Technical Data

TECHNICAL PROPERTIES AND DATA OF THE RASTRA® SYSTEM
Sound Qualities of RASTRA® Elements The RASTRA® element has exceptional sound absorbing and attenuation qualities. This means that the interior of the new RASTRA® structure will be shielded from most outside noises. RASTRA® elements are very effective when creating sound resistant rooms such as Theater Rooms, Sound Studios or Media Rooms.
Fire Resistance RASTRA® elements are very effective in areas where high fire resistance is required. In full-scale tests of RASTRA® walls it has been shown that the RASTRA® wall does not support combustion and does not emit smoke and has a four-hour fire rating. The fire rating, in combination with the sound absorption qualities, makes RASTRA® a natural for multi-unit/multi-family projects. In addition, RASTRA® has been approved as a thermal barrier.
Frost Protection - Thermal Performance The same component matrix THASTYRON which gives RASTRA® its fire resistance, also insulates the concrete grout placed inside the grout channels, resulting in extreme frost protection both during the pour and thereafter. Because of the minimal heat and cold transfer through the RASTRA® element, the concrete grout retains its heat and moisture longer thus allowing a consistent cure, unhindered by outside temperatures. This results in a stronger end product. During five-hour fire endurance testing of full-scale 10-inch (25cm) thick RASTRA® walls, applied temperatures exceeded 2000°F (1100°C) on the exposed face. However, the recorded temperature increase on the unexposed face was just 7°F (4°C) and that was attributed to changes in ambient temperature during the test. In essence, the wall did not conduct heat during the test. This low conductivity together with the thermal storage capacity of the concrete core make for excellent thermal performance of a RASTRA® wall. Another aspect is the low specific heat of THASTYRON, results in a wall surface temperature close to ambient room temperature. Tests have shown that thermostat settings can be lowered (increased for cooling) by as much as 9°F (5°C), if the wall temperature is within ±5°F (3°C) of the comfort level.
Mold & Mildew Resistance RASTRA® elements also have other features and qualities that make it unique. Because the component matrix THASTYRON will not hold or wick water the way concrete block or wood products do, RASTRA® elements will not promote or sustain mold and mildew. Rot is a thing of the past. As a building system used in Europe for more than 25 years, numerous tests have proven RASTRA® 's ability to resist mold and mildew. Building materials which seal too tight, cause poor air quality in a building. The porous composition of THASTYRON allows a slow interchange of air, which in turn, allows the building to "breathe". The exchange is slow enough not to let heat or cold escape but helps maintaining good air quality and prevents not only condensation but also "sick building syndrome".
Insect & Vermin Resistance Unlike solid polystyrene, the mixture of Portland cement and polystyrene creates an undesirable atmosphere for insects. Additionally, the concrete grout placed in the channels penetrates the pours of the THASTYRON surface, fusing the concrete and the THASTYRON together, therefore eliminating channels that termites and other insects could use for migration and nesting.