Abrasion resistance is a mechanical characteristic of a lined surface. Indicates the surface’s resistance to wear due to exposure to rubbing objects, surfaces, and materials. Which expressions do you think are correct?
Abrasion resistance also affects other functional characteristics of the ceramic tile surface, such as chemical and stain resistance and ease of maintenance. Naturally, this aspect is equally important for glazed and unglazed tiles, because... abrasion leads to a weakening of the tile structure itself, the appearance of pores and microcracks invisible to the naked eye, into which dirt, etc. gets clogged.
Abrasion resistance is a property characteristic only of glazed ceramic tiles. Since intense and prolonged exposure to the surface over time can lead to partial loss of the glazed layer, and this, in turn, will lead to exposure of the ceramic mass and, as a consequence, to the loss of not only the aesthetic, but also the functional qualities of the facing surface. Damage to unglazed tiles is almost invisible, since abrasion of the top layer leads to exposure of the ceramic mass, which in unglazed tiles is no different from the top layer.
According to the test method EN ISO 10545-7:1998, glazed tiles are divided into wear resistance classes, from "0" to "5". Where fifth class tiles are least resistant to abrasion.
The wear resistance requirements for unglazed ceramic tiles and slabs are set by EN 14411 and depend on water absorption and the method of their manufacture.
The important point is that unlike other quality tests on tiles, durability testing does not determine the value of the tile. The results of the study divide the tiles into classes, each of which corresponds to a specific purpose of the tile, and in no way to divide the tiles into “bad” and “good”.
Information on this issue is presented in the article Abrasion resistance, wear resistance .
Slip resistance is determined by the kinetic and dynamic conditions of motion of the body interacting with the surface. When it comes to flooring, it is obvious how the degree of slip is related to the safety of using the surface. Knowledge of surface properties is essential for the cladding designer, tiler, retailer and end user, as well as the safety inspector. Please mark the correct conclusions in your opinion:
According to the DIN 51097 method, in rooms where floors are often wet and where people walk on them barefoot (for example, swimming pool sides, children's pools, common shower rooms, saunas, etc.), the classification contains groups: A; B (A+B); C (A+B+C). Where A is the slipperiest tile.
The DIN 51130 and DIN 51097 methods, also called "incline plane methods", consist of a person walking back and forth on a platform covered with the tiles being tested. The inclination of the test section increases at a constant rate until an angle is reached at which the person begins to feel unsure when walking, that is, begins to slide.
According to the DIN 51130 method, floors in production facilities or work areas where there is a high risk of slipping are classified into the following groups (according to the average inclination angle): NC; R9; R10; R11; R12; R13. Where R13 is the slipperiest tile.
Friction coefficient is a parameter characterizing the degree of surface sliding. It is proportional to the force parallel to the interaction surface that must be applied in order to create relative motion between two bodies. The higher its characteristics such as smoothness and shine, the lower the coefficient of friction for floor surfaces, since this contributes to the appearance of a thin, continuous layer of water (as well as grease, dirt, etc.), which acts as a lubricant between the sole and the floor. Ceramic tiles, while smooth and shiny, create a slippery surface and increase the risk of falls and accidents.
Ceramic tiles, characterized by their smoothness and shine, form the most intimate contact between the surface and the sole, thereby increasing the coefficient of friction. While rough, uneven surfaces tend to allow water or other liquids to accumulate on them, as well as dirt, grease and other substances that act as lubricants. In addition, the area of contact with the sole, in this case, is limited by the protruding edges of the surface, which also reduces slip resistance. This factor must be taken into account when choosing tiles.
Material on this issue is presented in the article Slip resistance on dry and wet surfaces .
Thermal resistance is the ability of ceramic tiles to withstand without damage the stress caused by dimensional deformations due to sudden changes in temperature, especially if such changes are repeated frequently. Which statements do you think are correct?
