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Optimization of Ultra-fine Limestone Filler on Cement Grain Composition Wen Xua, Fei Guob and Qian Tianc State Key Laboratory of High Performance Civil Engineering Materials, Jiangsu Research Institute of Building Science, Jiangsu Bote New Materials Co., Ltd., Nanjing 210008, China axuwen@cnjsjk.cn, bguofei@cnjsjk.cn, ctianqian@cnjsjk.cn Keywords: limestone filler; grain composition; rheology; Andreasen model; cement.
An experimental investigation was carried out to evaluate the effect of limestone filler (LF) with equivalent replacement of cement on its grain composition.
Reasons for the above were discussed in this paper from the point of the perfect effect of LF on the cement grain composition.
(2) Where D is the least square error, i is some particle size distribution point, n is the number of particle size distribution points, mi is the cumulative percentage under sieve at particle size distribution point i and Mi is the cumulative percentage under sieve at particle size distribution point i when the particle system is ideal.
Table 2 Particle size distributions of different powder materials and their least square errors to reference particle size distribution (μm) <0.50 <1.50 <3.10 <6.00 <12.5 <25.0 <51.0 <73.0 <103 (%) C 0 4.37 9.40 19.54 40.99 69.25 90.29 95.79 98.69 0.831 LP1 3.25 14.19 28.45 46.14 64.39 75.09 85.99 93.69 99.02 / LP2 3.28 25.67 50.62 74.06 93.75 99.20 99.90 100 100 / LP3 3.88 40.68 60.84 82.71 99.15 100 100 100 100 / C+LP1 0.65 6.33 13.21 24.86 45.67 70.42 89.43 94.97 98.76 0.560 C+LP2 0.66 8.63 17.64 30.44 51.54 75.24 92.21 96.23 98.95 0.475 C+LP3 0.78 11.63 19.69 32.17 52.62 75.40 92.23 96.23 98.95 0.430 Mi (%) C 14.94 21.54 27.44 34.20 43.68 55.03 69.80 78.66 88.22 0 The situation of the grain composition of powder materials can be reflected by the least square error D and more differences are shown between the actual particle systems and the ideal one with larger D.

Introduction The behavior of solid materials put under the grinding operation is very different from a case to another, according to the great number of parameters which contribute to its performing.
A number of researchers have dealt with the study of the behavior of solid particles, belonging to different materials, under the action of concentrated forces of compression, aiming to highlight the dependence of "force-deformation".
In order to determine the final humidity of the grains, a special Granomat humidometer for cereal grains was used.
The geometry of the corn grain is presented in Fig 1.
Acknowledgement: This paper is supported by the Sectorial Operational Programme Human Resources Development (SOP HRD), financed from the European Social Fund and by the Romanian Government under the project number POSDRU/159/1.5/S/134378.

Additionally different second phases of varying sizes and shapes are present, including a large square-shaped Mg5(Gd,Y) particles which solidified from the melt and are located within the Mg grains and/or at grain boundaries, fine spherical zirconium-rich particles which are located in the Mg grains and fine needle-like precipitates of Mg5(Gd,Y) and Mg24(Gd,Y)5 which are uniformly distributed within the Mg grain interior.
Further, a number of deformation bands or twins were found existing in the magnesium grains.
Fig. 1b shows that a number of deformation bands or twins exist within near fully recrystallized, equiaxed α-Mg grains.
It should precipitate from the residual alloy melt at temperatures near 500 °C, as shown in Fig. 1a, and existed at grain boundaries and/or within magnesium grains near grain boundaries.
Zr-rich particles which precipitated from the alloy melt and acted as an efficient grain refiner for magnesium grains, provided locations for corrosion initiation in the Mg-Gd-Y-Zr alloy.

