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Grès Porcelain stoneware is a ceramic with a compact, hard, coloured and non-porous body. It is largely used as building materials, for a quality architecture, offering high resistance to impact, stress, wear, scratching, frost, chemical attach and stains. It is produced in flat tiles, billions of tons per year. A very prominent technology, based o...
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... are relatively fragile. The tensile strength of ceramic materials is very variable, ranging from very low values, of less than 0.7 MPa , up to about 7000 MPa of some types prepared under carefully controlled conditions. In any case, a few ceramic materials have the tensile strength exceeding 170 MPa. Moreover, the ceramic materials show a great difference between their tensile and compression; typically the compressive strength is 5 to 10 times higher than the tensile strength, which shows the main differences in advanced ceramic materials. Furthermore, many ceramic materials are hard and have a low toughness (low resistance to dynamic stress), due to the ion-covalent bonds. There is strict relation between elastic modulus and hardness of a material and its mechanical strength. The upper limit of the compressive strength of a material is defined as the stress to which it yields (i.e. deformation for sliding along the crystallographic planes). According to this definition of stress, a micro-plastic failure is in relation with the micro-hardness, measured by the Knoop or Vickers methods. In the case of various ceramic materials, the compressive strength corresponds to 1⁄2 or 3⁄4 of the stress of failure, calculated by dividing micro-hardness for 3 (Fragassa et al., 2014). According to this formulation, a draft estimation for compressive strength can be obtained considering that hardness for Grès Porcelain stoneware, measured by Vickers method, is commonly between 750-830HV. Consequently, the compressive strength is expected between 125-250 MPa. There are not standards or common guidelines used to evaluate the tensile or compressive behaviour of ceramics. Inside the EN ISO 10545, even if detailed in 16 different parts specifying test methods for determining several aspects of ceramics, compression is not mentioned. At the same time, the tensile strength of a simple compression in the stone could be evaluated using the procedure described in the ISO 12390-1, by a standardized vertical compression of specimens (the same as the procedure for the determination of the elastic tensile modulus for stones). In (Fragassa et al. , 2014) a complete experimental session for compressive test on ceramic specimens was also implemented. A preliminary evaluation of testing method is proposed. A large number of specimens were realized from ceramic tiles with the aim at testing this methodology. Each sample included cubic specimens with nominal dimension a 10x10x10mm. This dimension is lower than the minimal size declared in ISO 10545/3, but represents a possible upper limit in height according to the real dimensions of ceramic tiles Before testing for compressive strength (Figure 15), the dimensions of the specimen were measured in several positions and the mean values calculated. The cross-sectional area of the loading faces were calculated. Three measurements of dimensions were made in each of the orthogonal directions (x, y, z). The accuracy of measure was around 5% (higher than the 0.5% limit expressed in ISO 10545/3). Several specimens were ejected considering a relevant difference in dimensions respect to the designated size. The average area of each cube loading face was ...
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... The cooking process causes the vitrification of the dough, attributing the typical mechanical and chemical characteristics. Firing temperature and the composition of the oven atmosphere are decisive for the quality (solidity and appearance) of the final product [2]. Characteristic properties of porcelain are their high mechanical strength, their resistance to wear and their longevity. ...
... 17 Due to lack of additional experimental results, the tensile strength is conservatively considered equal to one-tenth of the corresponding compressive one, as it is the case with other cementitious and ceramic materials. [31][32][33] All the CTA 'seeds' and counterparts referred here are of a rise R equal to 10m, measured from the ground level to the centreline of the crown, and a span equal to 20 m, enclosed between the centrelines of the left and right springs ( Figure 3). In particular, the geometric characteristics of the most efficient EVTAs (for each loading scenario) from ref. 25, along with their corresponding CTA 'seeds' and counterparts, are graphically depicted in Figure 3. ...
With a new era emerging in the field of lunar exploration and habitation, there
is a need for research on structural forms made of local soil material (regolith),
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... The reactivity of aluminosilicate was affected by their chemical and mineral content, particle size distribution, morphology and crystalline/amorphous content. Moreover, the unique features of geopolymer can be utilized in a wide range of applications including building and construction materials [5][6][7][8][9][10][11][12], thermal insulation coatings [13], fire-resistant materials [14], repair and strengthening composites, low energy ceramic tiles [15] and refractory materials [16]. Another method of utilizing geopolymer technology is to reduce the high temperature necessary in the production of ceramic materials. ...
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... Step 1: Choosing the Predominant Criteria Fig. 1 Steps of the material selection process the square of the minimum thickness along the broken edge (Fragassa, 2015). The higher the modulus of rupture, the higher the quality of the tiles. ...
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... A three-point bending machine measured it. Modulus of rupture is measured by the following equation [8,11]: ...
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