregate uniformity evaluation index.
Ideally, when the number of scanning the section and each section thickness , the more scanning areas are got at this time, the more details of asphalt mixture inside is reflected, the better uniformity of mixture is evaluated and more close to the true value.
The each cross section scanning results of core samples from specimens are shown in table 1, in this table, located in the central position of No 20 and located in number at the bottom of the 40th section scanning images and sector scan image are shown in figure 5 and figure 6.
Section scan results Section number particle size ratio quantity maximum minimum average standard deviation variable coefficient Section 1 24 0.682 0.445 0.572 0.085 0.164 Section 2 24 0.724 0.443 0.571 0.083 0.158 Section 3 24 0.733 0.439 0.573 0.080 0.152 … … … … … … … Section 39 24 0.485 0.268 0. 545 0.068 0.135 Section 40 24 0.535 0.351 0.529 0.070 0.140 (a) No.20 cross section image (b) Sector scan images Fig .5, No 20 cross section images and sector scan images (a)No 40 cross section image (b) sector scan images Figure. 6, No 40 cross section images and sector scan images Coarse aggregate uniformity evaluation index.
Ideally, when the number of scanning the section and each section thickness , the more scanning areas are got at this time, the more details of asphalt mixture inside is reflected, the better uniformity of mixture is evaluated and more close to the true value.
Online since: January 2012
Authors: Xu Yan Song, Jing Yun Han, Zhi Hai Gao
Table 2 Effect of multiple complex activators on physical and mechanical properties of cement
serial number
activators
fluidity
[mm]
flexural strength [MPa]
compressive strength [MPa]
compressive strength ratio of 28d
type
W[%]
3d
7d
28d
3d
7d
28d
*DS8
—
—
225
6.4
8.2
8.6
29.7
36.9
46.6
1.000
**DS6
—
—
175
3.7
5.3
7.1
14.1
18.4
32.1
0.689
DFS1
J1
4
180
5.1
6.3
7.2
19.5
27.0
32.8
0.704
DFS2
6
185
5.4
7.0
8.2
20.4
27.8
38.5
0.826
DFS3
8
180
6.2
7.1
8.5
23.1
30.2
40.7
0.873
DFS4
J2
4
175
4.8
6.2
8.0
17.9
22.9
33.5
0.719
DFS5
6
160
4.4
5.9
8.0
18.8
25.2
35.8
0.768
DFS6
8
150
4.4
5.8
9.1
19.9
25.3
40.0
0.858
DFS7
J3
4
165
5.0
5.9
7.0
18.3
23.4
36.7
0.788
DFS8
6
175
5.4
6.5
7.5
18.2
22.7
37.3
0.800
DFS9
8
165
5.4
6.4
7.1
20.7
25.2
38.1
0.818
Note: *—pure cement; **—calcined coal gangue cement.
Table 3 Microstrain of chemically activated calcined coal gangue cement mortar serial number age DS6 DS8 DFS2 DFS8 1d 108.0000 197.3333 212.0000 184.0000 2d 276.0000 304.0000 385.3333 337.3333 3d 405.3333 358.6667 580.0000 424.0000 4d 542.6667 496.0000 664.0000 589.3333 5d 602.6667 574.6667 760.0000 708.0000 6d 660.0000 642.6667 804.0000 748.0000 7d 673.3333 692.0000 825.3333 780.0000 9d 712.0000 753.3333 918.6667 888.0000 14d 861.3333 980.0000 1125.3333 1000.0000 21d 954.6667 1121.3333 1137.3333 1086.6667 28d 861.3333 1026.6667 1097.3333 1054.6667 Note: The meanings of serial number were the same as those in Table 2.
At late hydration age, increasing hydration products can make calcined coal gangue cement close-grained and make contraction stop, with slight expansion.
Table 3 Microstrain of chemically activated calcined coal gangue cement mortar serial number age DS6 DS8 DFS2 DFS8 1d 108.0000 197.3333 212.0000 184.0000 2d 276.0000 304.0000 385.3333 337.3333 3d 405.3333 358.6667 580.0000 424.0000 4d 542.6667 496.0000 664.0000 589.3333 5d 602.6667 574.6667 760.0000 708.0000 6d 660.0000 642.6667 804.0000 748.0000 7d 673.3333 692.0000 825.3333 780.0000 9d 712.0000 753.3333 918.6667 888.0000 14d 861.3333 980.0000 1125.3333 1000.0000 21d 954.6667 1121.3333 1137.3333 1086.6667 28d 861.3333 1026.6667 1097.3333 1054.6667 Note: The meanings of serial number were the same as those in Table 2.
At late hydration age, increasing hydration products can make calcined coal gangue cement close-grained and make contraction stop, with slight expansion.
Online since: May 2017
Authors: Jan Richter, Marko Swoboda, Christian Beyer, Ralf Rieske, Wolfram Drescher
The cross-sections multi-photon processes fall off faster than can be compensated by their rate scaling with IN [13], where I is the laser intensity and N is the number of photons participating per event.
The number of photons needed is mostly defined by the material bandgap and the laser photon energy, in the case of SiC N=3.
Fig. 3 also illustrates how surface quality after separation is chiefly defined by the laser process and its interplay with crystal and/or grain structure.
As kerf-less method, COLD SPLIT can greatly expand the number of wafers obtained from a single boule of SiC compared to wire saws.
The number of photons needed is mostly defined by the material bandgap and the laser photon energy, in the case of SiC N=3.
Fig. 3 also illustrates how surface quality after separation is chiefly defined by the laser process and its interplay with crystal and/or grain structure.
As kerf-less method, COLD SPLIT can greatly expand the number of wafers obtained from a single boule of SiC compared to wire saws.
Online since: October 2008
Authors: Katrin Kempf, Claudia Ortmann, Thomas Oberbach
Due to the good tribological properties, the number of ceramic-ceramicpairings
is continuously increasing worldwide.
With the raising number of implanted couplings an additional effect occurs in seldom cases.
Due to the large number of measurements, abrased areas and changes of the roundness values could be recorded and detected in a good way.
Break-outs of grains are clearly visible.
With the raising number of implanted couplings an additional effect occurs in seldom cases.
Due to the large number of measurements, abrased areas and changes of the roundness values could be recorded and detected in a good way.
Break-outs of grains are clearly visible.
Online since: December 2014
Authors: Wen Li, Xiang Qu, Zhao Jun Chen
Compaction tamping hit several times and the number of selected
Set the number of tamping hit single point of tamping three hammers, two hit if the average amount of ram sink after a single point of not more than 25mm, a single point of tamping paper argues that the goal has been reached; Failure to achieve this standard, a single point is repeated ramming blow.
If the subgrade soil in the main part of the coarse grained soil, its permeability is strong, tamping passes can be set at a relatively low level.
Existing studies show that the foundation mainly gravel, gravel, sandy soil and rubbish soil composition, compaction construction tamping passes 2 to 3 times better; In this paper, the research many red sandstone compaction construction site and found to be two times the ordinary tamping, and then the low-energy full rammed it again, you can achieve the requirements of the tamping goal, which is the paper argues that a better compaction ram strike set number of times.
If the subgrade soil in the main part of the coarse grained soil, its permeability is strong, tamping passes can be set at a relatively low level.
Existing studies show that the foundation mainly gravel, gravel, sandy soil and rubbish soil composition, compaction construction tamping passes 2 to 3 times better; In this paper, the research many red sandstone compaction construction site and found to be two times the ordinary tamping, and then the low-energy full rammed it again, you can achieve the requirements of the tamping goal, which is the paper argues that a better compaction ram strike set number of times.