The test method described in GOST 27180-2001 is as follows: samples are subjected to 10 rapid cycles of temperature changes from 15 °C to 145 °C. The maximum temperature is achieved by placing the samples in an oven for at least 20 minutes, the minimum by completely immersing them in water at a temperature of 15°C. At the end of 10 cycles, samples are inspected for visible defects.
“Resistance to thermal shock” is a property characteristic only of refractory materials, the scope of which is the metallurgical, glass, chemical industries, as well as all other industries where work takes place using blast furnaces, shaft and rotary furnaces.
Thermal resistance is the ability of a material to resist the transfer of energy (heat exchange) from more heated parts of the body to less heated bodies, carried out by chaotically moving body particles (atoms, molecules, electrons, etc.).
If we compare the thermal resistance testing methods of the EN ISO 10545-9 standard and GOST 27180-2001, we can conclude that the test requirements of the EN ISO 10545-9 standard are somewhat stricter than the requirements of GOST 27180-2001.
Thermal resistance is an important physical property of ceramic tiles. Let's imagine, for example, the tiled surface of a kitchen countertop on which a hot pan is placed. The surface of the tile heats up sharply and, as a result, expands, and the lower layers become colder and less expanded as they move away from it. In this state of thermal inhomogeneity, the tile, which does not have the property of heat resistance, could be deformed and, being an inherently rigid material, could crack.
Material on this issue is presented in the article Thermal resistance .
Water absorption is a parameter that determines the porosity of ceramic tiles. It is measured by the amount of water that ceramic tiles absorb under certain laboratory conditions, and is expressed as a percentage of the dry weight of the tiles.
Mark the true statements.
A low water absorption coefficient indicates that the structure of the tile is porous, and a high coefficient indicates that the structure of the material is more dense.
According to EN ISO 10545-3, the penetration of water into the open pores of samples is determined exclusively using the water saturation method in a vacuum. The boiling method, as a test that does not allow determining open porosity and bulk density, is considered obsolete.
The lower the degree of water absorption, the more resistant the tile will be to intense mechanical and hydrothermal influences.
According to the EN 14411 standard, ceramic tiles and slabs are divided into three main groups based on water absorption. Where the third group corresponds to the lowest water absorption rates.
According to EN ISO 10545-3, the penetration of water into the open pores of samples is determined using two methods: boiling and water saturation in a vacuum. When boiling, water saturation occurs only in easily filled open pores; with the vacuum method, almost all open pores are filled.
Material on this issue is presented in the article Water absorption .
Linear thermal expansion is expressed by dimensional changes in any material, including ceramics, due to changes in temperature. Almost all known materials expand as temperature increases and contract as temperature decreases. Moisture expansion refers to the expansion of the tile due to the absorption of moisture. The consequences of such swelling are similar to the expansion of tiles due to an increase in temperature (linear thermal expansion) and are due to the porous structure of the material.
A moisture expansion test is required for tiles with a water absorption value greater than 6%.
The thermal coefficient of linear expansion α for ceramic tiles is calculated with an accuracy of 0.1•10 -6 °C -1 using the formula: α = dL/(L 0 •dT), where L 0 is the length of the test sample at room temperature; dL is the linear expansion of the test sample during the period of temperature change from room temperature to 100 °C; dT – temperature increase.
The recommended upper limit for moisture expansion of ceramic tiles and slabs is 0.06% when testing according to ISO 10545-10 is applied. This means that the upper limit of moisture expansion of ceramic tiles and slabs should not exceed 6 mm/m.
The coefficient of thermal expansion for floor and wall ceramic tiles varies from 4.1•10 -6 °C -1 to 8.1•10 -6 °C -1 . This means that elongation ranges from 40 to 80 thousandths of a millimeter per meter of ceramic tile and per degree rise in temperature.
Methods for determining moisture expansion and temperature coefficient of linear expansion are given in the standards EN ISO 10545-10 and EN ISO 10545-8, respectively.
Material on this issue is presented in the article Linear thermal expansion and moisture expansion .
