SpecificationsTechnical data & specifications
All porcelain pavers feature exceptionally low water absorption, excellent stain resistance, frost resistance, fade resistance, scuff resistance and fire resistance as a consequence of the basic raw materials used and the very high firing temperatures. But due to differences in raw material selection, processing and manufacturing techniques, technical specifications and characteristics will vary slightly between different makers.
Since Archatrak imports porcelain pavers from several different Italian manufacturers, we have prepared a chart showing typical technical characteristics in relation to relevant test methods and standards which apply to all porcelain pavers we supply, including static load, breaking strength, water absorption etc.
Breaking Strength & Modulus of Rupture
No industry standard specifically relating to the use of porcelain pavers for outdoor raised floors or decks currently exists. Right now, the only somewhat related standard is EN 12825 “Raised Floors” of August 2001 where the specific field of application and purpose refers to “raised access floors, mainly used in indoor applications”. Most porcelain paver manufacturers provide test result figures applying to this standard.
In the static load test procedure under EN12825-2001, a paver is placed with each corner resting on a pedestal support and a steadily increasing load is applied using a 25mm x 25mm steel cube at a specific point until failure of the paver occurs. The test is repeated four times at three different positions:
- at the center of the weakest edge (where this can be identified)
- at the center of the paver
- at a diagonal 70 mm from the edge of a pedestal head
The other test method commonly quoted is EN1339 which specifies materials, properties, requirements and test methods for cement bound non-reinforced concrete paving flags and complementary fittings for use in trafficked paved areas and roof coverings. In this standard, the breaking load is determined by applying increasing pressure from a load inducing bar placed across the full width of the paver and equidistant between two load bearing supports on the underside of the paver, as illustrated in the above diagram.
The standard test method used in the ceramics industry for determination of impact resistance is EN ISO 10545 – which measures the coefficient of restitution. In this test, a ¾” diam. steel ball is dropped from a height of 39” onto the center of 3” x 3” samples bonded to specially prepared concrete blocks 2” thick. The height of the rebound is measured, or, alternately, the interval of time between two successive rebounds. Any damage visible from the distance of 39” must be noted, but can be ignored in classifying tiles. A coefficient of restitution with a value of 0.55 is considered sufficient for normal low-stress levels of use; higher values are required in cases where greater stress is anticipated.
Whilst all Archatrak porcelain pavers exceed this minimum value, in elevated floor applications where pavers are supported only by adjustable height pedestals, the shock resistance under more severe conditions must be considered to avoid any risk of damage or injury should any paver suffer damage due to cracking. Despite the intrinsic density and stiffness of porcelain pavers, slabs may break if a heavy object is dropped from a significant height.
Consequently, project managers, specifiers and customers need to carefully assess the intended use of the floor or deck in relation to the technical specifications of the porcelain pavers.
Where hard and heavy objects are likely to be used, or where floor heights are greater than 4”, it is recommended that appropriate reinforcement is applied to the underside of the pavers, such as glued glass fiber mats, metal sheets or trays (available from Archatrak).
The majority of Archatrak porcelain pavers are rectified, meaning that all four sides have been machined after firing to give a precise dimension. Any paver that has been molded and then fired may exhibit slight dimensional differences. This could affect the installation precision if the spacing required between the pavers is very small. But in most cases, it is not an issue with paver installations because the spacing between pavers is normally at least 1/8″.