Fractal Characters of Micro-Pores in the Sinter

2011 ◽  
Vol 197-198 ◽  
pp. 662-666
Author(s):  
Qing Jun Zhang ◽  
Wen Ling Mo ◽  
Yuan Liang Li ◽  
Yu Zhu Zhang

The pore in the sinter is an important character. Because of multiphase and asymmetry in the sinter, the structure of the pore is very complex. To study the character of the pore effectively, the method of mercury intrusion porosimetry is applied to measure the pore in the sinter, and the results are dealt with by the fractal theory. The results prove that the pores in the sinter are actually fractal structure when the size of the pores is more than 204.5 nm because their curves in the log-log plot are linear, and some curves qualified with the linearity obviously possess of the segment linearity character. According to the calculation of the fractal D, the relationship of the strength and fractal D will be established.

2021 ◽  
Author(s):  
Qili Wang ◽  
Jiarui Sun ◽  
Yuehu Chen ◽  
Yuyan Qian ◽  
Shengcheng Fei ◽  
...  

Abstract In order to distinguish the difference in the heterogeneous fractal structure of porous graphite used for filtration and impregnation, the fractal dimensions obtained through the mercury intrusion porosimetry (MIP) along with the fractal theory were used to calculate the volumetric FD of the graphite samples. The FD expression of the tortuosity along with all parameters from MIP test was optimized to simplify the calculation. In addition, the percolation evolution process of mercury in the porous media was analyzed in combination with the experimental data. As indicated in the analysis, the FDs in the backbone formation regions of sample vary from 2.695 to 2.984, with 2.923 to 2.991 in the percolation regions and 1.224 to 1.544 in the tortuosity. According to the MIP test, the mercury distribution in porous graphite manifested a transitional process from local aggregation, gradual expansion, and infinite cluster connection to global connection.


2020 ◽  
pp. 16-23
Author(s):  
QI DAOZHENG ◽  
GU CONG ◽  
FU JIAJIA ◽  
WANG YAO

The clay-sand mixtures with diferent partcle sizes were prepared to investgate partcle and pore characteristcs. The microstructure characteristcs of the sand-clay mixtures were studied by the Mercury Intrusion Porosimetry (MIP) test and Scanning Electron Microscopy (SEM). Image-Pro Plus (IPP) image processing sofware was used to quantfy SEM images which investgated the micro-mechanism of structural evoluton of mixtures under diferent gradatons. The research results indicate that the units of mixtures develop from platelets and honeycomb to agglomerated and granular with the increase of sand content. The contact between partcles transits from face-face contacts to edge-face and pointface contacts. This artcle evaluated the fractal characteristc of partcle and pore structure based on the fractal theory. With the increase Circularity of the partcles, the ordered arrangement of the partcles in the mixed soil is further reduced. In general, the distributon of pores changes from intergranular pores to pores in aggregate, which provides a theoretcal basis for further study on the micro-macro correlaton of mixtures.


2013 ◽  
Vol 438-439 ◽  
pp. 1108-1111 ◽  
Author(s):  
Ya Bing Huang ◽  
Yan Jun Li ◽  
Tan Jiao

As an important factor that affects the compaction characteristics of the coarse grained fillers in the high speed railway subgrade, the grain composition is characterized by the application of the fractal theory. Several types of the coarse grained fillers were selected for testing and the results indicated that the relationship actually exists between the compaction characteristics and the fractal dimensions. The variation law of the maximum dry density fluctuating with the quality fractal dimension was analyzed and the results were supposed to estimate the compaction characteristics of the coarse grained fillers.


2010 ◽  
Vol 168-170 ◽  
pp. 615-618
Author(s):  
Zhi Qin Du ◽  
Wei Sun

The effect of different quantity of air-entraining agent on the impermeability of cement-based materials are studied in this paper. Impermeability test and mercury intrusion porosimetry (MIP) method were used to characterize the impermeability and pore structures. The fractal dimension is used to describe the characteristic of pore structure and calculated by the data of MIP experiment. The result shows that owing to the improvement of pore structure, the impermeability performance of the cement-based composites is noticeably enhanced when air-entraining agent is added with appropriate quantity.


2013 ◽  
Vol 703 ◽  
pp. 8-11
Author(s):  
Li Hui Guo ◽  
Wan Qiang Hu

Though there are a lot of rules and models for metal material fracture, it makes lots of troubles for engineering application, because of the lacking of reasonable description of fracture principle and change law. This article discusses some basic problems of applying fractal geometry to fracture research, mainly including sectional fractal characteristics and measurement, the relationship of fractal dimension and fracture toughness, and some kinds of metal fractal models. At last, application of fractal theory in metal fracture is stated.


2013 ◽  
Vol 750-752 ◽  
pp. 2221-2224
Author(s):  
Qing Jun Zhang ◽  
Qing Liu ◽  
Chun Liang Yan ◽  
Yu Zhu Zhang

With the combination of fractal theory and metallurgical properties of low silicon sinter, the influence of metallurgical properties in different content of R, MgO, SiO2 and C is analyzed on the condition of existing experiment and fuel, and by using the mercury intrusion machine it measured the volume of micro-pore structure after broken of low silicon sinter; and it combined with the multifractal theory measured multifractal spectrum for the pore structure, which is established the relationship between with the metallurgical properties and fractal theory.


2021 ◽  
Vol 5 (4) ◽  
pp. 148
Author(s):  
Nanxi Dang ◽  
Jin Tao ◽  
Qiang Zeng ◽  
Weijian Zhao

High piezoresistivity of cement-based composites tuned by conductible fillers provides a feasible way to develop self-sensing smart structures and buildings. However, the microstructural mechanisms remain to be properly understood. In the present work, the piezoresistivity of cement mortar with different dosages of graphene nanoplatelets (GNPs) was investigated, and the microstructure was assessed by electron scanning microscopy (SEM) and mercury intrusion porosimetry (MIP). Two surface fractal models were introduced to interpret the MIP data to explore the multi-scale fractal structure of the GNP-modified cement mortars. Results show that the incorporation of GNPs into cement mortar can roughen the fracture surfaces due to the GNPs’ agglomeration. Gauge factor (GF) rises and falls as GNP content increases from 0% to 1% with the optimal piezoresistivity observed at GNP = 0.1% and 0.05%. The GF values of the optimum mortar are over 50 times higher than those of the reference mortar. Fractal dimensions in macro and micro fractal regions change with GNP content. Analysis shows that the fractal dimensions in micro region decrease first and then increase with the increase of GF values. GNPs not only impact the fractal structure of cement mortar, but also alter the tunneling and contact effects that govern the piezoresistivity of composite materials.


2010 ◽  
Vol 150-151 ◽  
pp. 1214-1219
Author(s):  
Ping Zhang ◽  
Qiu Yi Li ◽  
Tie Jun Zhao ◽  
Xiang Xin Xue

This paper deals with RPC produced by superfine slag powder(measured specific surface area is 1824 m2/kg) and natural sands with a low water-binder ratio(0.2 or so),which strength can achieve 100MPa after 28d standand curing. An analysis,based on the mercury intrusion porosimetry,is made of the relationship between strength and pore structure parameters.The results show that the strength can be improved in the range of 30~45%, when the dosage of superfine slag powder varied from 5% to 15%;the linearity between compressive strength,water-binder ratio and the hole with a daimetre larger than 100nm are 0.72 and 0.92 respectively;and the RPC’s 28-day compressive strength produced by the natural sands, with a maximum grain size of 4.75 mm,is almost equal to the RPC produced by standard sands.


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