Type-I AEs with higher frequency components were detected during the pit growth and supposed to be produced by falling-off of surface grains due to intergranular attack, while a number of Type-II AEs (approximately 12,500 counts) with low frequency components were detected during SCC propagation and supposed to be produced by cracking of the chromium oxy-hydroxides.
We concluded that AEs were produced by falling-off of grains.
No AE data in the three gray bands means the exceeded memory capacity of the personal computer, since a number of AE signal was produced during this period.
The first AE was detected at 320 ks and the number of AEs increased gradually.
Cracking of the oxide produces a number of secondary AE.

The experimental result showed that there is significant number of small precipitates within the grains besides the icosahedral quasicrystals along the grain boundaries.
A number of studies have been carried out on the microstructure, properties and mechanical process of this category of alloys, and it has been widely accepted that the creep resistance of these alloys attributes greatly to the quasicrystal I-phase (Mg3Zn6Y) in grain boundaries [7,8,9].
However, since the precipitates within the grains also contribute to the strength, it is worth to investigate these precipitates.
From this figure one can see the fish-bone-like eutectic structure at grain boundary and uniformly distributed rods within the grains.
Although the density of this kind of precipitates is not as high as the Z-Mg12ZnY and MgZn2 precipitates, there are usually more than ten of Y-riched particles in each grain.

The phase states are represented by the continuous order parameter field although it has discontinuity on grain boundary in reality.
While, in the multi-phase-field method [7], each grain has its own order parameter field and it is necessary to calculate a much larger number of order parameters than the KWC model and rotation of crystal orientation is ignored, whereas the governing equations are relatively stable to calculation with large time increment.
Since analysis domain includes a number of grains whose crystal orientation can rotate, an evolution equation of crystal orientation is required in addition to that of order parameter.
In addition, the mobility of θ is set as 2 (1 )M M θ θφ= − so that the recrystallized grains do not rotate after they contact.
We can see that the high angle boundaries generate along the subgrain walls in each grain.

The reason of this the dislocation density is bigger near by the grain boundary than inside the grains.
The number of grains, the diameter of the grains, and the boundary interface were measured by the image analyzer software.
Where is eutectic along the grain boundary there are much more new grain.
In order to distinguish the non-deformed original grains from the DRX grains, the recrystallized grains are defined as grains having an average diameter of <50 μm and the volume fraction of fine grains Vf is defined as follows [6]: Vf=Total area of individual fine grains AfTotal sampling area Ai Fig. 11.
The nucleation and grain grow of recrystallized grains occur along the eutectic phase.

However, if the number of stacking layers and/or the reduction per pass increases some advantages will be expected [3].
Ia increases with the number of passes, which means that the severity of the process also does.
Evolution of the average intensity Ia with the number of passes in the ARBed samples.
Equiaxed cells/(sub)grains with diameter smaller than 1 µm are seen.
However, the cell/(sub)grain size of the three deformed samples is very similar.

The grain sizes of Al and Mg alloys were reached to 875 nm and 656 nm after 3 cycles.
Grain size distributed and hardness analyzed.
The grain size was decreased as the number of cycles of the ARB process was increased.
Ultra-fine grained Al/Mg compound alloys whose mean grain size were about 875nm (Al) and 656nm (Mg) were successfully produced by the 3 cycle ARB process.
Grain size of the Al and Mg with different ARB cycles.

Modelling grain boundary sliding from first principles Carla Molteni Physics Department, King’s College London, Strand, London WC2LR 2LS (UK), carla.molteni@kcl.ac.uk Keywords: Grain boundary, sliding, migration, density functional theory, first principles methods.
While in germanium sliding is controlled by local stick-slip events involving rebonding of a few atoms at the boundary interface, in aluminium larger numbers of atoms act in concert over extended areas, ultimately limited by boundary defects.
Grain boundary sliding plays a dominant role in the plastic deformation and fracture of polycrystals.
For the (0,0) translation state, the periodicity is that of the DSCL: the energy maxima occur when the atomic “bumps” belonging to each grain sit on top of each other at the interface, while the minima occur when the “bumps” of one grain fit nicely on the “hollows” of the other grain.
In general, in Al a large number of atoms act in concert over extended areas, ultimately limited by boundary defects.